Abstract
The objective for this work was to develop a commissioning methodology for the treatment delivery components of the AccuBoost system, as well as to establish a routine quality assurance program and appropriate guidance for clinical use based on the commissioning results. Various tests were developed: 1) assessment of the accuracy of the displayed separation value; 2) validation of the dwell positions within each applicator; 3) assessment of the accuracy and precision of the applicator localization system; 4) assessment of the combined dose profile of two opposed applicators to confirm that they are coaxial; 5) measurement of the absolute dose delivered with each applicator to confirm acceptable agreement with dose based on Monte Carlo modeling; 6) measurements of the skin‐to‐center dose ratio using optically stimulated luminescence dosimeters; and 7) assessment of the mammopad cushion's effect on the center dose. We found that the difference between the measured and the actual paddle separation is <0.1 cm for the separation range of 3 cm to 7.5 cm. Radiochromic film measurements demonstrated that the number of dwell positions inside the applicators agree with the values from the vendor, for each applicator type and size. The shift needed for a good applicator‐grid alignment was within 0.2 cm. The dry‐run test using film demonstrated that the shift of the dosimetric center is within 0.15 cm. Dose measurements in water converted to polystyrene agreed within 5.0% with the Monte Carlo data in polystyrene for the same applicator type, size, and depth. A solid water‐to‐water (phantom) factor was obtained for each applicator, and all future annual quality assurance tests will be performed in solid water using an average value of 1.07 for the solid water‐to‐water factor. The skin‐to‐center dose ratio measurements support the Monte Carlo‐based values within 5.0% agreement. For the treatment separation range of 4 cm to 8 cm, the change in center dose would be <1.0% for all applicators when using a compressed pad of 0.2 cm to 0.3 cm. The tests performed ensured that all treatment components of the AccuBoost system are functional and that a treatment plan can be delivered with acceptable accuracy. Based on the commissioning results, a quality assurance manual and guidance documents for clinical use were developed.PACS numbers: 87.55.Qr, 87.56.Da, 87.90.+y
Highlights
INTRODUCTION(standard and skin dose-optimized (SDO)) and D-shaped applicators of various sizes are designed with a channel running along the interior periphery so as to collimate the high dose rate (HDR) 192Ir source’s photons and to optimize the dose distribution at depth
130 Iftimia et al.: AccuBoost treatment delivery components(standard and skin dose-optimized (SDO)) and D-shaped applicators of various sizes are designed with a channel running along the interior periphery so as to collimate the high dose rate (HDR) 192Ir source’s photons and to optimize the dose distribution at depth
(standard and skin dose-optimized (SDO)) and D-shaped applicators of various sizes are designed with a channel running along the interior periphery so as to collimate the HDR 192Ir source’s photons and to optimize the dose distribution at depth
Summary
(standard and skin dose-optimized (SDO)) and D-shaped applicators of various sizes are designed with a channel running along the interior periphery so as to collimate the HDR 192Ir source’s photons and to optimize the dose distribution at depth. The commissioning process included: a) acceptance testing of the system upon completion of manufacturer’s installation; b) full physics evaluation of the mammography and CR components by a mammography-qualified medical physicist; c) assessment of the accuracy of the separation value displayed by the mammography system (which is used to compute the HDR 192Ir source dwell times to deliver the prescribed dose); d) validation of the number of dwell positions within each applicator using GafChromic-type radiochromic film (Ashland, Wayne, NJ); e) assessment of the accuracy and precision of the applicator localization system; f) assessment of the combined dose profile of two opposed applicators in the treatment position to ensure that they are coaxial and that the center of the radiation profile agrees with the location of the applicators as indicated on the localization calipers; g) determination of a method for absolute dose measurement from the HDR 192Ir source; h) measurement of the absolute dose delivered with each AccuBoost applicator to confirm acceptable agreement with the manufacturer’s stated dose based on MC modeling; i) skin-to-center (midplane) dose measurements using optically stimulated luminescence dosimeters (OSLDs) (Landauer Inc., Glenwood, IL); and j) mammopad (Hologic Inc., Bedford, MA) cushion effect on the center dose. Acceptance testing and routine QA tests for the imaging components of the AccuBoost system follow the standard methodology for a mammography unit in magnification stand mode, and will not be reviewed here
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
