Measurements of Relative Depth Doses Using Fiber-Optic Radiation Sensor and EBT Film for Brachytherapy Dosimetry

Abstract

In this study, we have fabricated a fiber-optic radiation sensor using an organic scintillator for brachytherapy dosimetry. Organic scintillators are made from a polystyrene base with wavelength-shifting fluors, and they do not disturb the radiation field due to their tissue or water-equivalent characteristics in a wide range of energies. The fiber-optic radiation sensor developed for this study provides a fast real-time response and convenient usage for brachytherapy dosimetry. For more accurate measurement, we have measured Cerenkov light using a dummy fiber and avoided dose measurement errors arising from high dose gradients in brachytherapy dosimetry. The Cerenkov light has been eliminated using a modified subtraction method. Also, the relative depth dose without the dose generated from Cerenkov lights is measured and compared with the results obtained using conventional EBT dosimetry films.Index Terms-Brachytherapy, cerenkov light, dosimeter, optical fiber, organic scintillator, relative depth dose.

Review of plastic and liquid scintillation dosimetry for photon, electron, and proton therapy

“…A silicon photodiode with an appropriate photo-amplification system can also be used as the photodetector in the PSDs for brachytherapy dosimetry. Lee et al (2010), in a phantom study, coupled a BCF-12 plastic scintillating fiber (10 mm long × 1 mm diameter) with a PMMA plastic optical fiber to guide the light to a photodiode system. Repeatability within 1.6% and a standard deviation of 0.94% were obtained for a source-to-detector distance of 5 mm.…”

Development of a Small-Sized, Flexible, and Insertable Fiber-Optic Radiation Sensor for Gamma-Ray Spectroscopy

“…Radiation sensors using an optical fiber have been developed in conjunction with many kinds of organic or inorganic scintillators; most of them, however, can only measure scintillating light intensity [ 5 , 6 , 7 ]. Although existing fiber-optic radiation sensors (FORSs) have many advantages, such as small sensing volume, high spatial resolution, good flexibility, real-time sensing, remote operation, and immunity to high electromagnetic interference (EMI) [ 8 , 9 , 10 ], they have not been used for accurate discrimination of radioactive isotopes using a spectroscopic technique [ 11 , 12 , 13 , 14 ].…”

Development of a fiber-optic dosimeter based on modified direct measurement for real-time dosimetry during radiation diagnosis

“…To overcome the problems of existing dosimeters for dosimetry in diagnostic radiology, we adopted a new dose measurement, namely modified direct measurement, using a fiber-optic dosimeter (FOD) that can be attached at the edge of a body section including the chest during radiography. For dosimetry in radiation diagnosis [7][8][9], radiotherapy [13][14][15] and nuclear medicine [16,17], the FOD is based on the real-time detection of scintillating light emitted from the fluorescent dopants in a small-sized organic scintillator during the irradiation. Since an optical fiber is used as a light guide for transmitting the scintillating light to a light-measuring device, the FOD normally offers many advantages, such as good flexibility, high spatial resolution due to the small diameter of an optical fiber, minimization of radiation image artifacts according to the use of low-Z materials, remote sensing and real-time dose monitoring capabilities without significant diminution of the light signal, and immunity to ambient environmental influences, including temperature, humidity, pressure and electromagnetic field.…”