DVH Analyzer: design and algorithm to reveal DVH bands for quantitative analysis of robust radiotherapy treatment plans

Background: Commercial treatment planning system (TPS) does not have any tool to provide the quantitative analysis of DVH bands (corresponding to each delineated structure) in a radiotherapy treatment plan (RTP). The proposed study reveals the design and algorithm of an in-house developed "DVH Analyzer" tool that provides quantitative analysis of DVH bands. Further, the clinical use of this tool demonstrated with the use of four different clinical cases. Methods: DVH bands for each of the delineated structures in different RTPs generated using the "Plan Uncertainty Parameters" (PUP) module in the TPS by simulating different patient setup errors (PSE) in iso-center of the base plan in x-, y-, and z-directions. DVH bands were exported from the TPS and imported into the DVH Analyzer for processing, analysis, and plotting through various modules. Results: Various user-defined volumetric and dosimetric parameters were calculated from DVH bands of each of the delineated structures in different RTPs. The impact of PSE on the user-defined parameters was also analyzed and graphically demonstrated for different clinical sites. Conclusions: The unique feature of DVH Analyzer to handle DVH bands provides a quantitative and qualitative evaluation of the robust RTPs generated with different PSE. The flexibility in design and implementation of DVH Analyzer makes it a promising tool for the clinics that could be utilized for clinical evaluation of robust treatment plans.