Stereotactic linac radiosurgery and hypofractionated stereotactic radiotherapy for pediatric arteriovenous malformations of the brain: experiences of a single institution

Pediatric cranial stereotactic radiosurgery: Meta-analysis and international stereotactic radiosurgery society practice guidelines

BACKGROUND

There are limited data on the use of stereotactic radiosurgery (SRS) for pediatric patients. The aim of this systematic review was to summarize indications and outcomes specific to pediatric cranial SRS to inform consensus guidelines on behalf of the International Stereotactic Radiosurgery Society.

METHODS

A systematic review, using the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses, analyzed English-language articles on SRS, published between 1989 and 2021, that included outcomes for at least 5 pediatric patients. MEDLINE database terms included tumor types and locations, and radiosurgical and age-specific terms. We excluded nonclinical reports, expert opinions, commentaries, and review articles. Meta-regressions for associations with local control were performed for medulloblastoma, craniopharyngioma, ependymoma, glioma, and arteriovenous malformation (AVM).

RESULTS

Of the 113 articles identified for review, 68 met the inclusion criteria. These articles described approximately 400 pediatric patients with benign and malignant brain tumors and 5119 with AVMs who underwent cranial SRS. The rates of local control for benign tumors, malignant tumors, and AVMs were 89% (95% CI, 82%-95%), 71% (95% CI, 59%-82%), and 65% (95% CI, 60%-69%), respectively. No significant associations were identified for local control with the patient-, tumor-, or treatment-related variables.

CONCLUSIONS

This review is the first to summarize outcomes specific to SRS for pediatric brain tumors and AVMs. Although data reporting is limited for pediatric patients, SRS appears to provide acceptable rates of local control. We present ISRS consensus guidelines to inform the judicious use of cranial SRS for pediatric patients.

A Rare Case of Facial Arteriovenous Malformation in a 3-Year-Old Female

Arteriovenous malformation (AVM) is a rare congenital vascular anomaly involving abnormal artery-vein connections that bypass the capillary system. AVMs are particularly uncommon in young children. A 3-year-old girl presented with a painless, progressively enlarging left cheek swelling since birth. Clinical examination showed left facial asymmetry with a nontender, pulsatile mass in the left parotid region without skin changes or visible collateral vessels. Computed tomography angiography revealed an enhancing mass in the left parotid region with feeding and draining vessels. The patient was referred to vascular surgery for further management. AVM's rarity in pediatrics highlights the need for further research in genetic and developmental factors, aiming to improve early detection, management, and outcomes for affected children.

Awake resection of a right motor cortex arteriovenous malformation in a pediatric patient: A case report and review of the literature

Background

Intracranial arteriovenous malformations (AVMs) are extremely rare in the pediatric population, with an estimated prevalence of 0.014-0.028%. About 75-80% of pediatric AVMs present with intracranial hemorrhage, a source of significant morbidity and mortality. Awake craniotomy (AC) has become the standard approach for resecting eloquent area intracranial lesions in the adult population. Its use, however remains limited in the pediatric population and has very rarely been reported for an AVM of the motor cortex in this age group.

Case Description

We report the case of a 17-year-old, right-handed boy who presented to our setup with a 2-month history of left-sided hemiparesis and left facial hypoesthesia following an episode of acute loss of consciousness (ALOC) while playing football. A computed tomography scan done after ALOC revealed an AVM in the right frontoparietal cortex with associated acute hemorrhage. Digital subtraction angiography (DSA) was done which revealed a right-sided grade II AVM with arterial supply from the right middle cerebral artery and venous drainage into the superior sagittal and cavernous sinuses. The patient underwent elective neuronavigation-guided right frontoparietal AC and resection of AVM. Postoperative DSA revealed no residual disease. The patient's neurologic deficits showed improvement in the first few days following surgery. He was discharged with advice to follow up in a neurosurgery clinic to monitor his postoperative recovery and ensure compliance with physiotherapy.

Conclusion

This case represents only the second pediatric patient in the available medical literature to have ever undergone AC for intracranial AVM resection. Pediatric AVMs are a rare entity and pose the risk of significant morbidity and mortality. Awake surgery has the potential to reduce iatrogenic neurological deficits in the pediatric population significantly. More work must be done to increase pediatric patient compliance with awake surgery.

Curative Embolization for Pediatric Spetzler-Martin Grade III Cerebral Arteriovenous Malformations

OBJECTIVE

Spetzler-Martin (SM) grade III arteriovenous malformations (AVMs) represent a gray zone due to their high variability in location, size, and angioarchitecture. In addition, there is a lack of information on curative embolization in the pediatric population, especially in this subgroup of lesions. Here we present our experience treating grade III AVMs by curative embolization in pediatric patients.

METHODS

Clinical and angiographic data from pediatric patients with grade III SM AVMs were retrospectively collected between 2011 and 2020 in a referral institution. We grouped the AVMs into subtypes according to size (S), venous drainage (V), and eloquence (E) and obtained subtypes: IIIA (S1V1E1), IIIB (S2V1E0), IIIC (S2V0E1), and IIID (S3V0E0).

RESULTS

A total of 61 embolization sessions were performed in 35 pediatric patients. There were 25 females (64%), and the mean age was 12.2 years (range 5-18). Complete angiographic occlusion was achieved in 16 patients (47%). In 13 patients (37%), the AVM was occluded with a single embolization session and most (12/13) had small lesions (IIIA subtype). Among the 19 patients with incomplete occlusion, most (58%) had large lesions (IIIB, IIIC, and IIID). Large AVMs (IIIB, IIIC, and IIID) underwent 36 sessions; however, only 3 patients (21%) achieved complete occlusion in 11 sessions. Eight intraoperative complications (13% procedures) occurred mainly in ruptured AVMs (7/8) and eloquent zones (7/8).

CONCLUSIONS

Curative embolization for SM grade III AVMs in children carries a high complication rate, especially in small, ruptured, and eloquent lesions. In addition, acceptable immediate complete angiographic occlusion rates were achieved, especially in small AVMs.

Hemorrhagic Cerebrovascular Pathology in the Pediatric Population

Hemorrhagic cerebrovascular disease in the pediatric population can have devastating and long-term effects. Progress in the fields of genetics, neuroimaging, pharmacology, and surgical techniques has led to improved diagnosis and management of pediatric cerebrovascular diseases. In this review we discuss the current etiologies and medical and surgical treatments of hemorrhagic cerebrovascular pathology affecting infants and children. A special emphasis is placed on neuroendovascular treatment options. Increased knowledge about this unique pathology and the medical and therapeutic options will empower practitioners to more quickly and accurately identify and accurately treat hemorrhagic diseases in the pediatric population.

Pediatric Intracranial Arteriovenous Malformation: Long-Term Outcomes with Linear Accelerator (LINAC)-Based Radiosurgery

Purpose

To analyze and report the long-term outcomes of intracranial arteriovenous malformations (AVM) treated with linear accelerator (LINAC)-based radiosurgery (LBRS) in the pediatric population.

Methods and Materials

A series of 34 pediatric patients (≤18 years old) who were treated between 2002 and 2016 were analyzed. All patients were treated with LBRS in a single fraction, with a median dose of 16.8 Gy to the 80% isodose line. Median age at treatment was 14.4 years (range 5.5-18.9). Median AVM volume was 2.91 mL (range 0.228-27.313). Median modified radiosurgery-based AVM score was 0.83 (range 0.18-2.96). The most common presenting symptom was intracranial hemorrhage (ICH) (n = 22, 64.7%). Nine patients underwent intervention before LBRS, which included prior embolization or resection. Seven lesions were in eloquent locations, defined as basal ganglia, thalamus, or brainstem. Cerebral angiography was done to confirm obliteration.

Results

Median follow-up time was 98 months (range 36-200 months). Twenty-two of the 34 lesions were obliterated (64.7%) with median time to obliteration of 37 months (range 14-79). No deaths occurred during the follow up period; however, two patients experienced ICH after treatment. Three other patients were treated for symptomatic radiation necrosis.

Conclusions

Treatment of intracranial AVM with LBRS in the pediatric population is demonstrated to be safe and effective with long-term follow up.

[Arteriovenous malformations of the brain in children: treatment results for 376 patients]

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Cerebral arteriovenous malformations (AVM) are increasingly detected in children.

Objective

To estimate the risk of hemorrhage in children with AVM before and after treatment and evaluate the outcomes of various methods of AVM management in children.

Material and methods

This study included 376 patients with various cerebral AVM under the age of 18 years. There were 273 patients with intracranial hemorrhage (72.6%).

Results

Recurrent hemorrhages within the first month were registered in 1.1% of patients with angiomatous AVM prior to treatment and in 15.4% of patients with fistulous AVM. Microsurgical resection of AVM was performed in 135 (35.9%) patients. Total resection was achieved in 97.8% of cases. There were no mortality after microsurgical procedures. Endovascular treatment was applied in 79 (21%) patients. Total embolization was achieved in 29.1% of patients. One patient (1.3%) died after endovascular procedure. Radiosurgery was performed in 140 (37.2%) patients with total obliteration after a single fraction in 64.4% of patients. Favorable long-term outcomes (GOS grades V-IV) were achieved in 89.6% of patients with available follow-up data (n=182). Recurrent hemorrhages were registered in 6% of patients (3.3% after radiosurgery, 2.7% after endovascular treatment). One patient with recurrent hemorrhage died after radiosurgery.

Conclusion

Early relapses of hemorrhage are not characteristic for children with cerebral AVM. Therefore, there are no indications for urgent surgery except for cases of intracerebral hematoma. In children, microsurgical treatment is preferred for angiomatous AVM, endovascular treatment - for fistulous AVM. Radiosurgery also ensures favorable outcomes. However, it is unreasonable to postpone AVM radiosurgical treatment in children with increased risk of recurrent hemorrhage considering relatively long period of post-radiation obliteration of AVM.

Clinical Outcomes of Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations in Pediatric Patients: Systematic Review and Meta-Analysis

BACKGROUND

Arteriovenous malformations (AVMs) in pediatric patients exhibit remarkable differences in terms of management and outcomes. Owing to a paucity of relevant data pertaining to AVMs in pediatric patients, special interest and investigation are required for an improved understanding of the available evidence by clinicians.

OBJECTIVE

To determine the clinical outcomes of single-session stereotactic radiosurgery (SRS) for AVMs in pediatric patients.

METHODS

A systematic literature review was performed to identify studies that reported the outcomes of SRS for AVMs in pediatric patients. Data pertaining to variables such as obliteration rate, post-SRS new hemorrhage rate, post-SRS new neurological deficit rate, and mortality rate were extracted and analyzed using meta-analysis techniques.

RESULTS

Based on pooled data from 20 studies with 1212 patients, single-session SRS resulted in complete obliteration in 65.9% (95% confidence interval [CI], 60.5%-71.1%; I2 = 66.5%) patients. Overall complication rate (including new hemorrhage, new neurodeficit, and mortality) was 8.0% (95% CI, 5.1%-11.5%; I2 = 66.4%). Post-SRS new neurological deficit rate was 3.1% (95% CI, 1.3%-5.4%; I2 = 59.7%), and post-SRS hemorrhage rate was 4.2% (95% CI, 2.5%-6.3%; I2 = 42.7%). There was no significant difference between studies disaggregated by treatment method (Gamma Knife [Elekta AB] vs other), treatment year (before year 2000 vs after year 2000), median AVM volume reported (≥3 vs <3 cm3), median dose reported (≥20 vs <20 Gy), or follow-up period (≥36 vs <36 mo).

CONCLUSION

Single-SRS is a safe treatment alternative that achieves high obliteration rates and acceptable complication rates for AVMs in pediatric patients.

The factors associated with hemorrhagic presentation in children with untreated brain arteriovenous malformation: a meta-analysis

OBJECTIVE Rupture of arteriovenous malformations (AVMs) would result in high mortality and prevalence of disability in pediatric patients. Decisions regarding the treatment of AVMs need to weigh the risk of rupture over the course of their natural history against the possibility of creating a lesion during treatment. Multiple factors have been proposed to predict hemorrhagic presentation of pediatric patients with AVMs. The aim of this meta-analysis was to evaluate the predictors of hemorrhagic presentation in pediatric patients with AVMs. METHODS The authors searched the PubMed and EMBASE databases. Studies reporting the predictors of hemorrhagic presentation in children with untreated brain AVMs were included. The predictive ability of identified predictors was assessed by odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS A higher risk of hemorrhagic presentation was found in AVMs with smaller size (< 3 cm, OR 2.97, 95% CI 1.94–4.54, p < 0.00001), deep venous drainage (OR 2.28, 95% CI 1.55–3.36, p < 0.0001), a single draining vein (OR 2.23, 95% CI 1.27–3.92, p = 0.005), a single feeder (OR 3.72, 95% CI 1.31–10.62, p = 0.01), a deep location (OR 1.82, 95% CI 1.22–2.72, p = 0.004), an infratentorial location (OR 2.25, 95% CI 1.19–4.26, p = 0.01), and diffuse morphology (OR 8.94, 95% CI 3.01–26.55, p < 0.0001). In addition, the AVMs with draining vein ectasia (OR 0.35, 95% CI 0.13–0.97, p = 0.04) and high Spetzler-Martin (SM) grade (OR 0.53, 95% CI 0.36–0.78, p = 0.001) had a lower risk of hemorrhagic presentation in pediatric patients. CONCLUSIONS Smaller AVMs, deep venous drainage, a single draining vein, a single feeder, deep/infratentorial location, diffuse morphology, and high SM grade were identified as positive predictors for hemorrhagic presentation. Particularly, patients with diffuse AVMs have a higher risk of hemorrhagic presentation than other factors and may need active treatments. However, factors such as age, sex, draining vein stenosis, and associated aneurysms were not associated with hemorrhagic presentation. ABBREVIATIONS AVM = arteriovenous malformation; CI = confidence interval; NOS = Newcastle-Ottawa Scale; OR = odds ratio; SM = Spetzler-Martin.

Arteriovenous Malformations in the Pediatric Population: Review of the Existing Literature

Arteriovenous malformations (AVMs) in the pediatric population are relatively rare but reportedly carry a higher rate of rupture than in adults. This could be due to the fact that most pediatric AVMs are only detected after rupture. We aimed to review the current literature regarding the natural history and the clinical outcome after multimodality AVM treatment in the pediatric population, as optimal management for pediatric AVMs remains controversial. A multidisciplinary approach using multimodality therapy if needed has been proved to be beneficial in approaching these lesions in all age groups. Microsurgical resection remains the gold standard for the treatment of all accessible pediatric AVMs. Embolization and radiosurgery should be considered as an adjunctive therapy. Embolization provides a useful adjunct therapy to microsurgery by preventing significant blood loss and to radiosurgery by decreasing the volume of the AVM. Radiosurgery has been described to provide an alternative treatment approach in certain circumstances either as a primary or adjuvant therapy.

Angioarchitectural Risk Factors for Hemorrhage and Clinical Long-Term Outcome in Pediatric Patients with Cerebral Arteriovenous Malformations

BACKGROUND

Intracranial arteriovenous malformation (AVM) in children is a rare diagnosis. Little is known about factors determining AVM rupture and appropriate treatment strategies to prevent hemorrhage and associated disability. Available data suggest that children are subject to an increased risk for AVM rupture compared with adults.

METHODS

In 46 pediatric patients with AVM, demographic factors, clinical presentation, angioarchitectural features, and treatment regimens as well as clinical and radiologic outcomes were retrospectively analyzed. First-line treatment option was microsurgical resection of the disease, with or without preoperative embolization.

RESULTS

Twenty-four boys (52.2%) and 22 girls (47.8%) with a mean age on admission of 12.4 years (4-18 years) were included. Mean follow-up was 4 years (median, 1.5; range, 0.1-16.4). Thirty-one children presented with intracerebral hemorrhage (67.4%). Small AVMs (<3 cm) ruptured in 83.3% (n = 25) and were shown to be more prone to hemorrhage than larger ones (P < 0.01). Small AVM size (P < 0.01; odds ratio [OR], 0.12; 95% confidence interval [CI] 0.02-0.59) and exclusive deep venous drainage (P < 0.01; OR, 29.74; 95% CI, 2.45-4445.34) were independent risk factors for hemorrhage in the presented cohort. Good long-term outcome was associated with a high score on the Glasgow Coma Scale on admittance (P < 0.05; OR, 0.148; 95% CI, 0.03-0.73).

CONCLUSIONS

Two-thirds of children with AVM are admitted with intracerebral hemorrhage. Microsurgical resection was successful as confirmed by radiologic studies in 95%, and 79.5% of patients presented in a good clinical condition on follow-up (modified Rankin Scale 0 or 1). Microsurgical treatment is recommended if the lesion is accessible and angioarchitectural risk factors favor definitive treatment.

Microsurgical treatment of arteriovenous malformations in pediatric patients: the Boston Children's Hospital experience

OBJECT

Outcomes of microsurgical treatment of arteriovenous malformations (AVMs) in children are infrequently reported across large cohorts.

METHODS

The authors undertook a retrospective review of departmental and hospital databases to obtain the medical data of all patients up to 18 years of age who were diagnosed with cerebral AVMs. Demographic and AVM angioarchitectural characteristics were analyzed, and for the patients who underwent surgery, the authors also analyzed the estimated intraoperative blood loss, postoperative angiographically confirmed obliteration rates, and neurological complications and outcomes classified according to the modified Rankin Scale (mRS).

RESULTS

Of 117 children with cerebral AVMs, 94 underwent microsurgical resection (80%). Twenty (21%) of these 94 patients underwent adjunctive preoperative embolization. The overall postoperative angiographically confirmed obliteration rate was 94%. As part of a new protocol, the last 50 patients in this series underwent immediate perioperative angiography, improving the subsequent obliteration rate from 86% to 100% (p = 0.01). No other factors, such as a hemorrhagic AVM, size of the AVM, location, drainage, or Spetzler-Martin grade, had a statistically significant impact on the obliteration rate. Perioperative neurological deficits occurred in 17% of the patients, but the vast majority of these (77%) were predictable visual field cuts. Arteriovenous malformations that were hemorrhagic or located in noneloquent regions were each associated with lower rates of postoperative neurological complications (p = 0.05 and 0.002, respectively). In total, 94% of the children had good functional outcomes (mRS Scores 0-2), and these outcomes were significantly influenced by the mRS score on presentation before surgery (p = 0.01). A review of 1- and 5-year follow-up data indicated an overall annual hemorrhage rate of 0.3% and a recurrence rate of 0.9%.

CONCLUSIONS

Microsurgical resection of AVMs in children is associated with high rates of angiographically confirmed obliteration and low rates of significant neurological complications. Implementation of a protocol using perioperative angiography in this series led to complete radiographically confirmed obliteration of all AVMs, with low annual repeat hemorrhage and recurrence rates.