Local Tumor Progression-free Survival Research Articles

Long-Term Survival after Percutaneous Radiofrequency Ablation of Pathologically Proven Renal Cell Carcinoma in 100 Patients.

To determine the long-term survival of patients treated with percutaneous radiofrequency (RF) ablation for pathologically proven renal cell carcinoma (RCC). In this single-center retrospective study, 100 patients with 125 RCCs (100 clear-cell, 19 papillary, and 6 chromophobe) 0.8-8 cm in size treated with RF ablation were evaluated at a single large tertiary-care center between 2004 and 2015. Technical success, primary and secondary technique efficacy, and pre- and postprocedural estimated glomerular filtration rate (eGFR) at 3-6 months and 2-3 years were recorded. Overall survival, cancer-specific survival, and local tumor progression-free survival were calculated by Kaplan-Meier survival curves. Complications were classified per the Clavien-Dindo system. Statistical testing was done via χ2 tests for proportions and paired t test for changes in eGFR. Statistical significance was set at α= 0.05. Overall technical success rate was 100%, and primary and secondary technique efficacy rates were 90% and 100%, respectively. Median follow-up was 62.8 months, ranging from 1 to 120 months. The 10-year overall, cancer-specific, and local progression-free survival rates were 32%, 86%, and 92%, respectively. The number of ablation probes used was predictive of residual unablated tumor (P < .001). There were no significant changes in preprocedure vs 2-3-years postprocedure eGFR (65.2 vs 62.1 mL/min/1.73 m2; P= .443). There was a 9% overall incidence of complications, the majority of which were grade I. Image-guided percutaneous RF ablation of RCCs is effective at achieving local control and preventing cancer-specific death within 10 years from initial treatment.

Tailoring ablation strategies for colorectal liver metastases based upon rat sarcoma viral oncogene mutation status

Rat sarcoma viral oncogene (RAS) is one of the most well-known tumor genes implicated in the oncological and surgical management of patients with colorectal liver metastases (CLM). More recently, RAS mutational status has also emerged as a relevant factor affecting the oncological outcomes of CLM treated with ablation procedures, a well-established local therapy modality routinely utilized in the oligometastatic disease (OMD) setting. Available evidence suggests that RAS mutation is a prognosticator of shorter local tumor progression free survival (LTPFS) following liver ablation, and that mutant RAS patients with CLM treated with ablation should have wider minimal ablation margins. In this review, we aim to discuss the current literature on the influence of RAS mutational status on ablation outcomes, as well to provide a perspective on the future research on the impact of tumor molecular biology on liver ablation procedures and the potential synergies between local and systemic therapies.

Propofol Compared to Midazolam Sedation and to General Anesthesia for Percutaneous Microwave Ablation in Patients with Hepatic Malignancies: A Single-Center Comparative Analysis of Three Historical Cohorts

PurposeIn percutaneous ablation procedures, periprocedural pain, unrest and respiratory concerns can be detrimental to achieve a safe and efficacious ablation and impair treatment outcome. This study aimed to compare the association between anesthetic technique and local disease control in patients undergoing percutaneous microwave ablation (MWA) of colorectal liver metastases (CRLM) and hepatocellular carcinoma (HCC).Materials and MethodsThis IRB-exempted single-center comparative, retrospective analysis of three cohorts analyzed 90 patients treated for hepatic malignancies from January 2013 until September 2018. The local tumor progression-free survival (LTPFS), safety and periprocedural pain perception were assessed using univariate and multivariate Cox proportional hazard regression analyses to correct for potential confounders.ResultsIn 114 procedures (22 general anesthesia; 32 midazolam; 60 propofol), 171 liver tumors (136 CRLM; 35 HCC) were treated with percutaneous MWA. Propofol and general anesthesia were superior to midazolam/fentanyl sedation regarding LTPFS (4/94 [4.3%] vs. 19/42 [45.2%] vs. 2/35 [5.7%]; P < 0.001, respectively). Local tumor progression rate was 14.6% (25/171). Eighteen tumors (72.0%) were retreated by ablation. Of them, 14 (78%) were previously treated with midazolam. Propofol versus midazolam (P < 0.001), general anesthesia versus midazolam (P = 0.016), direct postprocedural visual analog pain score above 5 (P = 0.050) and more than one tumor per procedure (P = 0.045) were predictors for LTPFS. Multivariate analysis revealed that propofol versus midazolam (HR 7.94 [95% CI 0.04–0.39; P < 0.001]) and general anesthesia versus midazolam (HR 6.33 [95% CI 0.04–0.69; P = 0.014]) were associated with LTPFS. Pain during and directly after treatment was significantly worse in patients who received midazolam sedation (P < 0.001).ConclusionsCompared to propofol and general anesthesia, midazolam/fentanyl sedation was associated with an increased periprocedural perception of pain and lower local tumor progression-free survival. To reduce the number of repeat procedures required to eradicate hepatic malignancies, general anesthesia and propofol sedation should be favored over midazolam.

Whole tumor ablation of locally recurred hepatocellular carcinoma including retained iodized oil after transarterial chemoembolization improves progression-free survival.

To evaluate and compare clinical outcomes of two different radiofrequency ablation (RFA) methods for locally recurred hepatocellular carcinoma (LrHCC) after locoregional treatment. Our institutional review board approved this study with a waiver of informed consent. A total of 313 patients previously treated with transarterial chemoembolization (TACE) (n = 167) and RFA (n = 146) with a single LrHCC ≤ 3cm was included from five tertiary referral hospitals. RFA was done for LrHCCs using either viable tumor alone ablation (VTA) method (VTA: n = 61 in the TACE group and n = 127 in the RFA group) or whole tumor ablation (WTA) method which includes both viable tumor and retained iodized oil or previously ablated zone (WTA: n = 106 in the TACE group and n = 19 in the RFA group). Local tumor progression (LTP)-free survival as well as progression-free survival (PFS) were estimated using the Kaplan-Meier method, and prognostic factors were evaluated using the Cox proportional hazards regression model. In 167 patients with LrHCC who underwent TACE, the 5-year LTP-free survival after RFA was significantly higher with the VTA method than with the WTA method (26.9% vs. 87.8%; p < 0.001; hazard ratio (HR) = 8.53 [4.16-17.5]). The estimated 5-year PFS after RFA for LrHCC after TACE using the VTA method was 5.7%, which was significantly lower than that with the WTA method (26.4%) (p = 0.014; HR = 1.62 [1.10-2.38]). However, in 146 patients with LrHCC after initial RFA, there were no significant differences in cumulative incidence of LTP (p = 0.514) or PFS (p = 0.905) after RFA between the two ablation methods. For RFA of LrHCC after TACE, the WTA method including both viable tumor and retained iodized oil could significantly lower LTP and improve PFS than VTA. • Whole tumor ablation (WTA) could provide significantly better local tumor control for locally recurred HCC (LrHCC) after TACE than viable tumor alone ablation (VTA). • WTA for LrHCC after TACE could also provide significantly better progression-free survival than VTA. • Regarding LrHCC after RFA, VTA would provide a comparable clinical outcome to WTA.

Irreversible Electroporation for Unresectable Hepatocellular Carcinoma: Initial Experience.

To evaluate the efficacy and safety of irreversible electroporation (IRE) in the treatment of unresectable hepatocellular carcinoma (HCC). A retrospective study was conducted from September 2014 to June 2017. A total of 21 HCCs in 21 patients with cirrhosis were treated with IRE. There were eight subcapsular or exophytic, ten perivascular and three peribiliary tumors. The median tumor size was 26mm (range 14-40mm). The technical success of the procedure was recorded. Median follow-up, median time to local recurrence, median local tumor progression-free survival (PFS) and complications were recorded. Technical success was achieved in all the patients. The median follow-up was 10months (range 2-30months). The median time to local recurrence and local tumor PFS were 4months (range 3-4months) and 7months (range 3-30months), respectively. The tumor-related factor that was significantly associated with local PFS was the size. Maximum tumor diameter < 25mm was significantly associated with local tumor PFS (p = 0.045). Other parameters including tumor location, segmental portal vein thrombosis, baseline alpha-fetoprotein level and underlying etiology did not affect local tumor PFS. Complications were noted in nine patients and were classified as grades 1 and 2. No procedure-related mortality was encountered. IRE is an effective treatment for ablation of small HCCs. Larger prospective studies with strict selection criteria will establish the safety and efficacy of IRE in the treatment of unresectable HCC in patients who cannot undergo thermal ablation.

A Meta-Analysis of Clinical Outcomes After Radiofrequency Ablation and Microwave Ablation for Lung Cancer and Pulmonary Metastases

PurposeWe conducted a meta-analysis assessing clinical outcomes of radiofrequency ablation (RFA) and microwave ablation (MWA) for treating lung cancer. MethodsDatabases were searched up to 2017 to identify high-quality studies. The results were presented as pooled estimates with 95% confidence intervals (CIs). ResultsFifty-three studies were included, and up to 3,432 patients were pooled. The estimated 1-, 2-, 3-, 4-, and 5-year overall survival (OS) rates were higher for RFA-treated patients compared with those treated by MWA. The median OS, median progression-free survival (PFS), median local tumor PFS, complete ablation rate, and adverse events did not differ significantly. Subgroup analyses by tumor type showed that the median OS for RFA-treated patients with pulmonary metastases was higher than that of the MWA-treated patients. ConclusionThermal ablation, both RFA and MWA, is an effective approach for treating lung cancer with low risk of adverse events. RFA is associated with longer survival than MWA, and patients with pulmonary metastases showed better survival after RFA compared with MWA-treated patients.

Prior hepatectomy predicts local tumor progression and survival after percutaneous ablation of colorectal liver metastasis

Background: We hypothesized that the currently utilized hepatic resection criteria for patients with colorectal liver metastasis (CLM) promotes selection of patients with optimal tumor biology translated in low rates of local tumor progression (LTP) at post-resection developed CLM treated with percutaneous ablation (PA). Methods: 82 consecutive patients with 97 CLMs treated with PA during 2004-2014 were included. Local tumor progression-free survival (LTPFS) at the ablated lesions between patients with (n=49) and without (n=33) prior hepatic resection were analyzed. Multivariate Cox regression analysis was utilized to identify factors associated with LTPFS. Results: Median follow-up period was 28 months. 3-year actuarial LTPFS at the ablated lesions was better in patients with prior hepatic resection when compared to patients without prior hepatic resection (73% vs 34%, P<0.001). 3-year recurrence-free survival (RFS) (23% vs 9.1%, P=0.02) and overall survival (OS) (78% vs 48%, P=0.003) were better on patients with prior hepatic resection. Negative predictors for LTPFS on multivariate analysis were: no prior hepatic resection (hazard ratio [HR] 2.35, 95% confidence interval [CI] 1.02-5.45; P=0.045), minimal ablation margin < 5 mm (HR 2.4, 95% CI 1.18-4.87; P=0.016), and RAS mutant (HR 2.65, 95% CI 1.18-5.94; P=0.019). Conclusion: Prior hepatic resection is associated with improved LTPFS, RFS, and OS after PA of CLMs. This suggests inherent differences in tumor biology among surgical and non-surgical populations.

Percutaneous ablation of RAS mutant colorectal liver metastases is associated with a high rate local tumor progression

Background: To evaluate the predictive values of RAS mutation status on local tumor progression (LTP) after percutaneous ablation (PA) of colorectal liver metastasis (CLM) Methods: A retrospective analysis of patients who underwent CT-guided PA of CLMs from 2004 through 2015 and had known RAS mutation status was performed. Patients were evaluated for LTP at CLMs treated with ablation. Multivariate Cox regression analysis was performed to determine factors associated with LTP-free survival. Results: 92 patients underwent PA of 137 CLMs. Thirty-six (39%) had mutant RAS. LTP rates were 14% (8/56) for patients with wild-type RAS and 39% (14/36) for mutant RAS (p=0·007). On analysis by individual CLM treated with ablation, LTP rates were 9.3% (8/86) for CLMs in patients with wild-type RAS and 33% (17/51) for CLMs in patients with mutant RAS (p=0.0004). LTP occurred earlier and at significantly higher rates for CLMs <2 cm in patients with mutant RAS, irrespective of PA margins, than for CLMs <2 cm in patients with wild-type RAS (p<0.001). Actuarial LTP-free survival were worse in patients with mutant RAS than wild-type RAS (3-year LTP-free survival rate: 35% versus 71%, p=0.001). In multivariate analysis, negative predictors of LTP-free survival were minimal PA margin <5 mm (hazard ratio [HR] 2·48, 95% confidence interval [CI] 1·31-4·72; p=0·006) and mutant RAS (HR 3·01, 95% CI 1·60-5·77; p=0·001). Conclusion: The presence of mutant RAS is associated with an earlier and higher rate of LTP among patients undergoing PA of CLMs.

Percutaneous cryoablation for renal cell carcinoma using ultrasound-guided targeting and computed tomography-guided ice-ball monitoring: radiation dose and short-term outcomes.

Usefulness of ultrasound (US)-guided mass targeting and computed tomography (CT)-guided ice-ball monitoring in percutaneous cryoablation (PCA) for renal cell carcinoma (RCC) is still uncertain. To assess radiation dose and short-term outcomes of PCA for RCC using US-guided targeting and CT-guided ice-ball monitoring. Thirty-nine consecutive patients who underwent PCA for biopsy-proven RCC were included. Mass targeting was performed with US and ice-ball was monitored with CT guidance. Effective radiation dose of CT during PCA was recorded. Follow-up was conducted with contrast-enhanced CT or magnetic resonance imaging (MRI) (mean follow-up time = 10.1 ± 7.0 months). Local tumor progression was defined by the presence of focal enhancing areas at the ablation zone (CT, ≥ 20 HU; MRI, presence of focal enhancement on subtraction contrast-enhanced image). Technical success, major complication rate (e.g. Clavien-Dindo classification ≥ 3), and one-year local tumor progression-free survival (PFS) rate were analyzed. Mean effective radiation dose in association with PCA was 12.1 ± 4.5 mSv (range = 7.0-25.2 mSv). Technical success was achieved in 100%. Local tumor progression occurred in a single patient (2.6%, 1/39), and one-year local tumor PFS rate was 95.7%. No major complication was found. PCA using US-guided targeting and CT-guided ice-ball monitoring may allow acceptable local tumor control for RCC, as a radiation-reducing strategy.

Percutaneous ablation of the tumor feeding artery for hypervascular hepatocellular carcinoma before tumor ablation

Objective: To evaluate the efficiency and safety of percutaneous ablation of the tumor feeding artery (PAA) before radiofrequency ablation (RFA) for hypervascular hepatocellular carcinoma (HCC) under ultrasound guidance.Patients and methods: In total, 94 patients with hypervascular HCC and tumor feeding artery visible by contrast-enhanced ultrasound were prospectively randomized to receive either PAA combined with RFA (RFA + PAA) or RFA alone. This study was registered at the clinical trials registry website (No. NCT03143140). The mean tumor size was 3.2 ± 0.9 cm (2.0–5.0 cm). The mean follow-up was 23.7 ± 9.7 months (4–44 months). The technical success, local tumor progression and intrahepatic distant recurrence rates were compared. Survival analysis was performed using the Kaplan–Meier method and compared with the log-rank test.Results: The local tumor progression rate was lower for the PAA + RFA group than for the RFA group (8.5% vs 21.3%, p = .082). No significant differences in the technical success and intrahepatic distant recurrence rates were observed between the two groups (97.9% vs 91.5%, p = .203 and 40.4% vs 42.6%, p = .834). The 1- and 3-year local tumor progression-free survival rates were 91.5% and 69.9% vs 68.1% and 52.1% for the PAA + RFA vs RFA groups, respectively (p = .052). The 1- and 3-year overall survival rates were 95.7% and 69.1% vs 89.4% and 66.6% in the PAA + RFA vs RFA groups, respectively (p = .744). The major complication rate was 4.3% in both groups.Conclusions: PAA appears to be an effective and safe technique for the treatment of hypervascular HCC, with a lower local tumor progression rate than that of conventional RFA.

Microwave Ablation in the Management of Colorectal Cancer Pulmonary Metastases.

To review outcomes following microwave ablation (MWA) of colorectal cancer pulmonary metastases and assess predictors of oncologic outcomes. Technical success, primary and secondary technique efficacy rates were evaluated for 50 patients with 90 colorectal cancer pulmonary metastases at immediate, 4-8weeks post-MWA and subsequent follow-up CT and/or 18F-FDG PET/CT. Local tumor progression (LTP) rate, LTP-free survival (LTPFS), cancer-specific and overall survivals were assessed. Complications were recorded according to SIR classification. Median follow-up was 25.6months. Median tumor size was 1cm (0.3-3.2cm). Technical success, primary and secondary technique efficacy rates were 99, 90 and 92%, respectively. LTP rate was 10%. One-, 2- and 3-year LTPFS were: 93, 86 and 86%, respectively, with median LTPFS not reached. Median overall survival was 58.6months, and median cancer-specific survival (CSS) was not reached. One-, 2- and 3-year overall and CSS were 94% and 98, 82 and 90%, 61 and 70%, respectively. On univariate analysis, minimal ablation margin (p < 0.001) and tumor size (p = 0.001) predicted LTPFS, with no LTP for minimal margin ≥ 5mm and/or tumor size < 1cm. Pleural-based metastases were associated with increased LTP risk (p = 0.002, SHR = 7.7). Pre-MWA CEA level > 10ng/ml (p = 0.046) and ≥ 3 prior chemotherapy lines predicted decreased CSS (p = 0.02). There was no 90-day death. Major complications rate was 13%. MWA with minimal ablation margin ≥ 5mm is essential for local control of colorectal cancer pulmonary metastases. Pleural-based metastases and larger tumor size were associated with higher risk of LTP. CEA level and pre-MWA chemotherapy impacted CSS.

Combination therapy of TACE and CT-guided partial hepatic segment ablation for liver cancer

Aim: This study aimed to investigate the safety and efficacy of combination therapy of transcatheter arterial chemoembolization (TACE) and CT-guided percutaneous partial hepatic segment ablation.Material and methods: Liver cancer patients undergoing TACE plus partial segment ablation from 2012 to 2016 were retrospectively analyzed. Patient characteristics were collected. TACE was performed for all patients before ablation. After ablation, CT imagings were used to evaluate treatment and follow-up. Overall survival (OS) and local tumor progression free survival (LTPFS) were calculated.Results: Twenty-three patients with 68 liver tumors were included. The median tumor maximum diameter was 55 mm (range, 24 to 91 mm). The complete response rate of combination therapy was 87%. The one-, two-, three- and four-year overall survival rates were 78%, 65%, 54% and 54%, respectively. The three-year survival rate for BCLC stage C HCC patients was 53%. The one-, two- and three-year LTPFS rates were 54%, 35% and 35%, respectively. Tumor maximum diameter, vascular invasion and partial treatment response were independent risk factors for LTPFS. Only one patient suffered a major complication.Conclusion: TACE combined with partial hepatic segment thermal ablation is a safe and effective treatment for liver cancer patients, especially for those with more advanced disease.

CT-guided percutaneous cryoablation for palliative therapy of gastric cancer liver metastases

ObjectiveLiver metastases occur in approximately 4%–14% of gastric cancer patients and are associated with high mortality. However, no standardized treatment approach is available for these patients. We aimed to assess the clinical outcomes of patients with gastric cancer liver metastases (GCLM) who underwent percutaneous cryoablation. MethodsWe retrospectively enrolled 19 patients with 27 metastatic hepatic tumors who underwent cryoablation for liver metastases after gastrectomy for primary gastric cancer. Complications, overall survival (OS), local tumor progression-free survival (PFS), recurrence rates, and quality of life were assessed. ResultsAfter cryoablation therapy, the median OS for all 19 patients was 16.0 months (range, 5–50 months), and the 1-, 2-, and 3-year OS rates were 78.9%, 43.4%, and 21.7%, respectively. The median local tumor PFS was 8.0 months (range, 3–24 months), and the local tumor PFS rates at 6 and 12 months were 59.2% and 23.2%, respectively. Overall, patients' quality of life improved after cryoablation therapy (P < 0.05). Complications in this study were mild; no severe complications caused by technique were detected. ConclusionsCryoablation provided good local control, improved patients' quality of life and had a low complication rate. Our research showed that cryoablation may be an effective palliative treatment for GCLM.

4:21 PM Abstract No. 180 Primary technique efficacy, local tumor progression, patient survival, and complications following outpatient percutaneous image-guided thermal ablation of primary intrahepatic cholangiocarcinoma

The purpose of this study was to determine primary technique efficacy (TE), time to local tumor progression (TTLP), patient survival and complications following outpatient percutaneous image-guided thermal ablation as the initial treatment for primary intrahepatic cholangiocarcinoma (ICC). Ethics board approved, single arm, retrospective, cohort study of patients with pathologically proven primary ICC treated with percutaneous thermal ablation as the initial therapy at a tertiary referral center from 1999 to 2017. Primary TE, defined as no tumor enhancement on the first post-thermal ablation follow-up imaging, was determined. Local tumor progression was defined as abnormal liver enhancement with nodularity or mass effect adjacent to an ablation zone on a follow-up CT or MRI. Complications were graded as per SIR guidelines. Factors affecting primary TE, TTLP, and complication rates were analyzed. The patient cohort consisted of 6 females and 10 males. Mean patient age was 65 years (range, 47-81). All 16 patients had chronic liver disease (hepatitis B: 6 patients, hepatitis C: 4, alcohol related cirrhosis: 3, NASH: 2, and hemochromatosis: 1). All 16 patients were Child-Pugh class A. Mean tumor diameter was 26 mm (range, 12-44). 12 patients were diagnosed with biopsy performed at the time of ablation, whereas 4 were diagnosed with biopsy prior to consultation for thermal ablation. 13 patients were treated with radiofrequency ablation and 3 patients treated with microwave ablation. Primary TE was 81%. No major complications occurred. Mean follow-up was 32 months (range, 4-135). In patients with primary effectively ablated tumors, 3, 14 and 25-month local tumor progression-free survival were 91.7 ± 8.0% [± SE], 81.5 ± 11.9% and 48.9 ± 19.2%. Overall, cumulative 1, 2 and 3-year patient survival was 73.3% (11/15), 53.8% (7/13) and 41.7% (5/12), there was 1 patient lost to follow-up at 4 months post procedure. Tumor size was associated with both reduced primary TE and shorter TTLP (p<0.05). Thermal ablation is a safe and effective treatment for small primary intrahepatic cholangiocarcinoma.

Ablation of colorectal liver metastasis: Interaction of ablation margins and RAS mutation profiling on local tumour progression-free survival.

To investigate effects of ablation margins on local tumour progression-free survival (LTPFS) according to RAS status in patients with colorectal liver metastases (CLM). This two-institution retrospective study from 2005-2016 included 136 patients (91 male, median age 60 years) with 218 ablated CLM. LTPFS was performed using the Kaplan-Meier method and evaluated with the log-rank test. Uni/multivariate analyses were performed using Cox-regression models. Three-year LTPFS rates for CLM with minimal ablation margin ≤10 mm were significantly worse than those with >10 mm in both mutant-RAS (29% vs. 48%, p=0.038) and wild-type RAS (70% vs. 94%, p=0.039) subgroups. Three-year LTPFS rates of mutant-RAS were significantly worse than wild-type RAS in both CLM subgroups with minimal ablation margin ≤10 mm (29% vs. 70%, p<0.001) and >10 mm (48% vs. 94%, p=0.006). Predictors of worse LTPFS were ablation margins ≤10 mm (HR: 2.17, 95% CI 1.2-4.1, p=0.007), CLM size ≥2 cm (1.80, 1.1-2.8, p=0.017) and mutant-RAS (2.85, 1.7-4.6, p<0.001). Minimal ablation margin and RAS status interact as independent predictors of LTPFS following CLM ablation. While minimal ablation margins >10 mm should be always the procedural goal, this becomes especially critical for mutant-RAS CLM. • RAS and ablation margins are predictors of local tumour progression-free survival. • Ablation margin >10 mm, always desirable, is crucial for mutant RAS metastases. • Interventional radiologists should be aware of RAS status to optimize LTPFS.

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.

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.

Local Control and Survival after Image-Guided Percutaneous Ablation of Adrenal Metastases

PurposeTo evaluate local control and survival after image-guided ablation of adrenal gland metastases. Materials and MethodsImage-guided ablations of adrenal metastases measuring < 5 cm performed at 2 academic medical centers between July 2002 and June 2016 were analyzed. There were 51 procedures performed on 46 tumors (mean diameter 2.8 cm ± 1.1; range, 0.7–4.9 cm) in 38 patients (mean age 66 y; range, 41–80 y) with renal cell carcinoma (n = 17 patients; 45%), non–small cell lung cancer (n = 10 patients; 26%), and other primary malignancies (n = 11 patients; 29%). Treatment modalities included cryoablation (n = 30 procedures; 59%), radiofrequency ablation (n = 12 procedures; 24%) and microwave ablation (n = 9 procedures; 18%). Technical success, primary and secondary efficacy, local progression rate, local progression-free survival, and overall survival were assessed. Mean follow-up was 37 months (range, 2–128 months). Statistical analysis was performed with univariate Cox hazards regression and Kaplan-Meier analyses. ResultsTechnical success, primary efficacy, and secondary efficacy were 96%, 72%, and 76%. Local progression rate during all follow-up was 25%. Local tumor progression-free survival at 1, 3, and 5 years was 82%, 69%, and 55%. Overall survival at 1, 3, and 5 years was 82%, 44%, and 34%. In 16 patients with isolated adrenal metastasis, median disease-free survival was 8 months; 4 patients had no evidence of disease during follow-up. Lung cancer was associated with decreased survival (hazard ratio 4.41, P = .002). ConclusionsImage-guided ablation can achieve local control for adrenal metastases < 5 cm.

CT-guided 125I interstitial brachytherapy for pelvic recurrent cervical carcinoma after radiotherapy.

ObjectiveThis retrospective study aimed to evaluate the feasibility, safety, and clinical efficacy of computed tomography (CT)-guided 125I seed interstitial brachytherapy for pelvic recurrent cervical cancer in patients with a history of pelvic radiotherapy.MethodsFrom March 2011 to December 2015, 35 pelvic recurrent lesions (33 patients) were reirradiated using this type of salvage therapy. The medical history, dose–volume histogram parameters, complications, local control, overall survival (OS), and affected factors were analyzed.ResultsAll patients were followed-up until expiration, and the median duration of follow-up was 16 months. The 1-, 3-, 6-, 12-, and 18-month local control rates were 84.5%, 74.2%, 60.0%, 55.5%, and 33.3%, respectively. The symptoms significantly improved after implantation. The median local tumor progression-free survival (LTPFS) and OS times were 7 months (range, 1–19 months) and 12 months (range, 2–42 months), respectively. The 1- and 2-year OS rates were 65.5% and 43.6%, respectively. In univariate analysis, a good performance status, a tumor diameter <4 cm, an interval time from last radiotherapy to seed implantation longer than 6 months and D90 (dose delivered to 90% of the target volume) ≥130 Gy were prognostic factors for LTPFS. Cox proportional hazards regression analysis revealed that tumor size and D90 were independent factors affecting LTPFS (P=0.033, hazard ratio [HR] =3.357, 95% CI =1.105, 10.212; P=0.035, HR =2.766, 95% CI =1.072, 10.212). Good performance status was identified as an independent factor affecting OS (P=0.001, HR =0.086, 95% CI =0.019, 0.387). Two patients showed grade 3–4 toxicity – 1 patient had rectovaginal fistula and 1 patient had incomplete intestinal obstruction – and 3 cases showed seed migration in our analysis. No grade 5 events occurred.ConclusionReirradiation with CT-guided 125I seed interstitial brachytherapy is a safe, effective, and minimally invasive method to treat patients with recurrent cervical cancer after radiotherapy.

Long-Term Clinical Outcomes Following Radiofrequency and Microwave Ablation of Renal Cell Carcinoma at a Single VA Medical Center

Microwave ablation (MWA) is a relatively newer treatment modality for treatment of renal cell carcinoma (RCC), and only a few small studies have examined the short- and long-term outcomes for MWA applied to renal tumors. The purpose of this retrospective review is to assess the initial experience including technical short- and long-term success rates of using radiofrequency ablation (RFA) and MWA for RCC at a single Veterans Affairs (VA) medical center. Tumor characteristics were recorded using the R.E.N.A.L. nephrometry score. Group comparisons were performed by using univariate logistic regression analysis to determine factors affecting primary treatment success, failure, and effectiveness. Kaplan-Meier local tumor progression-free survival following ablation was calculated. MWA and RFA groups were not significantly different in primary treatment success (P = 0.82). MWA primary treatment success (90.2%) was not associated with R.E.N.A.L criteria, whereas primary success in the RFA group (88.2%) was predicted by smaller tumor size (P = 0.002). Primary treatment effectiveness rates were not significantly different in MWA (88.2%) and RFA (80.3%) groups (P = 0.29). Although overall primary technique effectiveness was associated with size (P = 0.02), univariate analysis showed a significant association between tumor size and primary effectiveness for RFA (P = 0.002) but not MWA. There was no significant association between R.E.N.A.L score or criteria and primary treatment effectiveness in the RFA or MWA groups. RFA and MWA both represent effective treatment modalities for RCC; larger tumor size may be associated with decreased efficacy of thermal ablation techniques.