Methods for confirming the safety of radiation therapy in patients with left ventricular assist device: a case of extranodal NK/T-cell lymphoma, nasal type.

A left ventricular assist device (LVAD) is a treatment option for patients with end-stage heart failure; however, a certain number of patients on durable LVADs are diagnosed with malignancy. Radiation therapy (RT) for patients with durable LVADs has safety concerns, because RT may interfere with the device. Herein, we report a case of RT during durable LVAD management. A 48-year-old man with a durable LVAD was diagnosed with sinusitis. As his symptoms were resistant to drug therapy, endoscopic sinus surgery was performed, and extranodal NK/T-cell lymphoma, nasal type (ENKL) was pathologically detected. Since RT was the first-line treatment for ENKL, we conducted two types of irradiation experiments to determine whether RT can be safely performed in patients with durable LVADs as follows: (1) assessing the extent of the radiation levels at each site and evaluating device malfunction by irradiating the lesion sites in the patient model with the same protocol as planned, and (2) evaluating device malfunction by directly irradiating the durable LVAD equipment once at the scheduled total dose. The radiation doses at the pump, driveline, system controller, power cable, and power module of the durable LVAD reached 7.86 cGy, 6.34 cGy, 0.66 cGy, 0.38 cGy, and 0.14 cGy, respectively. In both experiments, durable LVAD malfunction or any type of alarm was not observed. We concluded that RT could be safely performed with chemotherapy in this patient and our irradiation experiments can be applied to RT for other malignancies.