A gut bacterial signature in blood and liver tissue characterizes cirrhosis and hepatocellular carcinoma.

BACKGROUND: HCC is the leading cause of cancer in chronic liver disease. A growing body of experimental mouse models supports the notion that gut-resident and liver-resident microbes control hepatic immune responses and, thereby, crucially contribute to liver tumorigenesis. However, a comprehensive characterization of the intestinal microbiome in fueling the transition from chronic liver disease to HCC in humans is currently missing. METHODS: Here, we profiled the fecal, blood, and liver tissue microbiome of patients with HCC by 16S rRNA sequencing and compared profiles to nonmalignant cirrhotic and noncirrhotic NAFLD patients. RESULTS: We report a distinct bacterial profile, defined from 16S rRNA gene sequences, with reduced α-and ß-diversity in the feces of patients with HCC and cirrhosis compared to NAFLD. Patients with HCC and cirrhosis exhibited an increased proportion of fecal bacterial gene signatures in the blood and liver compared to NAFLD. Differential analysis of the relative abundance of bacterial genera identified an increased abundance of Ruminococcaceae and Bacteroidaceae in blood and liver tissue from both HCC and cirrhosis patients compared to NAFLD. Fecal samples from cirrhosis and HCC patients both showed a reduced abundance for several taxa, including short-chain fatty acid-producing genera, such as Blautia and Agathobacter. Using paired 16S rRNA and transcriptome sequencing, we identified a direct association between gut bacterial genus abundance and host transcriptome response within the liver tissue. CONCLUSIONS: Our study indicates perturbations of the intestinal and liver-resident microbiome as a critical determinant of patients with cirrhosis and HCC.

Reliability of Stereotactic Radiofrequency Ablation (SRFA) for Malignant Liver Tumors: Novice versus Experienced Operators.

PURPOSE: To compare the results of a novice with those of experienced interventional radiologists (IRs) for stereotactic radiofrequency ablation (SRFA) of malignant liver tumors in terms of safety, technical success, and local tumor control. METHODS: A database, including all SRFA procedures performed in a single center between January 2011 and December 2018 was retrospectively analyzed. A total of 39 ablation sessions performed by a novice IR were compared to the results of three more experienced IRs. Comparative SRFA sessions were selected using propensity score matching considering tumor type, age, sex, tumor size, and tumor number as matching variables. Overall, 549 target tumors were treated in 273 sessions. Median tumor size was 2.2 cm (1.0-8.5 cm) for 178 hepatocellular carcinomas (HCCs) and 3.0 cm (0.5-13.0 cm) for 371 metastases. A median of 2 (1-11) tumors were treated per session. RESULTS: No significant differences were observed when comparing the results of more experienced IRs with those of a novice IR regarding the rates of major complications (6.8% [16/234] vs. 5.1% [2/39]; p = 0.477), mortality (1.3% [2/234] vs. 0% [0/39]; p = 0.690), primary technical efficacy (98.5% [525/533] vs. 98.9% [94/95]; p = 0.735), and local recurrence (5.6% [30/533] vs. 5.3% [5/95]; p = 0.886). However, the median planning/placement time was significantly shorter for the experienced IRs (92 min vs. 119 min; p = 0.002). CONCLUSIONS: SRFA is a safe, effective, and reliable treatment option for malignant liver tumors and favorable outcomes can be achieved even by inexperienced operators with minimal supervision.

Stereotactic radiofrequency ablation as a valid first-line treatment option for hepatocellular adenomas.

OBJECTIVES: This study aimed to assess the safety and efficacy of stereotactic radiofrequency ablation (SRFA) in patients with hepatocellular adenomas (HCA). METHODS: Retrospective analyses of all patients referred for SRFA treatment at our institution between January 2010 and October 2020 revealed 14 patients (10 women; mean age 34.4 [range, 17-73 years]) with 38 HCAs treated through 18 ablation sessions. Ablations were considered successful if a safety margin >5 mm was achieved. Demographic, interventional, and outcome data were collected and analyzed. Primary and secondary technical efficacy rates were assessed based on follow-up images consisting of contrast-enhanced CT or MR scans. RESULTS: The mean tumor size was 22 mm (range, 7-75 mm). Overall, 37/38 (97.4%) tumors were successfully ablated at the initial SRFA (primary efficacy rate of 97.4%). The median follow-up duration was 49.6 months. No deaths or adenoma-related complications (hemorrhage or malignant transformation) were observed. Disease-free survival rates at 1, 3, and 5 years from the date of the first SRFA were 100%, 85.8%, and 85.8%, respectively. Two patients developed new distant tumors retreated with consecutive re-ablation. No major complications occurred during any of the 18 ablation sessions. CONCLUSIONS: Percutaneous thermal ablation is efficient in the treatment of HCAs and may thus be considered a valid first-line treatment option. In addition, SRFA allows for an effective, minimally invasive treatment of large and multiple hepatic tumors within one session.

Technical efficacy and local recurrence after stereotactic radiofrequency ablation of 2653 liver tumors: a 15-year single-center experience with evaluation of prognostic factors.

PURPOSE: To assess the technical outcome and local tumor control of multi-probe stereotactic radiofrequency ablation (SRFA) in a large series of patients. Furthermore, to determine factors accounting for adverse outcomes. MATERIAL AND METHODS: Between 2003 and 2018, 865 patients were treated by SRFA for 2653 primary and metastatic liver tumors with a median tumor size of 2.0 cm (0.5 - 19 cm). Primary technical efficacy (PTE) and local recurrence (LR) were evaluated, and possible predictors for adverse events analyzed using uni- and multi-variable binary logistic regression. RESULTS: Overall, 2553 of 2653 tumors were successfully ablated at initial SRFA resulting in a PTE rate of 96.2%. Predictors of lower PTE rates were age > 70 years, tumor size > 5 cm, number of probes, location close to liver capsule/organs and segment II. LR occurred in 220 of 2653 tumors (8.3%) with the following predictors: age, tumor type/size, conglomerates, segments I/IVa/IVb, number of probes and location close to major vessels/bile duct. Multivariable analysis revealed tumor size > 5 cm (odds ratio [OR] 3.153), age > 70 years (OR 1.559), and location in segment II (OR 1.772) as independent prognostic factors for PTE, whereas tumor location close to major vessels (OR 1.653) and in segment IVb (OR 2.656) were identified as independent prognostic factors of LR. CONCLUSIONS: Stereotactic RFA is an attractive option in the management of primary or metastatic liver tumors with good local tumor control, even in large tumors. The presented prognostic factors for adverse local oncological outcome might help to stratify unfavorable tumors for ablation.

Aggressive local treatment for recurrent intrahepatic cholangiocarcinoma-Stereotactic radiofrequency ablation as a valuable addition to hepatic resection.

BACKGROUND: To evaluate the efficacy, safety and overall clinical outcome of local treatment for recurrent intrahepatic cholangiocellular carcinoma after hepatic resection. METHODS: Between 2007 and 2019 72 consecutive patients underwent hepatic resection for primary intrahepatic cholangiocellular carcinoma. If amenable, recurrent tumors were aggressively treated by HR or stereotactic radiofrequency ablation with local curative intent. Endpoints consisted of morbidity and mortality, locoregional and de novo recurrence, disease free survival, and overall survival. RESULTS: After a median follow-up of 28 months, recurrence of intrahepatic cholangiocellular carcinoma was observed in 43 of 72 patients undergoing hepatic resection (60.3%). 16 patients were subsequently treated by hepatic resection (n = 5) and stereotactic radiofrequency ablation (n = 11) with local curative intention. The remaining 27 patients underwent palliative treatment for first recurrence. Overall survival of patients who underwent repeated aggressive liver-directed therapy was comparable to patients without recurrence (p = 0.938) and was better as compared to patients receiving palliative treatment (p = 0.018). The 5-year overall survival rates for patients without recurrence, the repeated liver-directed treatment group and the palliative treatment group were 54.3%, 47.7% and 12.3%, respectively. By adding stereotactic radiofrequency ablation as an alternative treatment option, the rate of curative re-treatment increased from 11.9% to 37.2%. CONCLUSION: Repeated hepatic resection is often precluded due to patient morbidity or anatomical and functional limitations. Due to the application of stereotactic radiofrequency ablation in case of recurrent intrahepatic cholangiocellular carcinoma, the number of patients treated with curative intent can be increased. This leads to favorable clinical outcome as compared to palliative treatment of intrahepatic cholangiocellular carcinoma recurrence.

Stereotactic radiofrequency ablation of tumors at the hepatic venous confluence.

BACKGROUND: Radiofrequency ablation (RFA) is subject to "heat-sink" effects, particularly for treatment of tumors adjacent to major vessels. METHODS: In this retrospective study, 104 patients with 137 tumors (40 HCC, 10 ICC and 54 metastatic liver tumors) close to (≤1 cm from) the hepatic venous confluence underwent stereotactic RFA (SRFA) between June 2003 and June 2018. Median tumor size was 3.7 cm (1.4-8.5) for HCC, 6.4 cm (0.5-11) for ICC and 3.8 cm (0.5-13) for metastases. Endpoints comprised safety, local tumor control, overall and disease-free survival. RESULTS: The overall major complication rate was 16.0% (20/125 ablations), where 8 (40%) were successfully treated by the interventional radiologist in the same anesthetic session and did not prolong hospital stay. 134/137 (97.8%) tumors were successfully ablated at initial SRFA. Local recurrence (LR) developed in 19/137 tumors (13.9%). The median and overall survival (OS) rates at 1-, 3-, and 5- years from the date of the first SRFA were 51.5 months, 73.5%, 67.0%, and 49.7% for HCC, 14.6 months, 60.0%, 32.0% and 32.0% for ICC and 38.1 months, 91.4%, 56.5% and 27.9% for metastatic disease, respectively. CONCLUSION: SRFA represents a viable alternative to hepatic resection for challenging tumors at the hepatic venous confluence.

Stereotactic Radiofrequency Ablation of Breast Cancer Liver Metastases: Short- and Long-Term Results with Predicting Factors for Survival.

PURPOSE: To evaluate safety, local oncological control, long-term outcome and potential prognostic factors of stereotactic RFA (SRFA) for the treatment of BCLMs. METHODS: Between July 2003 and December 2019, 42 consecutive female patients with median age 54.0 years were treated with SRFA at our institution for 110 BCLMs in 48 ablation sessions. Median tumor size was 3.0 cm (0.8-9.0). Eighteen (42.9%) patients had extrahepatic metastasis at initial SRFA. RESULTS: Technical success rate was 100%, i.e., all coaxial needles were inserted with appropriate accuracy within 10 mm off plan and 107/110 (92.3%) BCLMs were successfully ablated at initial SRFA. Four Grade 1 (8.3%, 4/48) and one Grade 2 (2.1%, 1/48) complications occurred. No perioperative deaths occurred. Local recurrence developed in 8 of 110 tumors (7.3%). Overall survival (OS) rates of all patients at 1, 3, and 5 years from the date of the first SRFA were 84.1%, 49.3%, and 20.8% with a median OS of 32.3 months. Univariable cox regression analyses revealed age > 60 years and extrahepatic disease (without bone only metastases) as significant predictors of worse OS (p = 0.013 and 0.025, respectively). Size and number of metastases, hormone receptor status and time onset did not significantly affect OS after initial SRFA. CONCLUSIONS: SRFA is a safe, minimally invasive treatment option in the management of BCLMs, especially in younger patients without advanced extrahepatic metastasis, including those with large liver tumors.

Volumetric assessment of the periablational safety margin after thermal ablation of colorectal liver metastases.

OBJECTIVES: To retrospectively assess the periablational 3D safety margin in patients with colorectal liver metastases (CRLM) referred for stereotactic radiofrequency ablation (RFA) and to evaluate its influence on local treatment success. METHODS: Forty-five patients (31 males; mean age 64.5 [range 31-87 years]) with 76 CRLM were treated with stereotactic RFA and retrospectively analyzed. Image fusion of pre- and post-interventional contrast-enhanced CT scans using a non-rigid registration software enabled a retrospective assessment of the percentage of predetermined periablational 3D safety margin and CRLM successfully ablated. Periablational safety zones (1-10 mm) and percentage of periablational zone ablated were calculated, analyzed, and compared with subsequent tumor growth to determine an optimal safety margin predictive of local treatment success. RESULTS: Mean overall follow-up was 36.1 ± 18.5 months. Nine of 76 CRLMs (11.8%) developed local tumor progression (LTP) with mean time to LTP of 18.3 ± 11.9 months. Overall 1-, 2-, and 3-year cumulative LTP-free survival rates were 98.7%, 90.6%, and 88.6%, respectively. The periablational safety margin assessment proved to be the only independent predictor (p < 0.001) of LTP for all calculated safety margins. The smallest safety margin 100% ablated displaying no LTP was 3 mm, and at least 90% of a 6-mm circumscribed 3D safety margin was required to achieve complete ablation. CONCLUSIONS: Volumetric assessment of the periablational safety margin can be used as an intraprocedural tool to evaluate local treatment success in patients with CRLM referred to stereotactic RFA. Ablations achieving 100% 3D safety margin of 3 mm and at least 90% 3D safety margin of 6 mm can predict treatment success. KEY POINTS: • Volumetric assessment of the periablational safety margin can be used as an intraprocedural tool to evaluate local treatment success following thermal ablation of colorectal liver metastases. • Ablations with 100% 3D periablational safety margin of 3 mm and ablations with at least 90% 3D safety margin of 6 mm can be considered indications of treatment success. • Image fusion of pre- and post-interventional CT scans with the software used in this study is feasible and could represent a useful tool in daily clinical practice.

Stereotactic radiofrequency ablation (SRFA) for recurrent colorectal liver metastases after hepatic resection.

BACKGROUND: To evaluate the efficacy, safety and overall clinical outcome of multiprobe SRFA as a treatment for recurrent colorectal liver metastases after hepatic resection (HR). METHODS: A retrospective, single center study carried out between 2006 and 2018. 64 consecutive patients with recurrent or new CRLM after previous HR were treated by SRFA for 217 lesions (median size 2.7 cm, 1-7.5) in 103 ablation sessions. Endpoints consisted of i) technical efficacy ii) complication and mortality rates iii) local and distant recurrence, iv) disease free survival (DFS), and v) overall survival (OS). RESULTS: 213/217 tumors were successfully ablated at initial SRFA (97.7% primary technical efficacy rate). Four tumors required repeat ablation, resulting in a secondary technical efficacy rate of 99.5% (216/217). Local recurrence developed in 25/217 lesions (11.5%). Major complication rate was 5.8% (6/103 sessions) and mortality rate was 1.0% (1/103 ablation sessions), respectively.1-, 3-, and 5- year OS rates from date of first SRFA were 90.1%, 46.2%, and 34.8% (median 33.1 months). DFS rates were 54.2%, 17.2%, and 17.2%, at 1-, 3- and 5- years, respectively (median 13.3 months). CONCLUSION: SRFA is a safe, feasible and effective option for CRLM after HR with low morbidity levels and favorable clinical outcome.

Frequency and risk factors for major complications after stereotactic radiofrequency ablation of liver tumors in 1235 ablation sessions: a 15-year experience.

OBJECTIVES: To assess the frequency of major complications after multi-probe stereotactic radiofrequency ablation (SRFA) in a large cohort of patients over 15 years and to elucidate risk factors for adverse events. MATERIALS AND METHODS: A retrospective study was carried out between July 2003 and December 2018. Seven hundred ninety-three consecutive patients (median 65.0 years (0.3-88), 241 women and 552 men, were treated in 1235 SRFA sessions for 2475 primary and metastatic liver tumors with a median tumor size of 3.0 cm (0.5-18 cm). The frequency of major complications was evaluated according to SIR guidelines and putative predictors of adverse events analyzed using simple and multivariable logistic regression. RESULTS: Thirty-day mortality after SRFA was 0.5% (6/1235) with an overall major complication rate of 7.4% (91/1235). The major complication rate decreased from 11.5% (36/314) (before January 2011) to 6.0% (55/921) (p = 0.001). 50.5% (46/91) of major complications were successfully treated in the same anesthetic session by angiographic coiling for hemorrhage and chest tube insertion for pneumothorax. History of bile duct surgery/intervention, number of coaxial needles, and location of tumors in segment IVa or VIII were independent prognostic factors for major complications following multivariable logistic regression analysis. Simple logistic regression revealed the number of tumors, tumor size, location close to the diaphragm, tumor conglomerate, and segment VII as other significant predictors. CONCLUSION: SRFA of liver tumors is safe and can extend the treatment spectrum of conventional RFA. Adaptations over time combined with increasing experience resulted in a significant decrease in complications. KEY POINTS: • In 1235 ablation sessions in 793 patients over 15 years, we found a mortality rate of 0.5% (6/1235) and an overall major complication rate of 7.4%, which fell from 11.5 (36/314) to 6.0% (55/921, p = 0.001) after January 2011, likely due to procedural adaptations. • History of bile duct surgery/intervention (p = 0.013, OR = 3.290), number of coaxial needles (p = 0.026, OR = 1.052), and location of tumors in segment IVa (p = 0.016, OR = 1.989) or VIII (p = 0.038, OR = 1.635) were found to be independent prognostic factors. • Simple logistic regression revealed that number of tumors, tumor size, location close to the diaphragm, tumor conglomerates, and segment VII were other significant predictors of major complications.

Can accurate evaluation of the treatment success after radiofrequency ablation of liver tumors be achieved by visual inspection alone? Results of a blinded assessment with 38 interventional oncologists.

OBJECTIVES: To assess the difficulties in the immediate judgment of treatment success after radiofrequency ablation (RFA) of liver tumors by visual inspection alone and to evaluate whether radiologist's expertise affects the resultant judgment. METHODS: Peri-interventional CT-scans of nine patients with nine hepatocellular carcinomas with known outcomes after RFA were presented to 38 participants from 14 different countries. In a total of 342 reads, all interventional oncologists assessed the pre- and immediate post-interventional CT-scans through conventional side-by-side juxtapositioning of images and judged whether complete ablation (i.e., technical success and technique efficacy) was achieved. Results were compared regarding expertise in percutaneous tumor ablation (>50 interventions performed). An 'overcall' was defined as insufficient ablation that was misjudged as sufficient, and an 'undercall' as an erroneous assessment of complete ablation. RESULTS: Overall 3.97 ± 1.27 out of 9 (44.1%) cases per radiologist were misjudged. The mean number of overcalls and undercalls per radiologist were 0.74 ± 0.50 out of 2 (37.0%), and 3.24 ± 1.28 out of 7 (46.3%), respectively. 18/38 (47.4%) participants had considerable experience in percutaneous tumor ablation, with such expertise having no significant influence on the results (overall: p = 0.70; overcalls: p = 0.87; undercalls: p = 0.75). CONCLUSIONS: Conventional side-by-side evaluation of treatment success after RFA of liver tumors by the juxtaposition of pre- and post-interventional CT-scans is very difficult for experienced radiologists. The implementation of advanced processing techniques such as rigid/non-rigid image fusion with the assessment of the periablational margin is thus likely needed in order to decrease errors and objectively evaluate technical success and predict technique efficacy of liver RFA.

Stereotactic radiofrequency ablation of a variety of liver masses in children.

BACKGROUND AND AIMS: Surgical resection is currently the cornerstone of liver tumor treatment in children. In adults radiofrequency ablation (RFA) is an established minimally invasive treatment option for small focal liver tumors. Multiprobe stereotactic RFA (SRFA) with intraoperative image fusion to confirm ablation margins allows treatment for large lesions. We describe our experience with SRFA in children with liver masses. METHODS: SRFA was performed in 10 patients with a median age of 14 years (range 0.5-17.0 years) suffering from liver adenoma (n = 3), hepatocellular carcinoma (n = 1), hepatoblastoma (n = 2), myofibroblastic tumor (n = 1), hepatic metastases of extrahepatic tumors (n = 2) and infiltrative hepatic cysts associated with alveolar echinococcosis (n = 1). Overall, 15 lesions with a mean lesion size of 2.6 cm (range 0.7-9.5 cm) were treated in 11 sessions. RESULTS: The technical success rate was 100%, as was the survival rate. No transient adverse effects higher than grade II (Clavien and Dindo) were encountered after interventions. The median hospital stay was 5 d (range 2-33 d). In two patients who subsequently underwent transplant hepatectomy complete ablation was histologically confirmed. Follow-up imaging studies (median 55 months, range 18-129 months) revealed no local or distant recurrence of disease in any patient. CONCLUSIONS: SRFA is an effective minimal-invasive treatment option in pediatric patients with liver tumors of different etiologies.

Quality of life analysis after stereotactic radiofrequency ablation of liver tumors.

The purpose of this study was to evaluate the health-related quality of life (HRQoL) after stereotactic radiofrequency ablation (SRFA) of liver tumors and identify variables associated with decreased HRQoL and to compare it to other treatments in case of concurrency. From 2011 to 2017 577 patients underwent SRFA for liver tumors in 892 ablation sessions. 303 (52.5%) patients completed a HRQoL questionnaire once after the ablation. HRQoL was assessed by the Short Form (SF)-12 health survey with mental and physical component scales and by a general questionnaire to assess disease and treatment-specific items as well as to compare tolerability of SRFA to transarterial chemoembolization (TACE), hepatic resection (HR) and chemotherapy (CTX). The median SF-12 PCS was 46.6 and MCS was 53.2. Patients experiencing pain or complications and patients refusing repeat SRFA showed significantly lower PCS (43.2 vs 48.6, p = 0.0003; 32.8 vs 46.9, p = 0.005 and 40.6 vs 46.9, p = 0.009). 355 (97.8%) patients indicated willingness to undergo repeat SRFA with little to no fear in 292 (80.7%) patients. Among patients with multiple therapies, SRFA was rated by 40 (90.9%) as preferred re-treatment, HR by 1 (2.3%) and CTX by 3 (6.8%). In conclusion, we have shown that SRFA has good HRQoL-outcomes and reported low morbidity rates. Consequently the vast majority of study patients would accept a repeated SRFA if necessary (97.8%), without fear (80.7%). SRFA was preferred among patients who experienced concurrent treatments, such as HR or CTX.

Thermal ablation of CT 'invisible' liver tumors using MRI fusion: a case control study.

Purpose: To evaluate whether 'invisible' liver tumors on CT can be treated by stereotactic radiofrequency ablation (SRFA) using fusion of pre-ablation MRI.Methods: In this retrospective case-control study, 60 patients (14 with Hepatocellular carcinoma (HCC) and 46 with metastatic liver tumors) with CT 'invisible' lesions underwent SRFA using MRI-fusion between June 2005 and June 2018 ('fusion group'). For comparison, 60 patients who underwent SRFA without image fusion were selected using nearest neighbor propensity score matching ('control group'). Endpoints consisted of local tumor control, safety, overall and disease-free survival.Results: Major complications occurred in 6/69 ablations (8.7%) in the fusion group and in 6/89 ablations (6.7%) in the control group (p = 0.434). Primary technical efficacy rate (i.e., successful initial ablation) was 96.6% (28/29) for HCC and 97.9% (166/170) for metastatic disease in the fusion group and 100% (33/33) and 93.3% (184/194) in the control group, respectively (p = 0.468 and 0.064). Local recurrence (LR) was observed in 1/29 (3.5%) HCCs and in 6/170 metastases (4.0%) in the fusion group and 1/33 (3.0%) and 21/196 (10.7%) in the control group, respectively. The LR rate of metastasis in the control group was significantly higher (p = 0.007), although differences in OS and DFS did not reach statistical significance.Conclusions: Image fusion using pre-procedural MRI allows for ablation of CT-'invisible' liver tumors that are otherwise untreatable. Moreover, local oncological control was higher in metastatic liver tumors versus matched controls which suggests it could be useful tool for all stereotactic radiofrequency ablation procedures.

Simultaneous Stereotactic Radiofrequency Ablation of Multiple (≥ 4) Liver Tumors: Feasibility, Safety, and Efficacy.

PURPOSE: To assess feasibility, safety, and clinical outcome of simultaneous stereotactic radiofrequency (RF) ablation of multiple (≥ 4) primary and metastatic liver tumors. MATERIALS AND METHODS: This retrospective observational study included 92 patients (29 women, 62 men), 35 with ≥ 4 hepatocellular carcinomas (HCCs) and 57 with ≥ 4 metastatic liver tumors at initial stereotactic RF ablation between 2005 and 2018. The median size of 178 HCCs and 371 metastases was 2.2 cm (range, 1.0-8.5 cm) and 3.0 cm (range, 0.5-13 cm), respectively. At initial stereotactic RF ablation, 17 (48.6%) patients with HCC and 19 (33.3%) with metastases had 4 liver tumors, 11 (31.4%) and 19 (33.3%) had 5 tumors, and 7 (20%) and 19 (33.3%) had ≥ 6 tumors. RESULTS: Major complications occurred in 2 of 35 ablations (5.4%) in patients with HCCs and in 7 of 63 (10%) with metastases. The primary technical efficacy rate (ie, successful initial ablation) was 100% (178/178) in HCCs and 98.8% (363/371) in metastases. Local recurrence was observed in 4 of 178 (2.2%) HCCs and in 17 of 371 (4.6%) metastases. Overall survival (OS) rates at 1, 3, and 5 years from the date of the first stereotactic RF ablation were 88.0%, 54.0%, and 30.4% for patients with HCCs with a median OS of 38.2 months and 86.1%, 53.1%, and 37.3% for patients with metastases with a median OS of 37.4 months. CONCLUSIONS: Stereotactic RF ablation is a feasible, safe, and efficacious option in simultaneous management of multiple primary and metastatic liver tumors.

Stereotactic Radiofrequency Ablation of an Unresectable Intrahepatic Cholangiocarcinoma (ICC): Transforming an Aggressive Disease into a Chronic Condition.

In 2010, we reported on a 72-year-old patient with a large, unresectable cholangiocarcinoma with intrahepatic metastases, which was treated by stereotactic radiofrequency ablation (SRFA) in three consecutive sessions. Within the last nine years, the same patient has received seven additional ablation sessions for a total of ten recurrent intrahepatic lesions. One year after the last SRFA, the patient's liver function is still within the physiological range, suggesting that this approach is not only sufficient for locally controlling tumor disease, but also for sparing healthy tissue. Moreover, periods of hospitalization were relatively short, while procedure-related pain was generally mild. In summary, SRFA has turned an aggressive disease with a devastating prognosis into a chronic condition while improving the patient's quality of life.

Stereotactic radiofrequency ablation as first-line treatment of recurrent HCC following hepatic resection.

BACKGROUND: To evaluate the therapeutic efficacy, safety and overall clinical outcome of multiprobe stereotactic RF ablation (SRFA) as first-line treatment of HCC recurrence after hepatic resection (HR). STUDY DESIGN: In this retrospective single-center study, 34 consecutive patients with previous HR were treated by SRFA between 2006 and 2018 for 140 HCCs in 60 ablation sessions. RESULTS: The median treated tumor size was 3.0 cm (range 0.5-10 cm). SRFA was primarily successful for 133/140 (95%) tumors. Four tumors were successfully retreated, resulting in a secondary technical efficacy rate of 97.9%. Local tumor recurrence developed in 4 of 140 tumors (2.9%). The major complication rate was 4.8% (3 of 60 ablations). No periprocedural deaths occurred. The overall survival (OS) rates at 1-, 3-, and 5- years from the date of the first SRFA were 94.0%, 70.2%, and 53.3%, respectively, with a median OS of 69.1 months (95% CI 18.8-119.3). The disease-free survival (DFS) was 52.6%, 19.7% and 15.8%, at 1-, 3- and 5- years, respectively, with a median DFS of 12.8 months (95% CI 9.0-28.9). CONCLUSION: Stereotactic RFA is a safe, feasible and useful option in the management of recurrent HCC following HR with low morbidity paired with good clinical outcome.

Minimal ablative margin (MAM) assessment with image fusion: an independent predictor for local tumor progression in hepatocellular carcinoma after stereotactic radiofrequency ablation.

OBJECTIVES: To assess the minimal ablative margin (MAM) by image fusion of intraprocedural pre- and post-ablation contrast-enhanced CT images and to evaluate if it can predict local tumor progression (LTP) independently. Furthermore, to determine a MAM with which a stereotactic radiofrequency ablation (SRFA) can be determined successful and therefore used as an intraprocedural tool to evaluate treatment success. METHODS: A total of 110 patients (20 women, 90 men; mean age 63.7 ± 10.2) with 176 hepatocellular carcinomas were assessed by retrospective analysis of prospectively collected data. The MAM was determined through image fusion of intraprocedural pre- and post-ablation images using commercially available rigid imaging registration software. LTP was assessed in contrast-enhanced CTs or MR scans at 3-6-month intervals. RESULTS: The MAM was the only significant independent predictor of LTP (p = 0.036). For each millimeter increase of the MAM, a 30% reduction of the relative risk for LTP was found (OR = 0.7, 95% CI 0.5-0.98, p = 0.036). No LTP was detected in lesions with a MAM > 5 mm. The overall LTP rate was 9 of 110 (8.2%) on a patient level and 10 of 173 (5.7%) on a lesion level. The median MAM was 3.4 (1.7-6.9) mm. The mean overall follow-up period was 26.0 ± 10.3 months. CONCLUSIONS: An immediate assessment of the minimal ablative margin (MAM) can be used as an intraprocedural tool to evaluate the treatment success in patients treated with stereotactic RFA. A MAM > 5 mm has to be achieved to consider an ablation as successful. KEY POINTS: • An intraoperatively measured minimal ablative margin (MAM) > 5 mm correlates with complete remission. • MAM is the only significant independent predictor of LTP (OR = 0.7, 95% CI 0.5-0.98, p = 0.036) after stereotactic RFA of hepatocellular carcinoma. • Image fusion using commercially available rigid imaging registration software is possible, even though considerably complex. Therefore, improved (semi-)automatic fusion software is highly desirable.