Radiosurgical capsulotomy for treatment-resistant obsessive-compulsive disorder through a network neuroscience lens

Severe, treatment-resistant obsessive-compulsive disorder (OCD) remains disabling despite optimized pharmacotherapy and exposure and response prevention (ERP). Radiosurgical capsulotomy is an irreversible ablative intervention reserved for highly selected patients. This narrative review examines evidence from structural MRI, diffusion imaging, functional connectivity, electrophysiology, and radiobiology. The search was supplemented by a reproducible PubMed search across eight prespecified modules (856 records before and 739 after deduplication), with an audited 102-record core SRS/OCD set. Structural lesion mapping and a small longitudinal diffusion study support investigating pathway involvement alongside lesion volume, but do not establish a validated network mechanism or individualized targeting biomarker. Functional MRI and EEG findings in OCD and connectivity studies of other interventions provide complementary evidence but require cautious cross-modality extrapolation. Single-session irradiation must be distinguished from thermal capsulotomy; dose, prescription isodose, irradiated volume, and delayed toxicity require joint interpretation. We use "functional disconnection" as a hypothesis concerning downstream effects of tissue injury, not evidence of a nonablative or reversible treatment. Priorities include harmonized longitudinal imaging, dose-volume-connectivity analyses, cognitive and behavioral surveillance, and controlled evaluation of ERP timing. Current evidence supports a network-informed research framework without establishing a post-radiosurgery plasticity window or superiority of connectivity over conventional planning variables.