Intensity modulated radiotherapy for locally advanced and metastatic pancreatic cancer: a mono-institutional retrospective analysis.

Background: To evaluate the role of intensity modulated radiotherapy (IMRT) for locally advanced pancreatic cancer (LAPC) and metastatic pancreatic cancer (MPC), and the prognostic factors in the setting of multidisciplinary approach strategies.

Methods: 63 patients with LAPC and MPC receiving IMRT in our institution were retrospectively identified. Information on patient baseline, treatment characteristics and overall survival (OS) time were collected. Data of pain relief and toxicity were evaluated. Univariate and multivariate analyses were conducted to investigate the prognostic factors.

Results: All patients received IMRT with a median dose of 46.0 Gy. The median OS for LAPC and MPC patients were 15.7 months and 8.0 months, respectively (p = 0.029). Symptomatic improvements were observed in the 44 patients with abdominal/back pain after radiotherapy (RT) or concurrent chemoradiotherapy (CCRT), particularly in those with severe pain. Only 13.9% and 14.8% cases presented Grade ≥ 3 hematologic toxicities in RT and CCRT group, while no cases developed Grade ≥ 3 non-hematologic toxicities in both groups. Multivariate analysis indicated that tumors located in pancreas body/tail (HR 0.28, p = 0.008), pretreatment CA19-9 < 1000 U/mL (HR 0.36, p = 0.029) and concurrent chemotherapy (HR 0.37, p = 0.016) were independent favorable predictors for OS.

Conclusions: CCRT further improved OS for LAPC and MPC with acceptable toxicities, and use of RT markedly alleviated pain. Tumors located in pancreas body/tail, pretreatment CA19-9 level of < 1000 U/mL and CCRT were associated with better OS. However, regional intra-arterial chemotherapy did not show any survival benefit in our study.