Background: Our aim was to evaluate the feasibility and safety of isotoxic high-dose (iHD) stereotactic body radiation therapy (SBRT) in a total neoadjuvant sequence for the treatment of localized pancreatic adenocarcinoma. Materials and methods: Biopsy-proven borderline resectable/locally advanced pancreatic cancer (BR/LAPC) patients were included in this observational prospective analysis from August 2017 to April 2020 without excluding tumours showing a radiological direct gastrointestinal (GI) invasion. An induction chemotherapy by modified fluorouracil, irinotecan and oxaliplatin was performed for a median of six cycles. In case of non-progression, an isotoxic high-dose stereotactic body radiotherapy (iHD-SBRT) was delivered in 5 fractions followed by a surgical exploration. The primary endpoint was acute/late gastrointestinal grade ⩾3 toxicity. Secondary endpoints were overall survival (OS), progression-free survival (PFS) and local control (LC). Results: A total of 39 consecutive patients (21 BR and 18 LAPC) were included: 34 patients (87.2%, 18 BR and 16 LAPC) completed the planned neoadjuvant sequence. After iHD-SBRT, 19 patients [55.9% overall, 13/18 BR (72.2%) and 6/16 LAPC (37.5%)] underwent an oncological resection among the 25 patients surgically explored (73.5%). The median follow up was 18.2 months. The rates of acute and late GI grade 3 toxicity were, respectively, 2.9% and 4.2%. The median OS and PFS from diagnosis were, respectively, 24.5 and 15.6 months. The resected patients had improved median OS and PFS in comparison with the non-resected patients (OS: 32.3 versus 18.2 months, p = 0.02; PFS: 24.1 versus 7.1 months, p < 0.001). There was no survival difference between the BR and LAPC patients. The 1-year LC from SBRT was 74.1% and the median locoregional PFS was not reached for both BR and LAPC patients. Conclusions: iHD-SBRT displays an excellent toxicity profile, also for potentially high-risk patients with radiological direct GI invasion at diagnosis and can be easily integrated in a total neoadjuvant strategy. The oncological outcomes are promising and emphasise the need for further exploration of iHD-SBRT in phase II/III trials.

Background and study aims In borderline resectable/locally advanced pancreatic ductal adenocarcinoma (PDAC), stereotactic body radiation therapy (SBRT) is an emerging neoadjuvant treatment option. Endoscopic ultrasound (EUS)-guided insertion of fiducial markers being a prerequisite, our aim was to assess its feasibility and safety and also to evaluate its success, from both the endoscopist’s and radiotherapist’s perspectives. Patients and methods We prospectively collected data concerning PDAC patients submitted to EUS-guided fiducial placement, from February 2018 to November 2019. Technical success was defined as at least one marker presumed inside the tumor. Quality success was assessed at pre-SBRT computed tomography, accordingly to the number of markers inside or < 1 cm from the tumor, number of markers at the tumor extremity, their location in different planes, the distance between them, and their distance from the biliary stent (if present). A new quality score was then proposed and high-quality success defined as at least six of 12 points. Results Thirty-seven patients were enrolled. A total of 97 fiducials were implanted, with a median of three fiducials per patient (0–4). The technical success rate was 92 %, with failure of fiducial placement in three patients. Three patients (8 %) had adverse events (fever, mild acute pancreatitis, and biliary stent migration). At pre-SBRT evaluation, two patients’ markers had migrated. The high-quality success rate was 62.5 %. Conclusions Our results contribute to demonstrating the feasibility and safety of EUS-guided fiducial placement for SBRT treatment in PDAC. It is hoped that the newly proposed quality score will pave the way for improving fiducial positioning and SBRT delivery.

Given the lack of direct comparative evidence, we aimed to compare the oncological outcomes of localized pancreatic ductal adenocarcinoma (PDAC) treated in the same tertiary cancer center with isotoxic high-dose stereotactic body radiotherapy (iHD-SBRT) or conventional chemoradiotherapy (CRT). Biopsy-proven borderline/locally advanced patients treated with iHD-SBRT (35 Gy in 5 fractions with a simultaneous integrated boost up to 53 Gy) or CRT (45–60 Gy in 25–30 fractions) were retrospectively included from January 2006 to January 2021. The median overall survival (mOS) was evaluated trough uni- and multivariate analyses. The progression free survival (PFS) and the 1-year local control (1-yLC) were also reported. Eighty-two patients were included. The median follow-up was 19.7 months. The mOS was in favour of the iHD-SBRT group (22.5 vs. 15.9 months, p < 0.001), including after multivariate analysis (HR 0.39 [CI95% 0.18–0.83], p = 0.014). The median PFS and the 1-yLC were also significantly better for iHD-SBRT (median PFS: 16.7 vs. 11.5 months, p = 0.011; 1-yLC: 75.8 vs. 39.3%, p = 0.004). In conclusion, iHD-SBRT is a promising RT option and may offer an improvement in OS in comparison to CRT for localized PDAC. Further validation is required to confirm the exact role of iHD-SBRT and the optimal therapeutic sequence for the treatment of localized PDAC.