ESTRO 2024 - Abstract Book

S2273

Clinical - Upper GI

ESTRO 2024

1 Università Campus Bio-Medico di Roma, Research Unit of Radiation Oncology, Rome, Italy. 2 Fondazione Policlinico Universitario Campus Bio-Medico, Operative Research Unit of Radiation Oncology, Rome, Italy

Purpose/Objective:

Pancreatic cancer has a poor prognosis and it is often diagnosed in elderly patients who might not be eligible for surgery or chemoradiation approach due to both their age and concomitant comorbidities. A novel approach to the treatment of pancreatic cancer is the stereotactic body radiotherapy (SBRT) which consists of the precise application of high-dose radiation in few fractions to a limited target volume. The aim of our study is to evaluate the efficacy and the safety of SBRT in elderly patients with pancreatic cancer.

Material/Methods:

All patients in the study cohort had a histologically proven diagnosis of pancreatic cancer. Exclusive stereotactic body radiotherapy using the VMAT technique was administered with three schedules: 30 Gy in 5 fractions, 35 Gy in 5 fractions and 45 Gy in 5 fractions according to the tolerance of the adjacent normal tissues. Data were collected retrospectively and the statistical analysis was carried out for overall survival (OS), progression free survival (PFS), local progression-free survival (LPFS) and metastasis-free survival (MFS) using the Statistical Package for Social Sciences, version 27 (SPSS Inc., Chicago, IL, USA). The primary endpoint was the local control and it was assessed by CT scan or 18f-fdg PET-CT scan. In addition, to assess the safety of SBRT approach, acute and late toxicities were evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) scale, version 5.0.

Results:

The population study consisted of twenty-six patients (9 men and 17 women) with a median age of 77 years, ranging from 58 to 90 years, enrolled between July 2018 and May 2023. Pancreatic disease was defined as resectable or borderline resectable in twenty patients (77%), while in six cases (23%) it was considered unresectable. Fifteen patients (57.8%) were unfit for surgery due to comorbidities and five patients (19.2%) refused surgery. Among the cohort twenty patients (77%) were treated with 30 Gy in 5 fractions (600 cGy/die); five patients (19.2%) using 35 Gy in 5 fractions (700 cGy/die) and one patient (3.8%) with 45 Gy in 5 fractions (900 cGy/die). Median follow up was 11.4 months (range 0,5 – 25,6 months). Among the twenty-six patients undergoing SBRT, median PFS was 26.1 months. One-year and 2-year PFS rates were 79% and 60%, respectively. Median LPFS was 33.3 months. One year and 2-year LPFS rates were 86% and 70%, respectively. Median MFS was 29.6 months. One-year and two-year MFS rates were 85% and 79%, respectively. Median OS was 30 months, with one-year and two-year OS rates of 78% and 57%, respectively. SBRT was well tolerated with no acute toxicities, while late toxicities were observed in only two patients (7.7%), including one pancreatic fistula (grade 3) and one duodenal stenosis (grade 3).

Conclusion:

In our experience, SBRT is an effective and safe therapeutic approach in elderly patients with pancreatic cancer, with an impressive local control rate and without significant toxicities.