Comparisons between the dosimetric and clinical outcomes of tomotherapy and 3D conformal radiotherapy in gastric cancer treatment

Abstract

Introduction: Previous studies comparing tomotherapy (TOMO) and three dimensional (3D) conformal radiotherapy (3DCRT) in gastric radiotherapy are limited and tend to be based on dosimetry. The aim of the present study was to evaluate the clinical outcomes of these two treatment modalities. Methods: A total of 51 patients diagnosed with gastric cancer who were treated with postoperative adjuvant chemoradiotherapy and had subtotal/total gastrectomy and D2 lymphatic dissection were recruited to the present study: 30 patients were treated with TOMO and 21 patients were treated with 3DCRT. Results: The 3DCRT and TOMO treatment regimens were compared. There was no difference in planning target volume (PTV) 95%, but TOMO was statistically significant in regard to PTV 105% (P < 0.05). TOMO was also significantly different when compared with 3DCRT when evaluating liver mean dose, liver V40, right/left kidneys mean dose, right/left kidneys V20 and spinal cord mean dose values (P < 0.05). Grade 2 acute side effects were more frequent (85.7%) following 3DCRT. In addition, the median overall survival time for TOMO treated patients was 62 months while in 3DCRT treated patients it was 22.05 months. The difference in disease free survival was also significantly increased in patients treated with TOMO (66.7% vs. 19.0%; P < 0.05). Conclusion: TOMO treatment resulted in lower acute side effects with better patient survival following gastric cancer radiotherapy.