Open AccessBrachytherapy dose‐volume histogram commissioning with multiple planning systems
Author(s) -
Gossman Michael S.,
Hancock Samuel S.,
Kudchadker Rajat J.,
Lundahl Paul R.,
Cao Minsong,
Melhus Christopher S.
Publication year - 2014
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1120/jacmp.v15i2.4620
Subject(s) - brachytherapy , radiation treatment planning , dose volume histogram , nuclear medicine , dosimetry , quality assurance , mathematics , cuboid , computer science , radiation therapy , medicine , radiology , geometry , external quality assessment , pathology
The first quality assurance process for validating dose‐volume histogram data involving brachytherapy procedures in radiation therapy is presented. The process is demonstrated using both low dose‐rate and high dose‐rate radionuclide sources. A rectangular cuboid was contoured in five commercially available brachytherapy treatment planning systems. A single radioactive source commissioned for QA testing was positioned coplanar and concentric with one end. Using the brachytherapy dosimetry formalism defined in the AAPM Task Group 43 report series, calculations were performed to estimate dose deposition in partial volumes of the cuboid structure. The point‐source approximation was used for a 125I source and the line‐source approximation was used for a 192 Ir source in simulated permanent and temporary implants, respectively. Hand‐calculated, dose‐volume results were compared to TPS‐generated, dose‐volume histogram (DVH) data to ascertain acceptance. The average disagreement observed between hand calculations and the treatment planning system DVH was less than 1% for the five treatment planning systems and less than 5% for 1 cm ≤ r ≤ 5 cm . A reproducible method for verifying the accuracy of volumetric statistics from a radiation therapy TPS can be employed. The process satisfies QA requirements for TPS commissioning, upgrading, and annual testing. We suggest that investigations be performed if the DVH % Vol TPS“actual variance” calculations differ by more than 5% at any specific radial distance with respect to % Vol TG − 43 , or if the “average variance” DVH DVH % Vol TPScalculations differ by more than 2% over all radial distances with respect to % Vol TG − 43 . PACS numbers: 87.10.+e, 87.55.‐x, 87.53.Jw, 07.05.Tp