Gamma knife radiosurgery for arteriovenous malformations: clinical series of 199 patients

Abstract

ABSTRACTconsiderable effects on the patient's work activity and quality of life (8,17,22,30).AVMs can be treated with microsurgery, stereotactic radiosurgery (RS) and endovascular embolization (8). Surgical removal is the initial treatment of choice in appropriate patients as it removes immediate relief from hematoma in ruptured AVMs and decreases the bleeding risk (3,8,38). However, rates of permanent morbidity and mortality related to microsurgery range between 3.9-25% and 0.7-4.2%, respectively (3,4,8,12,15,19,20,24,25). █ InTRODuCTIOn C erebral arteriovenous malformations (AVM) are congenital and benign lesions detected in generally young and healthy individuals. AVMs are pathological connections between arteries and veins without capillaries (2,8,12,17,21,26,31). The prevalence of AVMs in general population is 1.4-4.3% (1,11,16,18,29), with a spontaneous hemorrhage risk of 2-5% in untreated AVMs, and 0.7-1% annual mortality rate (7,23,42). Permanent morbidity risk is 2-3% and annual mortality risk is 1% (8,30). Additionally, AVMs may cause headache, seizures and progressive neurological deficits due to ischemia of surrounding brain tissue, with AIM: Cerebral arteriovenous malformations (AVM) are pathological connections between arteries and veins without capillaries. Stereotactic radiosurgery (RS) is a proven and accepted treatment method for cerebral AVMs. Our objective was to analyze the factors influencing the clinical outcome in patients suffering from AVMs. MATERIAL and METhODS:We retrospectively reviewed 199 patients who were treated with Gamma-Knife RS for intracranial AVMs between 13 October 2005 and 31 October 2010. There were 89 male, 110 female patients with a median age of 32 years (range, 3-74 years). Obliteration was assessed with MRI angiography and DSA imaging. RESuLTS:Complete obliteration rate after RS was 71 % (141 out of 199), including second RS treatments. In terms of obliteration rates, there was no significant difference between patients younger and older than 21 years old (p=0.669). After RS, 3 patients died due to intracranial hemorrhage and 1 died of heart disease. Death from AVM was determined as 1.5 %. Intracranial hemorrhage was observed in 7 (3.5 %) patients post-RS.COnCLuSIOn: Obliteration was found to be associated with Spetzler-Martin Grade, Pollock-Flickinger Grade, AVM volume, RS dose, bleeding history before RS and no previous embolization before RS. Gamma knife RS is an effective treatment method for the treatment of AVMs both for pediatric and adult patients. It provides high obliteration and low mortality rates.

Cyst formation after stereotactic radiosurgery for brain arteriovenous malformations: a systematic review

“…54 These findings suggest that the pathophysiology of delayed cyst formation is distinct from that of post-SRS hemorrhage. 2,15,34,65,66 Indeed, histopathological examination of resected cysts suggests that cyst formation occurs secondary to a chronic, organized response to radiation-induced vascular telangiectasia and wall damage, which promotes microhemorrhage and protein exudation. 59 It is possible that prior AVM hemorrhage and embolization increase tissue susceptibility to damage, thereby increasing the risk of cyst formation.…”

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

“…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 ].…”

“…Complete nidus obliteration, confirmed on angiography imaging, was achieved in 56.7% (3092/5450) of patients in 21 cohorts, at the end of follow-up after single-stage Gamma knife treatment [ 5 – 8 , 14 – 16 , 24 , 31 , 32 , 36 , 39 , 46 , 47 , 49 , 51 , 52 , 54 , 57 , 58 , 65 ]. Overall nidus obliteration, confirmed with either angiography or MRI imaging, was achieved in 67.8% (4605/6792) of patients in 29 cohorts, at the end of follow-up after single-stage Gamma knife treatment [ 2 , 4 – 8 , 14 – 16 , 18 , 24 , 31 , 32 , 36 , 39 , 46 , 47 , 51 , 52 , 54 , 56 – 58 , 64 , 65 , 71 , 74 , 75 ]. Table 3 outlines AVM GKRS obliteration outcomes.…”

“…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].…”

Delayed cyst formation after stereotactic radiosurgery for brain arteriovenous malformations

“…Pan et al suggested that delayed cyst formation follows a disparate pathophysiological course compared with that of post-SRS hemorrhage. 4,12,34,45,57,58 Delayed radiation effects were observed with both chronic encapsulated expanding hematoma and nodular lesion. 50 Microscopically, these lesions revealed damage to dilated capillary walls with protein exudate, hyalinization and fibrinoid necrosis, and microhemorrhage.…”