HEARTS Trial for Thoracic Cancers

The goal of this clinical trial is to compare a new way of using magnetic resonance-guided adaptive radiation therapy (MRgART) to the standard of care linear accelerator (LINAC) radiation treatment in people with cancer in the thoracic region near the heart. The main question it aims to answer is whether MRgART affects the heart differently than LINAC. Participants will: * Receive radiation therapy * Undergo MRIs and bloodwork * Complete quality of life questionnaires

This clinical trial, The cARdiac Radiation Therapy Sparing (HEARTS) trial, will compare MR-guided adaptive radiation therapy (MRgART) with substructure sparing to standard of care x-ray based linac RT with whole-heart dose metrics for patients with cancer in the thoracic region based on longitudinal changes in cardiac function using MRI, quality of life, cardiac waveforms, and blood biomarkers.