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

Kano, Hideyuki,Kondziolka, Douglas,Flickinger, John C.,Park, Kyung-Jae,Iyer, Aditya,Yang, Huai-che,Liu, Xiaomin,Monaco, Edward A.,Niranjan, Ajay,Lunsford, L. Dade Journal of Neurosurgery Publishing Group 2012 Journal of Neurosurgery Vol.117 No.2

<B>Object</B><P>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.</P><B>Methods</B><P>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 cm<SUP>3</SUP> (range 0.2-26.3 cm<SUP>3</SUP>). The median margin dose was 18 Gy (range 13.5-25 Gy).</P><B>Results</B><P>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.</P><B>Conclusions</B><P>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 cm<SUP>3</SUP>, 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.</P>

Aneurysms increase the risk of rebleeding after stereotactic radiosurgery for hemorrhagic arteriovenous malformations.

Kano, Hideyuki,Kondziolka, Douglas,Flickinger, John C,Yang, Huai-che,Park, Kyung-Jae,Flannery, Thomas J,Liu, Xiaomin,Niranjan, Ajay,Lunsford, L Dade American Heart Association] 2012 Stroke Vol.43 No.10

<P>The purpose of this study was to define the risk of rebleeding after stereotactic radiosurgery (SRS) for hemorrhagic arteriovenous malformations with or without associated intracranial aneurysms.</P>

Outcomes of Gamma Knife surgery for trigeminal neuralgia secondary to vertebrobasilar ectasia

Park, Kyung-Jae,Kondziolka, Douglas,Kano, Hideyuki,Berkowitz, Oren,Ahmed, Safee Faraz,Liu, Xiaomin,Niranjan, Ajay,Flickinger, John C.,Lunsford, L. Dade American Association of Neurological Surgeons 2012 Journal of Neurosurgery Vol.116 No.1

<B>Object</B><P>Vertebrobasilar ectasia (VBE) is an unusual cause of trigeminal neuralgia (TN). The surgical options for patients with medically refractory pain include percutaneous or microsurgical rhizotomy and microvascular decompression (MVD). All such procedures can be technically challenging. This report evaluates the response to a minimally invasive procedure, Gamma Knife surgery (GKS), in patients with TN associated with severe vascular compression caused by VBE.</P><B>Methods</B><P>Twenty patients underwent GKS for medically refractory TN associated with VBE. The median patient age was 74 years (range 48-95 years). Prior surgical procedures had failed in 11 patients (55%). In 9 patients (45%), GKS was the first procedure they had undergone. The median target dose for GKS was 80 Gy (range 75-85 Gy). The median follow-up was 29 months (range 8-123 months) after GKS. The treatment outcomes were compared with 80 case-matched controls who underwent GKS for TN not associated with VBE.</P><B>Results</B><P>Intraoperative MR imaging or CT scanning revealed VBE that deformed the brainstem in 50% of patients. The trigeminal nerve was displaced in cephalad or lateral planes in 60%. In 4 patients (20%), the authors could identify only the distal cisternal component of the trigeminal nerve as it entered into the Meckel cave.</P><P>After GKS, 15 patients (75%) achieved initial pain relief that was adequate or better, with or without medication (Barrow Neurological Institute [BNI] pain scale, Grades I-IIIb). The median time until pain relief was 5 weeks (range 1 day-6 months). Twelve patients (60%) with initial pain relief reported recurrent pain between 3 and 43 months after GKS (median 12 months). Pain relief was maintained in 53% at 1 year, 38% at 2 years, and 10% at 5 years. Some degree of facial sensory dysfunction occurred in 10% of patients. Eventually, 14 (70%) of the 20 patients underwent an additional surgical procedure including repeat GKS, percutaneous procedure, or MVD at a median of 14 months (range 5-50 months) after the initial GKS. At the last follow-up, 15 patients (75%) had satisfactory pain control (BNI Grades I-IIIb), but 5 patients (25%) continued to have unsatisfactory pain control (BNI Grade IV or V). Compared with patients without VBE, patients with VBE were much less likely to have initial (p = 0.025) or lasting (p = 0.006) pain relief.</P><B>Conclusions</B><P>Pain control rates of GKS in patients with TN associated with VBE were inferior to those of patients without VBE. Multimodality surgical or medical management strategies were required in most patients with VBE.</P>

Surgical Management Options for Trigeminal Neuralgia

Lunsford, L. Dade,Niranjan, Ajay,Kondziolka, Douglas The Korean Neurosurgical Society 2007 Journal of Korean neurosurgical society Vol.41 No.6

Trigeminal neuralgia is a condition associated with severe episodic lancinating facial pain subject to remissions and relapses. Trigeminal neuralgia is often associated with blood vessel cross compression of the root entry zone or more rarely with demyelinating diseases and occasionally with direct compression by neoplasms of the posterior fossa. If initial medical management fails to control pain or is associated with unacceptable side effects, a variety of surgical procedures offer the hope for long-lasting pain relief or even cure. For patients who are healthy without significant medical co-morbidities, direct microsurgical vascular decompression [MVD] offers treatment that is often definitive. Other surgical options are effective for elderly patients not suitable for MVD. Percutaneous retrogasserian glycerol rhizotomy is a minimally invasive technique that is based on anatomic definition of the trigeminal cistern followed by injection of anhydrous glycerol to produce a weak neurolytic effect on the post-ganglionic fibers. Other percutaneous management strategies include radiofrequency rhizotomy and balloon compression. More recently, stereotactic radiosurgery has been used as a truly minimally invasive strategy. It also is anatomically based using high resolution MRI to define the retrogasserian target. Radiosurgery provides effective symptomatic relief in the vast majority of patients, especially those who have never had prior surgical procedures. For younger patients, we recommend microvascular decompression. For patients with severe exacerbations of their pain and who need rapid response to treatment, we suggest glycerol rhizotomy. For other patients, gamma knife radiosurgery represents an effective management strategy with excellent preservation of existing facial sensation.

Salvage gamma knife stereotactic radiosurgery followed by bevacizumab for recurrent glioblastoma multiforme: a case-control study.

Park, Kyung-Jae,Kano, Hideyuki,Iyer, Aditya,Liu, Xiaomin,Niranjan, Ajay,Flickinger, John C,Lieberman, Frank S,Lunsford, L Dade,Kondziolka, Douglas M. Nijhoff ; Kluwer Academic Publishers 2012 Journal of neuro-oncology Vol.107 No.2

<P>We evaluated the efficacy and safety of gamma knife stereotactic radiosurgery (GKSR) followed by bevacizumab combined with chemotherapy in 11 patients with recurrent glioblastoma multiforme who experienced tumor progression despite aggressive initial multi-modality treatment. Our experience included eight male and three female patients. The median patient age at GKSR was 62 years (range 46-72 years). At the time of GKSR, seven patients had a first recurrence and four had two or more recurrences. The median interval from the initial diagnosis until GKSR was 17 months (range 5-34.5 months). The median tumor volume was 13.6 cm(3) (range 1.2-45.1 cm(3)) and the median margin dose of GKSR was 16 Gy (range 13-18 Gy). Following GKSR, bevacizumab was administrated with irinotecan in nine patients and with temozolomide in one patient. One patient was treated with bevacizumab monotherapy. The treatment outcomes were compared to 44 case-matched controls who underwent GKSR without additional bevacizumab. At a median of 13.7 months (range 4.6-28.3 months) after radiosurgery, tumor progression was evident in seven patients. The median progression-free survival (PFS) was 15 months (95% confidential interval (CI), 6.5-23.3 months). Six-month and 1-year PFS rates were 73 and 55%, respectively. The median overall survival (OS) from GKSR was 18 months (95% CI, 10.1-25.7 months) and 1-year OS rate was 73%. One patient (9%) experienced grade III toxicity and one patient (9%) had major adverse radiation effects. Compared with patients who did not receive bevacizumab, the patients who received bevacizumab had significantly prolonged PFS (15 months vs. 7 months, P = 0.035) and OS (18 months vs. 12 months, P = 0.005), and were less likely to develop an adverse radiation effect (9 vs. 46%, P = 0.037). The combination of salvage GKSR followed by bevacizumab added potential benefit and little additional risk in a small group of patients with progressive glioblastoma. Further experience is needed to define the efficacy and long-term toxicity with this strategy.</P>