GKS radiosurgery is a minimally invasive technique that precisely delivers radiosurgical doses of 70–90 Gray units to the trigeminal nerve root at the point of vascular compression. The technique relies on accurate MRI mapping and sequencing. If no compressing vessels are identified, the site of exit of the trigeminal nerve from the pons or other preselected position on the trigeminal nerve is treated.
A recent pooled analysis reveals that 30%–66% of patients are pain free at 4–11 years after GKS. Comparing GKS with glycerol rhizotomy injection, it was concluded that despite greater facial numbness and a higher failure rate, glycerol provided more rapid pain relief than GKS. Indeed, the percentage of patients with GKS becoming pain free often increases over time (~24 months), suggesting cumulative effects.[209–211] GKS shows better long-term pain relief with less treatment-related morbidity than glycerol rhizotomy and may be indicated in patients who are poor candidates for MVD.[212,213] Although posterior fossa surgery (MVD or partial nerve section) was shown to be superior to GKS over a mean follow-up duration of about 2 years,[213,214] there are reports that GKS may be the procedure of choice for recurrent CTN. There are insufficient data at present to assess the long-term outcomes or complications of GKS, particularly the unknown effects of radiation in the area of the trigeminal root. With GKS, better outcomes are associated with higher dosages that, however, induce higher rates of sensory loss.
Headache. 2021;61(6):817-837. © 2021 Blackwell Publishing