Stereotactic Body Radiation Therapy for Refractory VT скачать в хорошем качестве

Stereotactic Body Radiation Therapy for Refractory VT

Description: https://johnsonfrancis.org/profession... Discussion on stereotactic body radiation therapy for refractory VT. Ablation of ventricular tachycardia is usually done by invasive catheter based mapping of arrhythmia focus within the ventricles. In a potentially path breaking report published in the NEJM, non-invasive cardiac radiation was used for ablation of ventricular tachycardia in 5 patients. Ventricular tachycardia was induced by the already implanted cardioverter-defibrillator and non-invasive electrocardiographic imaging of the tachycardia obtained. Stereotactic body radiation therapy was done after standard simulation, planning and treatment protocols. Treatment efficacy was assessed by counting the episodes of ventricular tachycardia recorded by the ICD. Assessment of safety of the procedure was done by serial imaging of the heart and thorax for any potential collateral damage. The mean non-invasive ablation time in the five patients was 14 minutes. Single fraction of 25 Gy radiation was delivered in the awake state. Patients had a total of 6577 episodes of ventricular tachycardia in the 3 months prior to treatment. 680 episodes of VT were recorded during the 6 week blanking period, which could be attributed to the inflammatory process after ablation and consequent ventricular irritability. After the blanking period, only 4 episodes of VT occurred over the next 46 patient-months, indicating a 99.96% reduction, which electrophysiologists say, is seldom attained after conventional ablation! Mild opacities were noted in the adjacent lung at 3 months, which resolved at one year. Though it is too early to think of non-invasive ablation for VT on a large scale as the procedure of choice, this study is definitely a call for action, to conduct larger scale studies of this technique. A prospective phase I/II trial of non-invasive cardiac radioablation in refractory episodes of VT or cardiomyopathy related to premature ventricular contractions has been published. SBRT with a single fraction of 25 Gy was delivered to the target. Serious treatment related adverse events in the first 90 days was the primary safety end point. Primary efficacy end point was reduction of episodes of VT tracked by the ICD or reduction in burden of ventricular ectopy as measured by a 24 hour Holter. There was a 6 week blanking period, and the treatment effect was evaluated for 6 months. SF-36 questionnaire was used for health related quality of life assessment. Two of the 19 patients developed serious treatment related adverse event. Median number of VT episodes was reduced to 3 from 119. There was improvement in 5 out of 9 domains of QoL in SF-36. Another study evaluated 10 patients with ischemic and non-ischemic advanced heart failure with ventricular tachycardia. As in the other studies, it was a collaborative effort of radiation oncologist, electrophysiologist, and cardiac imaging specialist. The authors concluded that SBRT was feasible and modestly effective at reducing VT burden in the critically ill heart failure patients. A single centre retrospective analysis of 8 patients with refractory scar related VT who underwent SBRT has been reported. In that study, the target for ablation was defined based on VT morphology on 12 lead ECG, cardiac magnetic resonance imaging and electroanatomic mapping data when available. 15-25 Gy SBRT was delivered to the target volume based on the combined clinical assessment of the cardiac electrophysiologist and radiation oncologist. There was overall reduction in VT burden following SBRT, though the effect was not immediate as in other series. Authors recommended further basic, translational and clinical studies to determine the benefit of SBRT and define optimal protocols and patient selection.