Radiation Therapy for Gastric Cancer: An ASTRO Clinical Practice Guideline

This guideline provides evidence-based recommendations addressing the indications for radiation therapy (RT) for gastric cancer in a variety of clinical settings, ranging from patients with resectable locoregional disease to metastatic and symptomatic disease.

The American Society for Radiation Oncology convened a task force to address 3 key questions: (1) indications for and timing of RT for patients with resectable and nonmetastatic gastric cancer; (2) indications for and timing of RT in patients with unresectable locoregional disease, oligometastases, and/or requiring palliation; and (3) appropriate RT dose-fractionation regimens, target volumes, and techniques in these clinical settings. Recommendations are based on a systematic literature review and were created using a predefined consensus-based methodology with a system for grading evidence quality and recommendation strength.

Multidisciplinary evaluation and decision-making are recommended for all patients. For patients with cT2-4 and/or N+ resectable gastric cancer, perioperative chemotherapy is recommended, preferably FLOT (5-fluorouracil, leucovorin, oxaliplatin, and docetaxel). Recently, perioperative durvalumab and FLOT has shown a significant improvement in event-free survival versus FLOT only for patients with resectable disease and is now being adopted as a standard of care. Preoperative chemoradiation is recommended for patients who are not candidates for perioperative chemotherapy and conditionally recommended if there is concern for a margin-positive (R1) or incomplete (R2) resection. Postoperative chemoradiation is conditionally recommended for patients who are not candidates for perioperative or postoperative chemotherapy or if a suboptimal resection was done (eg,

These evidence-based recommendations guide clinical practice on the use of RT for gastric cancer. Future studies will further refine the indications and role of RT in the management of these patients.