Researchers from UMC Utrecht found that radiotherapy may offer an alternative treatment option for patients with ventricular tachycardia (VT), a serious heart rhythm disorder that can lead to sudden cardiac death. In patients for whom all conventional therapies had failed, radiotherapy reduced dangerous heart rhythm episodes by 80 percent. Researchers evaluated the treatment in approximately 200 patients all over Europe, making it the largest clinical study of this approach to date.
In ventricular tachycardia (VT) the heart’s electrical signals become disturbed, causing the heart to beat dangerously fast and reducing blood circulation. Patients may experience shortness of breath, fainting, or even die suddenly from cardiac arrest. Current treatments, including medication, implantable cardioverter defibrillators (ICDs), and catheter ablation, offer no relief for up to 50 percent of patients. For those they do help, these treatments can lead to serious side effects or require invasive procedures.
To help patients who had run out of options, associate professor Martin Fast and PhD candidate Luuk van der Pol from UMC Utrecht explored whether radiotherapy could offer a solution. “It almost works like an ablation” Fast explains, “but instead of entering the heart with catheters, we target the abnormal tissue very precisely from outside the body.”
Most people will know radiotherapy as a way to treat cancer. “We use radiotherapy in a different way,” Van der Pol explains. “Cancer patients typically undergo 20 to 30 radiotherapy sessions. VT patients, on the other hand, need just one session of around ten minutes using a high radiation dose.” This makes it possible for patients to leave the hospital within one or two days.
Earlier studies on radiotherapy for VT only included a handful of patients. To build stronger scientific evidence, researchers from hospitals across Europe combined their data in the STOPSTORM.eu consortium. The study was recently published in the European Heart Journal and includes nearly 200 patients, making it the largest clinical study ever performed for this treatment.
After radiotherapy, the number of VT episodes fell by a median of 80 percent within six months. “This is a remarkable reduction, especially in a patient group that is out of treatment options,” Van der Pol says.
Serious side effects were also rare, with only ten patients experiencing complications requiring immediate medical attention. “There were concerns that the high radiation dose could damage the heart or nearby organs,” Fast explains. “But when the treatment is carefully planned and delivered, the benefits seem to outweigh the risks.”
Patients also lived longer than expected. After one year, 77 percent were still alive; after two years, 65 percent. “When we started the study, we did not expect that more than two years of follow-up would even be necessary,” Fast says.
The treatment may improve patients’ quality of life as well. “Many VT patients live in constant fear of another heart rhythm episode or a shock from their ICD,” Van der Pol says. “Some patients are even afraid to cycle to the supermarket alone. After radiotherapy, they experienced fewer episodes and fewer ICD shocks, helping them regain confidence and independence.”
The study focused on patients for whom existing treatments were no longer effective. A next step could be to compare radiotherapy directly with conventional treatments to determine whether it could become a standard option rather than a last resort. “It takes time for a new treatment to become part of routine care,” Fast says. “But these results are promising for patients with this life-threatening condition.”
