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内容記述 |
Background: Cardiac stereotactic radiation therapy is a potential treatment forrefractory ventricular tachycardia. We previously reported that carbon ion irradiation, with a higher dose concentration than X-rays, restored gap junction proteins and denervated excess sympathetic nerves in a rabbit heart model. However, histological analysis is limited to endpoint evaluations, requiring in vivo functional assessment.Objective: This study aimed to evaluate the effects of heavy ion therapy onmitochondrial and sympathetic nerve function in a hyperinnervated rabbit model using positron emission tomography (PET) imaging.Methods: A high-cholesterol disease model (HC, n=8) and a healthy control (Cont, n=8) were established. After 14 weeks, four rabbits per group received 15 Gy carbon ion irradiation targeting the left ventricular wall. After 6 weeks, mitochondrial function was assessed with 18F-FEDAC-PET and sympathetic nerve function with 18FFMeNER-d2-PET and tissue staining.Results: PET analysis showed that 15 Gy carbon ion irradiation slightly restoredphysiological dispersion in 18F-FEDAC uptake in HC rabbits, suggesting partialmitochondrial recovery. 18F-FMeNER-PET revealed normalized sympathetic nerve activity, and tyrosine hydroxylase staining confirmed the reinnervation of pathological nerves. In healthy hearts, nerve fibers remained intact, but PET suggested suppressed norepinephrine transporter function.Conclusion: PET imaging suggested that carbon ion irradiation promotes reverse remodeling in diseased hearts but may also affect healthy hearts. PET can evaluate therapeutic benefits and potential risks, supporting its clinical use for treatment optimization. |
