Radiation-induced imaging changes following Gamma Knife surgery for cerebral arteriovenous malformations

Yen, Chun-Po; Matsumoto, Julie A.; Wintermark, Max; Schwyzer, Lucia; Evans, Avery J.; Jensen, Mary E.; Shaffrey, Mark E.; Sheehan, Jason P.

doi:10.3171/2012.10.jns12402

Cited by 78 publications

(85 citation statements)

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“…1, most patients develop AREs in the initial 7-to 12-month period after GKRS, with a noted delay in ARE development in those patients in whom subtotal obliteration is finally achieved (a median of 10 months to the ARE appearance and 16 months for the ARE peak). In accordance with previous reports stating that the development of AREs often predicts AVM obliteration for many patients, 43 a similar finding is demonstrated in our cohort. The ARE index tool seems to better emphasize that patients who had only a subtotal, partial, or minimal angiographic response to GKRS also developed AREs to a much lower extent than patients who later developed a complete AVM nidus obliteration ( Table 3).…”

Section: 21supporting

confidence: 81%

“…37 Through extensive follow-up, we have found that a significant number of patients with symptomatic radiation-induced changes will recover over time. 43 An appreciable ARE index value defined after univariate and multivariate analysis (Table 4) was defined as a minimum ARE index > 8.…”

Section: 21mentioning

confidence: 99%

“…A quantitative analysis of adverse radiation effects following Gamma Knife radiosurgery for arteriovenous malformations weighted or FLAIR sequences are seen in the perinidal region, and such changes may occur in a substantial portion of patients. 43 The AREs may be accompanied by temporary symptoms in some patients, and, rarely, they may translate into permanent symptoms. In a somewhat ironic fashion, these same T2-weighted or FLAIR findings often predict AVM obliteration for many patients.…”

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confidence: 99%

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A quantitative analysis of adverse radiation effects following Gamma Knife radiosurgery for arteriovenous malformations

Cohen-Inbar

Lee

et al. 2015

JNS

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OBJECT The authors review outcomes following Gamma Knife radiosurgery (GKRS) of cerebral arteriovenous malformations (AVMs) and their correlation to postradiosurgery adverse radiation effects (AREs). METHODS From a prospective institutional review board–approved database, the authors identified patients with a minimum of 2 years of follow-up and thin-slice T2-weighted MRI sequences for volumetric analysis. A total of 105 AVM patients were included. The authors analyzed the incidence and quantitative changes in AREs as a function of time after GKRS. Statistical analysis was performed to identify factors related to ARE development and changes in the ARE index. RESULTS The median clinical follow-up was 53.8 months (range 24–212.4 months), and the median MRI follow-up was 36.8 months (range 24–212.4 months). 47.6% of patients had an AVM with a Spetzler-Martin grade ≥ III. The median administered margin and maximum doses were 22 and 40 Gy, respectively. The overall obliteration rate was 70.5%. Of patients who showed complete obliteration, 74.4% developed AREs within 4–6 months after GKRS. Late-onset AREs (i.e., > 12 months) correlated to a failure to obliterate the nidus. 58.1% of patients who developed appreciable AREs (defined as ARE index > 8) proceeded to have a complete nidus obliteration. Appreciable AREs were found to be influenced by AVM nidus volume > 3 ml, lobar location, number of draining veins and feeding arteries, prior embolization, and higher margin dose. On the other hand, a minimum ARE index > 8 predicted obliteration (p = 0.043). CONCLUSIONS ARE development after radiosurgery follows a temporal pattern peaking at 7–12 months after stereotactic radiosurgery. The ARE index serves as an important adjunct tool in patient follow-up and outcome prediction.

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Section: 21supporting

confidence: 81%

Section: 21mentioning

confidence: 99%

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A quantitative analysis of adverse radiation effects following Gamma Knife radiosurgery for arteriovenous malformations

Cohen-Inbar

Lee

et al. 2015

JNS

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“…7,11,28 Embolization decreases the volume of the AVM nidus, permitting a higher radiosurgical dose to be delivered to the smaller nidus. This approach is believed to lead to less morbidity 31,59,69 and a higher obliteration rate following SRS. 27 In addition, embolization can reduce the risk of AVM rupture by eliminating intranidal aneurysms and reduce the flow in shunting vessels by blocking the high-flow fistulas.…”

Section: Discussionmentioning

confidence: 99%

“…The grading system described by Yen et al was used. 69 Mild imaging changes with an area of increased T2 signal measuring less than 10 mm in thickness surrounding the treated nidi and imposing no mass effect were considered to represent Grade I AREs. Moderate imaging changes with increased T2 signal in areas of 10 mm thickness or greater, with some mass effect causing effacement of the sulci or compression of the adjacent ventricles, constituted Grade II; and severe imaging changes that caused midline shift of the brain, Grade III.…”

Section: Imaging Evaluationsmentioning

confidence: 99%

Stereotactic radiosurgery for arteriovenous malformations after Onyx embolization: a case-control study

Lee

Chen

Ball

et al. 2015

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E mbolization of intracranial arteriovenous malformations (AVMs) was first introduced by Luessenhop and Spence in 1960. 32 Over the next few decades, advances in embolization materials and techniques, including the introduction of transfemoral embolization, detachable or calibrated-leak balloons, particle or liquid embolization, and superselective angiography, made embolization a valuable tool for the management of intracranial AVM. Several reports demonstrated 0%-94% cure rate, 5%-35% morbidity rate, and 0%-5% mortality rate. 1,8,18,23,29,34,37,44,52 Following the introduction of radiosurgical technique in the early 1960s, Steiner et al. successfully treated a brain AVM with stereotactic radiosurgery (SRS) in 1970. 62Since then, SRS has been established as an effective treatment alternative for intracranial AVMs, particularly for those with small-or medium-sized nidi located in eloquent or deep regions. In previously reported series, intracranial AVMs treated with 20-25 Gy have 3-year obliteration rates between 55% and 81% and complication rates ranging from 2.5% to 9.3%. 16,22,49,67,68 Endovascular embolization and radiosurgery each have specific advantages, and either may be used as a standaBBreViatiONS ARE = adverse radiation effect; AVM = arteriovenous malformation; DSA = digital subtraction angiography; EVOH = ethylene-vinyl alcohol; GKS = Gamma Knife surgery; LINAC = linear accelerator; MRA = MR angiography; nBCA = n-butyl-2-cyanacrylate; PVA = polyvinyl alcohol; RBAS = radiosurgery-based AVM score; SRS = stereotactic radiosurgery. OBJect Onyx, an ethylene-vinyl alcohol copolymer mixed in a dimethyl sulfoxide solvent, is currently one of the most widely used liquid materials for embolization of intracranial arteriovenous malformations (AVMs). The goal of this study was to define the risks and benefits of stereotactic radiosurgery (SRS) for patients who have previously undergone partial AVM embolization with Onyx. methOdS Among a consecutive series of 199 patients who underwent SRS between January 2007 and December 2012 at the University of Virginia, 25 patients had Onyx embolization prior to SRS (the embolization group). To analyze the obliteration rates and complications, 50 patients who underwent SRS without prior embolization (the no-embolization group) were matched by propensity score method. The matched variables included age, sex, nidus volume before SRS, margin dose, Spetzler-Martin grade, Virginia Radiosurgery AVM Scale score, and median imaging follow-up period. reSultS After Onyx embolization, 18 AVMs were reduced in size. Total obliteration was achieved in 6 cases (24%) at a median of 27.5 months after SRS. In the no-embolization group, total obliteration was achieved in 20 patients (40%) at a median of 22.4 months after SRS. Kaplan-Meier analysis demonstrated obliteration rates of 17.7% and 34.1% in the embolization group at 2 and 4 years, respectively. In the no-embolization group, the corresponding obliteration rates were 27.0% and 55.9%. The between-groups difference in obliteration rate...

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Diagnostic Imaging Advances

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2019

Stereotactic Radiosurgery and Stereotactic Body Radiation Therapy

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Radiation-induced imaging changes following Gamma Knife surgery for cerebral arteriovenous malformations

Cited by 78 publications

References 21 publications

A quantitative analysis of adverse radiation effects following Gamma Knife radiosurgery for arteriovenous malformations

A quantitative analysis of adverse radiation effects following Gamma Knife radiosurgery for arteriovenous malformations

Stereotactic radiosurgery for arteriovenous malformations after Onyx embolization: a case-control study

Diagnostic Imaging Advances

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