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Program Information

Automated HDR Brachytherapy Treatment Planning and Quality Assurance System for Tandem-And-Ovoid Applicator


P Klages

P Klages*, C Shen , J Tan , K Albuquerque , X Jia , The University of Texas Southwestern Medical Center, Dallas, TX

Presentations

WE-AB-605-5 (Wednesday, August 2, 2017) 7:30 AM - 9:30 AM Room: 605


Purpose: HDR Brachytherapy planning is a time-consuming and complex process. It is typically performed in a manual fashion under tight time constraints. To eliminate human error, reduce plan quality variation, and improve clinical workflow, we have developed a system to perform a fully automated treatment planning and quality assurance (QA) for cases with a tandem-and-ovoid (T/O) applicator.

Methods: After the patient CT images were imported to our system, the program automatically detects the three applicator channels using thresholds, clustering analysis, spatial relational information, and weighted least squares polynomial fitting. Each applicator channel tip was determined by finding the position along the applicator channel with the highest CT number gradient. Dwell positions within the three applicators were placed. Based on physician-drawn organ contours, dwell time were determined via inverse optimization with a hybrid-input-output algorithm to handle dose-volume constraints. The points for As and Bs were placed based on their definitions. After that, the automatically generated plan was transferred to the clinical treatment planning system (TPS) via DICOM-RT standard for approval. Finally, a QA program was launched to comprehensively validate the plan and generate a QA report.

Results: Automatic segmented applicators matched manually segmented results within 1 mm. All points were placed accurately with average difference in position of 1.1 mm (voxel size: 1mm x 1mm x 2mm). Quality of the automated plan was clinically acceptable. It took approximately 1 min to finish the automatic treatment planning process. After the plan is approved in TPS, the QA test was completed in < 20 s with a 13-page QA report generated automatically.

Conclusion: Automated planning and QA for T/O HDR brachytherapy was achieved. Preliminary tests demonstrated acceptable plan quality and improved efficiency compared to conventional manual approach. Such a system is ready for comprehensive testing and clinical implementation.


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