Gamma Knife Radiosurgery in Refractory Obsessive-compulsive Disorder: An Efficacious and Cost Effective Option

Introduction: Objectives- To report the long term outcome and cost efficacy of Gamma Knife Radiosurgery (GKRS) for refractory Obsessive-Compulsive Disorder (OCD).

Methods: A retrospective review of patients receiving GKRS for refractory OCD between 2000 and 2021 was carried out. Case files of the eligible (N=10) patients were reviewed for clinical, radio-therapeutic and outcome data. Analysis of hospitalisation details and cost incurred was carried out.

Results: Mean age at the time of GKRS and mean duration of OCD prior to GKRS was 30.7 ± 9.1 years and 10.4 ± 5.5 years, respectively. Mean baseline Y-BOCS score was 29.4 ± 4.5. Our first patient received cingulotomy, while the rest underwent anterior capsulotomy. With a median margin dose (50% isodose) of 70 Gy, 23.1 ± 7.6 was the mean Y-BOCS score at the last follow-up (median=30 months). In anterior capsulotomy (9 patients), 66.7% patients showed full/partial response, with extreme OCD patients faring poorer. Single case of cingulotomy resulted in no-response.
One patient having undergone anterior capsulotomy needed further treatment with Radio frequency lesioning, needing additional hospitalisation.

Conclusion : GKRS is a safe, cost effective non-invasive treatment modality for refractory OCD with good long term outcome. Ventral anterior capsule is the preferred target, with radiation doses of 120 to 160 Gy being well tolerated.