Adverse effects of irreversible electroporation of malignant liver tumors under CT fluoroscopic guidance: a single-center experience

PURPOSE

We aimed to describe the frequency of adverse events after computed tomography (CT) fluoroscopy-guided irreversible electroporation (IRE) of malignant hepatic tumors and their risk factors.

METHODS

We retrospectively analyzed 85 IRE ablation procedures of 114 malignant liver tumors (52 primary and 62 secondary) not suitable for resection or thermal ablation in 56 patients (42 men and 14 women; median age, 61 years) with regard to mortality and treatment-related complications. Complications were evaluated according to the standardized grading system of the Society of Interventional Radiology. Factors influencing the occurrence of major and minor complications were investigated.

RESULTS

No IRE-related death occurred. Major complications occurred in 7.1% of IRE procedures (6/85), while minor complications occurred in 18.8% (16/85). The most frequent major complication was postablative abscess (4.7%, 4/85) which affected patients with bilioenteric anastomosis significantly more often than patients without this condition (43% vs. 1.3%, P = 0.010). Bilioenteric anastomosis was additionally identified as a risk factor for major complications in general (P = 0.002). Minor complications mainly consisted of hemorrhage and portal vein branch thrombosis.

CONCLUSION

The current study suggests that CT fluoroscopy-guided IRE ablation of malignant liver tumors may be a relatively low-risk procedure. However, patients with bilioenteric anastomosis seem to have an increased risk of postablative abscess formation.About 70% of hepatic metastases are nonresectable because of their anatomic location, the presence of comorbidities, or limited hepatic functional reserve (1). In these patients and in case of nonresectable primary liver tumors, percutaneous thermal ablation procedures, such as radiofrequency (RF) and microwave ablation, have become effective tools for treating hepatic malignancies (2–4). However, the effectiveness of RF and microwave treatment may be limited, either because of thermal damage to temperature-sensitive structures located in close proximity to the target tissue (5) or because of incomplete ablation of tumors adjacent to major hepatic vessels due to a phenomenon commonly termed “heat-sink effect” (6–10) which describes the loss of the applied thermal energy through the blood flow in those major vessels, whereby the effective energy application remains inadequate to ablate the target lesion.Irreversible electroporation (IRE) is a theoretically nonthermal ablation technique that delivers a series of high-voltage millisecond electrical pulses to the surrounding tissue, thus leading to irreversible disruption of the integrity of cell membranes and subsequent cell death by apoptosis (11–14). IRE may overcome the problems raised with thermal ablation: previous animal studies reported that bile ducts, blood vessels, nerves, and connective tissues are affected by IRE; however, regeneration is possible to some extent due to preservation of the tissue architecture (12, 13, 15–19). Moreover the feasibility of inducing cell death up to a vessel wall without any perivascular sparing was shown with IRE (12, 13, 18). The safety of IRE in the treatment of humans has been described (20). First reports have described potential complications after IRE, such as hemorrhage requiring blood transfusion (1.2%, two of 167 ablation procedures), portal vein thrombosis (3.2%, one of 31 ablation procedures), injury to bile ducts (1.8%, three of 167 ablation procedures), and infection (3.6%, six of 167 ablation procedures) (21, 22). However, few data are available for evaluating the potential risk factors associated with the occurrence of post-IRE complications.The purpose of this study was to review the frequency of mortality and morbidity after computed tomography (CT) fluoroscopy-guided liver IRE conducted at a single center and assess the factors influencing the occurrence of major complications.     

An innovative modification of the retrograde approach to angioplasty and recanalization of the superficial femoral artery

Endovascular therapy has been performed for chronic limb ischemia for nearly 50 years. Superficial femoral artery occlusions can be managed by the retrograde contralateral (“crossover”), antegrade ipsilateral, or retrograde popliteal (“facedown”) approaches. The retrograde approach was initially fraught with limitations and served as a backup option. Refinements to this technique have made it an enticing option and possibly the first choice in selected patients. We herein describe an innovative modification of this method.Endovascular therapy has been performed for chronic limb ischemia since 1964, with intraluminal and subintimal angioplasty of the superficial femoral artery (SFA) gaining popularity in the last decade (1). SFA occlusions can be managed by retrograde contralateral or antegrade ipsilateral approaches (2, 3); when these approaches fail, some practitioners resort to using a re-entry device (4, 5). The retrograde popliteal approach was initially fraught with limitations and served as a backup option (1, 4, 6). However, refinements to this technique have made this an enticing option (2–7), and it has been advocated as a first-line treatment in select patients (3). We herein describe another modification of this method.     

Development,growth, propagation,and angiographic utilization of the rabbit VX2 model of liver cancer: a pictorial primer and “how to” guide

The VX2 tumor is a leporine anaplastic squamous cell carcinoma characterized by rapid growth, hypervascularity, and facile propagation in the skeletal muscle. Since its introduction over 70 years ago, it has been used to model a variety of malignancies, and is commonly employed by interventional radiologists in preclinical investigations of hepatocellular carcinoma. However, despite the widespread and lasting popularity of the model, there are few technical resources detailing its use. Herein, we present a comprehensive pictorial outline of the technical methodology for development, growth, propagation, and angiographic utilization of the rabbit VX2 liver tumor model.The rabbit VX2 tumor model has played a longstanding role in experimental oncology. Developed in 1930–1940 by Rous et al. (1, 2), the VX2 tumor is a virus-induced anaplastic squamous cell carcinoma characterized by hypervascularity, rapid growth, and easy propagation in the skeletal muscle (3, 4). Since its introduction, the tumor has been used to model cancers of the head and neck (5), kidney (6), brain (7), lung (8), urinary bladder (9), uterus (10), liver (11, 12), bone (13), and pancreas (14). The high growth rate and the relatively large size of rabbit vasculature render the model particularly well suited for use by interventional radiologists, and in recent years the model has been employed in numerous studies pertaining to the imaging and locoregional treatment of hepatocellular carcinoma (15–19). However, despite the widespread and lasting popularity of the model, there are few, if any, comprehensive technical resources detailing its use, leaving many key procedural details to be conveyed anecdotally. Lack of a technical guide may also represent a barrier to entry of interventional radiologists into translational research. With that in mind, this review is intended to provide a complete pictorial overview of the development, growth, propagation, and angiographic utilization of the rabbit VX2 tumor model based on the experience of a single operator in order to serve as a reference for novice and experienced investigators alike.     

Single-stage endovascular treatment in patients with severe extracranial large vessel stenosis and concomitant ipsilateral unruptured intracranial aneurysm

PURPOSE

We aimed to evaluate the safety and effectiveness of single-stage endovascular treatment in patients with severe extracranial large vessel stenosis and concomitant ipsilateral unruptured intracranial aneurysm.

METHODS

Hospital database was screened for patients who underwent single-stage endovascular treatment between February 2008 and June 2013 and seven patients were identified. The procedures included unilateral carotid artery stenting (CAS) (n=4), bilateral CAS (n=2), and proximal left subclavian artery stenting (n=1) along with ipsilateral intracranial aneurysm treatment (n=7). The mean internal carotid artery stenosis was 81.6% (range, 70%–95%), and the subclavian artery stenosis was 90%. All aneurysms were unruptured. The mean aneurysm diameter was 7.7 mm (range, 5–13 mm). The aneurysms were ipsilateral to the internal carotid artery stenosis (internal carotid artery aneurysm) in five patients, and in the anterior communicating artery in one patient. The patient with subclavian artery stenosis had a fenestration aneurysm in the proximal basilar artery. Stenting of the extracranial large vessel stenosis was performed before aneurysm treatment in all patients. In two patients who underwent bilateral CAS, the contralateral carotid artery stenosis, which had no aneurysm distally, was treated initially.

RESULTS

There were no procedure-related complications or technical failure. The mean clinical follow-up period was 18 months (range, 9–34 months). One patient who underwent unilateral CAS experienced contralateral transient ischemic attack during the clinical follow-up. There was no restenosis on six-month follow-up angiograms, and all aneurysms were adequately occluded.

CONCLUSION

A single-stage procedure appears to be feasible for treatment of patients with severe extracranial large vessel stenosis and concomitant ipsilateral intracranial aneurysm.The concomitance of severe extracranial large vessel stenosis and unruptured ipsilateral distal intracranial aneurysm is often detected incidentally and their management is not clear (1). Although there are many studies in the literature that report different treatment approaches, there is no definite consensus on the management of the concomitant lesions (2–14). Various treatment options have been suggested, such as initial treatment of the aneurysm before revascularization of the stenosis, treating both lesions in the same surgical session and correcting the stenosis without treating the aneurysm (1, 5, 6, 9–11, 14–16). Few studies have reported single-stage endovascular treatment of both lesions as an effective method (17–19). On the other hand, the treatment of each lesion by this technique may lead to procedure-related undesired events such as cerebral ischemia/stroke or aneurysm rupture.In this study, we aimed to present the radiologic and clinical results of seven consecutive patients who underwent single-stage endovascular treatment of severe extracranial large vessel stenosis and concomitant unruptured ipsilateral intracranial aneurysm and discuss the safety and feasibility of this approach. In addition, distinct from the limited number of similar studies in the literature, we present our experience with bilateral carotid artery stenting (CAS) and proximal subclavian artery stenting during single-stage endovascular treatment.     

Radioembolization with yttrium-90 resin microspheres for neuroendocrine tumor liver metastases

PURPOSE

We aimed to evaluate the effectiveness and safety of radioembolization with yttrium-90 (⁹⁰Y) microspheres in cases with unresectable neuroendocrine tumor liver metastases (NETLMs).

METHODS

Thirty patients (mean age, 55 years) underwent resin-based ⁹⁰Y radioembolization for unresectable NETLM at a single institution between April 2008 and June 2013. Post-treatment tumor response was assessed by cross-sectional imaging using the Response Evaluation Criteria in Solid Tumors (RECIST). Prognostic variables that affected survival were determined.

RESULTS

The mean follow-up was 23.0±19.4 months and the median overall survival was 39 months (95% CI, 12.6–65.4 months), with one- and two-year survival rates of 71% and 45%, respectively. Imaging follow-up using RECIST at three-month intervals demonstrated partial response in 43%, complete remission in 3%, stable disease in 37%, and progressive disease in 17% of patients. Extent of tumor involvement was found to have a statistically significant influence on overall survival (P = 0.03). The existence of extrahepatic disease at the time of radioembolization, radiographic response, age, and primary neuroendocrine tumor site were not significant prognostic factors.

CONCLUSION

The current study demonstrates the effectiveness and safety of radioembolization for the treatment of unresectable NETLMs. We identified that the extent of tumor involvement has a significant effect on overall survival. The use of imaging methods reflecting metabolic activity or cellularity such as scintigraphy or diffusion-weighted MRI would be more appropriate, for the response evaluation of liver metastases after radioembolization.Neuroendocrine tumors (NETs) are a heterogenous group of slow-growing and hormon-releasing malignant tumors. Even though primary NETs originate from a number of locations, 40%–70% of all carcinoids arise in the small intestine and appendix (1, 2). The most common site for metastasis is the liver. Neuroendocrine tumor liver metastasis (NETLM) results in hormone-secretion-related symptoms leading to carcinoid syndrome, pressure on structures, or liver replacement (1–4). Patients with liver metastasis have a five-year survival rate of less than 20% (5). Over the years, improvements in local treatments yielded better control of the symptoms and survival rates, yet only 10% of the patients have limited illness and are eligible for surgery (6). Patient symptomatology and survival can be improved by transarterial treatments like embolization and chemoembolization (6). Limitations of these techniques include the short duration of the effects and the controversial approaches regarding the optimal timing and sequence of the procedures due to the variability of tumor progression (7, 8). Long-term survival benefit was not achieved with systemic chemotherapy (9–11) and treatment with somatostatin analogues is mostly associated with symptomatic relief; there is no clear knowledge of their effect on survival of patients who have carcinoid tumor and metastasis (12).Selective internal radiation therapy (SIRT) has been used to treat unresectable primary and secondary liver cancers for over a decade. Yttrium-90 (⁹⁰Y) is a pure high-energy β emitter with a mean tissue penetration of 2.5 mm. The radioactive microspheres prefer tumoral vascular distribution, so that normal liver tissue is relatively spared and high doses are directed to the tumoral tissue (13). Also, radioembolization-related acute and subacute toxicities are seemingly more tolerable than the ones related to other hepatic embolization procedures (14–16). In this study, we aimed to evaluate the effectiveness and safety of ⁹⁰Y microspheres in cases with unresectable NETLMs.     

Diffusion-weighted MRI findings of treated and untreated retroperitoneal fibrosis

PURPOSE

We aimed to evaluate diffusion-weighted imaging (DWI) findings in patients with treated and untreated retroperitoneal fibrosis (RPF).

METHODS

We analyzed magnetic resonance imaging examinations of 44 RPF patients (36 male, 8 female), of which 15 were untreated and 29 were under therapy. Qualitative DWI and T1 postcontrast signal intensities and the largest perivascular extent of RPF were compared between treated and untreated groups and correlated to erythrocyte sedimentation rate and C-reactive protein values. Quantitative DWI signal intensities and apparent-diffusion-coefficients were calculated in regions-of-interest, together with a relative index between signal intensities of RPF and psoas muscle in 15 untreated patients and 14 patients under treatment with remaining perivascular fibrosis of more than 5 mm.

RESULTS

The extent of RPF in untreated patients was significantly larger compared with the extent of RPF in treated patients (P < 0.0001). DWI signal intensities were significantly higher in untreated patients than in patients under therapy (mean, 27 s/mm² vs. 20 s/mm²; P = 0.009). The calculated DWI-index was significantly higher in untreated patients than in patients under therapy (P = 0.003).

CONCLUSION

Our data show significant differences in the DWI findings (b800 signal intensities and relative DWI-index) of patients with treated and untreated RPF. DWI is a promising technique in the assessment of disease activity and the selection of patients suitable for medical therapy.Retroperitoneal fibrosis (RPF) is a rare disease affecting the retroperitoneal space (1–3). It presents as retroperitoneal proliferation of fibrous tissue surrounding the retroperitoneal vascular structures and abutting the medial aspect of the ureters. Clinical findings of RPF are non-specific; the most common symptom is chronic back pain. Further symptoms include lower extremity edema, deep vein thrombosis, oliguria, and urinary tract infection (3). Computed tomography (CT) and magnetic resonance imaging (MRI) are the preferred imaging modalities for the diagnosis of RPF (3). Retroperitoneal fibrosis shows contrast enhancement of gadolinium containing contrast media in MRI (4). Medical treatment is classically based on steroids like prednisone (3). Recent studies suggested tamoxifen as another safe and effective treatment alternative (5).The assessment of disease activity is relevant for planning of further medical or surgical therapy (6, 7). Nowadays the disease activity is assessable by positron emission tomography tracer uptake (3), with a relatively low resolution and the need of ionized radiation. As an alternative, dynamic contrast-enhanced MRI was suggested for the evaluation of disease activity (7, 8). However, gadolinium may be contraindicated in patients with impaired renal function due to the potential development of nephrogenic systemic fibrosis (NSF) (9). This is especially relevant in RPF patients with postrenal failure due to ureteral compression. For those cases a supplemental method for the determination of disease activity would be helpful.Diffusion-weighted imaging (DWI) is a radiation-free unenhanced MRI modality that has been applied for the detection of bowel inflammation in patients with chronic inflammatory bowel diseases (10, 11), as well as for oncological retroperitoneal and abdominal applications (12–14). Therefore, we aimed to evaluate the application and findings of DWI in patients with treated and untreated RPF disease.     

Imaging of facial nerve schwannomas: diagnostic pearls and potential pitfalls

Schwannomas are uncommon in the facial nerve and account for less than 1% of tumors of temporal bone. They can involve one or more than one segment of the facial nerve. The clinical presentations and the imaging appearances of facial nerve schwannomas are influenced by the topographical anatomy of the facial nerve and vary according to the segment(s) they involve. This pictorial essay illustrates the imaging features of facial nerve schwannomas according to their various anatomical locations and also reviews the pertinent differential diagnoses and potential diagnostic pitfalls.Facial nerve schwannomas (FNSs) are rare slow-growing tumors, accounting for less than 1% of all temporal bone tumors. They are typically solitary, unilateral, and sporadic in nature. FNSs may be bilateral as part of neurofibromatosis-2 spectrum (1, 2). Rarely, multiple schwannomas may involve peripheral branches of the facial nerve (FN) (3). The age of presentation varies from 5 to 84 years. No gender or side predilection is seen (4, 5).Histologically, FNSs are neuroectodermal in origin. They are encapsulated, benign tumors arising from the Schwann cells. They may show intratumoral cystic change and hemorrhage (3, 4, 5). Malignant schwannoma of the FN is extremely rare (6). FNSs commonly present with peripheral facial neuropathy and/or various otologic symptoms including sensorineural and conducting hearing loss (2–5). Facial paralysis is often seen at a later stage or may not be seen at all. The reasons for this are thought to be neuronal tolerance induced by the extremely slow growth of the tumor, abundant tumor vascularity, and commonly associated dehiscence of adjacent bone (7). Occasionally, FNSs may present as an intraparotid mass or as an intracranial lesion (2–5).The clinical presentations and the imaging appearances of FNSs are influenced by the topographical imaging anatomy of the FN and vary according to the segment(s) they involve (8). Here, we briefly describe the anatomy of the FN, followed by general imaging features of FNSs on computed tomography (CT) and magnetic resonance imaging (MRI), and appropriate imaging protocols. Tumor involving each segment is reviewed in relation to its characteristic clinical presentations emphasizing diagnostic pearls and potential pitfalls. The imaging examples of FNSs illustrated in this pictorial review are all histopathologically proven cases.     

Paratracheal air cysts: prevalence and relevance to pulmonary emphysema and bronchiectasis using thoracic multidetector CT

PURPOSE

We aimed to determine the prevalence of paratracheal air cysts (PTACs) and the relationship of PTACs with emphysema and bronchiectasis through retrospective analysis of multidetector computed tomography (MDCT) findings.

METHODS

MDCT findings of 1027 consecutive patients who underwent routine thorax examination between January 2012 and January 2013 were evaluated retrospectively for the presence of PTACs. Localization of the PTACs, as well as their size, shape, and relationship with the trachea were examined. Presence of emphysema and bronchiectasis was recorded, and bronchiectasis severity index was calculated when present. We randomly selected 80 patients who had no visible PTACs as the control group. The findings of patients with and without PTACs were compared.

RESULTS

PTACs were determined in 82 of 1027 patients (8%), in 8.8% of females and 7.3% of males. The presence of PTACs was determined to be independent of gender (P = 0.361). Eighty-one PTACs (98.8%) were located in the right side of the trachea and 56.1% had a tracheal connection. The presence of PTACs significantly correlated with the presence and severity of bronchiectasis (P = 0.001 and P = 0.005 respectively). There was no significant relationship between the presence of PTACs and the presence of emphysema on CT images (P = 0.125).

CONCLUSION

The prevalence of PTACs was determined as 8% in this study. There was significant association between PTACs and bronchiectasis.Paratracheal air cysts (PTACs) are small collections of air adjacent to the trachea at the level of the thoracic inlet (1). Pathological diagnosis of PTACs in surgically confirmed cases includes tracheal diverticulum, lymphoepithelial cyst, and bronchogenic cyst (1–3). These cysts are covered with ciliary columnar epithelium and connected with the trachea (4). The majority of PTACs are reported as tracheal diverticula in the literature, due to their connection with the trachea (2). The thoracic inlet between the cartilage and muscle layers in right posterolateral wall of the trachea is the most common location for PTACs. A relationship may be seen between an isolated PTAC and the trachea l lumen (5). These lesions may cause recurrent infections by acting as a reservoir for secretions.Occasionally, PTACs can be confused with other causes of extraluminal air collections as laryngocele, pharyngocele, Zenker’s diverticulum, apical hernia of the lung, mediastinal air, apical paraseptal blebs, or bullae. To distinguish PTACs from other pathologies, its typical location in the right posterior paratracheal region at the thoracic inlet can be helpful: PTACs locate away from the lung pleura, communicate with the trachea and have rounded margins that can be differentiated from emphysematous changes (6).PTACs are usually discovered incidentally on thorax computed tomography (CT). They may be associated with a chronic cough or chronic obstructive pulmonary diseases (COPD). The reported prevalence of PTACs ranges from 0.75% to 8.1% (4, 6–8). There have been a limited number of studies reporting the incidence of PTACs related to COPD or emphysema as detected by CT, and the reported results are variable (4, 6, 8–11). The relationship between PTACs and pulmonary emphysema or bronchiectasis is still unclear. To our knowledge, no published study has evaluated the relationship between PTACs and bronchiectasis, using a bronchiectasis severity index and objective measures to determine the extent of bronchiectasis on CT images.The purpose of our study was to evaluate the prevalence and characteristics of PTACs, as well as their relationship with bronchiectasis and emphysema, on thorax CT scans.     

Predictive factors for invasive cancer in surgical specimens following an initial diagnosis of ductal carcinoma in situ after stereotactic vacuum-assisted breast biopsy in microcalcification-only lesions

PURPOSE

The aim of this study was to determine the incidence of invasive breast carcinoma in patients with preoperative diagnosis of ductal carcinoma in situ (DCIS) by stereotactic vacuum-assisted biopsy (SVAB) performed for microcalcification-only lesions, and to identify the predictive factors of invasion.

METHODS

From 2000 to 2010, the records of 353 DCIS patients presenting with microcalcification-only lesions who underwent SVAB were retrospectively reviewed. The mammographic size of microcalcification cluster, presence of microinvasion within the cores, the total number of calcium specks, and the number of calcium specks within the retrieved core biopsy specimen were recorded. Patients were grouped as those with or without invasion in the final pathologic report, and variables were compared between the two groups.

RESULTS

The median age was 58 years (range, 34–88 years). At histopathologic examination of the surgical specimen, 63 of 353 patients (17.8%) were found to have an invasive component, although SVAB cores had only shown DCIS preoperatively. The rate of underestimation was significantly higher in patients with microcalcification covering an area of 40 mm or more, in the presence of microinvasion at biopsy, and in cases where less than 40% of the calcium specks were removed from the lesion.

CONCLUSION

Invasion might be underestimated in DCIS cases diagnosed with SVAB performed for microcalcification-only lesions, especially when the mammographic size of calcification is equal to or more than 40 mm or if microinvasion is found within the biopsy specimen and less than 40% of the calcifications are removed. At least 40% of microcalcification specks should be removed from the lesion to decrease the rate of underestimation with SVAB.Because of the widespread use of breast screening mammography, the number of women diagnosed with ductal carcinoma in situ (DCIS) has increased dramatically in recent years. DCIS is a noninvasive form of breast cancer, accounting for up to 30% of breast cancers in screening populations and approximately 5% of breast carcinomas in symptomatic patients (1–3). DCIS has a variety of mammographic presentations, but the most common mammographic feature is microcalcification (4). Indeed 80%–90% of DCIS lesions present with microcalcifications only, without any accompanying mass lesions (4). Other findings such as masses, nodular abnormalities, dilated retroareolar ducts, architectural distortions, and developing densities have also been reported (5).Ultrasound-guided biopsy is often the method of choice for sonographically visible breast lesions as it provides easy access for biopsy. However, in cases when the abnormality seen on mammography is not visible on ultrasonography, stereotactic biopsy is the recommended sampling method. For microcalcification-only lesions with no accompanying mass, ultrasonography often fails to identify the site of the lesion; hence, stereotactic biopsy is used more frequently.In most breast units, stereotactic 14-gauge automated core biopsy has been replaced by stereotactic vacuum-assisted biopsy (SVAB) using 8- to 11-gauge needles (6). Large core SVAB allows larger samples to be obtained in a shorter period of time compared with samples obtained using automated core biopsy devices (7). Moreover, this technique has the advantage of a single insertion in the area of interest compared with automated core biopsy devices, which require repeated insertions. Several published articles have shown that SVAB decreased the rate of cancer underestimation and the rate of failure to retrieve breast microcalcifications (8).The management of noninvasive and invasive breast cancers is different and therefore, an accurate preoperative diagnosis is crucial for adequate surgical planning. Underestimation of DCIS lesions occurs when an invasive component is found after surgery, which had been missed at the initial preoperative sampling. The underestimation rate of stereotactic 14-gauge automated core biopsy in DCIS was reported as 16%–35% (9–11), while that of SVAB was 5%–29% (6, 9, 11–13).The purpose of this study was to determine the rate, causes, and predictive factors of underestimation of invasive carcinoma in patients diagnosed with DCIS following SVAB of microcalcification-only lesions.     

Clinical effect of double coaxial self-expandable metallic stent in management of malignant colon obstruction

PURPOSE

We aimed to evaluate the clinical effectiveness and safety of double coaxial self-expandable metallic stent (DCSEMS) in management of malignant colonic obstruction as a bridge to surgery or palliation for inoperable patients.

METHODS

Between April 2006 and December 2012, 49 patients (27 males and 22 females; median age, 68 years; age range, 38–91 years) were selected to receive decompressive therapy for malignant colonic obstruction by implanting a DCSEMS. Application of DCSEMS was attempted in 49 patients under fluoroscopic guidance. The obstruction was located in the transverse colon (n=2), descending colon (n=7), sigmoid colon (n=24), rectosigmoid junction (n=6), and the rectum (n=10). The intended use of DCSEMS was as a bridge to elective surgery in 23 patients and palliation in 26 patients.

RESULTS

Clinical success, defined as >50% dilatation of the stent with subsequent symptomatic improvement, was achieved in 48 of 49 patients (98%). The stent was properly inserted in all patients. No immediate major procedure-related complications occurred. One patient in the bridge-to-surgery group had colon perforation three days after DCSEMS application. Four patients had late migrations of the double stent.

CONCLUSION

Application of DCSEMS is safe and effective in management of malignant colonic obstruction; it prevents stent migration and tumor ingrowth and lowers perforation rate during the stent application.Fluoroscopic or endoscopic placement of either bare or covered expandable metallic stents was shown to be a safe, easy, and effective technique as a bridge to surgery and palliative treatment of colorectal cancer (1, 2). However, tumor ingrowth and stent migration have been reported as weaknesses in conventional single bare and covered stents, respectively (2–4). The use of bare stents has been hindered by progressive tumor ingrowth through the wire filaments of the bare stents and food residue or hard fecal impaction proximal to or at the level of the stent insertion site (5, 6). In contrast, the use of covered expandable metallic stents has been associated with stent migration (5, 7). To overcome the limitations associated with conventional bare and covered stents, a double coaxial self-expandable metallic stent (DCSEMS) has been developed to combine the strengths of bare and covered stents (7, 8).The purpose of the present study was to report our experiences with fluoroscopic-guided placement of double stents in management of malignant colorectal obstruction as a bridge to surgery or palliative treatment.     

Added value of diffusion-weighted MRI in detection of cervical cancer recurrence: comparison with morphologic and dynamic contrast-enhanced MRI sequences

PURPOSE

We aimed to evaluate the added value of diffusion-weighted imaging (DWI) to standard magnetic resonance imaging (MRI) for detecting post-treatment cervical cancer recurrence. The detection accuracy of T2-weighted (T2W) images was compared with that of T2W MRI combined with either dynamic contrast-enhanced (DCE) MRI or DWI.

METHODS

Thirty-eight women with clinically suspected uterine cervical cancer recurrence more than six months after treatment completion were examined with 1.5 Tesla MRI including T2W, DCE, and DWI sequences. Disease was confirmed histologically and correlated with MRI findings. The diagnostic performance of T2W imaging and its combination with either DCE or DWI were analyzed. Sensitivity, positive predictive value, and accuracy were calculated.

RESULTS

Thirty-six women had histologically proven recurrence. The accuracy for recurrence detection was 80% with T2W/DCE MRI and 92.1% with T2W/DWI. The addition of DCE sequences did not significantly improve the diagnostic ability of T2W imaging, and this sequence combination misclassified two patients as falsely positive and seven as falsely negative. The T2W/DWI combination revealed a positive predictive value of 100% and only three false negatives.

CONCLUSION

The addition of DWI to T2W sequences considerably improved the diagnostic ability of MRI. Our results support the inclusion of DWI in the initial MRI protocol for the detection of cervical cancer recurrence, leaving DCE sequences as an option for uncertain cases.Cervical cancer is the fourth most frequent cancer in women worldwide (1). Early stage disease is treated with surgery or chemoradiotherapy and has a good prognosis. However, around 30% of all patients treated for cervical carcinoma develop progressive or recurrent tumors (2).Recurrent cervical cancer is defined as local tumor regrowth or the development of distant organ/lymph node metastases at least six months after regression of the initial lesion. Approximately two-thirds of recurrences appear within the first two years following initial treatment, with 90% recurring by five years post-treatment (3). Risk factors for recurrence include histopathologic features, depth of tumor invasion, and nodal status (4).Pelvic recurrence can be located centrally (cervix, uterus, vagina, parametria, ovaries, bladder, or rectum) or in the pelvic sidewalls. Extrapelvic recurrence most commonly involves the para-aortic lymph nodes, lungs, liver, or bone (4–6).Treatment of recurrent cancer depends on the primary treatment approach, location, and extension. Patients with locally recurrent disease can be offered salvage treatments with curative potential (chemoradiotherapy, if not given previously, or pelvic exenteration in patients who already received chemoradiotherapy). Distant metastases, however, are nearly always incurable (3).In patients who successfully completed primary treatment, surveillance has been advocated to detect the residual or recurrent disease at curable stages (7). The use of imaging studies such as magnetic resonance imaging (MRI) is indicated on the basis of clinical suspicion (8).T2-weighted (T2W) imaging is the reference sequence for cervical cancer staging (9). Recurrent tumors are known to show high signal intensity on T2W MRI, contrasting with the low signal intensity of the cervical stroma. However, some benign conditions such as necrosis, inflammation, and edema may also increase signal intensity on T2W images, representing a potential challenge to the radiologist, particularly after radiotherapy (10–13).Moreover, post-treatment changes can result in areas of fibrosis that are also difficult to differentiate from recurrence (14). MRI has proven to be superior to computed tomography (CT) in distinguishing fibrosis and scarring from active disease, but imaging findings are sometimes indeterminate, complicating the evaluation of recurrent disease (3).In recent years, the functional MRI techniques such as dynamic multiphase contrast-enhanced (DCE) MRI and diffusion-weighted imaging (DWI) have emerged as fundamental tools in female pelvic imaging evaluation (15). Although DCE was shown to be more accurate than T2W alone for tumor recurrence identification, the use of both sequences is recommended (10).Recently, DWI has been added to pelvic MRI protocols to increase diagnostic accuracy in tumor staging. This technique is a functional tool that relies on tissue water displacement to create a contrasted image. For correct evaluation and avoidance of pitfalls, the generated images must be interpreted alongside anatomical sequences. The apparent diffusion coefficient (ADC) map is also needed to reduce image misinterpretation, for example due to the T2 shine-through effect (15). In highly cellular tissues, water movement is restricted and such lesions appear bright at high b-values (1000 s/mm²) and have low ADC value, appearing dark gray on ADC maps in contrast to areas of freely moving water such as urine in the bladder (14). Some recent studies have suggested that DWI and ADC maps can be potentially useful in oncologic follow-up (14, 16).The purpose of this study was to compare the accuracy of T2W/DWI with that of conventional anatomical sequences alone and T2W/DCE imaging sequences in the evaluation of recurrent disease in patients treated for uterine cervical carcinoma.     

Targeted endovenous treatment of Giacomini vein insufficiency-associated varicose disease: considering the reflux patterns

PURPOSE

We aimed to assess the technical feasibility of targeted endovenous treatment of Giacomini vein insufficiency (GVI)-associated varicose disease and report our early results.

METHODS

We retrospectively screened 335 patients with varicose disease who underwent endovenous laser ablation from September 2011 to January 2013, and determined 17 patients who underwent Giacomini vein ablation. Using a targeted endovenous treatment approach considering the reflux pattern, all healthy great saphenous veins (GSV) or vein segments were preserved while all insufficient veins (Giacomini vein, perforator veins, small saphenous vein, anterior accessory GSV, major tributary veins, or incompetent segments of the GSV) were ablated. Treatment success was analysed using Doppler findings and clinical assessment scores before and after treatment.

RESULTS

Targeted endovenous treatment was technically successful in all cases. Seven GSVs were preserved totally and three GSVs were preserved partially (10/17, 58%), with no major complications. Clinical assessment scores and Doppler findings were improved in all cases.

CONCLUSION

Targeted endovenous treatment of GVI-associated varicose disease is safe and effective. In majority of GVI cases saphenous vein can be preserved using this approach.The Giacomini vein (GV) is defined as a branch of cranial extension of the small saphenous vein (SSV) that connects the SSV with the posterior thigh circumflex vein (PTCV) (1). In 14% of the population, SSV continues directly as the GV (2). Although most varices are caused by reflux originating from the great saphenous vein (GSV), SSV, or accessory saphenous branches, varicose disease caused by a Giacomini vein insufficiency (GVI) is not a rare condition (3, 4). GVI is commonly seen with varices that arise on the posterior thigh or calf and accounts for 4%–6% of cases treated by endovenous laser ablation (ELA) (5–8). There is no defined standard treatment for GVI-associated varicose disease. Performing a phlebectomy as the only treatment may result in recurrent varicose disease for some patients. Classical saphenous vein-focused surgical therapies may result in overtreatment or undertreatment. Targeted endovenous treatment (TET) differs from surgical treatments by focusing on the reflux sources and preserving healthy GSV, either totally or partially, while ablating insufficient segments of the vein. The ablation may be applied to any vein including the GV, perforator vein, SSV, and anterior accessory GSV, except the deep veins.ELA has recently evolved into an accepted option for eliminating truncal reflux for an incompetent GSV or SSV, with successful saphenous vein ablation rates ranging from 88% to 100% (9–12). However, reports of ELA treatment of the GVI are rare (3, 4, 7, 13). Some authors recommend only GSV ablation (4), while others ablate the insufficient GV (3). To the best of our knowledge, there is only one study on treatment of GVI considering the reflux pattern, which used both ELA and sclerotherapy (13). The present study focuses on the saphenous vein sparing effect of TET while treating the GVI by ELA and sclerotherapy.Today, reflux sources other than the saphenous veins, such as the perforator veins or GVs, are also accessible and can be treated selectively with the help of new endovenous techniques. TET considering the various reflux patterns is a minimally invasive and selective treatment method for GVI that may prevent unnecessary saphenous ablations in some cases. The purpose of this study was to evaluate the technical feasibility of TET and report early treatment results of 17 patients who had GVI with various reflux sources.     

Percutaneous transluminal balloon angioplasty in stenosis of native hemodialysis arteriovenous fistulas: technical success and analysis of factors affecting postprocedural fistula patency

PURPOSE

We aimed to determine the predictors of technical success and patency after percutaneous transluminal angioplasty (PTA) of de novo dysfunctional hemodialysis arteriovenous fistulas (AVF).

METHODS

We performed a retrospective analysis of first time PTA in 228 patients (129 men, 99 women; mean age, 56.8±14.6 years). Anatomical (location, length, grade, and number of stenoses) and clinical variables (sex, age, prior AVF, diabetes mellitus, AVF age, side, and location) were reviewed.

RESULTS

A total of 330 stenoses were found in 228 patients. PTA was technically successful in 96.3% of the stenoses (n=319). Clinical success was achieved in 97.2% (n=321). Early dysfunction (within six months) was positively correlated with patient age (P < 0.001) and diabetes (P < 0.005). Older age (P < 0.001) and diabetes (P = 0.002) were associated with a lower primary patency rate. Patient age (P < 0.001), presence of diabetes (P = 0.023), length of stenosis (P = 0.003), early recurrence (P = 0.003) and presence of residual stenosis (P = 0.014) were associated with a lower secondary patency rate.

CONCLUSION

Patency of dysfunctional hemodialysis fistulas can be maintained safely with continuous follow-up and repeated interventions without shortening the venous segment by surgical revision. Percutaneous approach to hemodialysis access stenosis is an alternative to the conventional surgical approach and PTA is an effective treatment method for dysfunctional AVF.Hemodialysis, and therefore patent hemodialysis access, is of great importance to patients with end-stage renal disease (ESRD). The preferred type of access in patients undergoing hemodialysis is an arteriovenous fistula (AVF) (1). The Kidney Disease Outcomes Quality Initiative provides evidence-based clinical practice guidelines for all stages of ESRD and reports autogenous AVF as the reference standard for primary vascular access, due to their longevity and low infection rates (2, 3). Sands et al. (4) and Schwab et al. (5) demonstrated a 10-fold increase in thrombosis rate of synthetic polytetrafluoroethylene (PTFE) accesses when compared to AVFs. Despite proven advantages of AVF over PTFE, both types of access eventually fail and contribute to multiple hospital admissions, radiological and surgical interventions, and overall morbidity associated with chronic hemodialysis. Significant stenosis causing access dysfunction is a frequent complication in hemodialysis and requires repeated percutaneous transluminal balloon angioplasty (PTA) to maintain patency (6–9). The patency of PTA is limited, however, with first year primary patency rates ranging between 26% and 62% (6–8). Many factors influencing the patency rate have been studied in previously reported series (7, 8). Our study is the first to investigate the effect of early recurrence on secondary patency.     

A novel technique in the treatment of retroperitoneal lymphatic leakage: direct percutaneous embolization through the leakage pouch

Lymphangiography and percutaneous embolization of injured lymphatics are minimally invasive and effective techniques for the diagnosis and treatment of thoracic and retroperitoneal lymphatic leaks. We present a 58-year-old man who had abdominal chylous collection developed after multiple abdominal surgeries. Retroperitoneal lymphatic duct leakage was detected by ultrasound-guided intranodal lymphangiography and treated successfully using computed tomography (CT)-guided transabdominal embolization with percutaneous N-butyl cyanoacrylate (NBCA) glue and percutaneous NBCA glue and coil embolization by directly catheterizing the leaking lymphatic channel through the chylous collection. To the best of our knowledge, this is the first report of a lymphatic leakage case treated by percutaneous direct catheterization and embolization of leaking lymphatic channels through the chylous fluid collection.Abdominal lymphatic leakage is an unusual complication after abdominal surgery and has been reported after vascular, gastrointestinal, gynecologic, urologic surgeries, and liver and small bowel transplantations. It may cause loss of essential proteins, lipids, immunoglobulin, vitamins, electrolyte, and water, and lead to increased mortality in postoperative setting due to malnutrition, cachexia, immunosuppression, and sepsis (1, 2). The management of chylous leakage is a challenging condition and extends from conservative treatment (dietary management, medical and percutaneous drainage) to radiological intervention or surgical treatment (1–3). Bipedal or intranodal lymphangiography is the traditional imaging method for localizing the site of lymphatic leakage before surgical and endovascular treatment (3–6). In this report, we present successful treatment of abdominal collection developed after multiple abdominal surgeries using computed tomography (CT)-guided transabdominal embolization and percutaneous embolization through the leakage collection. To the best of our knowledge, this is the first report of a lymphatic leakage case treated by percutaneous embolization by catheterizing the leaking lymphatic channel through the chylous collection.     

Computed tomography arterial portography for assessment of portal vein injury after blunt hepatic trauma

PURPOSE

Intrahepatic portal vein injuries secondary to blunt abdominal trauma are difficult to diagnose and can result in insidious bleeding. We aimed to compare computed tomography arterial portography (CTAP), reperfusion CTAP (rCTAP), and conventional computed tomography (CT) for diagnosing portal vein injuries after blunt hepatic trauma.

METHODS

Patients with blunt hepatic trauma, who were eligible for nonoperative management, underwent CTAP, rCTAP, and CT. The number and size of perfusion defects observed using the three methods were compared.

RESULTS

A total of 13 patients (seven males/six females) with a mean age of 34.5±14.1 years were included in the study. A total of 36 hepatic segments had perfusion defects on rCTAP and CT, while there were 47 hepatic segments with perfusion defects on CTAP. The size of perfusion defects on CT (239 cm³; interquartile range [IQR]: 129.5, 309.5) and rCTAP (238 cm³; IQR: 129.5, 310.5) were significantly smaller compared with CTAP (291 cm³; IQR: 136, 371) (both, P = 0.002).

CONCLUSION

Perfusion defects measured by CTAP were significantly greater than those determined by either rCTAP or CT in cases of blunt hepatic trauma. This finding suggests that CTAP is superior to rCTAP and CT in evaluating portal vein injuries after blunt liver trauma.The liver is one of the most frequently injured solid abdominal organs in the setting of blunt abdominal trauma (1). Fortunately, most patients with blunt hepatic trauma have relatively stable vital signs and need only supportive treatment or transarterial embolization (TAE) (1–9). Only 15% of patients, who present with hemodynamic instability or fail with nonoperative management, require operative intervention to manage their liver injury.Embolic therapy has been shown to have a high success rate in hemodynamically stable patients with blunt hepatic injury. TAE is associated with decreased abdominal infections, decreased transfusions, and decreased length of hospital stay compared with operative management (2, 3, 7). However, angiography can only detect bleeding from the hepatic artery; it cannot locate bleeding from the hepatic or portal vein. In the literature, portal vein injuries are not commonly described and most are the result of penetrating injuries to the extrahepatic portal veins. Mortality after a portal vein injury due to trauma is primarily due to hypovolemic shock and can be as high as 50% or greater (10, 11).Since the intrahepatic portions of the hepatic and portal veins are low pressure systems, they can bleed insidiously. Nevertheless, this subtle bleeding may require multiple transfusions and result in a prolonged hospital stay. Relative to an extrahepatic portal vein injury, patients with an intrahepatic portal vein injury may have relatively stable vital signs and slowly decreasing hemoglobin levels (10, 11). In addition, traumatic occlusion and/or thrombosis of the portal vein may cause large hepatic parenchymal infarction.Computed tomography arterial portography (CTAP) is a useful method based on portal enhancement of the liver by infusion of contrast material through the superior mesenteric artery for evaluating the portal venous system (12–15) and is widely used in patients with hepatic tumors with portal venous invasion (13, 16, 17). CTAP has a high sensitivity and specificity in the evaluation of portal vein thrombosis due to tumor (90% sensitivity, 99% specificity, 95% positive predictive value, 97% negative predictive value) (14). However, few studies have focused specifically on the utility of CTAP in the evaluation of portal vein injury as a result of trauma.The liver has a dual blood supply and receives between 66% and 75% of its blood supply from the hepatic portal vein with the remainder supplied by the hepatic artery (18). CTAP reflects only portal venous perfusion while reperfusion CTAP (rCTAP) reflects hepatic arterial reperfusion. Both rCTAP and conventional computed tomography (CT) are useful for determining certain liver injuries. However, they do not specifically evaluate the portal vein.The purpose of this study was to compare CTAP, rCTAP, and CT for diagnosing portal vein injuries after blunt hepatic trauma. We hypothesized that CTAP would be superior to rCTAP and CT in assessing portal vein injury after blunt hepatic trauma.     

CT-guided percutaneous cryoablation of central lung tumors

PURPOSE

Cryoablation has been successfully used to treat lung tumors. However, the safety and effectiveness of treating tumors adjacent to critical structures has not been fully established. We describe our experience with computed tomography (CT)-guided percutaneous cryoablation of central lung tumors and the role of ice ball monitoring.

MATERIALS AND METHODS

Eight patients with 11 malignant central lung tumors (nine metastatic, two primary; mean, 2.6 cm; range, 1.0–4.5 cm) located adjacent to mediastinal or hilar structures were treated using CT-guided cryoablation in 10 procedures. Technical success and effectiveness rates were calculated, complications were tabulated and intraprocedural imaging features of ice balls were described.

RESULTS

All procedures were technically successful; imaging after 24 hours demonstrated no residual tumor. Five tumors recurred, three of which were re-ablated successfully. A hypodense ice ball with well-defined margin was visible during the first (n=6, 55%) or second (n=11, 100%) freeze, encompassing the entire tumor in all patients, and abutting (n=7) or minimally involving (n=4) adjacent mediastinal and hilar structures. Pneumothorax developed following six procedures (60%); percutaneous treatment was applied in three of them. All patients developed pleural effusions, with one patient requiring percutaneous drainage. Transient hemoptysis occurred after six procedures (60%), but all cases improved within a week. No injury occurred to mediastinal or hilar structures.

CONCLUSION

CT-guided percutaneous cryoablation can be used to treat central lung tumors successfully. Although complications were common, they were self-limited, treatable, and not related to tumor location. Ice ball monitoring helped maximize the amount of tumor treated, while avoiding critical mediastinal and hilar structures.Malignant lung tumors represent a major cause of morbidity and mortality in developed nations (1). While surgical resection remains the treatment of choice for the local control of both non-small cell lung cancer and metastases to the lung, percutaneous image-guided ablative therapies, particularly heat-based ablation techniques such as radiofrequency (RF) ablation, have emerged as safe and effective alternatives in patients who are not surgical candidates (2–7). However, treatment of lung tumors using RF ablation presents technical challenges, including high electrical resistance of alveolar air, poor thermal conductivity of aerated lung, and the heat-sink effect of blood and air flow in well-perfused and aerated lung tissue (8, 9). In addition, RF ablation has a limited role in the treatment of tumors that are close to mediastinal and hilar structures (2–9). Since intraprocedural visualization of ablation zone margins is not possible during heat-based ablation procedures, treatment of central tumors could harm mediastinal and hilar structures, including the tracheobronchial tree. As a result, tumors close to central structures are generally not amenable to treatment using percutaneous heat-based ablation techniques (2–10). Also, RF ablation may interfere with conduction system of the heart and function of the pacemakers (11).A growing body of literature describes the successful use of cryoablation in the treatment of malignancies in the liver, kidneys, and soft tissues (12–14). The ability to deploy multiple, individually-controlled cryoablation applicators facilitates the creation of ablation zones of desired shapes and sizes that can be tailored to the morphology of the tumor being ablated (15, 16). Cryoablation is also monitorable; ice balls can be visualized by computed tomography (CT) as a distinct ovoid area of low attenuation during the procedure. As a result, the treatment can be optimized while minimizing the risk of harming nearby critical structures (12–16). Also, cryoablation may be less painful than RF ablation (17). Finally, it has been suggested that cryoablation may be better suited for the treatment of thoracic tumors adjacent to the mediastinum because it spares the architecture of collagen-containing structures relative to RF ablation and enables preservation of the integrity of the tracheobroncheal tree (18). Heat-based ablation methods may not be safe in the treatment of central lung tumors because of a possibility of bronchial disruption or perforation, which may result in bronchopleural fistula formation (19). Although cryoablation has been used to treat lung malignancies (19–31), there are limited data on the safety and effectiveness of percutaneous cryoablation of central lung tumors. In this study, we describe our experience with CT-guided percutaneous cryoablation of central lung tumors and the role of ice ball monitoring.     

Use of shear wave elastography to differentiate benign and malignant breast lesions

PURPOSE

We aimed to determine the correlations between the elasticity values of solid breast masses and histopathological findings to define cutoff elasticity values differentiating malignant from benign lesions.

MATERIALS and METHODS

A total of 115 solid breast lesions of 109 consecutive patients were evaluated prospectively using shear wave elastography (SWE). Two orthogonal elastographic images of each lesion were obtained. Minimum, mean, and maximum elasticity values were calculated in regions of interest placed over the stiffest areas on the two images; we also calculated mass/fat elasticity ratios. Correlation of elastographic measurements with histopathological results were studied.

RESULTS

Eighty-three benign and thirty-two malignant lesions were histopathologically diagnosed. The minimum, mean, and maximum elasticity values, and the mass/fat elasticity ratios of malignant lesions, were significantly higher than those of benign lesions. The cutoff value was 45.7 kPa for mean elasticity (sensitivity, 96%; specificity, 95%), 54.3 kPa for maximum elasticity (sensitivity, 95%; specificity, 94%), 37.1 kPa for minimum elasticity (sensitivity, 96%; specificity, 95%), and 4.6 for the mass/fat elasticity ratio (sensitivity, 97%; specificity, 95%).

CONCLUSION

SWE yields additional valuable quantitative data to ultrasonographic examination on solid breast lesions. SWE may serve as a complementary tool for diagnosis of breast lesions. Long-term clinical studies are required to accurately select lesions requiring biopsy.Breast cancer is associated with high morbidity; ∼1.38 million new cases and 458 000 deaths occur annually worldwide (1). Breast cancer is by far the most common cancer in females of both developed and developing countries, and remains a major public health problem.Annual mammographic screening is valuable for early detection of breast cancer, reducing mortality and morbidity, particularly of patients with tumors in fatty breast tissue (2). Increase in breast tissue density over time is a serious problem; this reduces the diagnostic accuracy of breast cancer, especially in younger females (3). Thus, as the proportion of glandular breast tissue rises, other imaging methods are required (4).Gray-scale ultrasonography is a valuable adjunct to mammography and other breast imaging methods, affording highly sensitive assessment of breast masses and differentiating benign solid breast lesions from those that are malignant (5–7). However, ultrasonography is strongly subjective and poorly specific (8–10).Breast biopsy remains the gold standard for definitive diagnosis of suspicious breast lesions. Although the total number of females referred for interventional diagnostic procedures represents a small percentage of any screened population, the healthcare resources consumed by such females are disproportionately high (11). Further, the pathological result is benign in up to 75% of all cases (11–13). Therefore, a reliable, noninvasive, costeffective method helping to differentiate benign from malignant breast lesions, thus reducing the number of unnecessary interventional diagnostic procedures, would be valuable.Sonoelastography uses ultrasound to assess tissue stiffness (elasticity), which can be described using Young’s modulus: E=σ/ε, where σ is the applied stress and ε the resultant tissue deformation. Two principal sonoelastographic approaches are available; these are static (strain) and transient (vibration; shear wave) elastography. In static elastography, a transducer is used to compress tissue and the resulting strain is presented as a color map of tissue elasticity superimposed on the real-time gray-scale sonogram.Static elastography is associated with significant interobserver variability, and uses elastographic scoring (ES) or strain ratio (SR) measurement as a diagnostic parameter. Both ES and SR are subjective semi-quantitative measures (14, 15). Shear wave elastography (SWE) is a novel technique applicable to soft tissue. In SWE, transverse shear waves spreading laterally from the tissue are tracked, and the speed of propagation calculated. SWE yields real-time quantitative data and is highly reproducible compared to static elastography (16, 17). Reproducibility of the latter technique is considered to be a major problem and may compromise patient outcomes. Thus, further work on the utility of SWE is needed.In the present study we sought to correlate the SWE values of a series of solid breast masses with histopathological findings, and to determine cutoff elasticity values allowing benign and malignant tumors to be distinguished.     

Vacuum-assisted stereotactic biopsy for isolated BI-RADS 4 microcalcifications: evaluation with histopathology and midterm follow-up results

PURPOSE

The aim of this study was to evaluate the 10-gauge vacuum-assisted stereotactic biopsy (VASB) of isolated Breast Imaging Reporting and Data System (BI-RADS) 4 microcalcifications, using histology and follow-up results.

METHODS

From January 2011 to June 2013, VASB was performed on 132 lesions, and 66 microcalcification-only lesions of BI-RADS 4 were included into our study. VASB was performed using lateral decubitis stereotaxy for all patients. Pathologic results of VASB and further surgical biopsies were reviewed retrospectively. Patients who were diagnosed to have benign lesions by VASB were referred for follow-up. VASB and surgical histopathology results were compared to determine the underestimation ratios.

RESULTS

Fifteen out of 66 lesions from 63 patients (median age, 47 years; range, 34–88 years) were identified as malignant by VASB. Pathological results after surgery revealed three cases of invasive ductal carcinoma among the 12 VASB-diagnosed ductal carcinoma in situ (DCIS) lesions, for a DCIS underestimation rate of 25%. The atypical ductal hyperplasia underestimation rate was 0% for the three lesions. The follow-up period was at least 10 months, with an average of 22.7 months for all patients and 21.2 months for patients with VASB-diagnosed benign lesions. None of the patients had malignancy during the follow-ups. The false-negative rate was 0% in the follow-up of 48 patients.

CONCLUSION

VASB should be the standard method of choice for BI-RADS 4 microcalcifications. This method obviates the need for a surgical procedure in 73% of BI-RADS 4 microcalcification-only patients.Recently, growing concern regarding breast cancer has resulted in increasingly frequent recommendations for screening mammography and more intensive requirements for biopsies of subclinical (impalpable) lesions. Microcalcifications may be the only finding of early stage malignancies, including atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS). Isolated microcalcifications comprise 55% of the suspicious lesions detected by mammography (1, 2).Until recently, the most common approach for this type of pathology has been surgical excision of the lesion after wire localization by mammographic guidance. However, studies have shown that surgical excisions result in benign histology in 76%–81% of the cases (3, 4). Understandably, surgical excisions generate anxiety in most patients. Additionally, the cost and morbidity associated with the surgical procedures have prompted many physicians to explore less invasive, alternative procedures (5–7).For the past two decades, vacuum-assisted stereotactic biopsy (VASB) has been increasingly used for histologic diagnosis of suspicious microcalcifications. The 11-gauge VASB allows radiologists to obtain a sufficiently large specimen with better calcification retrieval (8), a lower re-biopsy rate, and fewer histologic underestimates (9–11), compared with other core-needle biopsy techniques. The false-negative rate of VASB procedure can be as low as 0.6% when performed by experienced radiologists (12). This technique also has some cost advantages compared to needle-localized surgical biopsy (NLSB)(13).Although numerous studies of VASB under real-time ultrasonography (US) or mammography guidance exist, none have included a sufficient subgroup analysis (2, 14). Core needle biopsy is the cheapest and easiest technique for lesions that can be visualized by US; however, isolated, suspicious microcalcifications can only be sampled by means of stereotaxy. To our knowledge, there is no study that has specifically evaluated isolated Breast Imaging Reporting and Data System (BI-RADS) 4 microcalcifications, even though these constitute the majority of subclinical lesions detected by screening mammography. BI-RADS 3 microcalcifications can be followed confidently, whereas BI-RADS 5 microcalcifications should be subjected to surgical excision in all cases.BI-RADS 4 microcalcifications are the most critical issue facing radiologists reporting screening mammography. Through the routine use of VASB for BI-RADS 4 microcalcifications, surgical excision can be avoided in most patients (3, 4). It is important to consider the underestimation and false-negative rates, specifically for isolated BI-RADS 4 microcalcifications, before considering more invasive methods (surgical biopsies) as a further step after VASB. The aim of this study was to evaluate the utility of VASB for isolated BI-RADS 4 microcalcifications by studying their midterm follow-up results.     

Contribution of real-time elastography in diagnosis of polycystic ovary syndrome

PURPOSE

We aimed to assess the feasibility and reproducibility of real-time elastography (RTE) for displaying the effects of morphological changes in the ovary in polycystic ovary syndrome (PCOS).

METHODS

Forty-eight patients diagnosed with PCOS and 48 healthy women were enrolled in the study. Ultrasonography and RTE were performed on the 3^rd day of the menstrual cycle. Evaluations were performed independently by two radiologists. Ovarian volume, number of follicles, elasticity pattern, and strain ratio were measured. Elasticity patterns were assessed as hard (type 1; blue or blue-green), moderate (type 2; green or green-yellow) or soft (type 3; red or orange-red).

RESULTS

Both radiologists determined the elasticity pattern as mostly type 1 in the PCOS group and type 3 in the control group (P < 0.01). The mean strain ratios obtained by the first and second radiologist were 6.1±1.8 (2.7–10.1) and 6.0±1.5 (3.0–9.0) in PCOS and 3.3±1.2 (1.7–7.2) and 3.2±0.9 (1.7–6.8) in the control group, respectively (P < 0.001). Interobserver agreement was moderate for the elasticity pattern (κ=0.48) and good for the strain ratio (intraclass correlation coefficient, 0.77). A strain ratio of 3.8 was determined as the optimized cutoff point by receiver operating curve analysis. Strain ratio was correlated with the ovarian volume and the number of detected follicles (P < 0.001).

CONCLUSION

Elasticity pattern and strain ratio can help identify morphological changes that make PCOS ovaries stiffer than normal ovaries.In reproductive-aged women, polycystic ovary syndrome (PCOS) is an important cause of infertility and is characterized by menstrual irregularities, hirsutism and signs of hyperandrogenism, and polycystic ovary appearance (1–3). In addition to insulin resistance, serum androgenic hormone levels are increased, causing undesired effects on women’s metabolic, reproductive, and cardiovascular health (1–5). PCOS is characterized by enlarged ovaries containing small cysts, for which the syndrome was named (6).Real-time elastography (RTE) is a novel and dynamic imaging technique that is simply based on the hardness or softness of tissues or organs under the appropriate compression and can be used with conventional ultrasonography (US) probes after performing gray-scale and Doppler US. Displacement of soft tissues is greater than hard tissues, and tissue hardness is displayed as a color-coded image that lays over the gray-scale US image translucently (7). Elastography has been used previously for differentiation of pathologies of tissues and organs, such as thyroid, breast, kidneys, and liver (7–9). There are limited studies about the elastographic properties of the ovaries, mostly focused on ovarian neoplasms and, to the best of our knowledge, there is no medical data concerning the elasticity properties of the ovary in PCOS (10, 11). In this study, our purpose was to assess the feasibility and reproducibility of RTE for displaying the effects of morphological changes in the ovary in PCOS and to put forward the value of RTE as a new diagnostic approach for diagnosing PCOS.