Purpose: To compare two MU calculation softwares in their calculation accuracy and automation workflow for secondary MU check of AAA and AcurosXB calculated plans.
Methods: ClearCalc is an API-based software that integrates to the treatment planning system (TPS). RadCalc is a standalone software equipped with two modes of heterogeneity correction: one based on path length and one performs the correction based on the structure contours (RadCalc-ROI). We developed an API script to eliminate the manual plan export/import and carry over the SSDs and effective-path-length information to RadCalc. The arrival of DICOM files to RadCalc triggers its own automatic calculation and reporting workflow. A total of 30 plans covering various sites were analyzed to test the MU calculation accuracy and workflow. Both AAA and AXB plans were created for each case to evaluate the accuracy of the secondary MU calculation for different algorithms. Planner’s user experience survey was performed to score the software/workflow design of the two software.
Results: The results are similar between AAA and AXB plans. With the finite-sized pencil beam (FSPB) algorithm and patient’s CT information, ClearCalc exhibited a better calculation accuracy in general. The frequency distribution of calculation failure (>5%) demonstrated that the RadCalc-ROI module improves the calculation accuracy to a comparable level as ClearCalc. For the lung site, all methods failed with very large difference (40-80%) which evidences that these softwares are not best suited for lung SBRT plans. ClearCalc provides an intuitive user interface and seamless process to switch calculation point while RadCalc offers automatic report printing and the calculation failure warning/stop-sign to prevent users from blindly passing a failed plan.
Conclusion: Both systems offer accurate secondary MU calculation. The integration with TPS via API minimizes the manual steps and ensures a safe workflow.