Optical fiber dosimeter for real-time in-vivo dose monitoring during LDR brachytherapy

P Woulfe; F J Sullivan; W Kam; S O'Keeffe

doi:10.1364/BOE.385610

Optical fiber dosimeter for real-time in-vivo dose monitoring during LDR brachytherapy

Biomed Opt Express. 2020 Jun 30;11(7):4027-4036. doi: 10.1364/BOE.385610. eCollection 2020 Jul 1.

Authors

P Woulfe^{1

2}, F J Sullivan^{3

4}, W Kam¹, S O'Keeffe¹

Affiliations

¹ Optical Fiber Sensors Research Centre, University of Limerick, Ireland.
² Dept. of Radiotherapy Physics, Galway Clinic, Ireland.
³ Prostate Cancer Institute, National University of Ireland Galway, Ireland.
⁴ Department of Radiotherapy, Galway Clinic, Ireland.

Abstract

An optical fiber sensor for monitoring low dose radiation is presented. The sensor, based on radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd₂O₂S:Tb), is embedded in a cavity of 700µm diameter within a 1mm plastic optical fiber. The sensor is compared with the treatment planning system for repeatability, angular dependency, distance and accumulated radiation activity. The sensor demonstrates a high sensitivity of 152 photon counts/Gy with a temporal resolution of 0.1 seconds, with the largest repeatability error of 4.1%, to 0.361mCi of Iodine-125 the radioactive source most commonly used in LDR brachytherapy for treating prostate cancer.