Radiofrequency ablation under 3D intraoperative Iso-C C-arm navigation for the treatment of osteoid osteomas

Objective:

To evaluate the efficacy of intraoperative three-dimensional (3D) Iso-C C-arm-navigated percutaneous radiofrequency ablation (RFA) of osteoid osteomas.

Methods:

35 patients (20 males and 15 females) with osteoid osteomas underwent treatment with intraoperative 3D Iso-C C-arm navigation-guided RFA. The tumour was first biopsied for pathological examination, the core needle was removed and the RFA needle was inserted into the nidus. Post-operative X-rays and CT scans were performed to evaluate the degree of ablation and to assess for recurrence at 3-month follow-up. Patients also completed a visual analogue scale (VAS) both pre-operatively and 3 days post-operatively to subjectively assess pain.

Results:

Pathological diagnosis confirmed osteoid osteoma in 19 cases. The other 16 cases were not pathologically diagnosed owing to inadequate biopsy specimens. In all cases, localized pain was immediately relieved following RFA. Patients reported significantly decreased pain, with mean pre-operative VAS scores of 3.4 reducing to 0.80 at 3 days post-operatively and further to 0.06 at 3-month follow-up (p < 0.05). The mean follow-up time was 15.5 months (range: 3–38 months).

Conclusion:

3D Iso-C C-arm navigation-guided RFA is a safe and effective option for the treatment of osteoid osteomas and may be considered in place of intraoperative CT-guided and open resection.

Advances in knowledge:

C-arm image-guided percutaneous RFA mitigates the need for pre-operative CT as well as intraoperative scintigraphy, provides real-time imaging of the anatomy, facilitates accurate resection of the tumour and enables immediate confirmation of excision.     

Radiofrequency Ablation for Treating Liver Metastases from a Non-Colorectal Origin

Objective

We wanted to assess the safety and efficacy of performing radiofrequency ablation (RFA) in patients with non-colorectal liver metastases.

Materials and Methods

In this retrospective study, 25 patients with 40 hepatic metastases (M:F = 17:8; mean age, 57 years; tumor size, 0.5-5.0 cm) from a non-colorectal origin (stomach, biliary, breast, pancreas, kidney and skin) were treated with RFA. The RFA procedures were performed using either an internally cooled electrode or a clustered electrode under ultrasound or CT guidance. Contrast-enhanced CT scans were obtained immediately after RFA and follow-up CT scans were performed within three months after ablation and subsequently at least every six months. The intrahepatic disease-free interval was estimated and the overall survival from the time of the initial RFA was analyzed using the Kaplan-Meier method.

Results

No intraprocedural deaths occurred, but four major complications developed, including abscesses (n = 3) and pneumothorax (n = 1). Technical effectiveness was determined on the initial follow-up images. During the follow-up period (range, 5.9-68.6 months; median time, 18.8 months) for 37 tumors in 22 patients where technical effectiveness was achieved, 12 lesions (32%, 12 of 37) showed local tumor progression and new intrahepatic metastases occurred in 13 patients (59%, 13 of 22). The median intrahepatic disease-free interval was 10.1 months. The 1-year, 3-year and 5-year overall survival rates after RFA were 86%, 39% and 19%, respectively.

Conclusion

RFA showed intermediate therapeutic effectiveness for the treatment of non-colorectal origin liver metastases.     

Radiofrequency Ablation to Treat Loco-Regional Recurrence of Well-Differentiated Thyroid Carcinoma

Objective

To evaluate the efficacy of radiofrequency ablation (RFA) in the treatment of loco-regional, recurrent, and well-differentiated thyroid carcinoma.

Materials and Methods

Thirty-five recurrent well-differentiated thyroid carcinomas (RTC) in 32 patients were treated with RFA, between March 2008 and October 2011. RTCs were detected by regular follow-up ultrasound and confirmed by biopsy. All patients had fewer than 3 RTCs in the neck and were at high surgical risk or refused to undergo repeated surgery. Average number of RFA sessions were 1.3 (range 1-3). Post-RFA biopsy and ultrasound were performed. The mean follow-up period was 30 months. Pre- and post-RFA serum thyroglobulin values were evaluated.

Results

Thirty-one patients with 33 RTCs were treated with RFA only, whereas 1 patient with 2 RTCs was treated with RFA followed by surgery. At the last follow-up ultrasound, 31 (94%) of the 33 RTCs treated with RFA alone completely disappeared and the remaining 2 (6%) RTCs showed decreased volume. The largest diameter and volume of the 33 RTCs were markedly decreased by 93.2% (from 8.1 ± 3.4 mm to 0.6 ± 1.8 mm, p < 0.001) and 96.4% (from 173.9 ± 198.7 mm³ to 6.2 ± 27.9 mm³, p < 0.001), respectively. Twenty of the 21 RTCs evaluated with post-RFA biopsies (95%) were negative for malignancy. One (5%) showed remaining tumor that was removed surgically. The serum thyroglobulin was decreased in 19 of 26 patients (73%). Voice change developed immediately after RFA in 6 patients (19%) and was spontaneously recovered in 5 patients (83%).

Conclusion

Radiofrequency ablation can be effective in treating loco-regional, recurrent, and well-differentiated thyroid carcinoma in patients at high surgical risk.     

Radiofrequency Ablation for Viable Hepatocellular Carcinoma around Retained Iodized Oil after Transcatheter Arterial Chemoembolization: Usefulness of Biplane Fluoroscopy Plus Ultrasound Guidance

Objective

To assess the technical feasibility and local efficacy of biplane fluoroscopy plus US-guided percutaneous radiofrequency ablation (RFA) for viable hepatocellular carcinoma (HCC) around retained iodized oil after transcatheter arterial chemoembolization (TACE).

Materials and Methods

Our prospective study was approved by our institutional review board and informed consent was obtained from all participating patients. For patients with viable HCC around retained iodized oil after TACE, biplane fluoroscopy plus US-guided RFA was performed. We evaluated the rate of technical success and major complications on a post-RFA CT examination and local tumor progression with a follow-up CT.

Results

Among 40 consecutive patients, 19 were excluded due to one of the following reasons: poorly visible HCC on fluoroscopy (n = 13), high risk location (n = 2), RFA performed under monoplane fluoroscopy and US guidance (n = 2), and poorly identifiable new HCCs on US (n = 2). The remaining 21 patients with 21 viable HCCs were included. The size of total tumors ranged from 1.4 to 5.0 cm (mean: 3.2 cm) in the longest diameter. Technical success was achieved for all 21 HCCs, and major complications were observed in none of the patients. During the follow-up period (mean, 20.3 months; range, 6.5-29.9 months), local tumor progression was found in two patients (2/21, 9.5%). Distant intrahepatic metastasis developed in 76.2% (16/21) of patients.

Conclusion

When retained iodized oil around the tumor after TACE hampers the targeting of the viable tumor for RFA, biplane fluoroscopy plus US-guided RFA may be performed owing to its technical feasibility and effective treatment for viable HCCs.     

Percutaneous Radiofrequency Ablation with Multiple Electrodes for Medium-Sized Hepatocellular Carcinomas

Objective

To prospectively evaluate the safety and short-term therapeutic efficacy of switching monopolar radiofrequency ablation (RFA) with multiple electrodes to treat medium-sized (3.1-5.0 cm), hepatocellular carcinomas (HCC).

Materials and Methods

In this prospective study, 30 patients with single medium-sized HCCs (mean, 3.5 cm; range, 3.1-4.4 cm) were enrolled. The patients were treated under ultrasonographic guidance by percutaneous switching monopolar RFA with a multichannel RF generator and two or three internally cooled electrodes. Contrast-enhanced CT scans were obtained immediately after RFA, and the diameters and volume of the ablation zones were then measured. Follow-up CT scans were performed at the first month after ablation and every three months thereafter. Technical effectiveness, local progression and remote recurrence of HCCs were determined.

Results

There were no major immediate or periprocedural complications. However, there was one bile duct stricture during the follow-up period. Technical effectiveness was achieved in 29 of 30 patients (97%). The total ablation time of the procedures was 25.4 ± 8.9 minutes. The mean ablation volume was 73.8 ± 56.4 cm³ and the minimum diameter was 4.1 ± 7.3 cm. During the follow-up period (mean, 12.5 months), local tumor progression occurred in three of 29 patients (10%) with technical effectiveness, while new HCCs were detected in six of 29 patients (21%).

Conclusion

Switching monopolar RFA with multiple electrodes in order to achieve a sufficient ablation volume is safe and efficient. This method also showed relatively successful therapeutic effectiveness on short-term follow up for the treatment of medium-sized HCCs.     

Computed Tomographic-Guided Radiofrequency Ablation of Recurrent or Residual Hepatocellular Carcinomas around Retained Iodized Oil after Transarterial Chemoembolization

Objective

To assess the clinical efficacy, safety, and risk factors influencing local tumor progression, following CT-guided radiofrequency ablation (RFA) of recurrent or residual hepatocellular carcinoma (HCC), around iodized oil retention.

Materials and Methods

Sixty-four patients (M : F = 51 : 13, 65.0 ± 8.2 years old) with recurrent or residual HCC (75 index tumors, size = 14.0 ± 4.6 mm) had been treated by CT-guided RFA, using retained iodized oil as markers for targeting. The technical success, technique effectiveness rate and complications of RFA were then assessed. On pre-ablative and immediate follow-up CT after RFA, we evaluated the size of enhancing index tumors and iodized oil retention, presence of abutting vessels, completeness of ablation of iodized oil retention, and the presence of ablative margins greater than 5 mm. Also, the time interval between transarterial chemoembolization and RFA was assessed. The cumulative local tumor progression rate was calculated using the Kaplan-Meier method, and the Cox proportional hazards model was adopted, to clarify the independent factors affecting local tumor progression.

Results

The technical success and technique effectiveness rate was 100% and 98.7%, respectively. Major complications were observed in 5.6%. The cumulative rates of local tumor progression at 1 and 2 years were 17.5% and 37.5%, respectively. In multivariate analyses, partial ablation of the targeted iodized oil retention was the sole independent predictor of a higher local tumor progression rate.

Conclusion

CT-guided RFA of HCC around iodized oil retention was effective and safe. Local tumor progression can be minimized by complete ablation of not only index tumors, but targeted iodized oil deposits as well.     

Percutaneous radiofrequency ablation of renal cell carcinomas in patients with solitary kidney: 6 years experience

Objective

In this study we attempt to present our clinical experience in RFA under CT-guidance, in patients with renal cell carcinoma in a solitary kidney.

Material and Method

Between October 2000 and June 2005, 18 patients with solitary kidney and renal cell carcinoma underwent percutaneous CT-guided radiofrequency ablation in our institution. Tumors diameter ranged from 1 to 7 cm and there was no evidence of spread beyond the kidney. The RFA-system used was with expandable needle electrode (7 or 9 arrays). Technical success, recurrence and survival rate and complications were accessed. Patients were available for clinical and laboratory evaluation at a mean follow-up time of 31.2 months (range: 12–72 months).

Results

In all cases the electrode was successfully placed at the lesion. The 18 tumors were treated with totally 24 RFA sessions. In small (1–3 cm) exophytic tumors technical success was 85.7%. Residual disease was totally seen in 6/18 tumors which required a 2nd RFA session. The recurrence rate was 11.1% but no recurrence was noticed in tumors less than 3 cm in diameter. No major complications were observed. Serum creatinine values were normal in 17/18 patients till the 3rd-month follow-up. Survival ranged from 12 to 72 months.

Conclusion

RFA is an acceptable alternative for patients with small RCCs in a solitary kidney, which are not ideal candidates for surgical resection as their renal function must be preserved. They have an immediate solution to their clinical problem, under a minimally invasive therapy with no serious complications.     

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.

     

Ablation of Symptomatic Cysts Using Absolute Ethanol in 11 Patients with Autosomal-Dominant Polycystic Kidney Disease

Objective

To evaluate the effects of cyst ablation with absolute ethanol in autosomal-dominant polycystic kidney disease (ADPKD) patients with symptomatic cysts.

Materials and Methods

Using absolute ethanol, cyst ablation was performed in 11 patients with documented ADPKD who suffered cyst pain refractory to medical treatment. An ethanol solution was instilled into the largest symptomatic cysts through a catheter. We assessed the therapeutic efficacy of the procedure by tracking subjective pain relief during a 3 to 24-month follow-up period after ablation.

Results

At follow-up, we found that the duration of subjective pain relief was 12 to 24 months in seven patients, 4 to11 months in one, and less than 3 months in three.

Conclusion

Selective ablation of a symptomatic cyst may be a valid option in managing chronic pain caused by one or a few large cysts in ADPKD patients.     

Cyst Ablation Using a Mixture of N-Butyl Cyanoacrylate and Iodized Oil in Patients with Autosomal Dominant Polycystic Kidney Disease: the Long-Term Results

Objective

We wanted to assess the long-term results of cyst ablation with using N-butyl cyanoacrylate (NBCA) and iodized oil in patients with autosomal dominant polycystic kidney disease (ADPKD) and symptomatic cysts.

Materials and Methods

Cyst ablation using a mixture of NBCA and iodized oil was performed in 99 cysts from 21 patients who had such symptoms as abdominal distension and pain. The collapse or reaccumulation of the ablated cysts after the procedure was assessed during the follow-up period of 36 to 90 months. The treatment effects, including symptom relief, and the clinical data such as the blood pressure and serum creatinine levels were also assessed, together with the complications.

Results

The procedure was technically successful in all 99 cysts from the 21 patients. Any procedure-related significant complications were not detected. Seventy-seven of 99 cysts (78%) were successfully collapsed on the follow-up CT. Twenty-two cysts showed reaccumulation during long-term follow-up period. The clinical symptoms were relieved in 17 of the 21 patients (76%). Four of 12 patients (33%) with hypertension and two of six patients (33%) with azotemia were improved. End stage renal disease (ESRD) occurred in six of the 21 patients (28%) during the follow-up period. The mean age of ESRD in our patients was 57 years. The mean time interval for the development of ESRD was 19 months.

Conclusion

Ablation using a mixture of NBCA and iodized oil may be an effective, safe method for obtaining symptom relief in patients with ADPKD.     

Pretreatment Evaluation with Contrast-Enhanced Ultrasonography for Percutaneous Radiofrequency Ablation of Hepatocellular Carcinomas with Poor Conspicuity on Conventional Ultrasonography

Objective

To determine whether pretreatment evaluation with contrast-enhanced ultrasonography (CEUS) is effective for percutaneous radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) with poor conspicuity on conventional ultrasonography (US).

Materials and Methods

This retrospective study was approved by the institutional review board and informed consent was waived. From June 2008 to July 2011, 82 patients having HCCs (1.2 ± 0.4 cm) with poor conspicuity on planning US for RFA were evaluated with CEUS prior to percutaneous RFA. We analyzed our database, radiologic reports, and US images in order to determine whether the location of HCC candidates on planning US coincide with that on CEUS. To avoid incomplete ablation, percutaneous RFA was performed only when HCC nodules were identified on CEUS. The rate of technical success was assessed. The cumulative rate of local tumor progression was estimated with the use of the Kaplan-Meier method (mean follow-up: 24.0 ± 13.0 months).

Results

Among 82 patients, 73 (89%) HCCs were identified on CEUS, whereas 9 (11%) were not. Of 73 identifiable HCCs on CEUS, the location of HCC on planning US corresponded with that on CEUS in 64 (87.7%), whereas the location did not correspond in 9 (12.3%) HCCs. Technical success was achieved for all 73 identifiable HCCs on CEUS in a single (n = 72) or two (n = 1) RFA sessions. Cumulative rates of local tumor progression were estimated as 1.9% and 15.4% at 1 and 3 years, respectively.

Conclusion

Pretreatment evaluation with CEUS is effective for percutaneous RFA of HCCs with poor conspicuity on conventional US.     

Percutaneous Radiofrequency Ablation of Hepatocellular Carcinomas Adjacent to the Gallbladder with Internally Cooled Electrodes: Assessment of Safety and Therapeutic Efficacy

Objective

The objective of this study was to evaluate the safety and therapeutic efficacy of percutaneous radiofrequency (RF) ablation for the treatment of hepatocellular carcinomas (HCCs) adjacent to the gallbladder with the use of internally cooled electrodes.

Materials and Methods

We retrospectively assessed 45 patients with 46 HCCs (mean size, 2.2 cm) adjacent to the gallbladder (≤1.0 cm) treated with RF ablation using an internally cooled electrode system. An electrode was inserted into the tumor either parallel (n = 38) or perpendicular (n = 8) to the gallbladder wall. The safety and therapeutic efficacy of the procedures were assessed with clinical and imaging follow-up examinations. Follow-up with the use of CT ranged from four to 45 months (mean, 19 months). The association between variables (electrode direction, electrode type, tumor size, tumor location, lobar location) and the presence of a residual tumor or local tumor progression was also analyzed.

Results

There were no major complications and minor complications were noted in three patients (7%) including one case of vasovagal syncope and two cases of bilomas. Wall thickening of the gallbladder adjacent to the RF ablation zone was noted in 14 patients (41%) as determined on immediate follow-up CT imaging. Wall thickening showed complete disappearance on subsequent follow-up CT imaging. The primary technique effectiveness rate was 96% (44/46) based on one-month follow-up CT imaging. Local tumor progression was noted in six (14%) of 44 completely ablated tumors during the follow-up period. The direction of electrode insertion (perpendicular), tumor size (≥3 cm) and tumor location (a tumor that abutted the gallbladder) were associated with an increased risk of early incomplete treatment. No variable was significantly associated with local tumor progression.

Conclusion

Percutaneous RF ablation of HCCs adjacent to the gallbladder using an internally cooled electrode is a safe and effective treatment. Significant risk factors that lead to early incomplete treatment include tumor size, tumor location and electrode direction.     

Therapeutic Efficacy and Safety of Percutaneous Ethanol Injection with or without Combined Radiofrequency Ablation for Hepatocellular Carcinomas in High Risk Locations

Objective

To evaluate the therapeutic efficacy and safety of percutaneous ethanol injection (PEI) alone and combined with radiofrequency ablation (RFA) for hepatocellular carcinomas (HCCs) in high risk locations.

Materials and Methods

We performed PEI for HCCs in RFA-high risk locations, either alone or in combination with RFA. There were 20 HCCs (1.7 ± 0.9 cm) in 20 patients (PEI group: n = 12; PEI + RFA group: n = 8). We evaluated technical success, local tumor progression and complications in both groups.

Results

Technical success was achieved in all HCCs in both groups. During follow-up, local tumor progression was found in 41.7% (5/12) in the PEI group, whereas 12.5% (1/8) for the PEI + RFA group (p = 0.32). Bile duct dilatation was the most common complication, especially when the tumors were in periportal locations; 55% (5/9) in the PEI group and 50% (2/4) in the PEI + RFA group (p = 1.00). One patient in the PEI group developed severe biliary stricture and upstream dilatation that resulted in atrophy of the left hepatic lobe. One patient treated with PEI + RFA developed cholangitis and an abscess.

Conclusion

Combined PEI and RFA treatment has a tendency to be more effective than PEI alone for managing HCCs in high risk locations, although the difference is not statistically significant. Even though PEI is generally accepted as a safe procedure, it may cause major biliary complications for managing HCCs adjacent to the portal vein.     

Image-Guided Percutaneous Radiofrequency Ablation of Central Renal Cell Carcinoma: Assessment of Clinical Efficacy and Safety in 31 Tumors

Purpose

To assess clinical efficacy and safety of image-guided percutaneous radiofrequency (RF) ablation of central renal cell carcinoma with adjunctive pyeloperfusion.

Imaging Features of Radiofrequency Ablation with Heat-Deployed Liposomal Doxorubicin in Hepatic Tumors

Introduction

The imaging features of unresectable hepatic malignancies in patients who underwent radiofrequency ablation (RFA) in combination with lyso-thermosensitive liposomal doxorubicin (LTLD) were determined.

Materials and Methods

A phase I dose escalation study combining RFA with LTLD was performed with peri- and post- procedural CT and MRI. Imaging features were analyzed and measured in terms of ablative zone size and surrounding penumbra size. The dynamic imaging appearance was described qualitatively immediately following the procedure and at 1-month follow-up. The control group receiving liver RFA without LTLD was compared to the study group in terms of imaging features and post-ablative zone size dynamics at follow-up.

Results

Post-treatment scans of hepatic lesions treated with RFA and LTLD have distinctive imaging characteristics when compared to those treated with RFA alone. The addition of LTLD resulted in a regular or smooth enhancing rim on T1W MRI which often correlated with increased attenuation on CT. The LTLD-treated ablation zones were stable or enlarged at follow-up four weeks later in 69 % of study subjects as opposed to conventional RFA where the ablation zone underwent involution compared to imaging acquired immediately after the procedure.

Conclusion

The imaging features following RFA with LTLD were different from those after standard RFA and can mimic residual or recurrent tumor. Knowledge of the subtle findings between the two groups can help avoid misinterpretation and proper identification of treatment failure in this setting. Increased size of the LTLD-treated ablation zone after RFA suggests the ongoing drug-induced biological effects.

     

Radiofrequency ablation of renal cell carcinoma in patients with a solitary kidney: a retrospective analysis of our experience

Purpose

This study was done to evaluate the feasibility and safety of radiofrequency ablation (RFA) of renal cell carcinomas (RCCs) in patients with solitary kidney.

Materials and methods

Seven patients (two men, five women; age range 52?C70 years; mean age 59.7 years) were treated under computed tomography (CT) and ultrasound (US) guidance. Three patients had single lesions, and the remaining four had multiple lesions. Seventeen lesions (4 cortical, 13 exophytic, maximum diameter range 12?C40 mm, mean 21.0 mm) not located close to the renal pelvis were treated. CT or magnetic resonance (MR) imaging follow-up studies were obtained for all patients at the end of the procedure and at 1, 3, 6 and 12 months; serum creatinine was also monitored.

Results

Ten ablation sessions were performed. In two patients, a perinephric haematoma was detected, and one of these patients had two episodes of self-limiting haematuria. Contrast-enhanced CT and MR imaging at the end of the procedure and at 1 month demonstrated 100% technical success; these results were confirmed at 3, 6 and 12 month. Fisher??s test comparing serum creatinine obtained 1 day before and 1 day after the procedure showed no case of acute renal failure (mean serum creatinine 24 h before the procedure 1.02 mg/dl; mean serum creatinine 24 h after the procedure 0.95 mg/dl; p=0.114; not significant). Serum creatinine at follow-up was always within the normal range.

Conclusions

Radiofrequency ablation in the solitary kidney is a safe and effective procedure for treating RCC.     

Radiofrequency Ablation Combined with Chemoembolization for Intermediate-Sized (3-5 cm) Hepatocellular Carcinomas Under Dual Guidance of Biplane Fluoroscopy and Ultrasonography

Objective

To assess the technical feasibility and local efficacy of percutaneous radiofrequency ablation (RFA) combined with transcatheter arterial chemoembolization (TACE) for an intermediate-sized (3-5 cm in diameter) hepatocellular carcinoma (HCC) under the dual guidance of biplane fluoroscopy and ultrasonography (US).

Materials and Methods

Patients with intermediate-sized HCCs were treated with percutaneous RFA combined with TACE. RFA was performed under the dual guidance of biplane fluoroscopy and US within 14 days after TACE. We evaluated the rate of major complications on immediate post-RFA CT images. Primary technique effectiveness rate was determined on one month follow-up CT images. The cumulative rate of local tumor progression was estimated with the use of Kaplan-Meier method.

Results

Twenty-one consecutive patients with 21 HCCs (mean size: 3.6 cm; range: 3-4.5 cm) were included. After TACE (mean: 6.7 d; range: 1-14 d), 20 (95.2%) of 21 HCCs were visible on fluoroscopy and were ablated under dual guidance of biplane fluoroscopy and US. The other HCC that was poorly visible by fluoroscopy was ablated under US guidance alone. Major complications were observed in only one patient (pneumothorax). Primary technique effectiveness was achieved for all 21 HCCs in a single RFA session. Cumulative rates of local tumor progression were estimated as 9.5% and 19.0% at one and three years, respectively.

Conclusion

RFA combined with TACE under dual guidance of biplane fluoroscopy and US is technically feasible and effective for intermediate-sized HCC treatment.     

Sonographically-Guided 14-Gauge Core Needle Biopsy for Papillary Lesions of the Breast

Objective

We wanted to assess the need for surgical excising papillary lesions of the breast that were diagnosed upon sonographically guided 14-gauge core needle biopsy.

Materials and Methods

Sixty-nine women (age range: 25-74 years, mean age: 51.7 years) with 69 papillary lesions (4.9%) were diagnosed and followed after performing sonographically guided 14-gauge core needle biopsies. Surgical excision was performed for 44 (64%) of 69 papillary lesions, and 25 lesions were followed with imaging studies (range: 6-46 months, mean: 17.9 months). The histologic findings upon core biopsy were compared with the surgical, imaging and follow-up findings.

Results

Core needle biopsies of 69 lesions yielded tissue that was classified as benign for 43 lesions, atypical for 18 lesions and malignant for eight lesions. Of the 43 lesions that yielded benign papilloma upon core needle biopsy, one had intraductal papillary carcinoma found upon surgery. An immediate surgical biopsy was recommended for this lesion because of the imaging-histologic discordance. No additional carcinoma was found during the imaging follow-up. Surgical excision was performed for 17 atypical papillary lesions, and this revealed intraductal (n = 6) or invasive (n = 2) papillary carcinoma in 8 (47%) lesions. Of the seven intraductal papillary carcinomas, surgery revealed invasive papillary carcinoma in one (14%).

Conclusion

Our results suggest that papillary lesions of the breast that are diagnosed as benign upon sonographically guided 14-gauge core needle biopsy can be followed when the results are concordant with the imaging findings.     

Central lower attenuating lesion in the ablation zone on immediate follow-up CT after percutaneous radiofrequency ablation for hepatocellular carcinoma: Incidence and clinical significance

Purpose

The purpose of this study was to evaluate the incidence of central lower attenuating (CLA) lesion in the ablation zone seen on immediate follow-up CT images after percutaneous radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), and the correlation of CLA lesions and local tumor progression (LTP).

Subjects and methods

The study group included 146 patients with 167 ablation zones that had undergone follow-up CT examinations for more than 12 months after percutaneous RFA. CLA lesions corresponding to index tumors and ablative margins (safety margins) were evaluated in the ablation zones seen on immediate follow-up CT including coronal and sagittal multiplanar reformatted (MPR) images with narrow window width settings.

Results

CLA lesions were depicted on 48 of 167 ablation zones (28.7%) on immediate follow-up CT images. Among the 48 ablation zones with CLA lesions, 27 (56.3%, 27/48) had ablative margins on all three of the orthogonal MPR images and they showed no LTP (0%) on follow-up CT examinations. Three of the ablation zones with CLA lesions (6.3%, 3/48) having an ablative margin on one plane only also showed no LTP (0%). LTP was observed in 2 of 18 ablation zones (11.1%) that had CLA lesions without ablative margins on all three planes. In the remaining 119 ablation zones without CLA lesions, 5 (4.2%, 5/119) showed LTP.

Conclusion

CLA lesions in ablation zones were occasionally (28.7%) seen on immediate follow-up CT images after RFA for HCCs. The presence of CLA lesions with ablative margins might be a negative predictor of LTP.     

Radiofrequency Ablation of the Gastrointestinal Tract with a Stent-Like Electrode: Experimental Study

Objective

To assess the technical feasibility of a newly designed stent-like electrode in rabbits.

Materials and Methods

A stent-like electrode was knitted from a single thread of nitinol wire and interconnected to a generator using similar wire. In order to gauge the extent of radiofrequency ablation (RFA), we measured the depth of the ablated area in cow liver using a combination of 180-sec time intervals and 20-watt power increments. For data processing, Cox regression analysis was used. RFA was also applied to the small intestine of rabbits using this stent-like electrode under six different sets of conditions: 10 watts for 1 min, 10 watts for 2 mins, 20 watts for 1 min, 20 watts for 2 mins, 30 watts for 1 min, and 30 watts for 2 mins. To determine the gross and microscopic findings, six animals were sacrificed immediately after the procedure and the results obtained under the different sets of conditions were correlated. Eight rabbits were monitored for 4 weeks prior to sacrifice.

Results

For both ex-vivo and in-vivo ablations, the depth of the thermal lesion showed linear correlation with both the duration of RFA and the power applied. RFA of the duodenum was technically successful in all 14 rabbits. The acute changes occurring in the rabbits'' small intestine included color change, cytoplasmic denaturation, fibrin deposition and hemorrhage, among which hemorrhage of the mucosal layer was the earliest finding. RF ablation for 2 mins at 30 watts caused serosal hemorrhage. The gross and histologic changes occurring showed close correlation under all six sets of conditions.

Conclusion

Use of the stent-like electrode proves technically feasible but to determine the nature of the chronic change occurring in the gastrointestinal tract after RF ablation, further investigation and long-term follow-up in animals are required.