Stereotactic radiosurgery as neuromodulation of refractory angina: an initial case series.

Background: This intervention pilot case series assessed 40-Gy stereotactic radiosurgery (SRS) neuromodulation applied to the bilateral stellate ganglion (SG) as a bailout procedure for patients with refractory angina pectoris (RAP).

Materials And Methods: The local institutional review board approved this feasibility study. In three patients with RAP, after repeated good response, symptoms were temporarily relieved after anaesthetic blockade of the left SG under ultrasound guidance. Radiosurgical neuromodulation with a dose of 40 Gy in one fraction was used for more permanent pain control. When RAP recurred after the initial SRS, right-sided procedures were considered after a confirmed positive response to right SG anesthetic block.

Results: No acute or late radiation-related toxicities were observed. Two patients (67%) responded to bilateral SRS (follow-up: 60 and 48 months, respectively). From baseline to 24 months, their average prescribed nitrate package count decreased from 5.5 to 0 and remained low. Daily emergency nitrates declined from 20 to 30 to 1-2 applications, and walking distance improved from 10 to 20 m to 200-400 m and remained stable. Quality of life as measured with the EQ-5D and all domains of the Seattle Angina Questionnaire improved. The third patient received only unilateral SRS, had a temporary improvement for 6 months before a return to baseline, and died after 42 months of follow-up.

Conclusions: Bilateral radiosurgical neuromodulation at 40 Gy appears to be feasible, safe, and effective as a bailout procedure for RAP.