Dosimetry Comparison of 3D Conformal Radiotherapy and Intensity-modulated Radiotherapy for the Treatment of Brain Tumors: A Meta-Analysis.

Background: This study aimed to evaluate IMRT and 3D-CRT in the therapy of brain tumor (BT) in relation to dose-volume histograms (DVHs) parameters, such as Heterogeneity Index (HI), Conformity index (CI), Equivalent Uniform Dose (EUD), and mean dose (Dmean) outcomes, including the program for the tumors of the brain and estimate whether a favored procedure can be found through the features of the pretreatment.

Method: A search of the PubMed, Cochrane Library, and Embase datasets from their beginnings from January 2006 to September 2022 was conducted. The authors separately selected and evaluated studies for qualifying criteria and bias risk.

Result: Seven studies in total were included. Of them, a total of 387 patients were integrated for the Heterogeneity index (HI), Conformity Index (CI), Equivalent Uniform Dose (EUD), and mean dose (Dmean) comparison analysis, which showed 3D-CRT & IMRT with odd ratio (OR) =1.93; 95% confidence interval (95% CI) =1.63, 2.22; and P value=0.00. For brain tumor patients, CI was higher in IMRT than 3D-CRT with OR= 0.72; 95% CI =0.41, 1.03; p value <0.001. EUD was higher in IMRT than 3D-CRT, resulting in an increased overall survival with OR=-0.86; 95% CI =-1.30, 0.42; and p value<0.001. However, no statistically significant variance was perceived in Dmean between 3D-CRT and IMRT.

Conclusion: Our records suggested that IMRT with conventional linacs results in a meaningfully lower regular percentage of brain tumor volumes compared to 3D-CRT. Finally, this meta-analysis indicated that IMRT is better than 3D-CRT and decreases the average percent irradiated amount of the brain.