Room: AAPM ePoster Library
To develop an automated treatment planning process for the CivaSheet brachytherapy source by combining the advantages of both the BrachyVision and VariSeed treatment planning systems.
CivaSheet is a planar brachytherapy source comprised of a flexible sheet with an embedded grid of CivaDots. CivaDot is a disk-shaped Pd-103 LDR source that is shielded on one side with a gold disk, providing a unidirectional dose distribution. The CivaDot was modeled in both BrachyVision and VariSeed. The dose distribution differences were investigated for a source strength of 100 U. Calculations from each treatment planning system were recorded and compared at 4 different angles (0°, 45°, 90°, and 180°) from the source at distances ranging from 0.25 to 4.5 cm.
Treatment planning for CivaSheet currently requires individual placement and orientation of the CivaDots. This process is time consuming and there are currently no built-in tools in either treatment planning system to automate this process. The development of an automated treatment planning process using ESAPI within BrachyVision is underway.
Calculated dose differences between BrachyVision and VariSeed varied from about 1% at a 1 cm distance from the source to 47% at 4.5cm from the source. At 0.5cm, a typical prescription depth, the dose difference was 4.2%, and at 0.25cm, the dose difference was 8.3%. At shorter distances, the dose difference increases due to limitations in geometric modeling within BrachyVision.
Either VariSeed or BrachyVision could be considered suitable for determining the dose distribution from a CivaSheet treatment. However, due to strengths and weaknesses of both systems, a combination of the two may be the best option in developing an automated treatment planning process. Developing an automated procedure for the clinical treatment planning process will decrease planning time and increase clinical efficiency.