Performance evaluation of an ultra-thin fiber-optic dosimeter using therapeutic photon beams

In this study, we fabricated the ultra-thin fiber-optic dosimeter (UTFOD) for high energy photon beam therapy dosimetry. The UTFOD has high spatial resolution due to the relatively small volume compared to conventional dosimeters therefore the UTFOD can measure depth doses precisely in build-up regions of therapeutic radiation beams. For 10 MV photon beams, we measured the scintillation signal generated from the UTFOD according to monitor units (MUs) and dose rates of the clinical linear accelerator (CLINAC). Also, we measured percentage depth doses (PDDs) at different depths of solid water phantoms using the UTFOD and the GAFCHROMIC ® EBT films, and the results were compared with those using the Monte Carlo N-Particle eXtended (MCNPX) code.