Potential for cure and predictors of long-term survival after radiofrequency ablation for colorectal liver metastases: A 20-years single-center experience

BackgroundAdditional radiofrequency ablation (RFA) of liver-limited colorectal liver metastases (CRLM) improves overall (OS) and recurrence-free survival (RFS) over systemic therapy alone. We aimed to assess the potential and predictive factors of long-term survival and cure to optimize patient selection for RFA application.MethodsRetrospective review of a prospectively maintained single-center database of consecutive patients undergoing RFA for liver-limited CRLM after systemic therapy between 2002 and 2020. Clinicopathologic characteristics and KRAS/BRAF-genotype data (tested routinely since 2010) were correlated to RFS and OS. Cure was defined as ≥10-years RFS (long-term survival as ≥5-years OS) following RFA.ResultsFor the entire cohort of 158 patients (median follow-up 13.6 years), co-occurrence of three factors, RECIST-defined response, number of ≤3 CRLM, and ≤3 cm maximum size determined a survival plateau that distinguished cured from non-cured patients (10-years RFS: 15.5% vs 0%, p < 0.0001). Among 59 patients (37.3%) being tested, 4(6.8%) were BRAF-mt, 15(25.4%) KRAS-mt, and 40(67.8%) KRAS/BRAF-wt. OS (median follow-up 8.3 years) was estimated to be higher with KRAS/BRAF-wt compared to a mutant KRAS or BRAF status (5-years OS: 22.8% vs 3.4%, p = 0.0018).ConclusionThis study indicates about 15% chance of cure following RFA of low-volume liver-limited CRLM after downsizing by systemic therapy and a negative effect of KRAS or BRAF mutation on long-term survival after CRLM ablation. These findings may improve clinical decision-making in patients potentially candidate to RFA of CRLM and encourage further investigations on molecular factors determining an oligometastatic state of CRLM curable with focal ablative therapy.     

Ablation therapy of non-colorectal cancer lung metastases: retrospective analysis of tumour response post-laser-induced interstitial thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA)

Purpose: To retrospectively compare the local tumour response and survival rates in patients with non-colorectal cancer lung metastases post-ablation therapy using laser-induced thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA).

Material and methods: Retrospective analysis of 175 computed tomography (CT)-guided ablation sessions performed on 109 patients (43 males and 66 females, mean age: 56.6 years). Seventeen patients with 22 lesions underwent LITT treatment (tumour size: 1.2–4.8?cm), 29 patients with 49 lesions underwent RFA (tumour size: 0.8–4.5?cm) and 63 patients with 104 lesions underwent MWA treatment (tumour size: 0.6–5?cm). CT scans were performed 24-h post-therapy and on follow-up at 3, 6, 12, 18 and 24 months.

Results: The overall-survival rates at 1-, 2-, 3- and 4-year were 93.8, 56.3, 50.0 and 31.3% for patients treated with LITT; 81.5, 50.0, 45.5 and 24.2% for patients treated with RFA and 97.6, 79.9, 62.3 and 45.4% for patients treated with MWA, respectively. The mean survival time was 34.14 months for MWA, 34.79 months for RFA and 35.32 months for LITT. In paired comparison, a significant difference could be detected between MWA versus RFA (p?=?0.032). The progression-free survival showed a median of 23.49?±?0.62 months for MWA,19.88?±?2.17 months for LITT and 16.66?±?0.66 months for RFA (p?=?0.048). The lowest recurrence rate was detected in lesions ablated with MWA (7.7%; 8 of 104 lesions) followed by RFA (20.4%; 10 of 49 lesions) and LITT (27.3%; 6 of 22 lesions) p value of 0.012. Pneumothorax was detected in 22.16% of MWA ablations, 22.73% of LITT ablations and 14.23% of RFA ablations.

Conclusion: LITT, RFA and MWA may provide an effective therapeutic option for non-colorectal cancer lung metastases with an advantage for MWA regarding local tumour control and progression-free survival rate.     

Systematic review and meta-analysis of local ablative therapies for resectable colorectal liver metastases

IntroductionLocal ablative therapies (LAT) have shown positive but heterogenous outcomes in the treatment of colorectal liver metastases (CRLM). The aim of this systematic review is to evaluate LAT and compare them with surgical resection.MethodsIn accordance with PRISMA guidelines, Medline, EMBASE, Cochrane and Web of Science databases were searched for reports published before January 2019. We included papers assessing radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation (CA) and electroporation (IRE) treating resectable CRLM with curative intention. We evaluated LAT related complications and oncological outcomes as tumour progression (LTP), disease-free survival (DFS) and overall survival (OS).ResultsThe literature search yielded 6767 records; 20 papers (860 patients) were included. No included studies related mortality with LAT. Median adverse events percentage was 7%: (8% RFA;7% MWA). Median 3y-DFS was 32% (24% RFA; 60% MWA); 5y-DFS was 27%: (18% RFA; 38.5% MWA). Median 3y-OS was 59% (60% RFA; 70% MWA; 34% CA), 5y-OS was 44.5% (43% RFA; 55% MWA; 20% CA).Surgical resection showed decreased LTP, improved DFS and OS than those reported with LAT, with RFA accounting for reduced 1y-DFS (RR 0.83, 95%CI 0.71–0.98), 3y-DFS (RR 0.5, 95%CI 0.33–0.76), 5y-DFS (RR 0.53, 95%CI 0.28–0.98) and 5y-OS (RR 0.76, 95%CI 0.58–0.98) in comparison with surgical resection.ConclusionsLow quality evidence suggests that both RFA and MWA seem superior to CA. MWA presents similar adverse events when compared to RFA with a possible increase in DFS and OS. Surgical resection still seems to provide superior DFS and OS in comparison with LAT.     

Propensity score matching demonstrates similar results for radiofrequency ablation compared to surgical resection in colorectal liver metastases

PurposeMinimally invasive ablative treatments, such as radiofrequency ablation (RFA), are increasingly used in the curative treatment of patients with colorectal liver metastases (CRLM). Selection bias plays an important role in the evaluation of early and late results between RFA and surgery. The purpose of this study was to evaluate recurrences and oncological survival following these two treatment modalities using single pair propensity score matching.MethodsBetween 2000 and 2018, patients curatively treated for CRLM were included in a multicentre database. Patients were excluded when receiving two-staged treatment, synchronous treatment with primary tumor or combination of modalities. Propensity score matching was used to minimize influence of known covariates, i.e., age, ASA, FONG CRS, location and T-stage of the primary tumor.ResultsBefore matching, the RFA group contained 39 patients and the surgery group 982 patients, after matching both groups contained 36 patients. After matching, mean age was 69 years (53–86) for RFA and 68 (50–86) for surgery, with a mean tumor size of respectively 2.5 cm (0.8–6.5) and 3.4 cm (1–7.5). Both groups showed similar complication rate according to Clavien-Dindo (17vs.33%; p = 0.18), recurrence rate (58vs.64%; p = 0.09) without significant differences in 5-year DFS and OS (RFA compared to surgery respectively 25vs.37%; p = 0.09 and 42vs.53%; p = 0.09).ConclusionAfter propensity score matching, RFA showed lower complications and similar oncological survival compared to surgical resection. In patients who are suboptimal candidates for surgery, RFA seems to be a good and safe alternative.     

Liver resection in elderly patients with extensive CRLM: Are we offering an adequate treatment? A propensity score matched analysis

BackgroundData on the management of elderly patients with extensive colorectal liver metastases (CRLM) are scarce and conflicting. This study assesses differences in management and long-term oncological outcomes between older and younger patients with CRLM and a high Tumour Burden Score (TBS).MethodsInternational multicentre retrospective study on patients with CRLM and a category 3 TBS, submitted to liver resection. Patients were divided into two groups according to their age (younger and older than 75) and were compared using propensity score matching (PSM) analysis and multivariable regression models. Differences in management and oncological outcomes including recurrence-free survival (RFS) and overall survival (OS) were assessed.ResultsThe study included 386 patients, median follow-up was 48 months. The unmatched comparison revealed a higher ASA score (p = 0.035), less synchronous CRLM (47% vs 68%, p = 0.003), a lower median number of lesions (1 vs 3, p = 0.004) and less perioperative chemotherapy (CTx) (66% vs 88%, p < 0.001) in the elderly group.Despite the absence of CTx being an independent predictor of decreased RFS and OS (HR 0.760, p = 0.044 and HR 0.719, p = 0.049, respectively), the elderly group still received less CTx (OR 0.317, p = 0.001) than the younger group.After PSM (n = 100 patients), the two groups were comparable, however, CTx administration was still significantly lower in the elderly group.ConclusionLiver resection should be considered in patients aged 75 and older, even if they present with extensive liver disease. Despite CTx being associated with improved oncological outcomes, a large percentage of elderly patients with CRLM are undertreated.     

Ablation versus resection for resectable colorectal liver metastases - Health care related cost and survival analyses from a quasi-randomised study

BackgroundThe aim of this study was to compare healthcare related costs and survival in patients treated with microwave ablation (MWA) versus surgical resection for resectable colorectal liver metastases (CRLM), in patients from a quasi-randomised setting.MethodsThe Swedish subset of data from a prospective multi-centre study investigating survival after percutaneous computer-assisted Microwave Ablation VErsus Resection for Resectable CRLM (MAVERRIC study) was analysed. Patients with CRLM ≤ 3 cm amenable to ablation and resection were considered for study inclusion only on even calendar weeks, while treated with gold standard resection every other week, creating a quasi-randomised setting. Survival and costs (all inpatient hospital admissions, outpatient visits, oncological treatments and radiological imaging) in the 2 years following treatment were investigated.ResultsMWA (n = 52) and resection (n = 53) cohorts had similar baseline patient and tumour characteristics and health care consumption within 1 year prior to CRLM treatment. Treatment related morbidity and length of stay were significantly higher in the resected cohort. Overall health care related costs from decision of treatment and 2 years thereafter were lower in the MWA versus resection cohort (mean ± SD USD 80′964±59′182 versus 110′059±59′671, P < 0.01). Five-year overall survival was 50% versus 54% in MWA versus resection groups (P = 0.95).ConclusionsMWA is associated with decreased morbidity, time spent in medical facilities and healthcare related costs within 2 years of initial treatment with equal overall survival, highlighting its benefits for patient and health care systems.     

Surgical microwave ablation of otherwise non-resectable colorectal cancer liver metastases: Expanding opportunities for long term survival

BackgroundColorectal liver metastases (CRLM) are the most common extra-lymphatic metastases in colorectal cancers, however, only 15–20% of these patients are candidates for resection. We reviewed our institutional experience with 135 surgical ablations for unresectable CRLM.MethodsRetrospective review of surgically ablated CRLM from 2009 to 2018. Patient-specific variables were obtained from the medical record. Kaplan-Meier modeling was performed for survival analyses.ResultsWe ablated 135 CRLM in 36 patients over 40 procedures. Median age was 52 years and 58% of patients were male. All patients received systemic chemotherapy. The ablation procedure was completed laparoscopically in 68% of procedures. Median number of ablated lesions per patient was 2 (range 1–15). Median maximum diameter of ablated lesions was 1.9 cm (range 0.5–12.2). Median follow up of the study was 28 months. In this time, median disease-free survival was not reached. Of the 135 lesions ablated, the per-lesion recurrence rate was 6/135 (4.4%). Median overall survival was 81 months.ConclusionsSurgical ablation of CRLM can provide excellent local control and long-term survival outcomes in patients who may otherwise not be candidates for other liver-directed therapies.     

Surgical microwave ablation for multifocal non-resectable liver metastases: a single institution experience treating five or more liver lesions

BackgroundThermal ablation is an effective treatment for patients with metastatic colon and rectal cancer and allows surgeons to offer curative intent therapy to patients who are otherwise not candidates for resection. We aimed to report outcomes of a single institution experience using microwave ablation (MWA) with or without resection to treat five or more liver metastases.MethodsIn this retrospective cohort study, the University of Minnesota Division of Surgical Oncology liver surgery database was queried to identify all patients who underwent thermal ablation of five or more colorectal liver metastases (CRLM) between 2012–2018. We reviewed patient, disease, and tumor characteristics and measured local, intrahepatic, and extrahepatic recurrence (EHR) rates. We also calculated median overall survival (OS) and disease-free survival (DFS).ResultsTen patients identified had five or more (range, 5–18) tumors ablated with or without combined liver and bowel resection. Median age was 50, and most patients were male (70%) and Caucasian (90%). Four patients received ablation alone (5–12 lesions), while six had combined resection and ablation (5–18 lesions). Ablation was performed laparoscopically in six patients, and four had ablations without resection. All patients received pre- and post-operative chemotherapy. A median of 7 tumors were ablated per patient. Median follow-up was 2.3 years. Among 75 tumors ablated, ablation site recurrence (ASR) (within 1 cm of ablation site) was seen in three with a per-lesion recurrence rate of 4%. Intrahepatic recurrence (IHR) occurred in 6 (60%) patients and EHR in 1 (10%). Five patients underwent retreatment of IHR during follow-up. Median OS was 3 years and DFS was 7.1 months. At the time of last follow up, 6 patients were disease-free.ConclusionsThermal ablation can provide acceptable DFS and OS, even with high volume metastatic colorectal cancers. Future efforts should be focused on defining selection criteria for those most likely to benefit from this aggressive approach.     

Minimally invasive surgery versus percutaneous radiofrequency ablation for early-stage hepatocellular carcinoma: Results from a high-volume liver surgery center in East Asia

Background & aimsThe outcomes of minimally invasive surgery (MIS) vs. percutaneous radiofrequency ablation (RFA) in treating early-stage hepatocellular carcinoma (HCC) remain inconclusive. This study thus aimed to compare the outcomes of both treatments for early-stage HCCs.MethodsThis retrospective study consecutively enrolled patients with newly diagnosed early-stage HCCs treated with MIS or percutaneous RFA between 2011 and 2018. Outcomes were compared between the MIS and RFA groups both before and after 1:1 propensity score matching (PSM).ResultsA total of 119 and 481 patients underwent MIS and percutaneous RFA, respectively. Patients undergoing percutaneous RFA exhibited older age (p = 0.007) and higher rates of Child–Pugh class B (p < 0.001) and multifocal disease (p < 0.001). The median overall survival (OS) was 73.7 months in the MIS group, which was significantly higher than that for the RFA group of 65.1 months (p = 0.003). 50% HCC recurrence after MIS was not reached. The mean recurrence-free survival (RFS) was 49.6 months for the MIS group, which was significantly higher than the RFA group of 41.3 months (p < 0.001). On multivariate analysis, age ≥65 (HR: 1.61; 95% CI: 1.13–2.31, p = 0.009), RFA (HR: 2.21; 95% CI: 1.14–4.29, p = 0.019), and Child–Pugh class B (HR: 2.03; 95% CI: 1.29–3.21, p = 0.002) remained risk factors for OS, and RFA (HR: 2.18; 95% CI: 1.42–3.35; p < 0.001) remained a risk factor for RFS. After PSM, 103 patients were included in each group. No significant difference in OS was identified (p = 0.198), but RFS was higher in the MIS group than the RFA group (p = 0.003). Severe postoperative complications occurred at the same rate (1%) in both groups (p > 0.99).ConclusionAfter PSM, severe postoperative complication and OS rates were found to be comparable between the MIS and RFA groups, but RFS was higher in the MIS group than the RFA group, suggesting that MIS may have better outcomes for patients with early-stage HCC.     

The value of a dedicated multidisciplinary expert panel to assess treatment strategy in patients suffering from colorectal cancer liver metastases

BackgroundFor patients with colorectal cancer liver metastases (CRLM), local treatment is the only treatment with curative intent. The majority of patients with CRLM are however evaluated in multidisciplinary teams of colorectal cancer specialists often lacking expertise in local treatment of liver tumors. The aim of this study was therefore to assess the value of a dedicated multidisciplinary panel consisting of hepatobiliary surgeons and interventional radiologists for patients suffering from liver-only CRLM.MethodsPatients diagnosed with liver-only CRLM in 2016 were identified in a tertiary referral hospital, and two of the referring hospitals in the Netherlands. Diagnostic imaging was independently reviewed by a panel of four hepatobiliary surgeons and two interventional radiologists to re-evaluate treatment strategy retrospectively. If two or more panelists assessed all lesions eligible for resection and/or ablation, patients were deemed eligible for local treatment with curative intent. Interrater reliability between hepatobiliary surgeons was assessed through intraclass correlation coefficient (ICC) and weighted Cohen's kappa.ResultsDiagnostic imaging of 61 patients with liver-only metastases were reviewed. Local treatment strategies appeared feasible in 40/61 (65.6%) patients. Five out of 25 patients (20.0%) initially assigned to systemic therapy were deemed eligible for upfront local treatment with curative intent (p = 0.015). In this subgroup, interrater reliability between hepatobiliary surgeons was substantial (ICC: 0.704, 95% CI: 0.536–0.838, n = 25).ConclusionAssessment of treatment strategy by a dedicated multidisciplinary panel including liver experts may result in an increased number of patients eligible for potentially curative treatment and reduce undertreatment of patients suffering from liver-only CRLM.     

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

BackgroundTo evaluate the efficacy, safety and overall clinical outcome of multiprobe SRFA as a treatment for recurrent colorectal liver metastases after hepatic resection (HR).MethodsA 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).Results213/217 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).ConclusionSRFA is a safe, feasible and effective option for CRLM after HR with low morbidity levels and favorable clinical outcome.     

Results of single-probe microwave ablation of metastatic liver cancer

Aims

Microwave ablation (MWA) is the most recent development in the field of local ablative therapies. The aim of this study was to evaluate the variability and reproducibility of single-probe MWA vs. radiofrequency ablation (RFA) of liver metastases smaller than 3 cm in patients without underlying liver disease.

Methods

Sixteen liver metastases were treated using MWA, and matched for size and localisation with 13 metastases treated by RFA. Tumour diameters and postoperative ablation diameters were recorded (D1 transverse; D2 antero-posterior; D3 cranio-caudal; mm) on computed tomography scans.

Results

Median D1, D2, and D3 ablation diameters after MWA vs. RFA were 18.5 (12–64) vs. 34 (16–41) mm (p = 0.003), 26 (14–60) vs. 35 (28–40) mm (p = 0.046), and 20 (10–73) vs. 32 (20–45) mm (p = 0.025), respectively. As compared to RFA, the variability between the lesions after MWA was significantly higher for D2 (p < 0.0001) and D3 (p = 0.002) but not for D1 (p = 0.15). The ablation diameters were less uniform after MWA than after RFA (p < 0.001).

Conclusion

Ablation diameters after single-probe MWA of metastatic liver tumours are highly variable and suboptimal. Improvements are needed before MWA can be implemented routinely.     

Selection for surgery and survival of synchronous colorectal liver metastases; a nationwide study

BackgroundResection of colorectal liver metastases (CRLM) is associated with improved survival but we currently have limited population-based data on selection for surgery.MethodsPatients in the Swedish Colorectal Cancer Register reported with liver metastases at diagnosis in 2007–2011 were identified. Clinical characteristics including American Society of Anesthesiologists classification, type of hospital and health care region were retrieved. Linkage to the National Patient Register and Statistics Sweden provided information on liver resection and socioeconomic variables.ResultsSynchronous CRLM was found in 4243/27,990 (15.2%) patients, of whom 1094 (25.8%) also had concurrent lung metastases. Of 3149 patients with liver-only metastases, 556 (17.8%) were subjected to liver resection. The resection rate varied by subsite; right-sided 11.7%, left-sided 19.7% and rectal cancer 22.7% (p = 0.001). It varied by type of hospital 14.1–23.6%, by region 11.5–22.7%, and was 19.8% in men and 14.9% in women (all p < 0.001).The adjusted odds were 0.74 (0.59–0.93) for females, 0.58 (0.46–0.74) for general district and 0.50 (0.37–0.68) for district hospital patients, and there were large regional differences. Patients >75 years were very unlikely to receive liver surgery 0.22 (0.15–0.32).In patients subjected to liver surgery, median survival was 57 months, 5-year survival rate was 45.4%, and those with left-sided colon cancer had the best outcome (48.8%; p = 0.02). Five-year hazard ratio for patients not subjected to liver surgery was 4.3 (3.7–5.0).ConclusionNationwide outcome after resection of synchronous CRLM was impressing but ambiguous selection mechanisms and inaccessibility need to be resolved. The implications of subsite deserve further attention.     

Combined microwave ablation and systemic chemotherapy for liver metastases from oesophageal cancer: Preliminary results and literature review

Purpose: Oesophageal cancer is a highly aggressive disease with about 50% of patients presenting with advanced or metastatic disease at initial diagnosis. In this study we assessed combined microwave ablation (MWA) and systemic chemotherapy in the treatment of liver metastases arising from oesophageal squamous cell carcinoma (OSCC). Materials and methods: Between February 2009 and June 2014, OSCC patients who underwent percutaneous MWA?+?concurrent systemic chemotherapy and systemic chemotherapy alone for liver metastases were enrolled in this study. Overall survival (OS) and progression-free survival (PFS) were recorded and compared between groups. Results: In total 15 patients with 25 liver metastases who underwent ultrasound-guided percutaneous MWA and chemotherapy were enrolled in this study. Technical success was achieved in 96% (24/25) of metastatic liver tumours. No major or minor complications associated with MWA procedures were observed. The median OS and PFS from initial MWA were 13 months and 4 months. The 1-, 2-, 3-, 4-year OS rates after MWA were 53.3%, 26.7%, 13.3%, and 13.3%, respectively. The 1- and 2-year PFS rates after MWA were 26.7% and 13.3%. The OS and PFS of the MWA?+?systemic chemotherapy group were superior than those of patients who received systemic chemotherapy alone (P?=?0.011 and 0.030, respectively). Conclusions: Combined MWA with systemic chemotherapy is a feasible, safe and effective treatment for liver metastases from OSCC.     

Impact of C-reactive protein–albumin–lymphocyte (CALLY) index on prognosis after hepatectomy for colorectal liver metastasis

AimThe C-reactive protein (CRP)-albumin-lymphocyte (CALLY) index is a novel inflammation-based biomarker. We aimed to investigate whether the CALLY can predict the prognosis in patients with colorectal liver metastases (CRLM) after hepatic resection.MethodsWe included 183 patients with CRLM who underwent hepatectomy. The CALLY index was defined as (albumin × lymphocytes)/(CRP × 10⁴). We investigated the association of the CALLY index with overall survival by univariate and multivariate analyses.ResultsIn total, 101 (55%) patients had a low CALLY index (<4). In the univariate analysis, overall survival was significantly worse in patients with lymph node metastases (p = 0.02), extrahepatic lesions (p < 0.01), and a low CALLY index (p < 0.01). In the multivariate analysis, independent and significant predictors of overall survival were lymph node metastases (p = 0.04), extrahepatic lesions (p = 0.03), and a low CALLY index (p = 0.03). Patients with a low CALLY index had significantly more postoperative complications than those with a high CALLY index (29% vs. 11%, p < 0.01).ConclusionThe CALLY index may be an independent and significant indicator of outcomes in patients who underwent liver resection for CRLM.     

The local efficacy and influencing factors of ultrasound-guided percutaneous microwave ablation in colorectal liver metastases: a review of a 4-year experience at a single center

Purpose: To investigate the clinical effectiveness and safety of ultrasound (US)-guided percutaneous microwave ablation (MWA) for colorectal liver metastasis (CRLM) and evaluate the influencing factors of local efficacy.

Methods: From January 2013 to January 2017, 137 CRLM patients accepting US-guided percutaneous MWA were included. The 2450-MHz microwave ablation system and a cooled-shaft antenna were used. All patients were regularly followed up for at least 6?months. Technical success, complete ablation, local tumor progression (LTP), complications and side effects were assessed. Logistic regression analysis was used to identify the independent prognostic factors for LTP.

Results: In total, 411 lesions (mean diameter 15.4?±?7.2?mm, range 5–67?mm) were treated. Complete ablation was achieved in 99.27% (408/411) of lesions and 97.81% (134/137) of patients. LTP occurred in 5.35% (22/411) of lesions and 16.06% (22/137) of patients. LTP was more likely to occur in lesions larger than 3?cm in diameter (OR: 14.71; p?<?.001; 95% CI: 3.7 3–57.92), near a large vascular structure (OR: 7.04; p?<?.001; 95% CI: 2.41–20.60), near the diaphragm (OR: 4.02; p?=?.049; 95% CI: 1.05–16.11) and in patients with no response to chemotherapy before MWA (OR: 3.25; p?=?.032; 95% CI: 1.14–15.30). MWA was well tolerated, with a major complication rate of 3.65%, a minor complication rate of 8.03% and a mortality rate of 0%. Fever and pain were the most common side effects after MWA.

Conclusions: US-guided percutaneous MWA of CRLM is a safe and effective method that is expected to become a routine treatment for local tumor control of CRLM.     

Hepatocellular carcinoma abutting large vessels: comparison of four percutaneous ablation systems

Purpose: To compare overall local tumour progression (OLTP), defined as the failure of primary ablation or local tumour progression, with single applicator monopolar radiofrequency ablation (RFA), microwave ablation (MWA), cluster-RFA and multi-bipolar radiofrequency (mbpRFA) in the treatment of hepatocellular carcinoma (HCC)?≤?5?cm abutting large vessels (≥3?mm).

Materials and methods: This multicenter, retrospective, per-nodule study was performed from 2007 to 2015. The study was approved by the ethics review board, and informed consent was waived. A total of 160/914 HCC nodules treated by thermal ablation and abutting large vessels (40 per treatment group) treated by monopolar RFA, MWA, cluster-RFA or mbpRFA were matched for tumour size, alpha-feto-protein level and vessel size. OLTP rates were compared by the log-rank test and the multivariate Cox model after matching.

Results: No differences were observed in tumour size, vessel size or alpha-feto-protein levels among the three groups (p?=?1). The cumulative 4-year OLTP rates following monopolar RFA, cluster-RFA, multi-bipolar RFA and MWA were 50.5%, 16.3%, 16.3% and 44.2%, respectively (p?=?0.036). On multivariate Cox regression, vessel size ≥10?mm, monopolar RFA and MWA were independent risk factors of OLTP compared to cluster-RFA or mbpRFA.

Conclusion: Multi-applicator RFA provides better local tumour control in HCC abutting large vessels than single-applicator techniques (monopolar RFA or MWA).     

Outcomes following synchronous liver resection,cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal liver and peritoneal metastases: A bi-institutional study

PurposeSynchronous liver resection, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal liver (CRLM) and peritoneal metastases (CRPM) has traditionally been contraindicated. However, latest practice promotes specialist, multidisciplinary-led consideration for select patients. This study aimed to evaluate the perioperative and oncological outcomes of synchronous resection in the management of CRLM and CRPM from two tertiary referral centres.MethodThis bi-institutional, retrospective, cohort study included patients undergoing simultaneous liver resection, CRS and HIPEC for metastatic colorectal cancer from 2013 to 2020. Patients treated with ablative liver techniques, staged operative approaches and extra abdominal disease were excluded. Overall survival (OS) and disease-free survival (DFS) rates were assessed. Univariate and multivariate analyses identified variables associated with survival and major morbidity (Clavien-Dindo grade III/IV).ResultsTwenty-three patients were included. The median peritoneal carcinomatosis index (PCI) was 9 (range 0–22). There were two major liver resections and 21 minor resections. CC-0 resections were achieved in all patients. Major morbidity occurred in 7 patients. There were no deaths at 90 days. PCI was independently associated with morbidity (p = 0.04). PCI >10 (p = 0.069), major morbidity (p = 0.083) and presence of KRAS mutation (p = 0.052) approached significance for poor OS. Median follow up was 21 months (4–54 months). Median OS was 37 months, 3-year survival 54%, and median DFS 18 months.ConclusionSynchronous liver resection, cytoreductive surgery and HIPEC is feasible in selected patients with low-volume CRPM and CRLM. Increasing PCI is associated with postoperative major morbidity, and should be considered during operative planning.     

Microwave Ablation Compared with Radiofrequency Ablation for The Treatment of Liver Cancer: a Systematic Review and Meta-analysis

BackgroundGuidelines have reported that although microwave ablation (MWA) has potential advantages over radiofrequency ablation (RFA), superiority in efficacy and safety remain unclear. Aim of the study is to compare MWA with RFA in the treatment of liver cancer.MethodsMeta-analysis was conducted according to the PRISMA guidelines for studies published from 2010 onwards. A random-effects model was used for the meta-analyses. Complete ablation (CA), local tumor progression (LTP), intrahepatic distant recurrence (IDR), and complications were analyzed.ResultsFour randomized trials and 11 observational studies with a total of 2,169 patients met the inclusion criteria. Although overall analysis showed no significant difference in LTP between MWA and RFA, subgroup analysis including randomized trials for patients with hepatocellular cancer (HCC) demonstrated statistically decreased rates of LTP in favor of MWA (OR, 0.40; 95% CI, 0.18–0.92; p = 0.03). No significant differences were found between the two procedures in CA, IDR, complications, and tumor diameter less or larger than 3 cm.ConclusionsMWA showed promising results and demonstrated better oncological outcomes in terms of LTP compared to RFA in patients with HCC. MWA can be utilized as the ablation method of choice in patients with HCC.Key words: liver, carcinoma hepatocellular, liver neoplasms, radiofrequency ablation, microwaves