Necrosis volume and Choi criteria predict the response to endoscopic ultrasonography-guided HybridTherm ablation of locally advanced pancreatic cancer

Abstract

Background and study aims Endoscopic ultrasound (EUS)-guided ablation of pancreatic ductal adenocarcinoma (PDAC) with HybridTherm-Probe (EUS-HTP) is feasible and safe, but the radiological response and ideal tool to measure it have not been investigated yet. The aims of this study were to: 1) assess the radiological response to EUS-HTP evaluating the vital tumor volume reduction rate, Response Evaluation Criteria in Solid Tumors (RECIST1.1) and Choi criteria; 2) determine the prognostic predictive yield of these criteria. Patients and methods A retrospective analysis was performed of patients with locally advanced PDAC after primary treatment or unfit for chemotherapy prospectively treated by EUS-HTP. Computed tomography scan was performed 1 month after EUS-HTP to evaluate: 1) vital tumor volume reduction rate (VTVRR) by measuring necrosis and tumor volumes through a computer-aided detection system; and 2) RECIST1.1 and Choi criteria. Results EUS-HTP was feasible in 22 of 31 patients (71 %), with no severe adverse events. Median post-HTP survival was 7 months (1 – 35). Compared to pre-HTP tumor volume, a significant 1-month VTVRR (mean 21.4 %) was observed after EUS-HTP (P = 0.005). We identified through ROC analysis a VTVRR > 11.46 % as the best cut-off to determine post-HTP 6-month survival outcome (AUC = 0.733; sensitivity = 70.0 %, specificity = 83.3 %). This cut-off was significantly associated with longer overall survival (HR = 0.372; P = 0.039). According to RECIST1.1 and Choi criteria, good responders to EUS-HTP were 60 % and 46.7 %, respectively. Good responders according to Choi, but not to RECIST1.1, had longer survival (HR = 0.407; P = 0.04). Conclusions EUS-HTP induces a significant 1-month VTVRR. This effect is assessed accurately by evaluation of necrosis and tumor volumes. Use of VTVRR and Choi criteria, but not RECIST 1.1 criteria, might identify patients who could benefit clinically from EUS-HTP.

Efficacy of Endoscopic Ultrasound-Guided Ablation with the HybridTherm Probe in Locally Advanced or Borderline Resectable Pancreatic Cancer: A Phase II Randomized Controlled Trial

“…This study confirmed the EUS-HTP safety in PDAC [ 9 , 10 ]. With respect to the other similar monopolar devices performing EUS-guided RFA, despite the less handy 14-gauge diameter the HTP device takes advantage from the bipolar and cooling systems to create larger ablation areas with less power input and less collateral thermal damage than other available EUS-RFA probes.…”

“…As previously described [ 8 , 9 , 10 ], the active tip (26-mm length) of the needle-shaped (14-gauge) HTP was placed directly into target lesion under EUS-guidance using colour power-doppler to avoid vascular structures, and activated at fixed RF power of 18W and cooling pressure of 650 psi, with application time between 240 and 480 s for a 2-cm up to >3-cm mass or until the electric resistance, induced by tumour tissue desiccation and devitalization, increased.…”

“…Tumour volume (cubic centimeter, cc) was also measured at each follow-up, using a computer-aided detection system (IntelliSpace Portal-ISP7.0, Philips Medical System DMC, Hamburg, Germany) [ 10 , 16 ]. Post-HTP vital tumour volume was defined as the difference between the lesion and necrosis volumes [ 10 , 17 , 18 ]. These measurements were double-checked by two radiology experts in pancreatic imaging.…”

“…We have reported that ablation with the HybridTherm-Probe (HTP, ERBE ElektroMedizin GmbH, Tübingen, Germany) [ 8 , 9 , 10 ], an internally carbon dioxide–cooled bipolar radiofrequency (RF)-energy device, under endoscopic ultrasound (EUS)-guidance, was safe in 22 LA-PDAC patients after failure of first-line CT or unfit for CT, inducing a significant tumour volume reduction at 1-month imaging. We also showed that the tumour volume reduction rate and radiological response using the Choi criteria were significantly associated with the patients’ overall survival (OS) [ 10 ].…”

Endoscopic Ultrasound-guided Radiofrequency Ablation for Pancreatic Adenocarcinoma

“…There was no evidence of vascular thrombosis or injury of the superior mesenteric/portal vein con uence, superior mesenteric artery or common hepatic artery from the RFA. A recent report of a phase-II randomized trial of EUS-RFA for PDAC demonstrated a similar safety pro le [17]. This trial included both borderline resectable or locally-advanced PDAC and was eventually closed as the RFA probe was no longer produced.…”