Provocative Cases -> Teaching Case Reports D-PO01 - Featured Poster Session (ID 11) Poster

D-PO01-100 - Myocardial Wall Thickness Before And After Stereotactic Radioablation Of Scar-related Ventricular Tachycardia (ID 89)


Background: Radioablation has been proposed as an alternative treatment strategy for patients with refractory, scar-related VT
By means of high-dose, single-fraction irradiation of the myocardium, it is postulated that radioablation works by creating radiation-induced necrosis, hence producing a homogeneous transmural scar
Methods: We compared the septal myocardial wall thickness of a patient with non-ischemic cardiomyopathy before and 18-months after it was targeted with a prescription radiation dose of 25 Gy
ECG-gated, mid-diastolic, arterial-enhanced CT images with a slice thickness < 0 75 mm were processed using the MUSIC platform Wall thickness was automatically computed from the endocardial and epicardial contours using the inHEART technology
Results: As shown in the figure, there is no significant change in wall thickness when comparing images obtained before and after radioablation, signifying lack of transmural lesion formation Indeed, this patient experienced VT recurrence at follow-up, which required increased AAD therapy and repeat RFCA for its management
Conclusion: Radioablation of the myocardial septum of a patient with non-ischemic cardiomyopathy using 25 Gy did not result in transmural lesion formation, as evidenced by no change in wall thickness at follow-up, a non-invasive imaging finding with potential clinical implications
Assessment of lesion formation in the irradiated myocardial tissue using CT-derived wall thickness appears feasible and could be incorporated in future human studies to better understand the dynamics of the biological effects of radioablation