On the physical, spectral, and dosimetric characteristics of a new {sup 125}I brachytherapy source

Journal Article · Sun Jul 15 04:00:00 EDT 2007 · Medical Physics

DOI:https://doi.org/10.1118/1.2739816· OSTI ID:20953329

Pirchio, Rosana; Galiano, Eduardo; Saravi, Margarita; Banchik, David; Munoz, Carlos ^[1]

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1. Centro Atomico Ezeiza, Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

A new {sup 125}I source under the name Braquibac{sup TM} has been developed in Argentina for interstitial brachytherapy applications. The aim of this work is to study the new seed's design and to calculate its dosimetric parameters. Radiographic and destructive tests were carried out on inactive seeds to determine the physical characteristics of the source. Values of g(r), {lambda}, F(r,{theta}), and {phi}{sub an}(r), were obtained in water and air by simulation using the MCNP5 Monte Carlo code according to the methodology recommended in TG-43 and updated in TG-43U1. The dose rate constant was determined to be 0.937{+-}0.004 cGy h{sup -1} U{sup -1} (overall statistical uncertainty {+-}2.7%). S{sub k} per unity activity was calculated to be 0.671{+-}0.003 cGy cm{sup 2} h{sup -1} mCi{sup -1} by simulation of the seed in dry air using point detectors. Spectroscopic studies for both the new and the Amersham model 6711 seed were performed using an HPGe planar detector. The emission spectra of both seeds proved to be very similar. The anisotropy of the total photon intensity in air was measured in planes containing the seed's short and long axes using the HPGe detector. The minimum photon intensity for the new seed was 31.14{+-}3.10% of the transverse intensity.

• OSTI ID: 20953329
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 7 Vol. 34; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
62 RADIOLOGY AND NUCLEAR MEDICINE
ANISOTROPY
BRACHYTHERAPY
DOSE RATES
DOSIMETRY
EMISSION SPECTRA
HIGH-PURITY GE DETECTORS
IODINE 125
MONTE CARLO METHOD
RADIATION SOURCE IMPLANTS
RADIATION SOURCES
RADIOPHARMACEUTICALS
SIMULATION