<p>Gamma Knife Radiosurgery For Brain Vascular Malformations: Current Evidence And Future Tasks</p>

Abstract

Gamma Knife radiosurgery (GKRS) has long been used for treating brain vascular malformations, including arteriovenous malformations (AVMs), dural arteriovenous fistulas (DAVFs), and cavernous malformations (CMs). Herein, current evidence and controversies regarding the role of stereotactic radiosurgery for vascular malformations are described. 1) It has already been established that GKRS achieves 70–85% obliteration rates after a 3–5-year latency period for small to medium-sized AVMs. However, late radiation-induced adverse events (RAEs) including cyst formation, encapsulated hematoma, and tumorigenesis have recently been recognized, and the associated risks, clinical courses, and outcomes are under investigation. SRS-based therapeutic strategies for relatively large AVMs, including staged GKRS and a combination of GKRS and embolization, continue to be developed, though their advantages and disadvantages warrant further investigation. The role of GKRS in managing unruptured AVMs remains controversial since a prospective trial showed no benefit of treatment, necessitating further consideration of this issue. 2) Regarding DAVFs, GKRS achieves 41–90% obliteration rates at the second post-GKRS year with a hemorrhage rate below 5%. Debate continues as to whether GKRS might serve as a first-line solo therapeutic modality given its latency period. Although the post-GKRS outcomes are thought to differ among lesion locations, further outcome analyses regarding DAVF locations are required. 3) GKRS is generally accepted as an alternative for small or medium-sized CMs in which surgery is considered to be too risky. The reported hemorrhage rates ranged from 0.5–5% after GKRS. Higher dose treatments (>15 Gy) were performed during the learning curve, while, with the current standard treatment, a dose range of 12–15 Gy is generally selected, and has resulted in acceptable complication rates (< 5%). Nevertheless, further elucidation of long-term outcomes is essential.

Giant vascular malformations invading the skull: A case report

“…However, larger AVMs require multiple procedures, with treatment intervals ranging from 3 to 6 months. The occlusion rate ranges from 33%-72% in treating larger AVMs[ 13 ]. We discontinued this treatment because of its lengthy duration and unpredictable outcomes.…”

Case Series: Gamma Knife Radiosurgery in Brain Arteriovenous, Is It Good Enough?

“…Based on size, Gamma Knife radiosurgery (GKRS) is ideal for small AVMs (< 3 cm). 12 Decisions on the management of cerebral AVMs are still being debated due to a lack of data on the risk of hemorrhage as well as predictors and treatment complications. 13 The main goal of treatment for brain AVM is complete nidus obliteration to prevent rebleeding and potential neurological deterioration.…”

Radiotherapy of non-tumoral refractory neurological pathologies

“…The main secondary effects reported following GammaKnife ® SRS for AVMs are: hemorrhage, radionecrosis and, in the long term, occurrence of cysts, chronic encapsulated hematoma and secondary cancers [51]. Among 581 patients treated with GammaKnife ® and followed during a median time of 10.1 years, Hasegawa et al reported cumulative incidence rates of cyst formation and encapsulated hematomas estimated at 2.8% at 10 years and 9.7% at 20 years, respectively [52].…”