Ablation Margin Research Articles

Impact of Prior Hepatectomy History on Local Tumor Progression after Percutaneous Ablation of Colorectal Liver Metastases

PurposeTo test the hypothesis that, given the current resection eligibility criteria for colorectal liver metastasis (CLM), prior hepatectomy would be associated with improved local tumor control and survival after percutaneous ablation of CLMs. Materials and MethodsThis single-institution retrospective study included 82 consecutive patients with 97 CLMs treated with ablation (radiofrequency ablation, microwave ablation, or cryoablation) from January 2005 to December 2014. Local tumor progression-free survival (LTPFS), recurrence-free survival (RFS) at any organ, and overall survival (OS) were calculated using the Kaplan-Meier method from the time of ablation and compared between patients with (n = 49) and without (n = 33) prior hepatectomy. Cox regression models were used to identify LTPFS predictors. ResultsMedian overall follow-up period was 28 months (range, 4.5–132 months). Three-year actuarial LTPFS (patient level: 73% vs 34%, P < .001) was significantly higher in patients with than without prior hepatectomy, respectively. Similarly, 3-year RFS (23% vs 9.1%, P = .026) and OS (78% vs 48%, P = .003) were improved in patients with prior hepatectomy. At multivariate analysis, predictors of worse LTPFS were: no prior hepatectomy (hazard ratio [HR] 2.35, 95% confidence interval [CI] 1.02–5.45; P = .045), minimal ablation margin < 5 mm (HR 2.4, 95% CI 1.18–4.87; P = .016), and RAS-mutant tumor (HR 2.65, 95% CI 1.18–5.94; P = .019). ConclusionsPrior hepatectomy for CLMs is associated with improved local tumor control after percutaneous ablation of post-resection-developed CLMs.

Prediction of Local Tumor Progression after Radiofrequency Ablation (RFA) of Hepatocellular Carcinoma by Assessment of Ablative Margin Using Pre-RFA MRI and Post-RFA CT Registration.

ObjectiveTo evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison.Materials and MethodsIn this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (≥ 3 mm) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method.ResultsThe two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79).ConclusionRegistration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

Eye Opener to EtOH Ablation for Juxta-Cardiac Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is notoriously refractory to systemic chemotherapy, mandating an interventional approach. Mortality may be avoided by neutralizing rapidly growing tumors that approach the heart and major vessels. When the risk/benefit ratio of surgery is unacceptable, percutaneous ablation can achieve remarkable results. High volumes of flowing blood adjacent to the treatment area may impact the ability to reliably achieve an adequate ablation margin for modalities that rely on extreme temperatures to destroy malignant cells. Ethanol ablation is safe, efficacious, and unaffected by this “thermal sink” effect. This report describes a juxta-cardiac (JC) HCC in segment 4a measuring 35 × 26 mm, which exhibited rapid growth until it was abutting the pericardium and 7.5 mm from the chamber of the right ventricle (RV). Methods: One 21-gauge needle was inserted using direct CT fluoroscopy into the center of the hepatic mass. In order to confirm the position of the needle, 0.5 mL of diluted Visipaque was injected. Then, under CT fluoroscopy guidance, a mixture of 1 mL of Ethiodol and 10 mL of 98% dehydrated alcohol was slowly injected into the mass. Results: Repeat CT scan 1 month post-ablation demonstrated decreased arterial enhancement and dense Ethiodol throughout the tumor consistent with ablation. Tumor size decreased to 30 × 23 mm with a distance of 12.4 mm from the chamber of the RV. Conclusion: Pericardial involvement or large vessels near the treatment area may limit the use of thermal ablation techniques for JC HCC. Percutaneous, intratumoral ethanol injection provides safe and effective alternative that is not subject to the “thermal sink” effect.

Recent Advances in the Image-Guided Tumor Ablation of Liver Malignancies: Radiofrequency Ablation with Multiple Electrodes, Real-Time Multimodality Fusion Imaging, and New Energy Sources.

Radiofrequency ablation (RFA) has emerged as an effective loco-regional treatment modality for malignant hepatic tumors. Indeed, studies have demonstrated that RFA of early stage hepatocellular carcinomas can provide comparable overall survival to surgical resection. However, the incidence of local tumor progression (LTP) after RFA is significantly higher than that of surgical resection. Thus, to overcome this limitation, multiple electrode radiofrequency (RF) systems that use a multi-channel RF generator have been developed, and they demonstrate better efficiency in creating larger ablation zones than that using the conventional RFA with a single electrode. Furthermore, RFA with multiple electrodes can allow the “no-touch” ablation technique which may also help to reduce LTP. Another technique that would be helpful in this regard is multi-modality-ultrasound fusion imaging, which helps to not only more accurately determine the target lesion by enabling the RFA of small, poorly visible or invisible tumors, but also improve the monitoring of procedures and determine the appropriateness of the ablation margin. In addition, new energy sources, including microwave and cryoablation, have been introduced in imaging-guided tumor ablation. In this review, these recently introduced ablation techniques and the results of the most current animal and clinical studies are discussed.

Active contour configuration model for estimating the posterior ablative margin in image fusion of real-time ultrasound and 3D ultrasound or magnetic resonance images for radiofrequency ablation: an experimental study

PurposeThe purpose of this study was to evaluate the accuracy of an active contour model for estimating the posterior ablative margin in images obtained by the fusion of real-time ultrasonography (US) and 3-dimensional (3D) US or magnetic resonance (MR) images of an experimental tumor model for radiofrequency ablation.MethodsChickpeas (n=12) and bovine rump meat (n=12) were used as an experimental tumor model. Grayscale 3D US and T1-weighted MR images were pre-acquired for use as reference datasets. US and MR/3D US fusion was performed for one group (n=4), and US and 3D US fusion only (n=8) was performed for the other group. Half of the models in each group were completely ablated, while the other half were incompletely ablated. Hyperechoic ablation areas were extracted using an active contour model from real-time US images, and the posterior margin of the ablation zone was estimated from the anterior margin. After the experiments, the ablated pieces of bovine rump meat were cut along the electrode path and the cut planes were photographed. The US images with the estimated posterior margin were compared with the photographs and post-ablation MR images. The extracted contours of the ablation zones from 12 US fusion videos and post-ablation MR images were also matched.ResultsIn the four models fused under real-time US with MR/3D US, compression from the transducer and the insertion of an electrode resulted in misregistration between the real-time US and MR images, making the estimation of the ablation zones less accurate than was achieved through fusion between real-time US and 3D US. Eight of the 12 post-ablation 3D US images were graded as good when compared with the sectioned specimens, and 10 of the 12 were graded as good in a comparison with nicotinamide adenine dinucleotide staining and histopathologic results.ConclusionEstimating the posterior ablative margin using an active contour model is a feasible way of predicting the ablation area, and US/3D US fusion was more accurate than US/MR fusion.

Percutaneous Microwave versus Radiofrequency Ablation of Colorectal Liver Metastases: Ablation with Clear Margins (A0) Provides the Best Local Tumor Control

PurposeTo identify and compare predictors of local tumor progression (LTP)-free survival (LTPFS) after radiofrequency (RF) ablation and microwave (MW) ablation of colorectal liver metastases (CLMs). Materials and MethodsThis is a retrospective review of CLMs ablated from November 2009 to April 2015 (110 patients). Margins were measured on contrast-enhanced computed tomography (CT) 6 weeks after ablation. Clinical and technical predictors of LTPFS were assessed using a competing risk model adjusted for clustering. ResultsTechnique effectiveness (complete ablation) was 93% (79/85) for RF ablation and 97% (58/60) for MW ablation (P = .47). The median follow-up period was significantly longer for RF ablation than for MW ablation (56 months vs. 29 months) (P < .001). There was no difference in the local tumor progression (LTP) rates between RF ablation and MW ablation (P = 0.84). Significant predictors of shorter LTPFS for RF ablation on univariate analysis were ablation margins 5 mm or smaller (P < .001) (hazard ratio [HR]: 14.6; 95% confidence interval [CI]: 5.2–40.9) and perivascular tumors (P = .021) (HR: 2.2; 95% CI: 1.1–4.3); both retained significance on multivariate analysis. Significant predictors of shorter LTPFS on univariate analysis for MW ablation were ablation margins 5 mm or smaller (P < .001) (subhazard ratio: 11.6; 95% CI: 3.1–42.7) and no history of prior liver resection (P < .013) (HR: 3.2; 95%: 1.3–7.8); both retained significance on multivariate analysis. There was no LTP for tumors ablated with margins over 10 mm (median LTPFS: not reached). Perivascular tumors were not predictive for MW ablation (P = .43). ConclusionsRegardless of the thermal ablation modality used, margins larger than 5 mm are critical for local tumor control, with no LTP noted for margins over 10 mm. Unlike RF ablation, the efficiency of MW ablation was not affected for perivascular tumors.

Ultrasound-ultrasound image overlay fusion improves real-time control of radiofrequency ablation margin in the treatment of hepatocellular carcinoma.

To assess the clinical feasibility of US-US image overlay fusion with evaluation of the ablative margin in radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). Fifty-three patients with 68 HCCs measuring 0.9-4.0 cm who underwent RFA guided by US-US overlay image fusion were included in this retrospective study. By an overlay of pre-/postoperative US, the tumor image could be projected onto the ablative hyperechoic zone. Therefore, the ablative margin three-dimensionally could be shown during the RFA procedure. US-US image overlay was compared to dynamic CT a few days after RFA for assessment of early treatment response. Accuracy of graded response was calculated, and the performance of US-US image overlay fusion was compared with that of CT using a Kappa agreement test. Technically effective ablation was achieved in a single session, and 59 HCCs (86.8 %) succeeded in obtaining a 5-mm margin on CT. The response with US-US image overlay correctly predicted early CT evaluation with an accuracy of 92.6 % (63/68) (k = 0.67; 95 % CI: 0.39-0.95). US-US image overlay fusion can be proposed as a feasible guidance in RFA with a safety margin and predicts early response of treatment assessment with high accuracy. • US-US image overlay fusion visualizes the ablative margin during RFA procedure. • Visualizing the margin during the procedure can prompt immediate complementary treatment. • US image fusion correlates with the results of early evaluation CT.

Heat stress induced, ligand-independent MET and EGFR signalling in hepatocellular carcinoma

Purpose: The aims of the present study were 2-fold: first, to test the hypothesis that heat stress induces MET and EGFR signalling in hepatocellular carcinoma (HCC) cells and inhibition of this signalling decreases HCC clonogenic survival; and second, to identify signalling pathways associated with heat stress induced MET signalling.Materials and Methods: MET+ and EGFR+ HCC cells were pre-treated with inhibitors to MET, EGFR, PI3K/mTOR or vehicle and subjected to heat stress or control ± HGF or EGF growth factors and assessed by colony formation assay, Western blotting and/or quantitative mass spectrometry. IACUC approved partial laser thermal or sham ablation was performed on orthotopic N1S1 and AS30D HCC tumours and liver/tumour assessed for phospho-MET and phospho-EGFR immunostaining.Results: Heat-stress induced rapid MET and EGFR phosphorylation that is distinct from HGF or EGF in HCC cells and thermal ablation induced MET but not EGFR phosphorylation at the HCC tumour ablation margin. Inhibition of the MET and EGFR blocked both heat stress and growth factor induced MET and EGFR phosphorylation and inhibition of MET decreased HCC clonogenic survival following heat stress. Pathway analysis of quantitative phosphoproteomic data identified downstream pathways associated with heat stress induced MET signalling including AKT, ERK, Stat3 and JNK. However, inhibition of heat stress induced MET signalling did not block AKT signalling.Conclusions: Heat-stress induced MET and EGFR signalling is distinct from growth factor mediated signalling in HCC cells and MET inhibition enhances heat stress induced HCC cell killing via a PI3K/AKT/mTOR-independent mechanism.

Ablative safety margin depicted by fusion imaging with post-treatment contrast-enhanced ultrasound and pre-treatment CECT/CEMRI after radiofrequency ablation for liver cancers.

To evaluate the value of fusion imaging with post-treatment contrast-enhanced ultrasound (CEUS) and pre-treatment contrast-enhanced CT/MRI (CECT/CEMRI) in evaluating ablative safety margin after percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) for liver cancers. 34 consecutive patients with 47 liver lesions who had undergone RFA were included. Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI was carried out to evaluate local treatment response and ablative safety margin within 1-3 days after RFA. The minimal ablative safety margins of the ablation zones were recorded. The complete response (CR) rate was calculated with reference to CECT/CEMRI results 1 month after RFA. The local tumour progression (LTP) was also recorded. Of the 47 ablation zones, 47 (100%) were clearly depicted with CEUS-CECT/CEMRI fusion imaging, 36 (76.6%) with US-CECT/CEMRI fusion imaging and 21 (44.7%) with conventional US (both p < 0.001). The minimal ablative safety margins were great than or equal to 5 mm in 28 ablation zones, between 0 and 5 mm in 15, and less than 0 mm in 4. For the four lesions without enough ablative safety margin, three were referred to follow-up because CEUS showed larger ablation zones than pre-treatment lesions and the remaining lesion was subject to additional RFA 5 days after the first RFA. The CR rate was 95.7% (45/47) with reference to CECT/CEMRI results 1 month after RFA. During 2 to 34 months follow-up, LTP was found in two (4.4%) of 45 lesions with CR. Insufficient ablative safety margin was more commonly found in those lesions with LTP than those without LTP (1/4 vs 1/43, p < 0.001). Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI can depict the ablative safety margin accurately after RFA. Inadequate ablative safety margin is associated with LTP. Depiction of ablative safety margin by fusion imaging after ablation might be considered as a routine procedure to assess the treatment response of RFA. Advances in knowledge: Fusion imaging with post-treatment CEUS and pre-treatment CECT/CEMRI is an effective method to evaluate the ablative safety margin early after RFA. Therefore, it should be recommended to be used as a routine procedure after RFA for liver cancers.

A prognostic nomogram for colorectal cancer liver metastases after percutaneous thermal ablation

Purpose: To assess the efficacy of percutaneous thermal ablation in treating colorectal cancer liver metastases (CRCLM), and to propose a prognostic nomogram for overall survival (OS).Materials and methods: Seventy-one patients with CRCLM undergoing thermal ablation at our institute from 2009 to 2013 were identified and analysed to formulate a prognostic nomogram. The concordance index (C-index) and calibration curve were calculated to evaluate the predictive accuracy of the nomogram. The nomogram was compared with two current prognostic nomograms for patients with CRCLM who had undergone hepatectomy (Kattan) and selective internal radiation therapy (Fendler). Predictive validity was assessed in the validation cohort of 25 patients who had undergone thermal ablation from 2014 to 2016.Results: The median OS in the primary cohort was 26.4 months, whereas the 1-, 3- and 5-year OS rates were 72.2%, 37.2% and 17%, respectively. The median progression-free survival was 4.2 months. After univariate and multivariate analysis, a prognostic nomogram was formulated based on four predictors, including the number of tumours, maximum diameter of the tumour, CA19–9 level and ablation margin. The C-index of the nomogram was 0.815. Based on the patients of this study, the C-index was significantly higher than that of the Fendler nomogram (C-index, 0.698) and Kattan nomogram (C-index, 0.514, p < 0.001). Predictive accuracy of the proposed nomogram was also satisfactory in the validation cohort, with a C-index of 0.884.Conclusions: Thermal ablation was an effective therapy for CRCLM. Moreover, the nomogram was effective and simple for CRCLM patients undergoing thermal ablation.

Evaluation of microwave ablation of liver malignancy with enabled constant spatial energy control to achieve a predictable spherical ablation zone

Objectives: To evaluate the clinical performance of a new microwave ablation (MWA) system with enabled constant spatial energy control (ECSEC) to achieve spherical ablation zones in the treatment of liver malignancies.Materials and methods: In this retrospective study, 56 hepatic tumours in 48 patients (23 men, 25 women; mean age: 59.6 years) were treated using a new high-frequency MWA-system with ECSEC. Parameters evaluated were technical success, technical efficacy, tumour diameter, tumour and ablation volume, complication rate, 90-day mortality, local tumour progression (LTP) at the 12-month follow-up, ablative margin and ablation zone sphericity. These parameters were compared using the Kruskal–Wallis test with the same parameters collected retrospectively from cohorts of patients treated with conventional high-frequency (HF) MWA (n = 20) or low-frequency (LF) MWA (n = 20).Results: Technical success was achieved in all interventions. The technical efficacy was 100% (ECSEC) vs. 100% (LF-MWA) vs. 95% (HF-MWA). There were no intra-procedural deaths or major complications. Minor complications occurred in 3.57% (2/56), 0% (0/20) and 0% (0/20) of the patients, respectively. The one-year mortality rate was 16.1% (9/56), 15% (3/20) and 10% (2/20), respectively. The LTP was 3.57% (2/56), 5% (1/20) and 5% (1/20), respectively. The median deviation from ideal sphericity (1.0) was 0.135 (ECSEC) vs. 0.344 (LF-MWA) vs. 0.314 (HF-MWA) (p < 0.001). The absolute minimal ablative margin was 8.1 vs. 2.3 vs. 3.1 mm (p < 0.001).Conclusions: Microwave ablation of liver malignancies is a safe and efficient treatment independent of the system used. Hepatic MWA with ECSEC achieves significantly more spherical ablation zones and higher minimal ablative margins.

Micropapillary and/or Solid Histologic Subtype Based on Pre-Treatment Biopsy Predicts Local Recurrence After Thermal Ablation of Lung Adenocarcinoma.

To investigate whether histologic subtyping from biopsies can predict local recurrence after thermal ablation for lung adenocarcinoma. Patients treated with CT-guided thermal ablation for lung adenocarcinoma that had pre-ablation needle biopsy with analysis of histologic components were identified. Age, gender, smoking status, treatment indication (primary stage 1 tumor versus salvage), histologic subtype, ground-glass radiographic appearance, tumor size, ablation modality, and ablation margin were evaluated in relation to time to local recurrence (TTLR). Cumulative incidence of recurrence (CIR) was calculated using competing risks analysis and compared across groups using Fine and Grey method with clustering. Multivariate analysis was conducted with stepwise regression. There were 53 patients with 57 tumors diagnosed as adenocarcinoma on pre-ablation biopsy and with histologic subtype analysis. Of these, 19% (11) had micropapillary components, 14% (8) had solid components, and 26% (15) had micropapillary and/or solid components. In the univariate analysis, solid (subdistribution hazard ratio [SHR]=4.04, p=0.0051, 95% confidence interval [CI]=1.52-10.7), micropapillary (SHR=3.36, p=0.01, CI=1.33-8.47), and micropapillary and/or solid components (SHR=5.85, p=0.00038, CI=2.21-15.5) were significantly correlated with shorter TTLR. On multivariate analysis, the presence of micropapillary and/or solid component (SHR=11.4, p=0.00021, CI: 3.14-41.3) was the only independent predictor of TTLR. The 1-, 2-, and 3-year CIR in patients with micropapillary and/or solid components was 33, 49, and 66% compared to 5, 14, and 18% in patients with no micropapillary or solid components on biopsy specimens. Micropapillary and/or solid histologic components identified in pre-ablation biopsy are associated with shorter TTLR after thermal ablation of lung adenocarcinoma.

Kras mutation is a marker of worse oncologic outcomes after percutaneous radiofrequency ablation of colorectal liver metastases.

BackgroundKras mutation has been associated with shorter overall survival and time to disease recurrence after resection of colorectal liver metastases (CLM). This study evaluated the prognostic value of Kras mutation in patients with CLM treated by percutaneous radiofrequency ablation (RFA).MethodsThis is an IRB waived retrospective analysis of the impact of KRAS mutation status on oncologic outcomes after CLM RFA. The endpoints were overall survival (OS), local tumor progression (LTP) rates, and incidence of new liver, lung, and peritoneal metastases. Survival times were calculated using Kaplan-Meier methodology from the time of RFA.ResultsThe study enrolled 97 patients. Kras exon 2 mutation was detected in 39% (38/97) of patients. On univariate analysis, Kras mutation (P=0.016) (HR: 1.8; 95% CI: 1.1 – 2.9) was a significant predictor of OS and retained significance on multivariate analysis. Kras mutation was a significant predictor of new liver metastases (P=0.037) (SHR: 2.0; CI: 1.0-3.7) and peritoneal metastases (P=0.015) (sHR: 3.0; 95% CI: 1.2-7.2) on multivariate analysis. Kras mutation was a significant predictor of LTP after RFA of CLM ablated with margins of 1-5 mm (P=0.018) (SHR: 3.0; 95% CI: 1.2-7.7) with an LTP rate of 80% (12/15) versus 41% (11/27) for wild type.ConclusionKras mutation is a significant predictor of overall survival, new liver, and peritoneal metastases after RFA of CLM. A minimal radiographic ablation margin ≥ 6 mm is essential for local tumor control especially for mutant CLM.

Radiofrequency Ablation of Hepatic Tumor: Subjective Assessment of the Perilesional Vascular Network on Contrast-Enhanced Computed Tomography Before and After Ablation Can Reliably Predict the Risk of Local Recurrence.

To determine whether simple, subjective analysis of the perilesional vascular network can predict the risk of local recurrence after radiofrequency ablation (RFA) of liver malignancies on contrast-enhanced computed tomography (CECT). Contrast-enhanced computed tomography's 103 patients (59 men and 44 women; mean age, 63 years (range, 31-84 years) with 134 lesions who underwent RFA between 2000 and 2010 were retrospectively analyzed. The primary tumors include colorectal carcinoma (58 patients), hepatocellular carcinoma (n = 13), breast carcinoma (n = 8), neuroendocrine tumor (n = 5), and others (n = 19). Three blinded radiologists independently reviewed the CECT (a triple phase liver protocol for hypervascular tumors and a single phase for the hypovascular tumors) before and 6 weeks after RFA and subjectively estimated the width of the ablative margin on a 3-point scale (optimal, 1; suboptimal, 2; and residual tumor, 3). Local recurrence was determined on follow-up CECT. The consensus score was 1 in 94, 2 in 28, and 3 in 12 lesions. κ among readers was 0.75. Local recurrence occurred in 3 lesions with a score of 1 and 12 lesions with a score of 2. The consensus score was a significant univariate predictor of local recurrence. Subjective estimation of the width of ablative margin can reliably predict the risk of local recurrence.

MP70-16 SAFETY AND FEASIBILITY OF REAL-TIME MRI-GUIDED FOCUSED ULTRASOUND FOR FOCAL THERAPY OF LOCALIZED PROSTATE CANCER USING THE EXABLATE 2100 DEVICE: PHASE 1 STUDY

You have accessJournal of UrologyProstate Cancer: Localized: Ablative Therapy I1 Apr 2017MP70-16 SAFETY AND FEASIBILITY OF REAL-TIME MRI-GUIDED FOCUSED ULTRASOUND FOR FOCAL THERAPY OF LOCALIZED PROSTATE CANCER USING THE EXABLATE 2100 DEVICE: PHASE 1 STUDY Nathan Perlis, Eugen Hlasny, Walter Kucharczyk, Masoom Haider, Antonio Finelli, Alexandre Zlotta, Girish Kulkarni, John Trachtenberg, and Sangeet Ghai Nathan PerlisNathan Perlis More articles by this author , Eugen HlasnyEugen Hlasny More articles by this author , Walter KucharczykWalter Kucharczyk More articles by this author , Masoom HaiderMasoom Haider More articles by this author , Antonio FinelliAntonio Finelli More articles by this author , Alexandre ZlottaAlexandre Zlotta More articles by this author , Girish KulkarniGirish Kulkarni More articles by this author , John TrachtenbergJohn Trachtenberg More articles by this author , and Sangeet GhaiSangeet Ghai More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.2292AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Organ preserving therapy is emerging as an option for localized prostate cancer to minimize the morbidity associated with whole-gland therapy. We examine the short-term oncologic and functional data of the initial phase 1 trial of patients treated with focal transrectal MRI-guided focused ultrasound (MRgFUS) in North America. METHODS This phase 1 prospective study was approved by institutional review board. Eight patients with organ-confined PC visible on multiparametric MRI (mpMRI) and confirmed by the MRI-fusion biopsy (Artemis, Eigen) were enrolled. Patients were eligible with PSA ≤10ng/mL and Gleason score (GS) ≤ 7(4+3). Tumors larger than 1.5 cm in any dimension, too peripheral for a 5mm ablation margin or with concern for extraprostatic extension were excluded. Under MRI-guidance and real-time MR thermography, focal lesions were ablated using high frequency ultrasound energy delivered via an endorectal transducer with 990 elements (ExAblate 2100, InSightec). Incidence and severity of treatment-related adverse events were recorded at 6 months. RESULTS Eight patients with 10 peripheral zone lesions were treated. Prostate volume ranged from 25 to 50 cc with mean target volume of 2.7cc (range 0.4 - 5.7cc). Mean procedure time was 248 minutes. Based on pre-treatment biopsy, six lesions were GS6(3+3), two were GS7(3+4) and two others were GS7(4+3). Treatments were all completed as planned without major technical delays or surgical complications. Mean post treatment non-perfused volume was 4.3cc (range 2.2 - 7.6cc). Quality of life parameters were similar between baseline and 6-months in 6 of 8 patients. One patient with bilateral ablation had significantly worse storage symptoms while a second patient developed self-limiting acute prostatitis with erectile dysfunction. Mean PSA decreased from 5.06 to 3.4 ng/ml at 6 months. All patients were MRI negative in their treated regions. On biopsy, five patients were disease-free in treated regions (7 of 10 lesions). In one patient with a presumed GS7(4+3) tumor, a 2mm MRI-invisible focus of GS8(4+4) PC was seen in 1 of 5 cores from the ablation site. He underwent prostatectomy with negative surgical margins. CONCLUSIONS MRgFUS is a feasible and safe method of ablating localized PC. Further work is required to improve patient selection and address causes of failed ablation. Our study is limited by small sample size and brief follow-up. More meaningful oncologic and functional outcomes for MRgFUS can be assessed with larger trials with longer follow-up. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e941 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Nathan Perlis More articles by this author Eugen Hlasny More articles by this author Walter Kucharczyk More articles by this author Masoom Haider More articles by this author Antonio Finelli More articles by this author Alexandre Zlotta More articles by this author Girish Kulkarni More articles by this author John Trachtenberg More articles by this author Sangeet Ghai More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Radiofrequency ablation using a 10-mm target margin for small hepatocellular carcinoma in patients with liver cirrhosis: A prospective randomized trial.

To compare 3-year clinical outcomes of radiofrequency ablation (RFA) targeting 5- or 10-mm margins for small hepatocellular carcinomas (HCCs) in cirrhotic patients. In total, 96 cirrhotic patients with a small solitary HCC (diameter ≤3 cm) were included in this prospective trial (ChiCTRTRC-10000954). Patients were stratified by Child-Pugh class and randomly allocated into groups targeting either wide margins (≥10 mm, WM) or narrow margins (≥5 mm but <10 mm, NM). RFA was performed under real-time monitoring, and ablative margins were evaluated by pre- and post-operative three-dimensional registration on CT. The mean follow-up time was 38.3 ± 4.8 months, 83.3% (40/48) of patients succeeded in obtaining a 10-mm margin in WM group. Based on intention-to-treat analysis, the 3-year incidences of local tumor progression (LTP) (14.9% vs 30.2%), intrahepatic recurrence (IHR) (15.0% vs 32.7%), and recurrence-free survival (RFS) (31.7 ± 12.1 vs 24.0 ± 11.7 months) for WM group were significantly improved compared to NM group. Several prognostic factors were identified from univariate and multivariate analyses. Additionally, cirrhosis-stratified subgroup analyses demonstrated significant survival benefits of WM in patients with Child-Pugh class B cirrhosis. RFA treatment targeting 10-mm margin may reduce the risk of tumor recurrence in cirrhotic patients with a single small HCC.

Local recurrence after laparoscopic radiofrequency ablation of malignant liver tumors: Results of a contemporary series.

The aims of this study were to determine the incidence of Local recurrence (LR) in patients at long-term follow-up after laparoscopic RFA (LRFA) and also to determine the risk factors for LR from a contemporary series. Patients undergoing LRFA between 2005 and 2014 by a single surgeon were reviewed. Demographic and perioperative data were analyzed from a prospective database. LRFA was performed on 316 patients with 901 lesions. Median follow-up was 25 months, with 76% of whom completed at least one year of follow-up. The LR rate was 18.4%. The LR in patients followed for less than 12 months was 13.8%, 20.3% for 12 months, and 19.7% for 18 months (P = 0.02). One-fourth of the LRs developed after the 1st year. Morbidity was 8.9% and mortality 0.3%. Tumor type, size, ablation margin, and surgeon experience affected LR, with tumor type, size, and ablation margin being independent. This study shows that 14% of malignant liver tumors will develop LR within a year after LRFA. Additional 4% of the lesions will demonstrate recurrence within 1 cm of the ablation zone, mostly as part of a multifocal recurrence. Ablation margin is the only parameter that the surgeon can manipulate to decrease LR.

Local tumour progression after percutaneous ablation of colorectal liver metastases according to RAS mutation status.

Percutaneous ablation is a common treatment for colorectal liver metastasis (CLM). However, the effect of rat sarcoma viral oncogene homologue (RAS) mutation on outcome after ablation of CLMs is unclear. Patients who underwent image-guided percutaneous ablation of CLMs from 2004 to 2015 and had known RAS mutation status were analysed. Patients were evaluated for local tumour progression as observed on imaging of CLMs treated with ablation. Multivariable Cox regression analysis was performed to determine factors associated with local tumour progression-free survival. The study included 92 patients who underwent ablation of 137 CLMs. Thirty-six patients (39 per cent) had mutant RAS. Rates of local tumour progression were 14 per cent (8 of 56) for patients with wild-type RAS and 39 per cent (14 of 36) for patients with mutant RAS (P = 0·007). The actuarial 3-year local tumour progression-free survival rate after percutaneous ablation was worse in patients with mutant RAS than in those with wild-type RAS (35 versus 71 per cent respectively; P = 0·001). In multivariable analysis, negative predictors of local tumour progression-free survival were a minimum ablation margin of less than 5 mm (hazard ratio (HR) 2·48, 95 per cent c.i. 1·31 to 4·72; P = 0·006) and mutant RAS (HR 3·01, 1·60 to 5·77; P = 0·001). Mutant RAS is associated with an earlier and higher rate of local tumour progression in patients undergoing ablation of CLMs.

Evaluation of the ablation margin of hepatocellular carcinoma using CEUS-CT/MR image fusion in a phantom model and in patients

BackgroundTo assess the accuracy of contrast-enhanced ultrasound (CEUS)-CT/MR image fusion in evaluating the radiofrequency ablative margin (AM) of hepatocellular carcinoma (HCC) based on a custom-made phantom model and in HCC patients.MethodsTwenty-four phantoms were randomly divided into a complete ablation group (n = 6) and an incomplete ablation group (n = 18). After radiofrequency ablation (RFA), the AM was evaluated using ultrasound (US)-CT image fusion, and the results were compared with the AM results that were directly measured in a gross specimen. CEUS-CT/MR image fusion and CT-CT / MR-MR image fusion were used to evaluate the AM in 37 tumors from 33 HCC patients who underwent RFA.ResultsThe sensitivity, specificity, and accuracy of US-CT image fusion for evaluating AM in the phantom model were 93.8, 85.7 and 91.3%, respectively. The maximal thicknesses of the residual AM were 3.5 ± 2.0 mm and 3.2 ± 2.0 mm in the US-CT image fusion and gross specimen, respectively. No significant difference was observed between the US-CT image fusion and direct measurements of the AM of HCC. In the clinical study, the success rate of the AM evaluation was 100% for both CEUS-CT/MR and CT-CT/MR-MR, and the duration was 8.5 ± 2.8 min (range: 4–12 min) and 13.5 ± 4.5 min (range: 8–16 min) for CEUS-CT/MR and CT-CT/MR-MR, respectively. The sensitivity, specificity, and accuracy of CEUS-CT/MR imaging for evaluating the AM were 100.0, 80.0, and 90.0%, respectively.ConclusionsA phantom model composed of carrageenan gel and additives was suitable for the evaluation of HCC AM. CEUS-CT/MR image fusion can be used to evaluate HCC AM with high accuracy.

Risk Factors for Local Progression after Percutaneous Radiofrequency Ablation of Lung Tumors: Evaluation Based on a Review of 147 Tumors

PurposeTo retrospectively evaluate risk factors related to incomplete computed tomography (CT)–guided radiofrequency (RF) ablation of metastatic and primary lung tumors. Materials and MethodsThis study included 93 patients with 147 tumors: 70 men, 23 women; median age 54 y (range, 19–81 y); 24 cases of primary lung tumors, 69 cases of metastases; average largest diameter of tumors, 1.8 cm ± 1.2 (range, 0.3–6.0 cm). Local efficacy was evaluated based on CT follow-up scans. Complete ablation rates (CARs) for tumors were calculated according to several variables; independent risk factors for local tumor progression (LTP) were examined by binary logistic regression analysis. ResultsCAR of tumors was 60.54% within first 6 months after lung RF ablation; median interval of LTP was 1.5 months (mean, 1.3 months ± 1.0; range, 0 days to 3 months). Compared with tumors > 3 cm, CAR of tumors ≤ 3 cm was significantly higher (68.55% vs 17.39%, P < .001). CAR of tumors with complete ablation margin (AM) was dramatically higher compared with tumors with incomplete AM (74.77% vs 16.67%, P < .001). Among tumors with complete AM, CAR of tumors with shortest distance between outer edge of tumor and AM (ablative margin D) ≥ 5 mm was compared with tumors with ablative margin D 1–4 mm (85.96% vs 62.96%, P = .005). Multivariate regression analysis showed that lobulation and/or spicules, contact with blood vessels, and ablative margin D < 5 mm were independent risk factors for incomplete lung RF ablation. LTP was likely to develop at the edge of ablated lesions and especially the site of incomplete AM or shortest AM. ConclusionsRF ablation for lung cancers should be individualized based on tumor size, morphology, and tumor type to obtain an adequate AM.