Efficacy and Safety of Reirradiation with Stereotactic Body Radiation Therapy for Locally Recurrent Pancreatic Adenocarcinoma.

AIMS

The purpose of this study was to report on outcomes of a cohort of patients who were treated with reirradiation with stereotactic body radiation therapy (SBRT) for locally recurrent pancreatic adenocarcinoma.

MATERIALS AND METHODS

Patients treated with SBRT reirradiation for locally recurrent pancreatic adenocarcinoma from December 2009 to April 2020 were included in the study. Descriptive statistics were used to record patient demographics, tumour and treatment characteristics. Kaplan-Meier analysis was used to evaluate overall survival, local progression-free survival (LPFS), distant metastasis-free survival and progression-free survival (PFS).

RESULTS

In total, 27 patients were included in the study. The median follow-up time from local recurrence was 19.7 months (range 4.2-43.1 months). Most patients received five-fraction SBRT (26/27, 96%). The median overall survival after local recurrence treatment was 18.3 months (range 3.0-42.6 months), with 6-month, 1-year and 2-year overall survival rates of 88.5%, 73.1% and 33.6%. The median LPFS after local recurrence treatment was 16.2 months (range 2.3-33.6 months), with 6-month, 1-year and 2-year LPFS rates of 95.8%, 62.9% and 27.2%. Peri-SBRT chemotherapy improved LPFS (median 17.5 versus 8.5 months; P = 0.010) and overall survival (median 19.3 versus 5.5 months; P = 0.049). Tumours ≤ 3 cm in the greatest dimension showed better local control (median LPFS 19.2 versus 10.2 months; P = 0.130). There was one case (4%) of acute grade 3 pain and one case (4%) of late grade 3 gastrointestinal toxicity.

CONCLUSIONS

Reirradiation with five-fraction SBRT is safe, but local control remains suboptimal. Patients with smaller tumours experienced improved outcomes, as did patients whose treatment plan included the administration of peri-SBRT chemotherapy.