Comparison of the Long-term Efficacy and Safety of Gamma Knife Radiosurgery for Arteriovenous Malformations in Pediatric and Adult Patients

Abstract

It is debated whether the efficacy and long-term safety of gamma knife radiosurgery (GKRS) for arteriovenous malformations (AVMs) differs between adult and pediatric patients. We aimed to clarify the long-term outcomes of GKRS in pediatric patients and how they compare to those in adult patients. We collected data for 736 consecutive patients with AVMs treated with GKRS between 1990 and 2014 and divided the patients into pediatric (age < 20 years, n = 144) and adult (age ≥ 20 years, n = 592) cohorts. The mean follow-up period in the pediatric cohort was 130 months. Compared to the adult patients, the pediatric patients were significantly more likely to have a history of hemorrhage (P < 0.001). The actuarial rates of post-GKRS nidus obliteration in the pediatric cohort were 36%, 60%, and 87% at 2, 3, and 6 years, respectively. Nidus obliteration occurred earlier in the pediatric cohort than in the adult cohort (P = 0.015). The actuarial rates of post-GKRS hemorrhage in the pediatric cohort were 0.7%, 2.5%, and 2.5% at 1, 5, and 10 years, respectively. Post-GKRS hemorrhage was marginally less common in the pediatric cohort than in the adult cohort (P = 0.056). Cyst formation/encapsulated hematoma were detected in seven pediatric patients (4.9%) at a median post-GKRS timepoint of 111 months, which was not significantly different from the rate in the adult cohort. Compared to adult patients, pediatric patients experience earlier therapeutic effects from GKRS for AVMs, and this improves long-term outcomes.

Gamma Knife radiosurgery for cerebral arteriovenous malformations: a systematic review and meta-analysis

“…Pollock et al [64] 1990-1999/1999-2009 cohorts and Hirschmann et al 2019 [35] reported Spetzler-Ponce classification which did not stratify SM 1/2 or SM 4/5 grade AVMs further. Orio et al 2006 [56] and Zhao et al2008 [75] did not report venous drainage e In addition to the previously stated papers, Hasegawa et al 2018 [32] does not stratify individually but groups SM 3-5 AVMs frequency (55%) Thirty-three (97%) studies were from single centres and one (3%) was multi-centre (Appendix 7). Thirteen (39%) studies were from North America [4, 14-16, 18, 41, 43-45, 52, 56, 66, 74], 12 (36%) from Asia [5,6,8,31,32,36,39,46,47,51,57,75] and 8 (24%) from Europe [2,24,35,49,54,58,65,71].…”

Endovascular treatment of intracranial vascular malformations in children

“…Even if EVT is the primary choice, complete exclusion is not always obtained and complementary treatment is usually planned. 42,43 With radiosurgery treatment, the obliteration rate ranges from 100% in very small lesions to 50% in large lesions. Combinations of embolization or microsurgery and stereotactic radiosurgery are routine in some centres, allowing complex lesions to be cured.…”

“…Complications such as intracranial malignancy or neuropsychological deficits have been reported but are still not well studied. [43][44][45][46] Moreover, symptomatic radionecrosis has been reported in about 3% to 4% of cases and is highly dependent on the dose:volume ratio of the treated target; it appears on neuroimaging as focal oedema. Neurological sequelae are seen in 5% to 15%.…”

“…The aim of partial treatment is to eliminate progressively dangerous portions of AVM and their effects on adjacent brain parenchyma, or to reduce seizures, progressive neurological deficits, or headaches. Even if EVT is the primary choice, complete exclusion is not always obtained and complementary treatment is usually planned 42,43 . With radiosurgery treatment, the obliteration rate ranges from 100% in very small lesions to 50% in large lesions.…”

“…Even though the existing data confirm radiosurgery as a safe and efficacious modality for selected children with AVM, long‐term follow‐up is needed because long‐term effects of ionizing radiation on the developing nervous system have not yet been fully evaluated. Complications such as intracranial malignancy or neuropsychological deficits have been reported but are still not well studied 43–46 . Moreover, symptomatic radionecrosis has been reported in about 3% to 4% of cases and is highly dependent on the dose:volume ratio of the treated target; it appears on neuroimaging as focal oedema.…”