Implementation of modern radiotherapy in a multimodal approach of locally advanced pancreatic cancer
PO-1359
Abstract
Implementation of modern radiotherapy in a multimodal approach of locally advanced pancreatic cancer
Authors: Sophie Dobiasch1,4,5, Maria Waltenberger1, Maximilian Reichert2, Helmut Friess3, Roland M. Schmid2, Stephanie E. Combs1,4,5, Stefan Münch6
1Klinikum rechts der Isar, Technical University of Munich (TUM), Department of Radiation Oncology, Munich, Germany; 2Klinikum rechts der Isar, Technical University of Munich (TUM), Medical Clinic and Polyclinic II, Munich, Germany; 3Klinikum rechts der Isar, Technical University of Munich (TUM), Department of Surgery, Munich, Germany; 4Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Neuherberg, Germany; 5Deutsches Konsortium für Translationale Krebsforschung (DKTK), Partner Site Munich, Munich, Germany; 6Klinikum rechts der Isar, Technical University of Munich (TUM), Department of Radiation Oncology , Munich, Germany
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Purpose or Objective
Pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive and lethal solid tumors with an estimated 5-year overall survival rate of less than 10%. The role of radiotherapy (RT) within a multidisciplinary therapeutic approach is controversially discussed due to a high resistance to standard treatment modalities. This study aims to analyze the clinical outcome of patients with locally advanced PDAC who underwent induction chemotherapy followed by RT.
Material and Methods
The present study is a retrospective single-center analysis including patients with non-metastatic, locally advanced histologically confirmed PDAC.
A total of 25 patients treated in our department of radiation oncology from 2014 to 2022 were included. All patients received induction chemotherapy with median 7 (range 2-12) cycles of FOLFIRINOX (77.8%), or median 4 (range 4-5) cycles of gemcitabine/paclitaxel (22.2%). RT was either performed as conventionally fractionated radiochemotherapy (RCHT, 66.7%) or stereotactic body radiation (SBRT, 33.3%). Toxicity was evaluated according to the CTCAE version 4, and survival was analyzed by Kaplan-Meier method and Log-Rank-Test (Mantel-Cox).
Results
The median age at diagnosis was 60 (range 48 - 77) years. Most tumors were located in the pancreatic head (64%), followed by the pancreatic body (28%), and pancreatic tail (8%).
The median prescribed total doses were 38.6 Gy (25.0 - 40.0 Gy) in 5 fractions for patients who underwent SBRT, and 55.6 Gy (45.0 - 58.8 Gy) in 25 - 31 fractions for patients who underwent RCHT, respectively. Concurrent gemcitabine‐ (16.7%) or capecitabine‐based (83.3%) chemotherapy regimens were applied in the RCHT group. Patients tolerated both radiation regimes without any acute or late severe toxicity (grade ≥ 3). A subsequent laparotomy was performed in 63% of all patients (17/27): a surgical resectability was feasible in 65% (11/17), whereas a R0-resection was achieved in 45% (5/11).
Median survival from the time of diagnosis was 22 months (6-54 months). Distant metastases free survival (DMFS) was 19 months (6-54 months). No significant differences in the median survival or DFMS were observed between the two treatment groups.
Conclusion
In this study, we demonstrated the feasibility, efficacy, favorable safety, and tolerability of two different concepts of modern RT after induction chemotherapy in patients with locally advanced PDAC. No statistically significant differences in the clinical outcome were observed between SBRT and RCHT. Prospective clinical trials comparing these two treatment concepts and patient stratification are urgently needed for the optimization of the oncological outcome.