Changing paradigm of radiation therapy for the treatment of pancreatic cancer

The evidence supporting the use of radiation therapy (RT) for pancreatic cancer (PC) treatment is highly variable, with studies both showing and failing to show that RT provides a survival benefit. Trials exploring the use of RT for PC treatment dates back to the 1960s with various dosing and fractionation schemes, as well as various chemotherapeutic combinations. Collectively, large retrospective studies using cancer databases have shown an overall survival benefit with the addition of RT. The combination of RT with efficacious chemotherapy regimens synergistically improves the benefits of RT. More recent studies have evaluated the use of stereotactic body radiation therapy in either single- or multi-fraction regimens. Modern studies using multifractionated stereotactic body radiation therapy have demonstrated maintenance of local control and safe toxicity profiles with shorter therapeutic regimens allowing for improved integration with other therapeutic modalities. Although the use of RT has been evaluated for ≥50 years for PC treatment, the heterogeneous nature of the studies carried out and the advancement of complementary chemotherapeutic regimens makes it difficult to clearly identify the direct effect of RT. Herein, we provide a comprehensive overview of the evidence for the use of RT in PC treatment, including a comparison of conventionally fractionated RT versus stereotactic body radiation therapy.