Indications and Benefits of Stereotactic Surgery
Stereotactic surgery is recommended for brain metastases, functional disorders, and certain psychiatric conditions when conventional treatments have failed, offering precise targeting with minimal damage to surrounding tissues. 1, 2
Brain Metastases Management
Stereotactic radiosurgery (SRS) is recommended as an alternative to surgical resection for solitary brain metastases when conventional surgery would likely cause new neurological deficits, and when tumor volume and location are not associated with radiation-induced injury to surrounding structures 1
SRS should be used after open surgical resection of a solitary brain metastasis to decrease local recurrence rates 1
For patients with 1-4 brain metastases, SRS is recommended for local tumor control instead of whole brain radiotherapy (WBRT) when their cumulative volume is <7 mL 1
SRS alone is recommended to improve median overall survival for patients with more than 4 metastases having a cumulative volume <7 mL 1
SRS provides high rates of local control without compromising survival, with less impact on neurocognitive function compared to WBRT 1, 2
Intracranial Cavernous Malformations
SRS is recommended for intracranial cavernous malformations when traditional surgery carries increased risks, particularly for difficult-to-reach lesions 1
Treatment notably lowers the annual rate of cavernous malformation hemorrhages, with nearly half of patients becoming seizure-free and more than 78% showing clinical improvements 1
Stereotactic MRI is recommended for localization and target definition, using T2-weighted gradient-echo or susceptibility-weighted imaging 1
Psychiatric Disorders
Stereotactic procedures for psychiatric disorders (including OCD and MDD) have level II evidence supporting their safety and efficacy in treatment-refractory cases 1
Current practiced stereotactic ablative procedures for psychiatric disorders include radiofrequency anterior capsulotomy for severe, treatment-refractory OCD and thermal anterior cingulotomy for MDD and OCD 1
Ablative procedures may be considered in resource-poor contexts where access to medication, psychotherapy, and more expensive neurosurgical interventions like DBS is limited 1
All investigational neurosurgery for psychiatric disorders must have ethical and regulatory oversight from independent Ethics Committees or Institutional Review Boards 1, 3
Functional Disorders
SRS is indicated for treatment of trigeminal neuralgia as a non-invasive alternative to conventional surgery 4
Radiosurgical ventrolateral thalamotomy may be indicated for treatment of tremor in patients with Parkinson's disease, multiple sclerosis, or essential tremor, particularly for patients with advanced age, significant medical conditions precluding open surgery, or those requiring anticoagulation therapy 4
Technical Benefits
Stereotactic techniques provide precise localization of intracerebral pathological processes using preoperative images (CT, MRI, fMRI, PET, SPECT) 5
The main advantages include targeting of small and deep intracerebral lesions while preserving neurological function 5
Modern stereotactic procedures combine imaging technologies with computer-assisted navigation to allow for minimally invasive approaches 6, 7, 8
Common Pitfalls and Limitations
Neurophysiological confirmation of target structures is not possible with SRS, requiring reliance exclusively on anatomical targeting 4
Lesion sizes may vary, and shielding adjacent radiosensitive neural structures may be difficult or impossible 4
For psychiatric disorders, at least two blinded randomized controlled clinical trials from different research groups showing an acceptable risk-benefit ratio are required before a surgical intervention can be considered "approved therapy" 1
Radiation-induced adverse effects underscore the need for precise dosimetric planning, particularly for cavernous malformations 1
For brain metastases, tumor size, total volume, and location may not always make SRS feasible 1