Dosimetric Comparisons of Intensity-Modulated Radiotherapy, Volumetric Modulated Arc Therapy, Tomotherapy, Stereotactic Radiosurgery, and Proton Therapy for Treatment of Patients with a Vestibular Schwannoma

This study compares the dosimetric characteristics of radiotherapy treatment methods for patients with a vestibular schwannoma. We generated and compared intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), tomotherapy (TOMO), and proton therapy (Proton) treatment plans among eight patients with a vestibular schwannoma who received stereotactic radiosurgery based on M3 (M3-SRS) treatment. The dose comparison of the planning target volume (PTV) was performed by calculating the homogeneity index (HI), conformity index (CI), coverage index (CVI), and equivalent uniform dose (EUD). A dose comparison for adjacent normal organs was performed by calculating the EUD and the normal tissue complication probability (NTCP). The PTV coverage showed excellent dose homogeneity and conformity on the target volume for M3-SRS treatment. The sparing of the organs at risk (OARs) was excellent in terms of dose delivery to most normal organs away from the target for Proton; however, the other modalities were also within the tolerance dose limit for the OARs. This study further confirmed the possibility of using radiotherapy, along with the use of other treatment methods, for patients with a vestibular schwannoma.