23. Radiation Treatment for Gastric Cancer
Authors: Carla Hajj, MD Karyn A. Goodman
Publisher: Springer International Publishing
Locoregional recurrence in the gastric or tumor bed, the anastomosis, or regional lymph nodes occurs in 40–65 % of patients after gastric resection with curative intent. Nearly every combination of adjuvant therapy to surgery can be justified. Two large randomized control studies have evaluated postoperative chemoradiation treatment in surgically resectable locally advanced gastric cancer. The Gastric Surgical Adjuvant Trial (INT-0116) assigned patients to surgery plus postoperative chemoradiotherapy or surgery alone and established postoperative chemoradiation as a standard of care for patients with resected stage IB through intravenous (IV) (M0), gastric or gastroesophageal junction adenocarcinoma. The Adjuvant Chemoradiation Therapy in Stomach Cancer (ARTIST) trial showed that in the subgroup of patients with pathologic lymph node metastases at the time of surgery, adjuvant chemoradiotherapy improves disease-free survival (DFS) compared with chemotherapy alone. Preoperative chemoradiation may also be a promising approach with a 26 % pathologic complete response rate demonstrated in the RTOG 99-04 phase II study. Perioperative chemotherapy with or without radiation treatment is currently being studied in the ongoing Chemoradiotherapy After Induction Chemotherapy of Cancer in the Stomach (CRITICS) and TOPGEAR trials. Radiation treatment for gastric cancer can be technically challenging and associated with significant toxicities. The clinical target volume for adjuvant radiation treatment for gastric cancer depends on the location of the primary disease as well as the status of the lymph nodes involved by disease. Intensity-modulated radiation therapy and respiratory gating allow selective delivery of high doses of radiation to the region of interest while lowering the doses to adjacent normal tissues such as the heart, lungs, kidneys, and liver.