DVH analysis for brachytherapy plaques and proton beam during intraocular tumor treatment using 3D film dosimetry

Abstract

Abstract Proton therapy and plaque-based brachytherapy are considered efficient radiotherapy modalities for intraocular tumor irradiation. The current study aims to measure and compare the dosimetric features of these methods through a film dosimetry approach inside an eyeball phantom. A 3D-printed PLA (polylactic acid)-based eyeball phantom was applied for phantom irradiation. For brachytherapy, COMS and CGD plaques respectively containing the 125I and 106Ru radioactive sources were employed. Proton irradiation was performed using the clinical beamline of the CNAO oncological hadron therapy center. PDD (percentage depth dose), transverse dose profile, 2D and 3D dose distribution, as well as DVH (dose volume histogram) data relevant to the tumor volume and surrounding healthy tissues were measured for applied treatment techniques using Gafchromic EBT3 film dosimetry approach and compared together. A more uniform dose distribution inside the tumor volume was found in the case of the proton beam concerning two other techniques. Furthermore, a proton beam can better spare healthy organs distributed around the tumor region. Besides, COMS plaque can lead to better clinical outcomes concerning CGD plaque. Viewpoint to the dose uniformity inside the target volume as well as sparing the healthy tissues, proton therapy would be the optimal choice. On the other hand, the photon beam can be preferred to the electron beam if proton therapy facilities are not available. Nevertheless, based on the importance of the healthy organ which should be spared, the COMS or CGD plaque can be selected for radiotherapy.