Measurements of relative depth doses and Cerenkov light using a scintillating fiber-optic dosimeter with Co-60 radiotherapy source.

In this study, we fabricated a scintillating fiber-optic dosimeter, which consists of an organic scintillator and a plastic optical fiber, for radiotherapy dosimetry. To select an adequate kind and length of scintillator for γ-rays generated from a Co-60 source, scintillating light from various kinds and lengths of organic scintillators is measured. Using a scintillating fiber-optic dosimeter, the γ-rays generated from a Co-60 therapy unit are measured and relative doses are obtained according to the field size of the γ-ray beam and the depth in a water phantom. Also, Cerenkov light generated by the interactions of primary or secondary electrons and the plastic optical fiber is measured with different field sizes and depths of a water phantom using a background optical fiber.