scholarly journals Radiosurgery for Arteriovenous Malformations: the University of Toronto Experience

1997 ◽  
Vol 24 (2) ◽  
pp. 99-105 ◽  
Author(s):  
C. Young ◽  
R. Summerfield ◽  
M. Schwartz ◽  
P. O'Brien ◽  
R. Ramani
Keyword(s):  
Linear Accelerator ◽  
Normal Tissue ◽  
Arteriovenous Malformations ◽  
Ct Scanning ◽  
University Of Toronto ◽  
Enhanced Ct ◽  
The University ◽  
Dynamic Rotation ◽  
Explicit Derivation

ABSTRACT:Background:From July 1989 to February 1996, 130 patients underwent sterotactic radiosurgery. We report the results of the first 50 patients eligible for a minimum of three years of follow-up.Methods:Twenty women and 30 men, (mean age: 37.5 years) were treated by dynamic rotation on a 6 MV linear accelerator. Prior treatment was embolization in seventeen, surgery in three and embolization and surgery in six. All had DSA and enhanced CT scanning, while some had MRI. Forty-seven treatments used a single isodose. Restricting eloquent normal tissue to 15 Gy, margin doses (at 50 - 90% isodose) were 12 Gy (one patient); 15 Gy (sixteen patients); 20 Gy (31 patients); 25 Gy (two patients). Maximum diameters were: <1.5 cm (12 patients); < 2.0 cm (nine patients); < 2.5 cm (twelve patients); < 3.0 cm (thirteen patients; 3.0 cm (four patients).Results:Forty-five patients were evaluable at three years, with thirty-nine having angiography. Twenty-five had angiographically confirmed obliterations; two had parenchymal AVMs obliterated but with residual dural components; four had MRI evidence of obliteration (refused angiography). One patient acutely had a seizure; one patient (with hemorrhages, resection, and embolizations preceding two applications of radiosurgery, separated by 3.5 years) had worsening of memory.Conclusions:Our uncorrected (five patients unevaluable at three years) and corrected angiographically confirmed obliteration rates are 54% and 60% respectively. Our follow-up (98% accounting of cohort; 78% angiographic rate) and explicit derivation of denominators help delineate the efficacy of radiosurgery at these doses.

Radiosurgical treatment for rolandic arteriovenous malformations

2006 ◽  
Vol 105 (5) ◽  
pp. 689-697 ◽  
Author(s):  
Yuri M. Andrade-Souza ◽  
Meera Ramani ◽  
Daryl Scora ◽  
May N. Tsao ◽  
Karel terBrugge ◽  
...  
Keyword(s):  
Arteriovenous Malformations ◽  
Latency Period ◽  
Obliteration Rate ◽  
University Of Toronto ◽  
First Choice ◽  
Study Population ◽  
Radiation Induced ◽  
Risk Of Hemorrhage ◽  
The University

Object The authors reviewed the radiosurgical outcomes in patients with arteriovenous malformations (AVMs) located in the rolandic area, including the primary motor and sensory gyri. Methods The study population consisted of 38 patients with rolandic-area AVMs who underwent linear accelerator radiosurgery at the University of Toronto between 1989 and 2000. Obliteration rate, risk of hemorrhage during the latency period, radiation-induced complications, seizure control, and functional status were evaluated. Patients were also divided into two subgroups according to AVM volume (< 3 cm3 and ≥ 3 cm3). Patients were followed up for a median of 42.4 months (range 30–103 months), and the median age of the patients was 40 years (range 12–67 years). The median AVM volume was 8.1 cm3 (range 0.32–21, mean 8.32 cm3), and the median dose at the tumor margin was 15 Gy (range 15–22, mean 16.8 Gy). The risk of hemorrhage after radiosurgery was 5.3% for the 1st year, 2.6% for the 2nd, and 0% for the 3rd. Two patients (5.3%) sustained adverse effects related to radiation for more than 6 months. Complete nidus obliteration after a single radiosurgical treatment was achieved in 23 patients (60.5%). The obliteration rate for AVMs smaller than 3 cm3 was 83.3% (10 of 12) and that for AVMs larger than or equal to 3 cm3 was 50% (13 of 26). Among the patients who had seizures as the initial presentation, 51.8% were free of seizures after radiosurgery and the seizure pattern improved in 40.7% during the 3rd and last year of follow up. Overall, excellent results (obliteration and no new or worsening neurological deficit) can be achieved in approximately 60% of patients. This percentage varies according to the AVM size and can reach 83% in patients with AVMs smaller than 3 cm3. Conclusions Radiosurgery is a safe and effective treatment for people with rolandic AVMs. The low rate of morbidity associated with radiosurgery, compared with other treatments, indicates that this method may be the first choice for patients with AVMs located in this area.

scholarly journals Long-term outcomes of pediatric arteriovenous malformations: the 30-year Pittsburgh experience

2020 ◽  
Vol 26 (3) ◽  
pp. 275-282
Author(s):  
Michael M. McDowell ◽  
Nitin Agarwal ◽  
Gordon Mao ◽  
Stephen Johnson ◽  
Hideyuki Kano ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Arteriovenous Malformations ◽  
Multimodality Treatment ◽  
Treatment Choice ◽  
University Of Pittsburgh ◽  
Poor Outcome ◽  
Poor Outcomes ◽  
The University

OBJECTIVEThe study of pediatric arteriovenous malformations (pAVMs) is complicated by the rarity of the entity. Treatment choice has often been affected by the availability of different modalities and the experience of the providers present. The University of Pittsburgh experience of multimodality treatment of pAVMs is presented.METHODSThe authors conducted a retrospective cohort study examining 212 patients with pAVM presenting to the University of Pittsburgh between 1988 and 2018, during which patients had access to surgical, endovascular, and radiosurgical options. Univariate analysis was performed comparing good and poor outcomes. A poor outcome was defined as a modified Rankin Scale (mRS) score of ≥ 3. Multivariate analysis via logistic regression was performed on appropriate variables with a p value of ≤ 0.2. Seventy-five percent of the cohort had at least 3 years of follow-up.RESULTSFive patients (2.4%) did not receive any intervention, 131 (61.8%) had GKRS alone, 14 (6.6%) had craniotomies alone, and 2 (0.9%) had embolization alone. Twenty-two (10.4%) had embolization and Gamma Knife radiosurgery (GKRS); 20 (9.4%) had craniotomies and GKRS; 8 (3.8%) had embolization and craniotomies; and 10 (4.7%) had embolization, craniotomies, and GKRS. Thirty-one patients (14.6%) were found to have poor outcome on follow-up. The multivariate analysis performed in patients with poor outcomes was notable for associations with no treatment (OR 18.9, p = 0.02), hemorrhage requiring craniotomy for decompression alone (OR 6, p = 0.03), preoperative mRS score (OR 2.1, p = 0.004), and Spetzler-Martin score (OR 1.8, p = 0.0005). The mean follow-up was 79.7 ± 62.1 months. The confirmed radiographic obliteration rate was 79.4% and there were 5 recurrences found on average 9.5 years after treatment.CONCLUSIONSHigh rates of long-term functional independence (mRS score of ≤ 2) can be achieved with comprehensive multimodality treatment of pAVMs. At this center there was no difference in outcome based on treatment choice when accounting for factors such as Spetzler-Martin grade and presenting morbidity. Recurrences are rare but frequently occur years after treatment, emphasizing the need for long-term screening after obliteration.

Ethiodized oil emulsion 13 in computed tomography of hepatoma.

1984 ◽  
Vol 2 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J P Dutcher ◽  
P J Haney ◽  
N O Whitley ◽  
R Finley ◽  
P Pearl ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ct Scanning ◽  
Tumor Location ◽  
Oil Emulsion ◽  
Accurate Definition ◽  
Enhanced Ct ◽  
Ethiodized Oil ◽  
Definition Of

Six patients with biopsy-proven hepatoma were prospectively evaluated both by conventional computed tomography (CT) and by scans using ethiodized oil emulsion 13 (EOE 13) as a contrast agent. EOE 13 infusion resulted in marked improvement in the demonstration of the neoplasm in all cases and allowed more accurate definition of tumor extent than was possible with standard scanning techniques. In two cases EOE 13 enhancement was essential for complete radiographic depiction of tumor location, size, and extent. EOE 13 also proved to be of considerable value in assessment of therapeutic response in three patients, permitting more objective determination of tumor growth or regression. EOE 13--enhanced CT scanning provides a valuable means of staging patients presenting with hepatoma and is a reliable, accurate means of radiographic follow-up.

Radiation Therapy for Arteriovenous Malformations: A Review

Neurosurgery ◽  
1990 ◽  
Vol 26 (5) ◽  
pp. 725-735 ◽  
Author(s):  
Christopher S. Ogilvy
Keyword(s):  
Proton Beam ◽  
Gamma Knife ◽  
Linear Accelerator ◽  
Arteriovenous Malformations ◽  
Proton Beam Therapy ◽  
Recurrent Hemorrhage ◽  
Brain Irradiation ◽  
History Of ◽  
Gamma Knife Therapy

Abstract There have been numerous case reports and series of patients treated with partial brain irradiation, linear accelerator-based radiosurgery, gamma knife radiosurgery, and Bragg peak therapy for inoperable arteriovenous malformations (AVMs). These cases are summarized and compared. There is convincing evidence that radiation therapy does have a role in obliterating carefully chosen inoperable lesions. The changes that occur in vessel walls after radiation are reviewed. Data about x-ray and gamma radiation are mostly historical and difficult to evaluate because of the techniques of partial brain irradiation. There is a lack of data about the volume of AVM treated and the minimum dose delivered to the AVM nidus. For gamma knife, heavy particle, and linear accelerator therapy, more complete data are available. The incidence of hemorrhage during the first 2 years after treatment, when radiation-induced vascular changes are proposed to occur, is approximately 2.6% per year for gamma knife therapy, 2% per year for proton beam therapy, 2.3% per year for helium beam therapy, and 2.3% per year for linear accelerator therapy. These rates are similar to the recurrence rate for hemorrhage of 2.2 to 3% per year expected based on the natural history of untreated AVMs. If AVM obliteration after therapy is not achieved, the incidence of recurrent hemorrhage remains between 2% per year after treatment with gamma knife therapy. The incidence of hemorrhage for all patients treated was reported as 0.15% per year in one study and 20% over 8 years in a follow-up study using proton beam therapy. Mortality from hemorrhage after treatment was 0.6% after gamma knife therapy, 2.3% after helium beam therapy, and 2 to 5% after proton beam therapy. These figures for mortality are all lower than the 11% observed for the natural history of untreated AVMs. Permanent neurological deficits experienced as a complication of radiation occurred in 2 to 3% of patients treated with gamma knife therapy, 4% of patients treated with helium beam therapy, 1.7% of patients treated with proton beam therapy, and 3% of patients treated with stereotactic linear accelerator therapy. Proton beam therapy has been used for both small and large lesions. The majority of lesions in patients treated with gamma knife, helium beam, and linear accelerator therapy have been small (usually less than 3.0 cm average diameter) lesions. In these patients with small inoperable lesions treated with accurately directed fields of isocentric radiation, the greatest incidence of AVM obliteration has been observed on follow-up angiograms. Larger lesions may undergo vascular wall thickening with subsequent protection from recurrent hemorrhage, but more data are needed to support this hypothesis.

Repeat Radiosurgery for Intracranial Arteriovenous Malformations

Neurosurgery ◽  
2011 ◽  
Vol 70 (1) ◽  
pp. 150-154 ◽  
Author(s):  
John M. Stahl ◽  
Yueh-Yun Chi ◽  
William A. Friedman
Keyword(s):  
Initial Treatment ◽  
Arteriovenous Malformations ◽  
Intracranial Arteriovenous Malformations ◽  
University Of Florida ◽  
The Status ◽  
Median Volume ◽  
Radiation Induced ◽  
Prescription Dose ◽  
The University

Abstract BACKGROUND Despite a high success rate in the stereotactic radiosurgical treatment of intracranial arteriovenous malformations (AVMs) that cannot be safely resected with microsurgery, some patients must be managed after treatment failure. OBJECTIVE To provide an update on the use of repeat linear accelerator radiosurgery as a treatment for failed AVM radiosurgery at the University of Florida. METHODS We reviewed 103 patients who underwent repeat radiosurgical treatment for residual AVM at the University of Florida between December 1991 and December 2007. Each of these patients had at least 2 radiosurgical treatments for the same AVM. Patient information, including AVM nidus volume, prescription dose, age, and sex, was collected at the time of initial treatment and again at the time of retreatment. Patients were followed up after treatment with magnetic resonance, computed tomography, and angiographic imaging at standard intervals to determine the status of their AVM. The median follow-up after retreatment was 31 months. RESULTS Between the first and second treatments, the median AVM nidus volume was decreased by 69% (from a median volume of 12.7 to 4.0 cm3), allowing the median prescribed dose to be increased from 1500 cGy on initial treatment to 1750 cGy on retreatment. The final obliteration rate on retreatment was 65.3%. After salvage retreatment, 5 patients (4.9%) experienced radiation-induced complications, and 6 patients (5.8%) experienced posttreatment hemorrhage. CONCLUSION Repeat radiosurgery is a safe and effective salvage treatment for AVMs.

Postoperative Color Flow Duplex Scanning in Aortic Endografting

1997 ◽  
Vol 4 (3) ◽  
pp. 262-271 ◽  
Author(s):  
Peter Heilberger ◽  
Christian Schunn ◽  
Wolfgang Ritter ◽  
Sepp Weber ◽  
Dieter Raithel
Keyword(s):  
Contrast Agent ◽  
Ultrasound Contrast Agent ◽  
Ct Scanning ◽  
Duplex Sonography ◽  
Duplex Scanning ◽  
Ultrasound Contrast ◽  
Contrast Enhanced Ct ◽  
Contrast Enhanced ◽  
Enhanced Ct

Purpose: To report the feasibility and sensitivity of duplex sonography compared to computed tomography (CT) for aortic endograft follow-up surveillance. Methods: In a 26-month period, 113 aortic aneurysm patients received 79 tube and 34 bifurcated stent-grafts. Follow-up used contrast-enhanced CT scanning and duplex sonography with an intravenous ultrasound contrast agent (Levovist). Results: Eleven patients (9.7%) were converted to open repair; 1 died from hemorrhagic shock secondary to retroperitoneal hematoma. The mean follow-up time was 7.2 months (range 1 to 24), during which 5 patients died of unrelated causes. Sixteen primary (within 30 days) and 5 secondary endoleaks were detected by duplex after tube graft implantation. Among 5 endoleaks due to retrograde side-branch perfusion, 3 were detected only with contrast-enhanced duplex scanning. Iliac artery occlusion was also documented using duplex; however, 2 stent fractures could not be seen with ultrasound. Ten primary endoleaks were detected in bifurcated stent-graft patients. One endoleak originating from the distal iliac limb anchoring site was missed by duplex owing to bowel gas. Graft limb thrombosis was clearly identified by lack of a flow signal on duplex. Conclusions: Duplex sonography could be a valuable, reliable, and economical surveillance tool for endovascular aortic reconstructions. The adjunctive use of an intravenous ultrasound contrast agent increased the sensitivity for detecting endoleak to a level comparable to contrast-enhanced CT scanning. However, stent fractures may not be seen on ultrasound, and bowel gas can interfere with obtaining an adequate image.

Treatment of arteriovenous malformations with linear accelerator–based radiosurgery compared with Gamma Knife surgery

2006 ◽  
Vol 105 (Supplement) ◽  
pp. 58-63 ◽  
Author(s):  
Peter Orio ◽  
Keith J. Stelzer ◽  
Robert Goodkin ◽  
James G. Douglas
Keyword(s):  
Ct Angiography ◽  
Gamma Knife ◽  
Linear Accelerator ◽  
Arteriovenous Malformations ◽  
Mr Angiography ◽  
Gamma Knife Surgery ◽  
Median Dose ◽  
Obliteration Rate ◽  
Linac Radiosurgery

ObjectThe authors sought to compare the outcomes of patients with arteriovenous malformations (AVMs) treated by Gamma Knife surgery (GKS) with those of patients treated by linear accelerator–based (LINAC) radiosurgery.MethodsOne hundred and eighty-seven patients with AVMs were treated at our institution between 1992 and 2003. Ninety-one patients were treated with GKS and 96 patients were treated with LINAC radiosurgery. Patient and treatment characteristics in the two groups included the following. In the LINAC group, the median age was 33 years (range 9–66 years); the median dose was 16 Gy (70% isodose line); the median treated AVM volume was 5.5 cm3; and 46% of patients in this group were treated after hemorrhage. In the GKS group, the median age was 38 years (range 6–63 years); the median dose was 20 Gy (50% isodose line); the median treated AVM volume was 4.3 cm3; and 44% of patients in this group were treated after hemorrhage. Obliteration of AVMs was determined by performing computed tomography (CT) angiography and/or magnetic resonance (MR) angiography and angiography. Patient follow-up evaluation included obtaining an MR angiogram/MR image or CT angiogram at 6 months, at 1 year, and then annually thereafter. Angiography was performed to confirm obliteration when MR angiography and/or CT angiography no longer revealed evidence of an AVM.The 5-year estimated AVM obliteration rate was 66% in the entire patient group; the LINAC group was 60%; the GKS group was 72%; this difference was not statistically significant (p = 0.97). Twelve patients who underwent treatment with LINAC radiosurgery underwent retreatment with GKS and one was retreated with LINAC radiosurgery. The obliteration rate was 82%. Six patients treated with GKS were retreated with GKS, but the follow-up time is of short duration. Chronic toxicity occurred in 8% of both the GKS and the LINAC groups (p = 0.61). Posttreatment hemorrhage during the time of risk before AVM obliteration was 13% in the GKS group and 6.2% in the LINAC group (p = 0.05).Conclusions Treatment of patients with AVMs by using LINAC radiosurgery and GKS treatment produces high obliteration rates with acceptable long-term radiation toxicity in the patients treated.

Complications of embolization of arteriovenous malformations of the brain

2006 ◽  
Vol 104 (2) ◽  
pp. 226-232 ◽  
Author(s):  
Charles S. Haw ◽  
Karel terBrugge ◽  
Robert Willinsky ◽  
George Tomlinson
Keyword(s):  
Vascular Malformation ◽  
Neurological Deficit ◽  
Arteriovenous Malformations ◽  
Study Group ◽  
Mortality And Morbidity ◽  
University Of Toronto ◽  
The University ◽  
The Brain

Object The goal of this study was to determine the rates of mortality and morbidity associated with the embolization of arteriovenous malformations (AVMs) of the brain and to analyze the factors related to embolization-related complications. Methods The University of Toronto Brain Vascular Malformation Study Group database was reviewed. Three hundred six patients underwent 513 embolization sessions between November 1984 and September 2002. The combined rate of death and any permanent disabling neurological deficit was 3.9% per patient. Location of the AVM in an eloquent part of the brain, presence of a fistula, and a venous deposition of glue were related to complications. A clinically important reduction in the rate of death and disabling morbidity occurred in the second half of the study period. Conclusions Embolization of AVMs in the brain is associated with low overall rates of mortality and disabling morbidity.

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