Stereotactic Radiosurgery for the Treatment of Chronic Intractable Pain: A Systematic Review

Abstract

Background: Since the advent of neuromodulation, the role and efficacy of stereotactic radiosurgery (SRS) for chronic pain has not been carefully scrutinized.

Objective: To perform a systematic review to evaluate the clinical efficacy, both short- and long-term, of SRS for the treatment of chronic intractable pain.

Methods: A systematic search in PubMed, Web of Science, and PsycINFO was performed using keywords and controlled vocabulary. The search included peer-reviewed articles reporting clinical outcomes of SRS for chronic pain with a minimum 3-mo follow-up for nonmalignant and 1 mo for malignant pain.

Results: Six articles (113 patients) were evaluated on the basis of radiation target (thalamus vs pituitary) and pain etiology (malignant vs nonmalignant). Across studies, at least 35% of patients were reported to have lasting significant pain relief. By cohort, clinical success was achieved in 51% of pituitary SRS, at least 23% of thalamic SRS, 39% of nonmalignant, and at least 33% of malignant pain patients. Adverse events were noted in 21% of patients; the majority related to hormonal deficits from pituitary SRS.

Conclusion: Despite decreased utilization, SRS is effective for select patients with chronic pain and is associated with an acceptable complication rate. Pituitary SRS is superior in patients with cancer-related pain (87% success), while thalamic SRS is superior in patients with nonmalignant pain (65% success). Because reports of SRS for pain largely stem from a period before the common use of neuromodulatory and intrathecal therapies, the efficacy in patients who fail such therapies remains unclear and requires further characterization.

Keywords: Chronic pain; Gamma knife surgery; Hypophysectomy; Intractable pain; Refractory pain; Stereotactic radiosurgery; Thalamotomy.