Stereotactic Radiotherapy (SBRT) in Patients With Locally Advanced Pancreatic Cancer (LAPC)

Combination chemotherapy (e.g. FOLFIRINOX (5-fluorouracil, irinotecan, oxaliplatin), Gem-Abraxane, Gem-Cap, Gem-S1) is standard of care in patients with LAPC but more and more scientific studies point to the fact that patients without sign of progressive disease (PD) will benefit from additional radiotherapy and especially SBRT. The sample size is based on Simon's two stages mini-max design. This design ensures early study termination if there is insufficient effect. A resection rate less than 10% after SBRT is not clinically acceptable. Assuming a significance level at 0.1 (α = 0.1) and a power at 90% (β = 0.10) it can be calculated, that 16 patients should be included in the first part of the study. The enrolment will continue until 16 patients have completed SBRT and have been re-evaluated for resection by CT scan (and endoscopic ultrasonography + laparoscopic ultrasound, if available). If 1 or less out of the first 16 consecutive patients are being resected the investigators will reject our hypotheses and close the study after the first stage of accrual. If 2 or more patients are resected, an additional 9 patients will be accrued in the second stage. If at least 4 out of 25 patients are resected, a true resection rate of 30% cannot be excluded, and the investigators will conclude that the treatment is effective enough to continue with future studies. To ensure 25 evaluable patients the investigators will include a total of 30 patients.