Real-time dosimetry in radiotherapy using tailored optical fibers. (May 2016)

• Record Type: Journal Article
• Authors: Rahman, A.K.M. Mizanur; Zubair, H.T.; Begum, Mahfuza; Abdul-Rashid, H.A.; Yusoff, Z.; Omar, Nasr Y.M.; Ung, N.M.; Mat-Sharif, K.A.; Bradley, D.A.
• Is Part Of: Radiation physics and chemistry. Volume 122(2016:May)
• Page Start: 43
• Page End: 47
• Publication Date: 2016-05
• Subjects: Real-time dosimetry -- Radioluminescence -- Ge-doped optical fiber -- Radiotherapy; Radiation chemistry -- Periodicals; Radiometry -- Periodicals; Radiation -- Periodicals; Chimie sous rayonnement -- Périodiques; 539.2
• DOI: 10.1016/j.radphyschem.2016.01.019
• Languages: English
• ISSNs: 0969-806X

Abstract

Abstract: Real-time dosimetry plays an important role for accurate patient-dose measurement during radiotherapy. A tiny piece of laboratory fabricated Ge-doped optical fiber has been investigated as a radioluminescence (RL) sensor for real-time dosimetry over the dose range from 1 Gy to 8 Gy under 6 MV photon beam by LINAC. Fiber-coupled software-based RL prototype system was used to assess essential dosimetric characteristics including dose response linearity, dose rate dependency, sensitivity, repeatability and output dependence on field sizes. The consistency level of RL photon counts versus dose rate was also compared with that of standard Al2 O3 :C chips. Sensitivity of Ge-doped fiber were found to be sufficiently sensitive for practical use and also provided linear dose responses for various dose rates from 100 cGy/min to 600 cGy/min using both 6 MV photon and 6 MeV electron beams. SEM-EDX analysis was performed to identify Ge-dopant concentration level within the optical fiber RL material. Accumulated doses were also estimated using simple integral technique and the error was found to be around less than 1% under dissimilar dose rates or repeat measurements. The evaluation of the Ge-doped optical fiber based RL dosimeter system indicates its potential in medical dosimetry. Highlights: Tailored-made Ge-doped optical fiber for radioluminescence based dosimetery. Sensitivity to photon and electron beam in radiotherapy range. No plateau effect compared to Al2 O3 :C. Dose rate independent for case of absorbed dose measurement.