scholarly journals Stereotactic radiosurgery for arteriovenous malformations of the postgeniculate visual pathway

2015 ◽  
Vol 122 (2) ◽  
pp. 433-440 ◽  
Author(s):  
Greg Bowden ◽  
Hideyuki Kano ◽  
Ellen Caparosa ◽  
Daniel Tonetti ◽  
Ajay Niranjan ◽  
...  
Keyword(s):  
Visual Field ◽  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Latency Period ◽  
Visual Pathway ◽  
Target Volume ◽  
Visual Deficit ◽  
Study Interval ◽  
Actuarial Risk ◽  
Latency Interval

OBJECT A visual field deficit resulting from the management of an arteriovenous malformation (AVM) significantly impacts a patient's quality of life. The present study was designed to investigate the clinical and radiological outcomes of stereotactic radiosurgery (SRS) performed for AVMs involving the postgeniculate visual pathway. METHODS In this retrospective single-institution analysis, the authors reviewed their experience with Gamma Knife surgery for postgeniculate visual pathway AVMs performed during the period between 1987 and 2009. RESULTS During the study interval, 171 patients underwent SRS for AVMs in this region. Forty-one patients (24%) had a visual deficit prior to SRS. The median target volume was 6.0 cm3 (range 0.4–22 cm3), and 19 Gy (range 14–25 Gy) was the median margin dose. Obliteration of the AVM was confirmed in 80 patients after a single SRS procedure at a median follow-up of 74 months (range 5–297 months). The actuarial rate of total obliteration was 67% at 4 years. Arteriovenous malformations with a volume < 5 cm3 had obliteration rates of 60% at 3 years and 79% at 4 years. The delivered margin dose proved significant given that 82% of patients receiving ≥ 22 Gy had complete obliteration. The AVM was completely obliterated in an additional 18 patients after they underwent repeat SRS. At a median of 25 months (range 11–107 months) after SRS, 9 patients developed new or worsened visual field deficits. One patient developed a complete homonymous hemianopia, and 8 patients developed quadrantanopias. The actuarial risk of sustaining a new visual deficit was 3% at 3 years, 5% at 5 years, and 8% at 10 years. Fifteen patients had hemorrhage during the latency period, resulting in death in 9 of the patients. The annual hemorrhage rate during the latency interval was 2%, and no hemorrhages occurred after confirmed obliteration. CONCLUSIONS Despite an overall treatment mortality of 5%, related to latency interval hemorrhage, SRS was associated with only a 5.6% risk of new visual deficit and a final obliteration rate close to 80% in patients with AVMs of the postgeniculate visual pathway.

Stereotactic radiosurgery for arteriovenous malformations of the cerebellum

2014 ◽  
Vol 120 (3) ◽  
pp. 583-590 ◽  
Author(s):  
Greg Bowden ◽  
Hideyuki Kano ◽  
Daniel Tonetti ◽  
Ajay Niranjan ◽  
John Flickinger ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Posterior Fossa ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Latency Period ◽  
Target Volume ◽  
Outcome Data ◽  
Cerebellar Malformations ◽  
Latency Interval ◽  
Permanent Neurological Deficit

Object Arteriovenous malformations (AVMs) of the posterior fossa have an aggressive natural history and propensity for hemorrhage. Although the cerebellum accounts for the majority of the posterior fossa volume, there is a paucity of stereotactic radiosurgery (SRS) outcome data for AVMs of this region. The authors sought to evaluate the long-term outcomes and risks of cerebellar AVM radiosurgery. Methods This single-institution retrospective analysis reviewed the authors' experience with Gamma Knife surgery during the period 1987–2007. During this time 64 patients (median age 47 years, range 8–75 years) underwent SRS for a cerebellar AVM. Forty-seven patients (73%) presented with an intracranial hemorrhage. The median target volume was 3.85 cm3 (range 0.2–12.5 cm3), and the median marginal dose was 21 Gy (range 15–25 Gy). Results Arteriovenous malformation obliteration was confirmed by MRI or angiography in 40 patients at a median follow-up of 73 months (range 4–255 months). The actuarial rates of total obliteration were 53% at 3 years, 69% at 4 years, and 76% at 5 and 10 years. Elevated obliteration rates were statistically higher in patients who underwent AVM SRS without prior embolization (p = 0.005). A smaller AVM volume was also associated with a higher rate of obliteration (p = 0.03). Four patients (6%) sustained a hemorrhage during the latency period and 3 died. The cumulative rates of AVM hemorrhage after SRS were 6% at 1, 5, and 10 years. This correlated with an overall annual hemorrhage rate of 2.0% during the latency interval. One patient experienced a hemorrhage 9 years after confirmed MRI and angiographic obliteration. A permanent neurological deficit due to adverse radiation effects developed in 1 patient (1.6%) and temporary complications were seen in 2 additional patients (3.1%). Conclusions Stereotactic radiosurgery proved to be most effective for patients with smaller and previously nonembolized cerebellar malformations. Hemorrhage during the latency period occurred at a rate of 2.0% per year until obliteration occurred.

Stereotactic radiosurgery for arteriovenous malformations, Part 5: management of brainstem arteriovenous malformations

2012 ◽  
Vol 116 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Hideyuki Kano ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
Huai-che Yang ◽  
Thomas J. Flannery ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Latency Period ◽  
Target Volume ◽  
Neurological Deficits ◽  
Latency Interval ◽  
Brain Avms

Object In this paper, the authors' goal was to define the long-term outcomes and risks of stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) of the medulla, pons, and midbrain. Methods Between 1987 and 2006, the authors performed Gamma Knife surgery in 996 patients with brain AVMs; 67 patients had AVMs in the brainstem. In this series, 51 patients (76%) had a prior hemorrhage. The median target volume was 1.4 cm3 (range 0.1–13.4 cm3). The median margin dose was 20 Gy (range 14–25.6 Gy). Results Obliteration of the AVMs was eventually documented in 35 patients at a median follow-up of 73 months (range 6–269 months). The actuarial rates of documentation of total obliteration were 41%, 70%, 70%, and 76% at 3, 4, 5, and 10 years, respectively. Higher rates of AVM obliteration were associated only with a higher margin dose. Four patients (6%) suffered a hemorrhage during the latency period, and 2 patients died. The rate of AVM hemorrhage after SRS was 3.0%, 3.0%, and 5.8% at 1, 5, and 10 years, respectively. The overall annual hemorrhage rate was 1.9%. Permanent neurological deficits due to adverse radiation effects (AREs) developed in 7 patients (10%) after SRS, and a delayed cyst developed in 2 patients (3%). One patient died at an outside institution with symptoms of AREs and unrecognized hydrocephalus. Higher 12-Gy volumes and higher Spetzler-Martin grades were associated with a higher risk of symptomatic AREs. Ten of 22 patients who had ocular dysfunction before SRS had improvement, 9 were unchanged, and 3 were worse due to AREs. Eight of 14 patients who had hemiparesis before SRS improved, 5 were unchanged, and 1 was worse. Conclusions Although hemorrhage after obliteration did not occur in this series, patients remained at risk during the latency interval until obliteration occurred. Thirty-eight percent of the patients who had neurological deficits due to prior hemorrhage improved. Higher dose delivery in association with conformal and highly selective SRS is required for safe and effective radiosurgery.

Stereotactic radiosurgery for arteriovenous malformations, Part 1: management of Spetzler-Martin Grade I and II arteriovenous malformations

2012 ◽  
Vol 116 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Hideyuki Kano ◽  
L. Dade Lunsford ◽  
John C. Flickinger ◽  
Huai-che Yang ◽  
Thomas J. Flannery ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Bleeding Event ◽  
Latency Period ◽  
Bleeding Risk ◽  
Target Volume ◽  
Maximum Diameter ◽  
Martin Grade

Object The aim of this paper was to define the outcomes and risks of stereotactic radiosurgery (SRS) for Spetzler-Martin Grade I and II arteriovenous malformations (AVMs). Methods Between 1987 and 2006, the authors performed Gamma Knife surgery in 996 patients with brain AVMs, including 217 patients with AVMs classified as Spetzler-Martin Grade I or II. The median maximum diameter and target volumes were 1.9 cm (range 0.5–3.8 cm) and 2.3 cm3 (range 0.1–14.1 cm3), respectively. The median margin dose was 22 Gy (range 15–27 Gy). Results Arteriovenous malformation obliteration was confirmed by MR imaging in 148 patients and by angiography in 100 patients with a median follow-up of 64 months (range 6–247 months). The actuarial rates of total obliteration determined by angiography or MR imaging after 1 SRS procedure were 58%, 87%, 90%, and 93% at 3, 4, 5, and 10 years, respectively. The median time to complete MR imaging–determined obliteration was 30 months. Factors associated with higher AVM obliteration rates were smaller AVM target volume, smaller maximum diameter, and greater marginal dose. Thirteen patients (6%) suffered hemorrhages during the latency period, and 6 patients died. Cumulative rates of AVM hemorrhage 1, 2, 3, 5, and 10 years after SRS were 3.7%, 4.2%, 4.2%, 5.0%, and 6.1%, respectively. This corresponded to rates of annual bleeding risk of 3.7%, 0.3%, and 0.2% for Years 0–1, 1–5, and 5–10, respectively, after SRS. The presence of a coexisting aneurysm proximal to the AVM correlated with a significantly higher hemorrhage risk. Temporary symptomatic adverse radiation effects developed in 5 patients (2.3%) after SRS, and 2 patients (1%) developed delayed cysts. Conclusions Stereotactic radiosurgery is a gradually effective and relatively safe option for patients with smaller volume Spetzler-Martin Grade I or II AVMs who decline initial resection. Hemorrhage after obliteration did not occur in this series. Patients remain at risk for a bleeding event during the latency interval until obliteration occurs. Patients with aneurysms and an AVM warrant more aggressive surgical or endovascular treatment to reduce the risk of a hemorrhage in the latency period after SRS.

Stereotactic radiosurgery for Spetzler-Martin Grade III arteriovenous malformations

2014 ◽  
Vol 120 (4) ◽  
pp. 973-981 ◽  
Author(s):  
Hideyuki Kano ◽  
John C. Flickinger ◽  
Huai-che Yang ◽  
Thomas J. Flannery ◽  
Daniel Tonetti ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Target Volume ◽  
Safe Management ◽  
Cumulative Rate ◽  
Hemorrhage Risk ◽  
Martin Grade ◽  
Latency Interval ◽  
Grade Iii

Object The purpose of this study was to define the outcomes and risks of stereotactic radiosurgery (SRS) for Spetzler-Martin (SM) Grade III arteriovenous malformations (AVMs). Methods Between 1987 and 2009, SRS was performed in 474 patients with SM Grade III AVMs. The AVMs were categorized by scoring the size (S), drainage (D), and location (L): IIIa was a small AVM (S1D1L1, N = 282); IIIb was a medium/deep AVM (S2D1L0, N = 44); and IIIc was a medium/eloquent AVM (S2D0L1, N = 148). The median target volume was 3.8 ml (range 0.1–26.3 ml) and the margin dose was 20 Gy (range 13–25 Gy). Eighty-one patients (17%) underwent prior embolization, and 58 (12%) underwent prior resection. Results At a mean follow-up of 89 months, the total obliteration rates documented by angiography or MRI for all SM Grade III AVMs increased from 48% at 3 years to 69% at 4 years, 72% at 5 years, and 77% at 10 years. The SM Grade IIIa AVMs were more likely to obliterate than other subgroups. The cumulative rate of hemorrhage was 2.3% at 1 year, 4.4% at 2 years, 5.5% at 3 years, 6.4% at 5 years, and 9% at 10 years. The SM Grade IIIb AVMs had a significantly higher cumulative rate of hemorrhage. Symptomatic adverse radiation effects were detected in 6%. Conclusions Treatment with SRS was an effective and relatively safe management option for SM Grade III AVMs. Although patients with residual AVMs remained at risk for hemorrhage during the latency interval, the cumulative 10-year 9% hemorrhage risk in this series may represent a significant reduction compared with the expected natural history.

Stereotactic radiosurgery for arteriovenous malformations, Part 2: management of pediatric patients

2012 ◽  
Vol 9 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Hideyuki Kano ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
Huai-che Yang ◽  
Thomas J. Flannery ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Pediatric Patients ◽  
Cyst Formation ◽  
Target Volume ◽  
Brain Regions ◽  
Neurological Deficits ◽  
Maximum Diameter ◽  
Latency Interval

Object The authors conducted a study to define the long-term outcomes and risks of stereotactic radiosurgery (SRS) for pediatric arteriovenous malformations (AVMs). Methods Between 1987 and 2006, the authors performed Gamma Knife surgery in 996 patients with brain AVMs; 135 patients were younger than 18 years of age. The median maximum diameter and target volumes were 2.0 cm (range 0.6–5.2 cm) and 2.5 cm3 (range 0.1–17.5 cm3), respectively. The median margin dose was 20 Gy (range 15–25 Gy). Results The actuarial rates of total obliteration documented by angiography or MR imaging at 71.3 months (range 6–264 months) were 45%, 64%, 67%, and 72% at 3, 4, 5, and 10 years, respectively. The median time to complete angiographically documented obliteration was 48.9 months. Of 81 patients with 4 or more years of follow-up, 57 patients (70%) had total obliteration documented by angiography. Factors associated with a higher rate of documented AVM obliteration were smaller AVM target volume, smaller maximum diameter, and larger margin dose. In 8 patients (6%) a hemorrhage occurred during the latency interval, and 1 patient died. The rates of AVM hemorrhage after SRS were 0%, 1.6%, 2.4%, 5.5%, and 10.0% at 1, 2, 3, 5, and 10 years, respectively. The overall annual hemorrhage rate was 1.8%. Larger volume AVMs were associated with a significantly higher risk of hemorrhage after SRS. Permanent neurological deficits due to adverse radiation effects developed in 2 patients (1.5%) after SRS, and in 1 patient (0.7%) delayed cyst formation occurred. Conclusions Stereotactic radiosurgery is a gradually effective and relatively safe management option for pediatric patients in whom surgery is considered to pose excessive risks. Although hemorrhage after AVM obliteration did not occur in the present series, patients remain at risk during the latency interval until obliteration is complete. The best candidates for SRS are pediatric patients with smaller volume AVMs located in critical brain regions.

Stereotactic radiosurgery for arteriovenous malformations, Part 4: management of basal ganglia and thalamus arteriovenous malformations

2012 ◽  
Vol 116 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Hideyuki Kano ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
Huai-che Yang ◽  
Thomas J. Flannery ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Latency Period ◽  
Target Volume ◽  
Neurological Deficits ◽  
Maximum Diameter ◽  
Lower Margin ◽  
Factors Associated

Object The authors conducted a study to define the long-term outcomes and risks of stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) of the basal ganglia and thalamus. Methods Between 1987 and 2006, the authors performed Gamma Knife surgery in 996 patients with brain AVMs; 56 patients had AVMs of the basal ganglia and 77 had AVMs of the thalamus. In this series, 113 (85%) of 133 patients had a prior hemorrhage. The median target volume was 2.7 cm3 (range 0.1–20.7 cm3) and the median margin dose was 20 Gy (range 15–25 Gy). Results Obliteration of the AVM eventually was documented on MR imaging in 78 patients and on angiography in 63 patients in a median follow-up period of 61 months (range 2–265 months). The actuarial rates documenting total obliteration after radiosurgery were 57%, 70%, 72%, and 72% at 3, 4, 5, and 10 years, respectively. Factors associated with a higher rate of AVM obliteration included AVMs located in the basal ganglia, a smaller target volume, a smaller maximum diameter, and a higher margin dose. Fifteen (11%) of 133 patients suffered a hemorrhage during the latency period and 7 patients died. The rate of post-SRS AVM hemorrhage was 4.5%, 6.2%, 9.0%, 11.2%, and 15.4% at 1, 2, 3, 5, and 10 years, respectively. The overall annual hemorrhage rate was 4.7%. When 5 patients with 7 hemorrhages occurring earlier than 6 months after SRS were removed from this analysis, the annual hemorrhage rate decreased to 2.7%. Larger volume AVMs had a higher risk of hemorrhage after SRS. Permanent neurological deficits due to adverse radiation effects (AREs) developed in 6 patients (4.5%), and in 1 patient a delayed cyst developed 56 months after SRS. No patient died of AREs. Factors associated with a higher risk of symptomatic AREs were larger target volume, larger maximum diameter, lower margin dose, and a higher Pollock-Flickinger score. Conclusions Stereotactic radiosurgery is a gradually effective and relatively safe management option for deep-seated AVMs in the basal ganglia and thalamus. Although hemorrhage after obliteration did not occur in the present series, patients remain at risk during the latency interval between SRS and obliteration. The best candidates for SRS are patients with smaller volume AVMs located in the basal ganglia.

Stereotactic radiosurgery for sylvian fissure arteriovenous malformations with emphasis on hemorrhage risks and seizure outcomes

2014 ◽  
Vol 121 (3) ◽  
pp. 637-644 ◽  
Author(s):  
Greg Bowden ◽  
Hideyuki Kano ◽  
Daniel Tonetti ◽  
Ajay Niranjan ◽  
John Flickinger ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Seizure Control ◽  
Cyst Formation ◽  
Target Volume ◽  
Sylvian Fissure ◽  
Neurological Deficits ◽  
Single Institution ◽  
Latency Interval

Object Sylvian fissure arteriovenous malformations (AVMs) present substantial management challenges because of the critical adjacent blood vessels and functional brain. The authors investigated the outcomes, especially hemorrhage and seizure activity, after stereotactic radiosurgery (SRS) of AVMs within or adjacent to the sylvian fissure. Methods This retrospective single-institution analysis examined the authors' experiences with Gamma Knife surgery for AVMs of the sylvian fissure in cases treated from 1987 through 2009. During this time, 87 patients underwent SRS for AVMs in the region of the sylvian fissure. Before undergoing SRS, 40 (46%) of these patients had experienced hemorrhage and 36 (41%) had had seizures. The median target volume of the AVM was 3.85 cm3 (range 0.1–17.7 cm3), and the median marginal dose of radiation was 20 Gy (range 13–25 Gy). Results Over a median follow-up period of 64 months (range 3–275 months), AVM obliteration was confirmed by MRI or angiography for 43 patients. The actuarial rates of confirmation of total obliteration were 35% at 3 years, 60% at 4 and 5 years, and 76% at 10 years. Of the 36 patients who had experienced seizures before SRS, 19 (53%) achieved outcomes of Engel class I after treatment. The rate of seizure improvement was 29% at 3 years, 36% at 5 years, 50% at 10 years, and 60% at 15 years. No seizures developed after SRS in patients who had been seizure free before treatment. The actuarial rate of AVM hemorrhage after SRS was 5% at 1, 5, and 10 years. This rate equated to an annual hemorrhage rate during the latency interval of 1%; no hemorrhages occurred after confirmed obliteration. No permanent neurological deficits developed as an adverse effect of radiation; however, delayed cyst formation occurred in 3 patients. Conclusions Stereotactic radiosurgery was an effective treatment for AVMs within the region of the sylvian fissure, particularly for smaller-volume AVMs. After SRS, a low rate of hemorrhage and improved seizure control were also evident.

scholarly journals Hemorrhage during pregnancy in the latency interval after stereotactic radiosurgery for arteriovenous malformations

2014 ◽  
Vol 121 (Suppl_2) ◽  
pp. 226-231 ◽  
Author(s):  
Daniel Tonetti ◽  
Hideyuki Kano ◽  
Gregory Bowden ◽  
John C. Flickinger ◽  
L. Dade Lunsford
Keyword(s):  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
First Trimester ◽  
Target Volume ◽  
Childbearing Age ◽  
Bleeding Events ◽  
Increased Risk ◽  
Study Population ◽  
Latency Interval

ObjectThe presentation for patients with arteriovenous malformations (AVMs) is often intracranial hemorrhage; for women, this frequently occurs during the prime childbearing years. Although previous studies have addressed the risk for AVM hemorrhage during pregnancy, such studies have not assessed the risk for hemorrhage among women who become pregnant during the latency interval between stereotactic radiosurgery (SRS) and documented obliteration of the lesion. The authors sought to evaluate the risk for hemorrhage in patients who become pregnant during the latency interval after SRS.MethodsThis single-institution retrospective analysis reviewed the authors' experience with Gamma Knife SRS during 1987–2012. During this time, 253 women of childbearing age (median age 30 years, range 15–40 years) underwent SRS for intracranial AVM. The median target volume was 3.9 cm3 (range 0.1–27.1 cm3), and the median marginal dose was 20 Gy (range 14–38 Gy). For all patients, the date of AVM obliteration was recorded and the latency interval was calculated. Information about subsequent pregnancies and/or bleeding events during the latency interval was retrieved from the medical records and supplemented by telephone contact.ResultsAVM obliteration was confirmed by MRI or angiography at a median follow-up time of 39.3 months (range 10–174 months). There were 828.7 patient-years of follow-up within the latency interval between SRS and the date of confirmed AVM obliteration. Among nonpregnant women, 20 hemorrhages occurred before AVM obliteration, yielding an annual hemorrhage rate of 2.5% for nonpregnant women during the latency interval. Among women who became pregnant during the latency interval, 2 hemorrhages occurred over the course of 18 pregnancies, yielding an annual hemorrhage rate of 11.1% for women who become pregnant during the latency interval. For the 2 pregnant patients who experienced hemorrhage, the bleeding occurred during the first trimester of pregnancy.ConclusionsThe authors present the first series of data for women with intracranial AVMs who became pregnant during the latency interval after SRS. Hemorrhage during the latency interval occurred at an annual rate of 2.5% for nonpregnant women and 11.1% for pregnant women. The data suggest that pregnancy might be a risk factor for AVM hemorrhage during the interval between SRS and AVM obliteration. However, this suggestion is not statistically significant because only 18 patients in the study population became pregnant during the latency interval. To mitigate any increased risk for hemorrhage, patients should consider deferring pregnancy until treatment conclusion and AVM obliteration.

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

2012 ◽  
Vol 117 (2) ◽  
pp. 265-275 ◽  
Author(s):  
Hideyuki Kano ◽  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
Kyung-Jae Park ◽  
Aditya Iyer ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Latency Period ◽  
Cyst Formation ◽  
Target Volume ◽  
Case Control ◽  
Neurological Deficits ◽  
Maximum Diameter ◽  
Factors Associated

Object In this paper the authors' goal was to define the long-term benefits and risks of stereotactic radiosurgery (SRS) for patients with arteriovenous malformations (AVMs) who underwent prior embolization. Methods Between 1987 and 2006, the authors performed Gamma Knife surgery in 996 patients with brain AVMs; 120 patients underwent embolization followed by SRS. In this series, 64 patients (53%) had at least one prior hemorrhage. The median number of embolizations varied from 1 to 5. The median target volume was 6.6 cm3 (range 0.2–26.3 cm3). The median margin dose was 18 Gy (range 13.5–25 Gy). Results After embolization, 25 patients (21%) developed symptomatic neurological deficits. The overall rates of total obliteration documented by either angiography or MRI were 35%, 53%, 55%, and 59% at 3, 4, 5, and 10 years, respectively. Factors associated with a higher rate of AVM obliteration were smaller target volume, smaller maximum diameter, higher margin dose, timing of embolization during the most recent 10-year period (1997–2006), and lower Pollock-Flickinger score. Nine patients (8%) had a hemorrhage during the latency period, and 7 patients died of hemorrhage. The actuarial rates of AVM hemorrhage after SRS were 0.8%, 3.5%, 5.4%, 7.7%, and 7.7% at 1, 2, 3, 5, and 10 years, respectively. The overall annual hemorrhage rate was 2.7%. Factors associated with a higher risk of hemorrhage after SRS were a larger target volume and a larger number of prior hemorrhages. Permanent neurological deficits due to adverse radiation effects (AREs) developed in 3 patients (2.5%) after SRS, and 1 patient had delayed cyst formation 210 months after SRS. No patient died of AREs. A larger 12-Gy volume was associated with higher risk of symptomatic AREs. Using a case-control matched approach, the authors found that patients who underwent embolization prior to SRS had a lower rate of total obliteration (p = 0.028) than patients who had not undergone embolization. Conclusions In this 20-year experience, the authors found that prior embolization reduced the rate of total obliteration after SRS, and that the risks of hemorrhage during the latency period were not affected by prior embolization. For patients who underwent embolization to volumes smaller than 8 cm3, success was significantly improved. A margin dose of 18 Gy or more also improved success. In the future, the role of embolization after SRS should be explored.

scholarly journals Stereotactic radiosurgery at a low marginal dose for the treatment of pediatric arteriovenous malformations: obliteration, complications, and functional outcomes

2014 ◽  
Vol 14 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Matthew B. Potts ◽  
Sunil A. Sheth ◽  
Jonathan Louie ◽  
Matthew D. Smyth ◽  
Penny K. Sneed ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Functional Outcomes ◽  
Arteriovenous Malformations ◽  
Target Volume ◽  
Neurological Deficits ◽  
Single Institution ◽  
Risks And Benefits ◽  
Scale Scores ◽  
Time Of Presentation

Object Stereotactic radiosurgery (SRS) is an established treatment modality for brain arteriovenous malformations (AVMs) in children, but the optimal treatment parameters and associated treatment-related complications are not fully understood. The authors present their single-institution experience of using SRS, at a relatively low marginal dose, to treat AVMs in children for nearly 20 years; they report angiographic outcomes, posttreatment hemorrhage rates, adverse treatment-related events, and functional outcomes. Methods The authors conducted a retrospective review of 2 cohorts of children (18 years of age or younger) with AVMs treated from 1991 to 1998 and from 2000 to 2010. Results A total of 80 patients with follow-up data after SRS were identified. Mean age at SRS was 12.7 years, and 56% of patients had hemorrhage at the time of presentation. Median target volume was 3.1 cm3 (range 0.09–62.3 cm3), and median prescription marginal dose used was 17.5 Gy (range 12–20 Gy). Angiograms acquired 3 years after treatment were available for 47% of patients; AVM obliteration was achieved in 52% of patients who received a dose of 18–20 Gy and in 16% who received less than 18 Gy. At 5 years after SRS, the cumulative incidence of hemorrhage was 25% (95% CI 16%–37%). No permanent neurological deficits occurred in patients who did not experience posttreatment hemorrhage. Overall, good functional outcomes (modified Rankin Scale Scores 0–2) were observed for 78% of patients; for 66% of patients, functional status improved or remained the same as before treatment. Conclusions A low marginal dose minimizes SRS-related neurological deficits but leads to low rates of obliteration and high rates of hemorrhage. To maximize AVM obliteration and minimize posttreatment hemorrhage, the authors recommend a prescription marginal dose of 18 Gy or more. In addition, SRS-related symptoms such as headache and seizures should be considered when discussing risks and benefits of SRS for treating AVMs in children.

Sign in / Sign up

Export Citation Format

Share Document