The evolving role of radiotherapy in oligometastatic pancreatic cancer: from palliation to disease-modifying multidisciplinary integration.

Oligometastatic pancreatic ductal adenocarcinoma (PDAC) may benefit from aggressive multidisciplinary therapy, yet the role of stereotactic body radiotherapy (SBRT) remains controversial and frameworks for patient selection remain incompletely defined. While SBRT has become a standard option in oligometastatic lung and prostate cancer, its application in PDAC faces unique challenges related to tumor biology, anatomic constraints, and a paucity of randomized evidence. This narrative review searched PubMed, Embase, and Cochrane Library (January 2000-May 2026) for English-language studies addressing PDAC, oligometastases, and SBRT. Of 1,247 records screened, 186 studies were included. Six domains were systematically examined: patient selection integrating clinical, molecular, and metabolic imaging biomarkers; pancreas-specific SBRT technical considerations including dose-fractionation and organ-at-risk constraints; systemic therapy integration and sequencing; clinical outcomes and progression patterns; quality-of-life evidence; and ongoing prospective clinical trials. Available evidence from predominantly retrospective series suggests 1-year local control rates of 70-80% for pancreatic primary tumors, 85-95% for lung metastases, and >95% for lymph node metastases, with median overall survival of 12-18 months after SBRT-based consolidative therapy. Emerging biomarkers-including ctDNA dynamics, KRAS mutational subtypes, and transcriptomic classifiers-and advanced technologies such as MR-guided adaptive SBRT and proton therapy show promise for improving the therapeutic ratio. The TREX1/cGAS-STING axis provides a mechanistic rationale for combining SBRT with immune checkpoint inhibitors, though dedicated quality-of-life data remain absent from the literature. Radiotherapy in oligometastatic PDAC has evolved from a purely palliative modality to a disease-modifying component of multidisciplinary care. Prospective validation through pancreas-specific randomized trials incorporating biomarker-driven patient selection and patient-reported outcomes is essential to define the optimal role of SBRT in this setting. Fang Fang and Peng Zhen contributed equally and are co-corresponding authors. Jiarui Zhang and Siming Shi contributed equally to this work.