Date Approved


Graduate Degree Type


Degree Name

Medical Dosimetry (M.S.)

Degree Program

Diagnostic & Treatment Sciences

First Advisor

Kristen Vu

Academic Year



The purpose of this study was to determine if using deep inspiration breath hold (DIBH) on right sided breast cancer with internal mammary (IM) node involvement showed any improvement in organ sparing versus the traditional free breathing radiation therapy technique. Partial wide tangents on the right breast to include the IM nodal chain were designed on 10 patients who were previously treated to the left breast. Constraints were measured and compared for both free breathing and DIBH scans to the healthy tissue in the ipsilateral lung, heart, and liver. A generalized estimating equation statistical analysis was done to compare plans. In all patients (n=10) there was a statistically significant reduction in organ dose to the ipsilateral lung, heart, and liver with the DIBH plan. The cm3 of liver which received 50% of t the prescription showed the biggest benefit with a 70.6% mean reduction in dose in the DIBH plan. Future research should be performed to expand on this study and establish new recommendations for the use of DIBH for right sided breast cancer patients when including the IM nodal chain.