Julia Withrow, Ph.D. candidate in the Bolch Lab, received a National Institutes of Health (NIH) Ruth L. Kirschstein National Research Service Award (NRSA) Individual Predoctoral Fellowship (Parent F31) for her project titled Development of Models of Comprehensive Blood and Lymphatic Systems for Radiation Dosimetry.
The overall aim of this study is to develop a comprehensive model of blood and lymphatic systems within the ICRP reference adult male and female computational phantoms to investigate their impact on dosimetry in radiopharmaceutical therapy and external beam radiotherapy applications.
Radiation induced lymphopenia (RIL) occurs in approximately one-half of cancer patients receiving external beam radiotherapy (EBRT) and is associated with a significant decline in five-year survival rates. It is theorized that RIL is induced by direct lymphocyte cell kill, but reference computational models from the International Commission on Radiological Protection (ICRP) – used widely as anatomic patient models for medical radiation dosimetry – do not currently include detailed blood and lymphatic systems. As a result, we do not have the tools for accurate assessment of the radiation absorbed dose to lymphocytes residing in these systems – information vital for consideration of dose sparing to avoid lymphopenia and other unwanted radiotherapy outcomes. Therefore, for improvements in treatment planning both in radiopharmaceutical therapy (RPT) and EBRT, blood and lymphatic system modeling is imperative.
Completion of this study will result in the development of two whole-body reference adult phantoms with associated vasculature and lymphatic systems at both their macroscopic and microscopic levels. Application of these models will allow for improved organ dosimetry in radiopharmaceutical therapy through explicit accounting for radionuclide decays in blood and organ tissue independently. Furthermore, these models will enhance our ability to track radiation dose to lymphocytes in all their anatomical locations to mitigate the risk of lymphopenia during external beam radiotherapy. These enhanced adult reference mesh-type phantoms will further be the basis for patient-specific phantom creation for personalized dosimetry.
Funding Source: NIH National Heart, Lung, and Blood Institute (NHLBI)