Percutaneous Renal Tumor Ablation: Radiation Exposure During Cryoablation and Radiofrequency Ablation

Introduction

Once reserved solely for non-surgical cases, percutaneous ablation is becoming an increasingly popular treatment option for a wider array of patients with small renal masses and the radiation risk needs to be better defined as this transition continues.

Materials and Methods

Retrospective review of our renal tumor ablation database revealed 425 patients who underwent percutaneous ablation for treatment of 455 renal tumors over a 5-year time period. Imparted radiation dose information was reviewed for each procedure and converted to effective patient dose and skin dose using established techniques. Statistical analysis was performed with each ablative technique.

Results

For the 331 cryoablation procedures, the mean DLP was 6987 mGycm (SD = 2861) resulting in a mean effective dose of 104.7 mSv (SD = 43.5) and the mean CTDI_vol was 558 mGy (SD = 439) resulting in a mean skin dose of 563.2 mGy (SD = 344.1). For the 124 RFA procedures, the mean DLP was 3485 mGycm (SD = 1630) resulting in a mean effective dose of 50.3 mSv (SD = 24.0) and the mean CTDI_vol was 232 mGy (SD = 149) resulting in a mean skin dose of 233.2 mGy (SD = 117.4). The difference in patient radiation exposure between the two renal ablation techniques was statistically significant (p < 0.001).

Conclusion

Both cryoablation and RFA imparted an average skin dose that was well below the 2 Gy deterministic threshold for appreciable sequela. Renal tumor cryoablation resulted in a mean skin and effective radiation dose more than twice that for RFA. The radiation exposure for both renal tumor ablation techniques was at the high end of the medical imaging radiation dose spectrum.

     

Radiofrequency ablation versus cryoablation for T1b renal cell carcinoma: a multi-center study

Purpose

To compare the clinical outcomes between radiofrequency ablation (RFA) and cryoablation for the treatment of clinical T1b (cT1b) renal cell carcinoma (RCC).

Materials and methods

The data of 46 patients [(39 men and 7 women, median age; 73 years, range 39–87 years)] were gathered from 3 institutions. RFA and cryoablation were performed on 23 patients each. The median number of ablation needle was 2 (range 1–4) and 4 (range 3–5, p?<?0.0001) in RFA and cryoablation, respectively. Technique efficacy defined as coverage of the tumor by ablative zone, adverse events, local tumor progression, and survival were compared between the RFA and cryoablation groups.

Results

The primary technique efficacy rate was significantly higher in the cryoablation group (96%, 22/23) than in the RFA group (65%, 15/23, P?=?0.02). There was no significant difference in the secondary technique efficacy rate after additional RFA and cryoablation [21/23 (91%) vs. 23/23 (100%); P?=?0.24]. The incidence of grade 3 or higher adverse events was similar between the 2 groups (P?>?0.99). There was no significant difference between local tumor progression rate after RFA and cryoablation [3/21 (14%) vs. 2/23 (9%); P?=?0.66]. The 5-year overall survival rates were comparable between RFA and cryoablation (78 vs. 82%; P?=0.82).

Conclusion

Other than primary technique efficacy, the clinical outcomes between RFA and cryoablation were similar in patients with cT1b RCC.

     

Diagnostic Ability of Percutaneous Needle Biopsy Immediately After Radiofrequency Ablation for Malignant Lung Tumors: An Initial Experience

Purpose

To evaluate the safety and diagnostic ability of percutaneous needle biopsy performed immediately after lung radiofrequency ablation (RFA).

Materials and Methods

From May 2013 to April 2014, percutaneous needle biopsy was performed immediately after RFA for 3 patients (2 men and 1 woman, aged 57–76 years) who had lung tumors measuring 1.3–2.6 cm in diameter. All patients had prior history of malignancy, and all tumors were radiologically diagnosed as malignant. Obtained specimens were pathologically classified using standard hematoxylin and eosin staining.

Results

We completed three planned sessions of RFA followed by percutaneous needle biopsy, all of which obtained tumor tissue that could be pathologically diagnosed. Two tumors were metastatic from renal clear cell carcinoma and rectal adenocarcinoma, respectively; one tumor was primary lung adenocarcinoma. There was no death or major complication related to the procedures. Although pneumothorax occurred in two patients, these resolved without the need for aspiration or chest tube placement. Tumor seeding was not observed, but 21 months after the procedure, one case developed local tumor progression that was treated by additional RFA.

Conclusion

Pathologic diagnosis was possible by needle biopsy immediately after RFA for lung tumors. This technique may reduce the risks and efforts of performing biopsy and RFA on separate occasions.

     

Retrospective review of thoracic neural damage during lung ablation – what the interventional radiologist needs to know about neural thoracic anatomy

Background and Purpose

Radiofrequency ablation (RFA) is associated with low neural morbidity compared with surgery, which commonly causes debilitating long-term pain. The purpose was to review the thoracic neural anatomy relevant to percutaneous RFA and to retrospectively review symptomatic nerve injury after lung RFA at our institution.

Materials and Methods

We retrospectively examined all symptomatic nerve injuries occurring after computed tomography (CT)-guided RFA treatment of lung tumors for 462 patients/509 procedures/708 lesions treated at our large tertiary referral centre during 10 years.

Results

Eight patients experienced neurological complications after heating during the RFA procedure. These complications occurred in the phrenic (n = 1), brachial (n = 3), left recurrent (n = 1), and intercostal nerves (n = 2) and the stellate ganglion (n = 1). Three were grade 2, four grade 3 and one grade 4 injuries (CTCAE v3).

Conclusion

Although rare, neurological complications can occur after RFA, and they can occasionally be severe. To prevent these complications, it is important for the interventional radiologist to be aware of the anatomy of nervous structures and to attempt to identify nerves on CT scans during the RFA procedure. Creating a pneumothorax can be useful to avoid nerve damage and related clinical complications.

     

Phase I/II Study of Radiofrequency Ablation for Malignant Renal Tumors: Japan Interventional Radiology in Oncology Study Group 0701

Purpose

This multicenter phase I/II study evaluated the safety, feasibility, and initial efficacy of radiofrequency ablation (RFA) for small malignant renal tumors.

Methods

Thirty-three patients were enrolled in the study. A single session of RFA was performed in patients with a renal tumor of 1–3 cm in greatest diameter, with the exception of lesions adjacent to the renal hilum. The primary endpoint was the safety of renal RFA, and the secondary endpoints were its feasibility and initial efficacy for local control, as well as the incidence and grade of adverse events. Clinical efficacy was evaluated by CT scans within 1 week and at a further 4 weeks after the procedure using the criteria adapted from the Response Evaluation Criteria in Solid Tumors.

Results

The RFA procedure was completed in 100 % (95 % confidence interval [CI] 89–100 %) of all 33 patients. There were no severe adverse events (0 % [95 % CI 0–11 %]). Among the 33 patients, a complete response, partial response, progressive disease, and stable disease were seen in 28 (85 %), 0 (0 %), one (3 %), and one (3 %) patient(s), respectively, with a tumor response rate of 85 % [95 % CI 68–95 %]). Three patients (9 %), including one ineligible patient (3 %), were not evaluable. Out of 30 evaluable patients, a complete response was achieved in 28 (93 %).

Conclusion

The current multicenter trial revealed that RFA is a safe, feasible, and effective treatment for small malignant renal tumors in patients who are not candidates for surgery.

     

Percutaneous Radiofrequency Ablation Versus Robotic-Assisted Partial Nephrectomy for the Treatment of Small Renal Cell Carcinoma

Introduction

The authors compared the oncologic outcomes of radiofrequency ablation (RFA) with robotic-assisted partial nephrectomy (RPN) for the treatment of T1 stage renal cell carcinoma (RCC).

Materials and methods

This was a retrospective data analysis of a high-volume single tertiary centre. Patients were treated with RFA or RPN following multidisciplinary decision making. Only histologically proven RCCs were included. Baseline demographics were collected, and PADUA scores of tumour features were calculated to standardize baseline anatomy. Peri-operative complications, kidney function and oncological outcomes were compared.

Results

Sixty-three cases were included in each group. Baseline renal function was poorer in RFA, and 16/63 RFA patients had tumours in single kidneys compared to 1/63 RPN cases (p < 0.001). Length of stay was shorter in RFA (1 vs. 3 days, p < 0.0001). Post-procedure renal function decline at 30 days was significantly less in RFA [(?0.8) ± 9.6 vs. (?16.1) ± 19.5 mls/min/1.73 m²; p < 0.0001]. More minor complications were recorded in RPN (10/63 vs. 4/63, p = 0.15), but local recurrence was numerically higher in RFA (6/63 vs. 1/63, p = 0.11). Disease-free survival (DFS) was not significantly different (adjusted HR = 0.6, 95 % Cl 0.1–3.7; p = 0.60). Increasing tumour size was an independent predictor of local recurrence (adjusted HR = 1.7; 95 % Cl 1.1–2.6 per cm; p = 0.02).

Conclusions

Both RPN and RFA offer very good oncological outcomes for the treatment of T1 RCC with low peri-operative morbidity and similar oncologic outcomes. RFA demonstrated fewer peri-operative complications and better preservation of renal function, whereas RPN had an insignificantly lower local recurrence rate. RFA should be offered alongside RPN for selected cases.

     

In vivo effects of radiofrequency ablation on long bones and the repair process in swine models

Purpose

To investigate in vivo effect of radiofrequency ablation (RFA) on swine long bones and the repair process.

Materials and methods

RFA was performed in six swine at the end and middle part of the tibia or femur. After RFA, radiological examinations were performed, and the swine were killed immediately and at different time points post-RFA for histopathological examination.

Results

All swine had successful RFA. The RFA-induced elliptical necrotic area ranged from 3.81–5.24 cm² (mean 4.08 ± 0.73 cm²) at the bone end but 5.60–8.98 cm² (mean 7.58 ± 1.41) at the middle part immediately after RFA until 10 days, with the necrosis area significantly smaller (P = 0.000) at the end than at the middle. RFA only damaged the cortical bone slightly (0.01 cm thick) with no damage to the soft tissues outside the compact bone at both the end and middle. Surrounding the elliptic pale zone of coagulative necrosis was a narrow brown band of hemorrhage and inflammatory exudate. From day 10 until week 12, tissue proliferation and repair became increasingly apparent, with proliferated granulation, fibrous tissue, and fresh and mature bone trabecula.

Conclusion

RFA can quickly and effectively destroy the cancellous bone tissue without affecting the cortical bone and activate bone remodeling.

     

RF Ablation of Giant Hemangiomas Inducing Acute Renal Failure: A Report of Two Cases

Objective

In patients that require treatment for hepatic giant cavernous hemangiomas (GCH), radiofrequency ablation (RFA) has been suggested to represent a safe and effective alternative to invasive surgery. In a recent report of bipolar RFA, using two expandable needle electrodes, was uneventfully performed in patients with large GCH (>10 cm). The objective of this report is to present two cases in which bipolar RFA of symptomatic GCH was complicated by acute kidney injury.

Materials and methods

In 2015 we treated two patients for very large symptomatic GCH (15.7 and 25.0 cm) with bipolar RFA during open laparotomy.

Results

In both patients the urine showed a red–brown discoloration directly after the ablation. They became anuric and presented with progressive dyspnea, tachypnea, and tachycardia, requiring hemodialysis for a period of 1 month in one case. Lab results revealed hemepigment-induced acute kidney. Both patients fully recovered and both showed a complete relief of symptoms at 3 months following the procedure.

Conclusion

RFA for large GCHs can cause hemepigment-induced acute kidney injury due to massive intravascular hemolysis. The presented cases suggest that caution is warranted and advocate an upper limit regarding the volume of GCHs that can be safely ablated.

     

Effectiveness and safety of computed tomography-guided radiofrequency ablation of renal cancer: a 14-year single institution experience in 203 patients

Objectives

To define effectiveness and safety of CT-guided radiofrequency ablation (RFA) of renal tumours and prognostic indicators for treatment success.

Methods

Patients with a single treatment of a solitary, biopsy-proven renal tumour with intent to cure over a 14-year period were included (n?=?203). Probability of residual disease over time, complication rates and all-cause mortality were assessed in relation to multiple variables.

Results

Mean tumour size was 2.5 cm (range 1.0–6.0). Mean follow-up was 34.1 months (range 1–131). There was an increase in likelihood of residual disease for tumours ≥3.5 cm (P?<?0.05), clear cell subtype of renal cell carcinoma (P?≤?0.005) and maximum treatment temperature ≤70 °C (P?<?0.05). There was a decrease in likelihood of residual disease for exophytic tumours (P?=?0.01) and no difference based on age, gender, tumour location or type of radio freqency (RF) electrode used. Major complications occurred in 3.9 %. Median post-treatment survival was 7 years for patients with tumours <4 cm, and 5-year overall survival was 80 %. Probability of minor complication increased with tumour size (P?=?0.03), as did all-cause mortality (P?=?0.005).

Conclusions

CT-guided RFA is safe and effective for early-stage renal cancer, particularly for exophytic tumours measuring <3.5 cm. Overall 5-year survival with tumours <4 cm is comparable to partial nephrectomy.

Key points

? Prognostic indicators for success of CT-guided RFA of renal tumours are reported. ? Tumour size ≥3.5 cm confers an increased risk for residual tumour. ? Clear cell renal cell carcinoma subtype confers increased risk for residual tumour. ? Tmax <70 °C within the ablation zone confers increased risk for residual tumour. ? Exophytic tumours have a lower probability of residual disease.

     

Radiofrequency ablation versus magnetic resonance guided focused ultrasound surgery for minimally invasive treatment of osteoid osteoma: a propensity score matching study

Objectives

To compare outcomes in pain relief and motor functional recovery in patients with an osteoid osteoma treated by magnetic resonance guided focused ultrasound surgery (MRgFUS) or radiofrequency ablation (RFA) using a propensity score matching study design.

Methods

Thirty patients with osteoid osteomas were included in this institutional review board (IRB)-approved study. MRgFUS was performed in 15 subjects. These subjects were matched by propensity analysis with a group of 15 subjects treated by RFA. Pain relief in terms of complete response (CR) and motor functional recovery were measured.

Results

A similar proportion of subjects treated by MRgFUS (94 %) or RFA (100 %) experienced CR 12 weeks after treatment, with no significant difference. The improvement in pain control following MRgFUS or RFA paralleled with improved motor functional recovery. The treatment failure rate was 6.6 % in the MRgFUS group and 0 % in the RFA group. No major complications were observed following either ablative treatment.

Conclusions

Although this study involved a limited number of patients, MRgFUS favourably improves perceived pain and motor functional recovery, with no major complications. No difference was found in the achievement of primary and secondary outcome measures with respect to RFA.

Key Points

? To demonstrate the effectiveness of a recent technique for treating osteoid osteoma ? MRgFUS results compared with results of the gold standard treatment (RFA) ? MRgFUS is effective both from a clinical and functional point of view ? No significant side effects compared with RFA

     

Ablation protocols and ancillary procedures in tumor ablation therapy: consensus from Japanese experts

Purpose

A panel of Japanese experts on tumor ablation therapy gathered to reach a general consensus on topics surrounding ablation therapy.

Materials and methods

Questionnaires relating to ablation protocols for radiofrequency ablation (RFA) and cryoablation, as well as ancillary procedures required for safe and secure ablation therapy, were sent to seven institutions. Experts from these institutions discussed each topic based on the evidence and the questionnaire data, and a consensus was reached at an annual meeting of the Japan Image-guided Ablation Group in Maebashi, Japan, in October 2015.

Results

A consensus was reached on each of six topics, including “management of antiplatelet and anticoagulation drug therapy”; “pain control in the perioperative period”; “arterial embolization combined with ablation therapy”; “protection of non-target organs”; “RFA and cryoablation protocols”; and “ablative margins.”

Conclusions

The consensus achieved here will serve as the framework for tumor ablation therapies in Japan.

     

Percutaneous Endovascular Radiofrequency Ablation for Malignant Portal Obstruction: An Initial Clinical Experience

Purpose

The Habib? VesOpen Catheter is a new endovascular radiofrequency ablation (RFA) device used to treat malignant portal obstruction. The purpose of this study was to evaluate the clinical feasibility and safety of RFA with this device.

Methods

We collected the clinical records and follow-up data of patients with malignant portal obstruction treated with percutaneous endovascular portal RFA using the Habib? VesOpen Catheter. Procedure-related complications, improvement of symptoms, portal patency, survival, and postoperative biochemical tests were investigated.

Results

The 31 patients enrolled in the study underwent 41 successful endovascular portal RFA procedures. Patients were divided into a portal-stenting (PS) group (n = 13), which underwent subsequent portal stenting with self-expandable metallic stents, and a non-stenting (NS) group (n = 18), which did not undergo stenting. No procedure-related abdominal hemorrhage or portal rupture occurred. Postablation complications included abdominal pain (n = 26), fever (n = 13), and pleural effusion (n = 15). Improvements in clinical manifestations were observed in 27 of the 31 patients. Of the 17 patients experiencing portal restenosis, 10 underwent successful repeat RFA. The rate of successful repeat RFA was significantly higher in the NS group than in the PS group. Median portal patency was shorter in the PS group than in the NS group. No mortality occurred during the 4 weeks after percutaneous endovascular portal RFA.

Conclusions

Percutaneous endovascular portal RFA is a feasible and safe therapeutic option for malignant portal obstruction. Prospective investigations should be performed to evaluate clinical efficacy, in particular, the need to evaluate the necessity for subsequent portal stenting.

     

Percutaneous Intraductal Radiofrequency Ablation for Extrahepatic Distal Cholangiocarcinoma: A Method for Prolonging Stent Patency and Achieving Better Functional Status and Quality of Life

Purpose

The clinical efficacy of intraductal radiofrequency ablation (RFA) with Habib? EndoHPB catheter, a newly developed intervention for malignant extrahepatic biliary obstruction, remains uncertain. The aim of this study was to investigate the clinical efficacy of intraductal RFA.

Methods

Data from 71 patients with extrahepatic distal cholangiocarcinoma were retrospectively analyzed. The study patients were divided into RFA and control groups. The RFA group had undergone percutaneous transhepatic intraductal RFA with a Habib? EndoHPB catheter, followed by placement of covered or uncovered biliary self-expandable metallic stents (SEMs) whereas the control group had undergone percutaneous transhepatic covered or uncovered SEMs placement. Procedure-related complications, stent patency, patient survival, and postoperative serum bilirubin concentrations were compared between the two groups. The Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep) questionnaire was administered to evaluate functional status, improvement in clinical manifestations, and quality of life.

Results

The RFA group had a longer median stent patency than the control group (p = 0.001 for uncovered SEMs placement). Higher functional well-being, hepatobiliary-specific cancer subscale, Trial Outcome Index, and total FACT-Hep scores were observed during post-procedure follow-up in the RFA group. However, median survival did not differ significantly between the two groups (p > 0.05).

Conclusions

Prolongation of stent patency and better functional status and quality of life, which are all important clinical endpoints, were observed in patients treated with intraductal RFA. Prospective randomized controlled clinical trials are necessary to further investigate the clinical efficacy and long-term benefits of intraductal RFA.

     

Multicenter Prospective Clinical Series Evaluating Radiofrequency Ablation in the Treatment of Painful Spine Metastases

Background

Radiofrequency ablation (RFA) of vertebral body metastases (VBM) has been reported as safe and effective in retrospective studies. This single-arm prospective multicenter clinical study evaluates RFA in the treatment of painful VBM.

Methods

Fifty patients with VBM were prospectively enrolled during a 13-month period at eight US centers under an IRB-approved study. Percutaneous RFA was performed under imaging guidance with cement augmentation at the discretion of the operator. Pain, disability and quality of life were evaluated at baseline, prior to discharge, days 3, 7, 30 and 90 using the Numerical Pain Rating Scale, Oswestry Disability Index (ODI), the Functional Assessment of Cancer Therapy-General 7 (FACT-G7) and Functional Assessment of Cancer Therapy Quality-of-Life Measurement in Patients with Bone Pain (FACT-BP). Adverse events were monitored throughout this time interval.

Results

Twenty-six male and 24 female patients (mean age 61.0) underwent 69 treatments (30 thoracic and 39 lumbar). Cement augmentation was performed in 96 % of reported levels. Significant improvement in mean scores for pain, disability and cancer-specific health-related quality of life from baseline to all time intervals was seen. NRPS improved from 5.9 to 2.1 (p < 0.0001). ODI improved from 52.9 to 37.0 (p < 0.08). FACT-G7 improved form 10.9 to 16.2 (p = 0.0001). FACT-BP improved from 22.6 to 38.9 (p < 0.001). No complications related to the procedure were reported.

Conclusion

RFA with cement augmentation safely and effectively reduces pain and disability rapidly, while increasing quality of life in patients suffering from vertebral body metastases.

     

Intra-patient comparison of reduced-dose model-based iterative reconstruction with standard-dose adaptive statistical iterative reconstruction in the CT diagnosis and follow-up of urolithiasis

Objectives

To evaluate the accuracy of reduced-dose CT scans reconstructed using a new generation of model-based iterative reconstruction (MBIR) in the imaging of urinary tract stone disease, compared with a standard-dose CT using 30% adaptive statistical iterative reconstruction.

Methods

This single-institution prospective study recruited 125 patients presenting either with acute renal colic or for follow-up of known urinary tract stones. They underwent two immediately consecutive scans, one at standard dose settings and one at the lowest dose (highest noise index) the scanner would allow. The reduced-dose scans were reconstructed using both ASIR 30% and MBIR algorithms and reviewed independently by two radiologists. Objective and subjective image quality measures as well as diagnostic data were obtained.

Results

The reduced-dose MBIR scan was 100% concordant with the reference standard for the assessment of ureteric stones. It was extremely accurate at identifying calculi of 3 mm and above. The algorithm allowed a dose reduction of 58% without any loss of scan quality.

Conclusions

A reduced-dose CT scan using MBIR is accurate in acute imaging for renal colic symptoms and for urolithiasis follow-up and allows a significant reduction in dose.

Key points

? MBIR allows reduced CT dose with similar diagnostic accuracy ? MBIR outperforms ASIR when used for the reconstruction of reduced-dose scans ? MBIR can be used to accurately assess stones 3 mm and above

     

Early Stage Hepatocellular Carcinomas Not Feasible for Ultrasound-Guided Radiofrequency Ablation: Comparison of Transarterial Chemoembolization Alone and Combined Therapy with Transarterial Chemoembolization and Radiofrequency Ablation

Purpose

To report the results of combined therapy with transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) for early stage hepatocellular carcinoma (HCC) considered infeasible for ultrasound (US)-guided RFA in comparison with those of TACE monotherapy.

Methods

From January 2007 through December 2010, 91 patients with early or very early stage HCC infeasible for US-guided RFA received either TACE alone (TACE group; n = 54) or TACE immediately followed by RFA (TACE–RFA group; n = 37) as a first-line treatment. 1-month tumor response, time to progression (TTP), and overall survival (OS) rates were calculated. Univariate and multivariate analyses were performed to identify prognostic factors.

Results

TACE–RFA group showed a better 1-month tumor response than TACE group (P < .001). The mean TTP was 29.7 ± 3.4 months (95 % confidence intervals [CIs] 23.0–36.5) in TACE group and 34.9 ± 2.8 months (95 % CIs 29.4–40.4) in TACE–RFA group. TACE–RFA group had a significantly longer TTP (P = .014). Cumulative 1-, 2-, and 3-year OS rates in the TACE and TACE–RFA groups were 91, 79, and 71 % and 100, 97, and 93 %, respectively (P = .008). Initial treatment of TACE was found to be the only significant risk factor for tumor progression and OS in multivariate analysis.

Conclusion

TACE–RFA combination therapy appears superior to TACE monotherapy in terms of 1-month tumor response, TTP, and OS when performed for early stage HCC infeasible for US-guided RFA.

     

Clinical utility of radiofrequency ablation following transarterial injection of miriplatin-iodized oil suspension in small hepatocellular carcinoma

Purpose

To retrospectively evaluate the clinical utility of radiofrequency ablation (RFA) following transarterial injection of miriplatin-iodized oil suspension (MPT–RFA) for hepatocellular carcinoma treatment.

Materials and methods

We evaluated clinical outcomes of MPT–RFA for three or fewer hepatocellular carcinomas. Twenty-one patients with 30 tumors (maximum diameter: mean 1.4 ± 0.4 cm, range 0.7–2.2 cm) received MPT–RFA.

Results

Nineteen patients (90.5 %, 19/21) achieved complete ablation at the first RFA session. Two patients (9.5 %, 2/21) required a second RFA session but achieved complete ablation. Primary and secondary technical success rates were 90.5 and 100 %. There were no deaths related to the procedures performed. Grade 3 or 4 increases in the serum aspartate aminotransferase, alanine aminotransferase, and bilirubin levels were found in six patients (38.1 %, 8/21). There were no liver infarctions. During the median follow-up period of 24.1 months (mean ± SD 24.7 ± 6.9 months, range 13.8–38.9 months), the local tumor progression rate and overall survival rate at 2 years was 5.0 % (95 % confidence interval 0.3–20.6 %) and 86.7 % (95 % confidence interval 56.3–96.5 %), respectively. The mean hospital stay was 8.4 ± 3.1 days (range 5–18 days).

Conclusion

MPT–RFA is a safe therapeutic option that initially provides therapeutic results.

     

Transcatheter Arterial Embolization with a Mixture of Absolute Ethanol and Iodized Oil for Poorly Visualized Endophytic Renal Masses Prior to CT-Guided Percutaneous Cryoablation

Purpose

To retrospectively evaluate the feasibility of transcatheter arterial embolization (TAE) using a mixture of absolute ethanol and iodized oil to improve localization of endophytic renal masses on unenhanced computed tomography (CT) prior to CT-guided percutaneous cryoablation (PCA).

Materials and Methods

Our institutional review board approved this retrospective study. From September 2011 to June 2015, 17 patients (mean age, 66.8 years) with stage T1a endophytic renal masses (mean diameter, 26.5 mm) underwent TAE using a mixture of absolute ethanol and iodized oil to improve visualization of small and endophytic renal masses on unenhanced CT prior to CT-guided PCA. TAE was considered successful that accumulated iodized oil depicted whole of the tumor edge on CT. PCA was considered successful when the iceball covered the entire tumor with over a 5 mm margin. Oncological and renal functional outcomes and complications were also evaluated.

Results

TAE was successfully performed in 16 of 17 endophytic tumors. The 16 tumors were performed under CT-guided PCA with their distinct visualization of localization and safe ablated margin. During the mean follow-up period of 15.4 ± 5.1 months, one patient developed local recurrence. Estimated glomerular filtration rate declined by 8 % with statistical significance (P = 0.01). There was no procedure-related significant complication.

Conclusion

TAE using a mixture of absolute ethanol and iodized oil to improve visualization of endophytic renal masses facilitated tumor localization on unenhanced CT, permitting depiction of the tumor edge as well as a safe margin for ablation during CT-guided PCA, with an acceptable decline in renal function.

     

Percutaneous Management of Accidentally Retained Foreign Bodies During Image-Guided Non-vascular Procedures: Novel Technique Using a Large-Bore Biopsy System

Objective

To describe a novel percutaneous image-guided technique using a large-bore biopsy system to retrieve foreign bodies (FBs) accidentally retained during non-vascular interventional procedures.

Materials and Methods

Between May 2013 and October 2015, five patients underwent percutaneous retrieval of five iatrogenic FBs, including a biopsy needle tip in the femoral head following osteoblastoma biopsy and radiofrequency ablation (RFA); a co-axial needle shaft within a giant desmoid tumour following cryoablation; and three post-vertebroplasty cement tails within paraspinal muscles. All FBs were retrieved immediately following original procedures under local or general anaesthesia, using combined computed tomography (CT) and fluoroscopic guidance. The basic technique involved positioning a 6G trocar sleeve around the FB long axis and co-axially advancing an 8G biopsy needle to retrieve the FB within the biopsy core. Retrospective chart review facilitated analysis of procedures, FBs, technical success, and complications.

Results

Mean FB size was 23 mm (range 8–74 mm). Four FBs were located within 10 mm of non-vascular significant anatomic structures. The basic technique was successful in 3 cases; 2 cases required technical modifications including using a stiff guide-wire to facilitate retrieval in the case of the post-cryoablation FB; and using the central mandrin of the 6G trocar to push a cement tract back into an augmented vertebra when initial retrieval failed. Overall technical success (FB retrieval or removal to non-hazardous location) was 100 %, with no complications.

Conclusion

Percutaneous image-guided retrieval of iatrogenic FBs using a large-bore biopsy system is a feasible, safe, effective, and versatile technique, with potential advantages over existing methods.

     

Comparison of digital tomosynthesis and computed tomography for lung nodule detection in SOS screening program

Purpose

To compare the lung nodules’ detection of digital tomosynthesis (DTS) and computed tomography (CT) in the context of the SOS (Studio OSservazionale) prospective screening program for lung cancer detection.

Materials and methods

One hundred and thirty-two of the 1843 subjects enrolled in the SOS study underwent CT because non-calcified nodules with diameters larger than 5 mm and/or multiple nodules were present in DTS. Two expert radiologists reviewed the exams classifying the nodules based on their radiological appearance and their dimension. LUNG-RADS classification was applied to compare receiver operator characteristics curve between CT and DTS with respect to final diagnosis. CT was used as gold standard.

Results

DTS and CT detected 208 and 179 nodules in the 132 subjects, respectively. Of these 208 nodules, 189 (91%) were solid, partially solid, and ground glass opacity. CT confirmed 140/189 (74%) of these nodules but found 4 nodules that were not detected by DTS. DTS and CT were concordant in 62% of the cases applying the 5-point LUNG-RADS scale. The concordance rose to 86% on a suspicious/non-suspicious binary scale. The areas under the curve in receiver operator characteristics were 0.89 (95% CI 0.83–0.94) and 0.80 (95% CI 0.72–0.89) for CT and DTS, respectively. The mean effective dose was 0.09 ± 0.04 mSv for DTS and 4.90 ± 1.20 mSv for CT.

Conclusions

The use of a common classification for nodule detection in DTS and CT helps in comparing the two technologies. DTS detected and correctly classified 74% of the nodules seen by CT but lost 4 nodules identified by CT. Concordance between DTS and CT rose to 86% of the nodules when considering LUNG-RADS on a binary scale.