title: Gafchromic film dosimetry of a new HDR 192Ir brachytherapy source.
abstract: High-dose-rate (HDR) brachytherapy is a popular modality for treating cancers of the prostate, cervix, endometrium, breast, skin, bronchus, esophagus, and head and neck as well as soft-tissue sarcomas. Because of different source designs and licensing issues, there is a need for specific dosimetry dataset for each HDR source model. The main objective of the present work is to measure 2D relative dose distribution around a new prototype 192Ir source, referred to as IRAsource-HDR, in PMMA phantom in the framework of AAPM TG-43 and TG-55 recommendations for radial distances of 0.5cm to 4 cm. Radiochromic films (RCFs) Gafchromic EBT and HD-810 were used for measurements. The dose rate constant, Λ, of the source was determined to be 1.084± 4.6%, 1.129 ± 4.4%, and 1.112 ± 0.8% cGyh-1U-1 using EBT RCF, HD-810 RCF, and Monte Carlo (MC) simulation, respectively. The results obtained in this study are in good agreement with previously published data for HDR interstitial 192Ir-HDR sources with a maximum discrepancy of ± 4.5%. An acceptable agreement (within ± 2%) between MC calculations and RCFs measurements showed that HD-810 RCF dosimetry is as good as EBT RCF, within HDR brachytherapy, and justifies the use of specific data for this new source. These data could be used as a benchmark for dose calculations in the conventional brachytherapy treatment planning systems.
authors.affiliation: University of Isfahan. n.ayoobian@ast.ui.ac.ir.
authors.forename: Navid
authors.initials: N
authors.lastname: Ayoobian
authors.forename: Akbar Sarabi
authors.initials: AS
authors.lastname: Asl
authors.forename: Hosein
authors.initials: H
authors.lastname: Poorbaygi
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Javanshir
mesh_terms: D001918:Brachytherapy / Q000295:instrumentation* / Q000379:methods; D005373:Film Dosimetry / Q000379:methods*; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D009010:Monte Carlo Method; D009369:Neoplasms / Q000532:radiotherapy*; D019047:Phantoms, Imaging; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy / Q000379:methods*
chemical_list: D007496:Iridium Radioisotopes