Purpose: To characterize the dose distribution in water of a novel beta-emitting brachytherapy source for use in a Conformal Superficial Brachytherapy (CSBT) device. Methods and materials: Yttrium-90 (90Y) sources were designed for use with a uniquely designed CSBT device. Depth dose and planar dose measurements were performed for bare sources and sources housed within a 3D printed source holder. Monte Carlo simulated dose rate distributions were compared to film-based measurements. Gamma analysis was performed to compare simulated and measured dose rates from seven 90Y sources placed simultaneously using the CSBT device. Results: The film-based maximum measured surface dose rate for a bare source in contact with the surface was 3.35 × 10–7 cGy s−1 Bq−1. When placed in the source holder, the maximum measured dose rate was 1.41 × 10–7 cGy s−1 Bq−1. The Monte Carlo simulated depth dose rates were within 10% or 0.02 cm of the measured dose rates for each depth of measurement. The maximum film surface dose rate measured using a seven-source configuration within the CSBT device was 1.78 × 10−7 cGy s−1 Bq−1. Measured and simulated dose rate distribution of the seven-source configuration were compared by gamma analysis and yielded a passing rate of 94.08%. The gamma criteria were 3% for dose-difference and 0.07056 cm for distance-to-agreement. The estimated measured dose rate uncertainty was 5.34%. Conclusions: 90Y is a unique source that can be optimally designed for a customized CSBT device. The rapid dose falloff provided a high dose gradient, ideal for treatment of superficial lesions. The dose rate uncertainty of the 90Y-based CSBT device was within acceptable brachytherapy standards and warrants further investigation.
Bibliographical noteFunding Information:
This research was funded by the Institute for Engineering in Medicine, University of Minnesota . Robert Hall of MURR was essential in construction of the 90 Y sources. Thank you to our institution’s Department of Radiation Safety for assisting in the preparation and management of the sources.
This research was funded by the Institute for Engineering in Medicine, University of Minnesota. Robert Hall of MURR was essential in construction of the 90Y sources. Thank you to our institution's Department of Radiation Safety for assisting in the preparation and management of the sources. Disclosures: The authors report no proprietary or commercial interest in any product mentioned or concept discussed in this article.
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- Monte Carlo
- Superficial Brachytherapy
PubMed: MeSH publication types
- Journal Article