Characterization of the components of a scintillation dosimeter prototype for brachytherapy

Abstract

In-vivo dosimetry for brachytherapy has been investigated since decades with a number of different detectors and measurement technologies. X-ray films, semiconductor detectors, thermo-luminescent dosimeters and ionization chambers are the systems most currently used. However, ionization chambers do not allow point-like dose measurements near the tumor, semiconductor detectors are not water equivalent and are very sensitive to temperature changes, and thermo-luminescent dosimeters do not allow real-time measurements. For these reasons, during the last two decades, there has been an increased interest for scintillation dosimetry using scintillating fibers, due to their most favorable characteristics and dosimetric properties, as water equivalence, response linearity with increasing dose rates, independence from temperature and small size. In the present work, we present experimental studies of key characteristics of the components of a scintillation dosimeter: the light collection in different types of scintillating fibers and the gain as a function of temperature of a silicon photomultiplier (SiPM), for the design and construction of an in-vivo scintillation dosimeter prototype for brachytherapy.