The Effect of Bone Marrow-sparing Intensity-Modulated Radiotherapy to GI Cancer

Inclusion Criteria:

All gastric cancer patients had to fulfill the following criteria: histologically confirmed adenocarcinoma of the stomach, cancer resected without residual disease (R0 gastrectomy), at least a D1 lymph node dissection, a classification as stage II through III according to the 2009 staging criteria of the American Joint Commission on Cancer, at least 4 cycles of chemotherapy, age greater than 18 years and less than or equal to 75 years, a performance status of 1 or lower according to Eastern Cooperative Oncology Group (ECOG) criteria, adequate function of major organs (including cardiac, hepatic, and renal functions), adequate bone marrow function (hemoglobin\>10g/dL; absolute neutrophil count \[ANC\]≥2,000/μL; platelet count≥100,000/μL; leukocyte count ≥4,000/μL), a caloric intake greater than 1,500 kcal/day by oral route, treatment beginning no later than 4 weeks after the last cycles of chemotherapy (but a delay of 1 week was allowed to permit full recovery, with restoration of adequate nutritional intake).

All rectal cancer patients with histologically confirmed rectal adenocarcinoma that involved the distal 12 cm of the rectum without evidence of distant metastases were eligible. The patients had to have undergone a staging evaluation within 6 weeks before initiation of the study by endoscopic ultrasonography (US), with evidence of Stage T3 or T4 tumor and/or evidence of lymph node involvement defined by the presence of at least one enlarged perirectal lymph node \>8 mm in size and sonographically suspicious for metastasis. No previous RT to the pelvis and no previous chemotherapy for rectal cancer were allowed. Other inclusion criteria are age greater than 18 years and less than or equal to 75 years, a performance status of 1 or lower according to Eastern Cooperative Oncology Group (ECOG) criteria, adequate function of major organs (including cardiac, hepatic, and renal functions), adequate bone marrow function (hemoglobin\>10g/dL; absolute neutrophil count \[ANC\]≥2,000/μL; platelet count≥100,000/μL; leukocyte count ≥4,000/μL), a caloric intake greater than 1,500 kcal/day by oral route.

Exclusion Criteria:

For gastric patients, cases with stage IA or IB (T2aN0) disease (according to the American Joint Committee on Cancer 2002 staging system), microscopically positive resection margin, and involvement of M1 lymph node or distant metastases were excluded from the study; prior abdominal irradiation;

For rectal patients, cases were excluded from the study if they had metastatic rectal cancer, other tumour types than adenocarcinoma of the rectum; prior pelvic irradiation;

Other key exclusion criteria were: past or concurrent history of neoplasm except curatively treated non-melanoma skin cancer or in situ carcinoma of the cervix; current uncontrolled infection; unresolved bowel obstruction or subobstruction; uncontrolled Crohn's disease or ulcerative colitis; current history of chronic diarrhoea; other serious illness or medical conditions; contraindication towards study drugs and radiation; prior radiotherapy, chemotherapy or any targeting therapy; administration of any other experimental drug under investigation concomitantly or within 4 weeks before eligibility; and pregnant or lactating patients.