Benefits and challenges of radiation therapy in gastric cancer: techniques for improving outcomes.

Gastric cancer is a highly virulent neoplasm with high morbidity and mortality. Although the benefit of radiation therapy (RT) combined with chemotherapy in gastric cancer has been established, challenges remain in providing accurate and safe radiation delivery. Improved understanding of patterns of gastric cancer relapse and tumor spread, and of organ motion in the abdomen, has allowed for implementation of more conformal radiation techniques. At a minimum, successful implementation of conformal RT requires a detailed understanding of gastric anatomy and radiobiologic principles, an individualized assessment of organ motion, precise patient immobilization techniques, and adequate physics and dosimetry expertise. To aid the practicing clinician, the Gastric Surgical Adjuvant Radiotherapy Consensus Report and National Comprehensive Cancer Network have recently formulated detailed recommendations on simulation, treatment planning, target volumes, and dose limits for select critical normal structures. The practicing clinician is urged to draw upon the multitude of resources now available to ensure that optimal RT for gastric cancer is delivered safely and accurately.