Proton planning Proton cardiac radioablation treatment plan for one of the patients in the study. All patients received single-fraction proton irradiation with a prescription dose of 30 Gy directed to the target using two or three beams. (Courtesy: Reprinted from K C Siontis et al. Heart Rhythm 10.1016/j.hrthm.2026.04.021 ©2026, with permission from Elsevier)"> Proton planning Proton cardiac radioablation treatment plan for one of the patients in the study. All patients received single-fraction proton irradiation with a prescription dose of 30 Gy directed to the target using two or three beams. (Courtesy: K C Siontis et al. Heart Rhythm 10.1016/j.hrthm.2026.04.021) A first-in-human study from researchers at the Mayo Clinic has shown how proton therapy could provide a new treatment option for patients with hard-to-treat ventricular tachycardia (VT), a life-threatening heart rhythm disorder.…