Room: Exhibit Hall
Purpose: Intensity-modulated radiation therapy, rotational or helical delivery technologies were developed to focus on maximizing dose to target volume while sparing health tissue. To achieve this, the dose distribution to surrounding healthy tissues is determined by organ type and physician constraints and published normal tissue tolerance criteria. With defined constraints, dosimetrists optimize each patient’s plan to meet these objectives. However, for unidentified organs or healthy tissue for which no explicit dosimetric constraints are defined optimization procedure might omit them, allowing high levels of dose to be unnecessarily deposited. To enhance plan development and reduce dose to healthy tissue an application was developed that provides dosimetrists and physicians a means of outlining and working with an ideal patient plan.
Methods: An application was developed that incorporates the planning CT set with structures and calculates an ideal theoretical dose distribution for a patient plan using real machine PDD parameters. Each structure is capable of having multiple objectives that are manipulated in real time to develop an ideal plan based on physician’s preferences. A few historical patient plans from the head & neck, thorax, and pelvis regions were outlined using the application and then utilized in the Pinnacle TPS to compare to original plans.
Results: The application demonstrated the ability to create effective plans quickly and provided an outline defining which OARs or health tissue areas allowed for greater sparing without impacting PTV coverage. Historical plan comparisons showed the capability of developing plan outlines that could be used in developing real patient plans that require less time and have preferred DVHs over historical.
Conclusion: The application has demonstrated its practicality when compared to historical plans and provides insight into coverage and acceptable dosimetric criteria. Implementations are being made to include NTCP/TCP values and plan achievability.