Improving the Early Detection of Cardiovascular Toxicity Secondary to Radiotherapy for Lung Cancer via Patient-specific Quantitative Magnetic Resonance Imaging

Author

Alireza Omidi, Virginia Commonwealth UniversityFollow

DOI

https://doi.org/10.25772/M9Q0-A726

Author ORCID Identifier

https://orcid.org/0000-0003-3407-2160

Defense Date

2022

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Biomedical Engineering

First Advisor

Dr. John S. Wilson

Abstract

Purpose: To assess the cardiopulmonary-induced dose variation on the left ventricle (LV) and evaluate the spatiotemporal evolution of cardiac/aortic function following radiotherapy (RT).

Methods: 8 lung cancer patients who were scheduled to receive RT were recruited for this study. Each patient underwent one 4D-CT at baseline. MRI scans including cine GRE, T1/T2, LGE, and 4D-flow were acquired at baseline, 3-months and 6-months post-RT to evaluate the cardiac/aortic function. Finally, image registration was used to assess the cardiopulmonary-induced dose variation on the LV.

Results: Mean RT-dose was minimum during inspiration and systole (at expiration). No significant differences were found in the maximum dose during cardiac/respiratory motion. Finally, higher mean segmental cumulative doses were estimated at regions closer to the tumor location.

In regards to RT-induced cardiac/aortic toxicity, global metrics did not show any significant changes post-RT except for T2/LGE. Though, regional metrics showed significant changes over at least one follow-up with a dose-dependency response among radiobiological metrics. A correlation was observed between T1 and T2 signal, and between aortic dose and radial/circumferential strain drop at basal anteroseptal of the LV at 6-months post-RT completion.

Conclusion: To minimize the LV RT-dose, it is recommended to deliver the radiation during inspiration and systole. Radiobiological metrics precede mechanical changes in evaluation of RT-induced toxicity with a dose-dependency response over higher doses (>50 Gy). Myocardial fibrosis may induce edema or vice versa given the T1/T2 signal correlation at 6-months. Finally, aortic dose may indirectly damage LV function where LV and aorta are in mechanical continuity.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

8-10-2022