Purpose: To compare standard radiotherapy field (SRTF) with whole abdomen irradiation (WAI), used in conjunction with adjuvant chemotherapy following curative surgery in patients with gastric cancer.
Methods and material: Ninety patients were included in the study and divided into two treatment arms. In the first treatment arm, SRTF, including 45 Gy radiation to the primary tumor and regional lymph nodes, was performed in 45 patients. In the second treatment arm, a total of 45.2 Gy RT was delivered; 20 Gy to the whole abdomen followed by 25.2 Gy RT to the tumor and regional lymph nodes, in 45 patients. An intravenous bolus dose of 250 mg/m(2)/week 5-fluorouracil (5-FU) was administered concomitantly with RT in both treatment arms. Patients who completed concomitant chemoradiotherapy, received adjuvant treatment, including 4 cycles of 5-FU (425 mg/m(2)) and folinic acid (20 mg/m(2)) in 4 week intervals.
Results: Median age was 56 years (range: 22-81), 89% of the patients (n = 80) had serosal involvement, 78% (n = 70) were node positive. The rate of hematological (40% vs. 16%, p = 0.010) and gastrointestinal toxicities (80% vs. 53%, p = 0.010) were higher, and performance loss (60% vs. 29%, p = 0.003) was greater in the second treatment arm. Number of patients who experienced Grade 3 and Grade 4 gastrointestinal toxicities (especially diarrhea) were higher in the second treatment arm (4% vs. 16%, p = 0.049). The median follow-up was 19 months (range: 7-96). The median 5-year survival was 29% and 17%, locoregional control was 30% and 25%, and disease-free survival was 27% and 16% in the first and second treatment arms, respectively. There was no significant difference between the treatment groups in terms of survival, locoregional control and disease-free survival rates (p > 0.05).
Conclusion: Whole abdomen irradiation was not found to be superior to standard field radiotherapy used in conjunction with adjuvant chemotherapy in gastric cancer.