A comparative planning study on the treatment of gastric cancer patients with tomotherapy, coplanar and non-coplanar three-dimensional conformal radiotherapy (3D-CRT)

Background: the main purpose of this study is to investigate different methods of radiotherapy (rt) using coplanar three-dimensional conformal rt (3d-crt (cp)), noncoplanar 3d-crt rt (3d-crt (ncp)) and helical tomotherapy (ht) techniques to find the optimal method to treat gastric cancer patients. materials and methods: twenty patients with gastric cancer were retrospectively enrolled. three different treatment plans including ht, 3d-crt (cp) and 3d-crt (ncp) were generated and optimized for each patient. all plans were then evaluated with respect to dosimetric parameters exported from dose-volume histogram curves of target and organ-at-risk (oar). spss software was used for statistical analysis. results: the conformity index in the target was similar for all plans (p > 0.05), but ht showed significantly better homogeneity compared to the two 3d-crt methods (p-value < 0.05). compared to the 3d-crt (cp) and 3d-crt (ncp) plans, the ht plans significantly reduced the mean dose, v13 and v20 values of the kidneys (p-value < 0.05); v5 values of both kidneys were lower in the 3d-crt (ncp) plan compared to 3d-crt (cp) and ht. the difference was statistically significant. moreover, the results proved that the 3d-crt (ncp) could better preserve kidneys rather than 3d-crt (cp). dmean of the liver for ht plans (20.03) was significantly higher than those for both coplanar and non-coplanar 3d-crt plans (17.86 and 17.7, respectively). conclusion: generally, ht plans appear to be the best, but in the case of selecting an optimum method, it is necessary to pay attention to the location of tumors compared to oars.