Date Approved

7-17-2026

Graduate Degree Type

Project

Degree Name

Medical Dosimetry (M.S.)

Degree Program

School of Interdisciplinary Health

First Advisor

Jacob Belardo

Second Advisor

Kristen Vu

Academic Year

2025/2026

Abstract

This research investigates the potential improvements in treatment planning workflow efficiency using Multi-Criteria Optimization (MCO) planning in RayStation for patients receiving VMAT SBRT lung treatments with previous lung radiation therapy. Stereotactic Body Radiation Therapy (SBRT) regimens have become widely utilized throughout external beam radiation therapy planning. Along with modernizing treatment techniques, technology is being updated to accommodate higher expectations of treatment plan quality. Treatment planning system (TPS) evaluation is necessary as transitions occur between multiple platforms. RayStation’s Multi-Criteria Optimization (MCO) function may help solve complex optimization problems visually and help make the treatment planning process more efficient. As re-irradiation of the lung has become more common in the past decade, MCO may be utilized to avoid previous treatment areas, while sparing organs at risk (OARs). Ten patient’s treatment plans were anonymized and sent to RayStation for planning. These patient’s were selected as a sample population of typical VMAT SBRT Lung re-irradiation cases typically seen in one multi center hospital system. The VMAT SBRT plans were reoptimized using the MCO workflow in the DMPO workspace. The parameters of beam arrangement, energy, prescription, structure set and CT were kept consistent. Following plan evaluation in RayStation to meet the criteria, the plan was sent to MIM, a treatment planning platform, where an EQD2 was created for the original Pinnacle plans, along with the new Pinnacle-RayStation plan for composite comparison. Comparisons of the composite plans were then evaluated for significance. Plan evaluation between the two composite dose distributions showed clinical quality was similar for the main treatment planning objectives, some statistical significance was seen as a result of the algorithmic differences in the planning systems. The analysis of the EQD2’s showed the conformity index (CI) and lungs minus the internal gross target volume (IGTV) did show significance (P< .05) using a two-tailed t-test. The additional metrics evaluated did not show clinically significant data. Supplementary information was observed when reviewing the RayStation versus Pinnacle plans prior to EQD2 integration. Deliverable plans created in the MCO workspace did not satisfy the institution’s clinical standards for SBRT lung treatment, so the researcher used MCO with additional fine tuning in the plan optimization workspace. Subsequent analysis of the composite plans was observed in MIM. Many OARs showed no statistically significance, however the lungs-IGTV D60% and conformity index did show significance. Possible reasons for this significant difference are explored. The researcher’s findings provide valuable insight into RayStation’s plan quality for reirradiation SBRT lung treatment.

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