BackgroundRadiofrequency ablation (RFA) and microwave ablation (MWA) are widely accepted techniques to eliminate small unresectable colorectal liver metastases (CRLM). Although previous studies labelled thermal ablation inferior to surgical resection, the apparent selection bias when comparing patients with unresectable disease to surgical candidates, the superior safety profile, and the competitive overall survival results for the more recent reports mandate the setup of a randomized controlled trial. The objective of the COLLISION trial is to prove non-inferiority of thermal ablation compared to hepatic resection in patients with at least one resectable and ablatable CRLM and no extrahepatic disease.MethodsIn this two-arm, single-blind multi-center phase-III clinical trial, six hundred and eighteen patients with at least one CRLM (≤3 cm) will be included to undergo either surgical resection or thermal ablation of appointed target lesion(s) (≤3 cm). Primary endpoint is OS (overall survival, intention-to-treat analysis). Main secondary endpoints are overall disease-free survival (DFS), time to progression (TTP), time to local progression (TTLP), primary and assisted technique efficacy (PTE, ATE), procedural morbidity and mortality, length of hospital stay, assessment of pain and quality of life (QoL), cost-effectiveness ratio (ICER) and quality-adjusted life years (QALY).DiscussionIf thermal ablation proves to be non-inferior in treating lesions ≤3 cm, a switch in treatment-method may lead to a reduction of the post-procedural morbidity and mortality, length of hospital stay and incremental costs without compromising oncological outcome for patients with CRLM.Trial registrationNCT03088150, January 11th 2017.

Purpose To (a) investigate the safety of percutaneous irreversible electroporation (IRE) for locally advanced pancreatic cancer and (b) evaluate the quality of life (QOL), pain perception, and efficacy in terms of time to local progression, event-free survival, and overall survival (OS). Materials and Methods The study was approved by the local review board (NL42888.029.13). All patients provided written informed consent for study participation, the ablation procedure, and data usage. Between January 2014 and June 2015, 25 patients with histologically proved locally advanced pancreatic cancer 5 cm or smaller (13 women, 12 men; median age, 61 years; age range, 41-78 years) were prospectively included to undergo percutaneous computed tomographic-guided IRE. Patients with a metallic biliary Wallstent, epilepsy, or ventricular arrhythmias were excluded. Kaplan-Meier estimates were used to investigate time to local progression, event-free survival, and OS. Safety was assessed on the basis of adverse events, which were graded according to the Common Terminology Criteria for Adverse Events. Pain perception and QOL were evaluated by using specific questionnaires. Results All patients underwent IRE. The median largest tumor diameter was 4.0 cm (range, 3.3-5.0 cm). After a median follow-up of 12 months (interquartile range: 7-16 months), median event-free survival after IRE was 8 months (95% confidence interval [CI]: 4 months, 12 months); the median time to local progression after IRE was 12 months (95% CI: 8 months, 16 months). The median OS was 11 months from IRE (95% CI: 9 months, 13 months) and 17 months from diagnosis (95% CI: 10 months, 24 months). There were 12 minor complications (grade I or II) and 11 major complications (nine grade III, two grade IV) in 10 patients. There were no deaths within 90 days after IRE. Conclusion Percutaneous IRE for locally advanced pancreatic cancer is generally well tolerated, although major adverse events can occur. Preliminary survival data are encouraging and support the setup of larger phase II and III clinical trials to assess the efficacy of IRE plus chemotherapy in the neoadjuvant and adjuvant or second-line setting compared with more widely adopted regimens such as chemotherapy and/or radiation therapy. RSNA, 2016 Online supplemental material is available for this article.

Purpose: Local tumor ablation through irreversible electroporation (IRE) may offer a novel therapeutic option for locally advanced pancreatic cancer (LAPC). It may also serve as a means of in vivo vaccination. To obtain evidence of the induction of systemic antitumor immunity following local IRE-mediated ablation, we performed an explorative immune monitoring study. Methods: In ten patients enrolled in a clinical trial exploring the safety, feasibility, and efficacy of percutaneous image-guided IRE in LAPC, we determined the frequency and activation state of lymphocytic and myeloid subsets in pre- and post-treatment peripheral blood samples using flow cytometry. Tumor-specific systemic T cell responses to the pancreatic cancer associated antigen Wilms Tumor (WT)1 were determined after in vitro stimulation in an interferon-y enzyme-linked immunospot assay (Elispot), at baseline and at 2 weeks and 3 months after IRE. Results: Our data showed a transient decrease in systemic regulatory T cells (Treg) and a simultaneous transient increase in activated PD-1+ T cells, consistent with the temporary reduction of tumor-related immune suppression after the IRE procedure. Accordingly, we found post-IRE boosting of a pre-existing WT1 specific T cell response in two out of three patients as well as the de novo induction of these responses in another two patients. There was a trend for these WT1 T cell responses to be related to longer overall survival (p = .055). Conclusions: These findings are consistent with a systemic and tumor-specific immune stimulatory effect of IRE and support the combination of percutaneous IRE with therapeutic immune modulation.

P ancreatic adenocarcinoma is the fourth leading cause of cancer death in the United States (1). The 5-year relative survival of patients with pancreatic cancer is less than 8% (1). Contributing to the dismal survival rate is that most patients are diagnosed with advanced disease because of lack of symptoms at early stage pancreatic cancer (1). Surgical resection with adjuvant chemotherapy is considered the best treatment option for long-term survival. However, fewer than 20% of patients present with resectable disease, and, even in this subset of patients, median overall survival (OS) after successful resection and adjuvant therapy is only 28 months (2). Furthermore, one-third of patients develop isolated local recurrence after resection (3), which is commonly unresectable because of vascular involvement (4).Approximately 30% of patients present with locally advanced pancreatic cancer (American Joint Committee on Cancer stage III), defined as greater than 180° circumference tumor encasement of the superior mesenteric or celiac

PurposeTo retrospectively analyse the safety and efficacy of radiofrequency ablation (RFA) versus microwave ablation (MWA) in the treatment of unresectable colorectal liver metastases (CRLM) in proximity to large vessels and/or major bile ducts.Method and MaterialsA database search was performed to include patients with unresectable histologically proven and/or 18F–FDG–PET avid CRLM who were treated with RFA or MWA between January 2001 and September 2014 in a single centre. All lesions that were considered to have a peribiliary and/or perivascular location were included. Univariate logistic regression analysis was performed to assess the distribution of patient, tumour and procedure characteristics. Multivariate logistic regression was used to correct for potential confounders.ResultsTwo hundred and forty-three patients with 774 unresectable CRLM were ablated. One hundred and twenty-two patients (78 males; 44 females) had at least one perivascular or peribiliary lesion (n = 199). Primary efficacy rate of RFA was superior to MWA after 3 and 12 months of follow-up (P = 0.010 and P = 0.022); however, after multivariate analysis this difference was non-significant at 12 months (P = 0.078) and vanished after repeat ablations (P = 0.39). More CTCAE grade III complications occurred after MWA versus RFA (18.8 vs. 7.9 %; P = 0.094); biliary complications were especially common after peribiliary MWA (P = 0.002).ConclusionFor perivascular CRLM, RFA and MWA are both safe treatment options that appear equally effective. For peribiliary CRLM, MWA has a higher complication rate than RFA, with similar efficacy. Based on these results, it is advised to use RFA for lesions in the proximity of major bile ducts.