Dosimetric comparison of conformal technique (3D) with volumetric modulated arc therapy with respect to doses obtained in the temporal lobe area in patients irradiated for brain meningioma

The aim of the analysis was to compare doses obtained for temporal lobes in patients being irradiated for meningiomas of the brain using the conformal technique and volumetric modulated arc therapy (VMAT). We try to answer the question whether the application of VMAT would lead to higher doses within temporal lobes. In recent years a significant increase in the detection of meningiomas and effectiveness of treatment has been observed. Hence quality of life should be considered as an important aspect after a treatment course. Treatment plans of 27 patients were evaluated retrospectively. Radiotherapy procedures were carried out from 2007 until 2016 at the Department of Radiation Oncology in Wroclaw, Poland. For individual patients, alternative treatment plans were generated in relation to the ones originally used, wherein from dynamic techniques, volumetric modulated arc therapy was selected for analysis. Evaluated dosimetric parameters for temporal lobes were: mean dose, V10Gy, V20Gy, V45Gy. Statistically significant differences were observed for V45Gy for both temporal lobes (p=0.023) and for V45Gy for the right (p=0.001) and the left temporal lobe (p=0.016) considered for VMAT. The mean values of the V45Gy for both temporal lobes, for the right temporal lobe and for the left temporal lobe were lower for VMAT than for 3D, respectively: 7.54% and 7.90%, 6.82% and 9.47%, 5.67% and 7.14%. Analysis of the remaining results found no statistical differences. Application of VMAT in patients treated for meningioma of the brain is not related to higher doses of radiation in the temporal lobe area, compared with the conformal technique.