BACKGROUND AND PURPOSE: To determine the effect of the curvature of Harrison-Anderson-Mick applicators on the dose distribution in high-dose-rate intraoperative radiation therapy (HDR-IORT). MATERIAL AND METHODS: Treatment planning was performed with flat applicators using (192)Ir as the radioactive source, and dwell times were optimized using dose-point optimization techniques. These optimized dwell times were then used for the curved applicators, and the dose distributions that would actually be delivered to patients were determined. RESULTS: The dose directly below the central catheter was strongly dependent on the curvature of the applicator. Steep parabolic curves caused underdoses of as much as 19% at a point 1cm from the convex side of the applicator. The rate of dose reduction with increasing distance from the applicator surface was also a function of the curvature of the applicator. CONCLUSIONS: The curvature of the applicator profoundly affects dosimetry and can be exploited to optimize coverage of the target during HDR-IORT procedures. To ensure accurate dose delivery, these dose perturbations must be accounted for in the planning process. We recommend maintaining a dosimetry atlas of various applicator sizes and curvatures in addition to one for flat applicators.
BACKGROUND AND PURPOSE: To determine the effect of the curvature of Harrison-Anderson-Mick applicators on the dose distribution in high-dose-rate intraoperative radiation therapy (HDR-IORT). MATERIAL AND METHODS: Treatment planning was performed with flat applicators using (192)Ir as the radioactive source, and dwell times were optimized using dose-point optimization techniques. These optimized dwell times were then used for the curved applicators, and the dose distributions that would actually be delivered to patients were determined. RESULTS: The dose directly below the central catheter was strongly dependent on the curvature of the applicator. Steep parabolic curves caused underdoses of as much as 19% at a point 1cm from the convex side of the applicator. The rate of dose reduction with increasing distance from the applicator surface was also a function of the curvature of the applicator. CONCLUSIONS: The curvature of the applicator profoundly affects dosimetry and can be exploited to optimize coverage of the target during HDR-IORT procedures. To ensure accurate dose delivery, these dose perturbations must be accounted for in the planning process. We recommend maintaining a dosimetry atlas of various applicator sizes and curvatures in addition to one for flat applicators.
Authors: F A Calvo; C V Sole; M E González; E D Tangco; J López-Tarjuelo; I Koubychine; J A Santos; J Pascau; R Herranz; C Ferrer Journal: Clin Transl Oncol Date: 2013-03-05 Impact factor: 3.405
Authors: Gil'ad N Cohen; Karen Episcopia; Seng-Boh Lim; Thomas J LoSasso; Mark J Rivard; Amandeep S Taggar; Neil K Taunk; Abraham J Wu; Antonio L Damato Journal: Brachytherapy Date: 2017-08-18 Impact factor: 2.362