Gamma knife radiosurgical technique and clinical outcomes for C1-C4 cervical spine lesions: A decade-long experience

Gamma Knife radiosurgery (GKRS) has traditionally been limited to intracranial targets, with the foramen magnum considered its practical inferior boundary. Treating cervical spine lesions poses inherent challenges, including cervical mobility, frame collision risk, and difficulties in achieving stereotactic accuracy near the spinal cord. We report a decade-long experience using GKRS for upper cervical spine lesions (C1-C4), emphasizing an innovative maxillary frame-fixation technique that extends the anatomical reach of GKRS safely below C2.

This was a retrospective study carried out over a 10-year period (from January 2015 to Dec 2024). All patients who were treated by the senior author (DA) were included in the study. The procedure was performed using Leksell Gamma knife Perfexion/Icon model. Neck immobility was achieved with a hard Philadelphia collar application.

We treated 10 patients over the study period. Two patients had lesions centred at or beyond C3 level for which the frame was fixed at the maxilla deviating from the conventional lowermost anterior limit of the frame at supraorbital margin. Age of the patients treated ranged from 13 to 59 yrs. The predominant lesions treated were schwannomas (5) followed by meningiomas (3). The median maximal dose given was 24 Gy while median marginal dose was 12 Gy. Follow up ranged from 12-120 months, with all the lesions showing reduction in size at last follow up. Clinical improvement in symptoms was seen in 6 cases (60%) and no radiation induced clinical or radiological complications were observed during follow up.

GKRS can be effectively utilised to treat high cervical spine lesions especially in patients undergoing treatment for intracranial lesions and those with high surgical risks.