Innovative Radiation Therapy Shows Potential in Treating Severe Heart Rhythm Disorders

Recent research indicates that stereotactic radiation therapy (STAR) may serve as a safer and effective alternative to traditional catheter ablation for patients suffering from severe, drug-resistant heart rhythm disorders, such as ventricular tachycardia (VT). This noninvasive approach involves delivering precisely targeted radiation beams to the scarred cardiac tissue responsible for abnormal rhythms, aiming to restore normal heart function without the risks associated with invasive procedures.

A groundbreaking retrospective analysis compared outcomes between patients treated with STAR and those who underwent repeat catheter ablation, the current standard for refractory VT. The study involved 43 high-risk patients from a single specialized center between 2015 and 2018, most of whom had previously undergone ablation procedures or were deemed too high-risk for invasive intervention. Patients in the radiation group received a single dose of radiation, administered through close collaboration between cardiology and radiation oncology teams.

Results demonstrated that patients treated with STAR experienced significantly fewer serious complications within a year of treatment—only 9% faced adverse events necessitating hospitalization—compared to 38% in the ablation group. Early adverse events and mortality rates were notably lower in the radiation cohort, with no treatment-related deaths observed during the three-year follow-up period in the radiation group.

Both treatment modalities showed similar effectiveness in delaying the recurrence of VT episodes, with median times of 8.2 months for radiation versus 9.7 months for ablation. However, patients treated with radiation had a median overall survival of 28.2 months compared to 12.2 months for those who underwent ablation, although this difference was not statistically significant due to small sample size. One-year survival rates favored the radiation group at 73%, versus 58% for ablation, and survival at three years was comparable.

Dr. Shannon Jiang, lead researcher and radiation oncologist, emphasized that STAR's noninvasive nature reduces early complication risks, especially important for fragile patients. She pointed out that avoiding anesthesia and invasive procedures can significantly lower patient risk, particularly for those with advanced disease who are often medically vulnerable.

While findings are promising, the researchers acknowledge limitations due to the retrospective design and limited sample size. They are currently enrolling patients for the RADIATE-VT trial—an international, multi-center randomized study aimed at definitively assessing the safety and effectiveness of radiation therapy versus catheter ablation.

This emerging treatment offers a new avenue for managing refractory VT in high-risk patients, with the potential to improve survival and quality of life while minimizing invasive risks. As further research continues, STAR could become a vital component of treatment strategies for severe heart rhythm disorders.