Plan Quality Comparisons Between 3D-CRT, IMRT, and VMAT Based on 4D-CT for Gastric MALT Lymphoma

Background/Aim: We compared three-dimensional conformal RT (3D-CRT), intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT) for gastric mucosa-associated lymphoid tissue (MALT) lymphoma using four-dimensional computed tomography (4D-CT) images. Patients and Methods: Three treatment plans of 3D-CRT, IMRT, and VMAT with 30 Gy were created based on 4D-CT images of seven patients. We calculated D95, homogeneity index (HI), and conformity index (CI) of planning target volume, and organs at risk doses. Results: There was no significant difference among the three plans in D95. HI of the IMRT plan was significantly better than that of the VMAT (p=0.047) and 3D-CRT (p=0.047) plans. CIs of the IMRT and VMAT plans were significantly better than those of the 3D-CRT plan (p=0.047 and p=0.047, respectively). D-mean of the liver for 3D-CRT was significantly higher than that for the IMRT (p=0.047) and VMAT (p=0.047) plans. Conclusion: The IMRT plan yields the best plan quality for gastric MALT lymphoma.

Automated summary

In this study comparing 3D-CRT, IMRT, and VMAT for gastric MALT lymphoma using 4D-CT images, it was found that the IMRT plan yielded the best plan quality with significantly better homogeneity and conformity indices. The D95 did not show significant differences among the three plans, but the IMRT plan showed superior HI and CI values compared to VMAT and 3D-CRT plans. The D-mean of the liver was also significantly lower in the IMRT and VMAT plans compared to 3D-CRT plan.