Stereotactic cyst aspiration directly followed by Gamma Knife radiosurgery for large cystic brain metastases.

BACKGROUND: Gamma Knife radiosurgery (GKRS) has been proven to be a successful primary treatment for metastatic brain tumors (BM). BM can come in cystic lesions and are often too large for GKRS. An alternative approach to treat cystic BM is stereotactic cyst aspiration (SCA) for volume reduction, making it suitable for GKRS afterwards. OBJECTIVE: Our objective is evaluation of volumetric reduction after SCA, tumor control, and complications after SCA directly followed by GKRS. METHODS: We performed a retrospective analysis of all patients who underwent SCA directly followed by GKRS at the Gamma Knife Center of the Elisabeth-Tweesteden Hospital in Tilburg between 2002 and 2015. In total, 54 patients had undergone this combined approach. Two patients were excluded because of prior intracranial treatment. The other 52 patients were included for analysis. RESULTS: SCA resulted in a mean volumetric reduction of 56.5% (range 5.50-87.00%). In 83.6% of the tumors (46 tumors), SCA led to sufficient volumetric reduction making GKRS possible. The overall local tumor control (OLTC) of the aspirated lesions post-GKRS was 60.9% (28 out of 46 tumors). Median progression-free survival (PFS) and overall survival (OS) for all patients were 3 (range 5 days-14 months) and 12 months (range 5 days-58 months), respectively. Leptomeningeal disease was reported in 5 (9.6%) cases. CONCLUSION: SCA directly followed by GKRS is an effective and time-efficient treatment for large cystic BM in selected patients in which surgery is contraindicated and those with deeply located lesions.

WHO grade I meningiomas that show regrowth after gamma knife radiosurgery often show 1p36 loss.

WHO grade I meningiomas occasionally show regrowth after radiosurgical treatment, which cannot be predicted by clinical features. There is increasing evidence that certain biomarkers are associated with regrowth of meningiomas. The aim of this retrospective study was to asses if these biomarkers could be of value to predict regrowth of WHO grade I meningiomas after additive radiosurgery. Forty-four patients with WHO grade I meningiomas who underwent additive radiosurgical treatment between 2002 and 2015 after Simpson IV resection were included in this study, of which 8 showed regrowth. Median follow-up time was 64 months (range 24-137 months). Tumors were analyzed for the proliferation marker Ki-67 by immunohistochemistry and for deletion of 1p36 by fluorescence in situ hybridization (FISH). Furthermore, genomic DNA was analyzed for promoter hypermethylation of the genes NDRG1-4, SFRP1, HOXA9 and MGMT. Comparison of meningiomas with and without regrowth after radiosurgery revealed that loss of 1p36 (p = 0.001) and hypermethylation of NDRG1 (p = 0.046) were correlated with regrowth free survival. Loss of 1p36 was the only parameter that was significantly associated with meningioma regrowth after multivariate analysis (p = 0.01). Assessment of 1p36 loss in tumor tissue prior to radiosurgery might be considered an indicator of prognosis/regrowth. However, this finding has to be validated in an independent larger set of tumors.

Volumetric changes and clinical outcome for petroclival meningiomas after primary treatment with Gamma Knife radiosurgery.

OBJECTIVEPetroclival meningiomas (PCMs) can cause devastating clinical symptoms due to mass effect on cranial nerves (CNs); thus, patients harboring these tumors need treatment. Many neurosurgeons advocate for microsurgery because removal of the tumor can provide relief or result in symptom disappearance. Gamma Knife radiosurgery (GKRS) is often an alternative for surgery because it can cause tumor shrinkage with improvement of symptoms. This study evaluates qualitative volumetric changes of PCM after primary GKRS and its impact on clinical symptoms.METHODSThe authors performed a retrospective study of patients with PCM who underwent primary GKRS between 2003 and 2015 at the Gamma Knife Center of the Elisabeth-Tweesteden Hospital in Tilburg, the Netherlands. This study yields 53 patients. In this study the authors concentrate on qualitative volumetric tumor changes, local tumor control rate, and the effect of the treatment on trigeminal neuralgia (TN).RESULTSLocal tumor control was 98% at 5 years and 93% at 7 years (Kaplan-Meier estimates). More than 90% of the tumors showed regression in volume during the first 5 years. The mean volumetric tumor decrease was 21.2%, 27.1%, and 31% at 1, 3, and 6 years of follow-up, respectively. Improvement in TN was achieved in 61%, 67%, and 70% of the cases at 1, 2, and 3 years of follow-up, respectively. This was associated with a mean volumetric tumor decrease of 25% at the 1-year follow-up to 32% at the 3-year follow-up.CONCLUSIONSGKRS for PCMs yields a high tumor control rate with a low incidence of neurological deficits. Many patients with TN due to PCM experienced improvement in TN after radiosurgery. GKRS achieves significant volumetric tumor decrease in the first years of follow-up and thereafter.

Gamma Knife radiosurgery for intracranial meningiomas: Do we need to treat the dural tail? A single-center retrospective analysis and an overview of the literature.

BACKGROUND: The dural tail (DT) has been described as a common feature in meningiomas. There is a great variation of tumor invasion and extent of tumor cells in the DT. Therefore, the necessity to include the whole DT in Gamma Knife radiosurgery is not clear, since inclusion increases the target volume and therefore increases the risk of complications. In this analysis, we evaluated whether the complete tail should be included as part of the target in Gamma Knife radiosurgery for meningiomas. METHODS: Between June 2002 and December 2010, Gamma Knife radiosurgery was performed in 160 patients with 203 meningiomas with a DT. In 105 tumors, the diagnosis was based on magnetic resonance imaging (MRI) characteristics, and in 98 tumors, the diagnosis was confirmed by histopathologic examination after surgery. The median volume of the tumors was 3.55 cc. All tumors were treated with Gamma Knife radiosurgery with a median prescribed dose of 13 Gy (range 11-15), resulting in a median marginal dose of 11 Gy (range 10-15). Only the part of the DT closely related to the tumor mass was included in the target. The median follow-up period was 41 months (range 12-123). RESULTS: In image-based meningiomas, the overall local control rate was 96.2% with 2- and 5-year control rates of 98.0% and 95.1%, respectively. In WHO grade I tumors, the overall local control rate was 85.9% with 2- and 5-year control rates of 94.5% and 88.0%, respectively. The overall local control rate in World Health Organization (WHO) grade II tumors was 70.6% with control rates of 83.4% and 64.4% after 2 and 5 years, respectively. The growth of all new tumors was found in the radiation target area. No tumor growth was observed in the part of the DT that had been excluded from the target volume. CONCLUSION: We found in this study that routinely excluding the DT from the target does not lead to out-of-field tumor progression. Given the possibility that the DT is infiltrated with tumor cells, regular follow-up is needed.

Gamma Knife surgery for trigeminal neuralgia: a review of 450 consecutive cases.

OBJECT: The success rates and side effects of Gamma Knife surgery (GKS) in patients with trigeminal neuralgia (TN) are not fully clear. A comparison of data across previous reports is hampered by differences in treatment protocols, lengths of follow-up, and outcome criteria. The purpose of this paper is to contribute to knowledge of the efficacy of GKS in TN by reviewing data in a large group of patients with this disorder, who were treated with a uniform treatment protocol and evaluated using a well-established pain scale and Kaplan-Meier analysis. METHODS: The authors reviewed 450 treatments in 365 patents with medically refractory TN who were treated between June 2002 and October 2009 at the Gamma Knife Center Tilburg. In all patients 80 Gy was prescribed, with a single 4-mm isocenter located at the root entry zone (REZ). In 79 patients repeated GKS was performed using a uniform dose of 80 Gy, which was delivered, in a highly standardized manner, to a spot anterior to the position of the first treatment. Follow-up was obtained by reviewing the patients' medical records and conducting telephone interviews. Outcome was assessed using the Barrow Neurological Institute (BNI) pain scale and the BNI facial numbness scale. RESULTS: The median follow-up period was 28 months. In the idiopathic TN group, rates of adequate pain relief, defined as BNI Pain Scores I-IIIB, were 75%, 60%, and 58% at 1, 3, and 5 years, respectively. In the multiple sclerosis (MS)-related TN group the rates of adequate pain relief were 56%, 30%, and 20% at 1, 3, and 5 years, respectively. Repeated GKS was as successful as the first. An analysis of our treatment strategy of repeated GKS showed rates of adequate pain relief of 75% at 5 years in the idiopathic TN and 46% in the MS-related TN group. Somewhat bothersome numbness was reported by 6% of patients after the first treatment and by 24% after repeated GKS. Very bothersome numbness was reported in 0.5% after the first GKS and in 2% after the second treatment. CONCLUSIONS: In this study the authors analyzed outcomes of GKS in a large cohort of patients with TN; uniform treatment consisted of 80 Gy delivered to the REZ. The initial and long-term outcomes of pain relief and sensory dysfunction are comparable to recently published results at other institutions, where similar outcome criteria were used. These data should prove helpful to assist patients and clinicians in their TN management decisions.