Date Approved
8-6-2024
Graduate Degree Type
Project
Degree Name
Medical Dosimetry (M.S.)
Degree Program
Health Professions
First Advisor
Jessica Fountain
Second Advisor
Kristen Vu
Academic Year
2023/2024
Abstract
Abstract
Introduction
Esophageal cancer is the fifth most common gastrointestinal cancer in the United States. As oncology treatment includes radiation as a standard of care, it is vital to examine effective treatment delivery options. Understanding the dosimetric differences between VMAT and hybrid-VMAT can help providers choose the most appropriate care plan for patients undergoing esophageal irradiation. The purpose of this study was to evaluate if VMAT or hybrid-VMAT delivery would be the superior planning method for patients with planning target volumes greater than ten centimeters. Adequately covering the tumor volume while sparing dose to adjacent critical structures is the goal and this study examines dose to critical structures such as the heart, lungs, and spinal canal.
Method
The retrospective study provides a dosimetric analysis of ten randomly selected patients who have been previously treated for esophageal cancer. Patients were previously treated with VMAT at a midwestern hospital. All patients were prescribed a total dose of 5040 cGy and a hybrid-VMAT plan was created for comparison. This study exclusively involves the initial volume receiving 4500 cGy for comparison. Treatment plans were created using Varian Eclipse version 16.1.0.
Results
Heart mean, lung mean, lung V5 Gy, lung V10 Gy, lung V20 Gy, spinal canal max and conformity index metrics indicate no statistically significant difference between the planning techniques. The gradient measure is the only observed metric for which we can conclude the two plans differ.
Conclusion
The results of this study indicate that there is no dosimetric evidence for improved lung doses between a traditional VMAT plan versus a hybrid-VMAT among this group of patients. Further research with a larger patient population and varied VMAT to 3D ratio is warranted to expand upon this study.
Keywords: Esophageal cancer, Hybrid-VMAT, dosimetric comparison
ScholarWorks Citation
Cozzie, Colleen, "Retrospective Dosimetric Comparison of Radiation Therapy Treatment Using Hybrid-VMAT Technique for Esophageal Cancer" (2024). Culminating Experience Projects. 503.
https://scholarworks.gvsu.edu/gradprojects/503
