Safety and Efficacy of Stereotactic Body Radiotherapy in the Treatment of Hypertrophic Obstructive Cardiomyopathy

The intervention in this study utilizes Stereotactic Body Radiotherapy (SBRT) for treating Hypertrophic Obstructive Cardiomyopathy (HOCM). The process begins with precise localization and planning, employing CT scans, Cardiac MRI (CMR), and echocardiography to accurately identify the target area in the interventricular septum, while avoiding critical structures like the aortic valve, His bundle, and left ventricular papillary muscles. Pre-treatment preparation involves using customized fixation devices to limit patient movement and breathing, coupled with cone-beam CT scans for accurate alignment with the Treatment Planning System (TPS). The treatment itself is delivered using image-guided linear accelerators, administering a single, focused dose of 25 Gy to the targeted area. This approach ensures precise radiation delivery, maximizing treatment efficacy while minimizing risks to surrounding cardiac tissues.

The sham procedure in this study is designed to closely mimic the actual Stereotactic Body Radiotherapy (SBRT) process without delivering any radiation. Participants in this arm are subjected to the same initial steps as those in the SBRT group, including precise alignment with the linear accelerator using CT scans and the application of customized fixation devices to limit movement and breathing. However, in this sham intervention, the linear accelerator is activated but does not emit any radiation. The procedure replicates the environmental aspects of the actual treatment, such as the equipment's sounds and lighting, to maintain the study's single-blind nature. This method ensures that participants in the sham group experience a procedure identical in appearance and feel to the SBRT treatment, without receiving any therapeutic dose, thereby serving as an effective control for evaluating the true impact of SBRT in treating HOCM.