Dosimetric comparison of volumetric-modulated arc therapy (VMAT) and fixed field intensity-modulated radiotherapy (IMRT) in patients with nasal tumor: a meta-analysis

In recent years, volumetric-modulated arc therapy (VMAT) and fixed field intensity-modulated radiotherapy (IMRT) have been used as the two mainstream radiotherapy techniques for the treatment of nasal tumors. In this study, we compared effectiveness of these two radiotherapy techniques in the treatment of nasal tumors through analysis of relevant literature and meta-analysis.

A search was performed on PubMed, Web of Science, Embase, and Cochrane Library databases on April 2022 to identify all related literature in line with pre-determined eligibility criteria. The included/excluded studies were screened manually and relevance data were extracted. Forest plots were plotted and analyze, Egger’s asymmetry tests and sensitivity analysis were conducted using software Stata 16.0.

Eight studies were included in the meta-analysis. We found no significant difference in D2% and D98% of the Planning Target Volumes (PTV) between VMAT and IMRT. In contrast, the conformity index (CI) and the homogeneity index (HI) were significantly different between the two groups. Further analysis revealed no significant differences in dose sparing for all analyzed organs at risk (OARs) between VMAT and IMRT techniques. In addition, the monitor unit (MUs) of VMAT plan was significantly lower than that of the IMRT plan.

VMAT has better local tumor control rate compared with IMRT, but it does not significantly reduce maximum dose (Dmax) or mean dose (Dmean) of OARs. We suggest that VMAT plan may be a better radiation therapy technology in the treatment of nasal tumors.