Lhermitte-Duclos disease (LDD), also known as dysplastic gangliocytoma, is a rare cerebellar lesion. It has long been regarded as avascular. We report two patients with surgically proven LDD in whom contrast enhancement was observed on MRI. Neuropathological examination revealed proliferation of veins. We suggest that peripheral enhancement of LDD probably reflects vascular proliferation of the cerebellar venous draining system, and should be considered part of the imaging features of LDD.

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.

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.

GKRS can safely be used as salvage treatment for recurrent glioma and seems to improve survival rates in (high grade) glioma patients with minimal burden.