A case of developmental pedophilia unmasked by frontotemporal dementia.

A 65-year-old right-handed man gradually became socially indifferent and less active. Four years later, he was indicted for molesting children on multiple occasions. Psychomotor slowness and executive impairment contrasted with sparing of language, semantic memory, visuospatial perception, construction praxis, and right-left orientation. Neuroimaging showed asymmetric atrophy of dorsomedial frontal and anterior temporal lobes, and hypoperfusion of medial prefrontal cortex consistent with a diagnosis of behavioral variant of frontotemporal dementia. Further information revealed that the patient exhibited pedophilic behavior several years prior to symptom onset. We conclude that preexisting developmental pedophilia was "unmasked" by the underlying progressive frontotemporal degeneration.

Effect of Cranial Window Diameter During Deep Brain Stimulation Surgery on Volume of Pneumocephalus.

OBJECTIVE: Successful deep brain stimulation (DBS) surgery necessitates high accuracy in targeting specific intracranial nuclei. Brain shift due to pneumocephalus can contribute to decreased accuracy. Larger burr holes and dural openings may increase pneumocephalus volume due to a greater degree of communication between the subdural space and extracranial air. The aim of this study is to determine if there is a statistically and clinically significant difference in postoperative pneumocephalus volume related to burr hole and durotomy size. MATERIALS AND METHODS: DBS electrodes were surgically implanted through either large (14 mm) burr holes or small (4 mm) twist drill holes. Immediate postoperative computerized tomography (CT) scans of 165 electrode implantations in 85 patients from 2010 to 2013 were retrospectively analyzed. Student's t-test and Mann-Whitney U-test were employed with a threshold of significance set at p ≤ 0.05. RESULTS: No significant difference in pneumocephalus was identified between patients who had implantation of DBS electrodes through 4 mm twist drill holes (N = 71 hemispheres, 12.84 ± 9.79 cm(3) ) and those with large 14 mm burr holes (N = 87, 11.70 ± 7.46 cm(3) , p = 0.42). Volume of pneumocephalus did not correlate with duration of surgery or patient age. The groups did not differ significantly with respect to other aspects of surgical implantation technique or surgical duration. CONCLUSION: While identifying factors that may reduce pneumocephalus volume may be critical to improving stereotactic accuracy and targeting, the current results suggest that burr hole size may not alter the degree of brain shift.

Stereotactic radiation therapy for progressive residual pilocytic astrocytomas.

This report shows the results of stereotactic radiation therapy for progressive residual pilocytic astrocytomas. Medical records of patients who had undergone stereotactic radiation therapy for a progressive residual pilocytic astrocytoma were reviewed. Between 1995 and 2010, 12 patients with progression of a residual pilocytic astrocytoma underwent stereotactic radiation therapy at UCLA. Presentation was headache (4), visual defects (3), hormonal disturbances (2), gelastic seizures (2) and ataxia (1). MRI showed a cystic (9), mixed solid/cystic (2) or solid tumor (1); located in the hypothalamus (5), midbrain (3), thalamus (2), optic chiasm (1) or deep cerebellum (1). Median age was 21 years (range 5-41). Nine tumors received stereotactic radiotherapy (SRT). Three tumors received stereotactic radiosurgery (SRS), two of them to their choline positive regions. SRT median total dose was 50.4 Gy (40-50.4 Gy) in a median of 28 fractions (20-28), using a median fraction dose of 1.8 Gy (1.8-2 Gy) to a median target volume of 6.5 cm(3). (2.4-33.57 cm(3)) SRS median dose was 18.75 Gy (16.66-20 Gy) to a median target volume of 1.69 cm(3) (0.74-2.22 cm(3)). Median follow-up time was 37.5 months. Actuarial long-term progression-free and disease-specific survival probabilities were 73.3 and 91.7 %, respectively. No radiation-induced complications were observed. Stereotactic radiation therapy is a safe and effective modality to control progressive residual pilocytic astrocytomas. Better outcomes are obtained with SRT to entire tumor volumes than with SRS targeting choline positive tumor regions.

Endonasal transsphenoidal surgery and multimodality treatment for giant pituitary adenomas.

OBJECTIVE: Giant pituitary adenomas (> or =40 mm) pose a major management challenge. We describe the experience of a single surgeon and a dedicated neuro-endocrine team with multimodality treatment of these tumours in three specialized institutions. DESIGN: Retrospective data set analyses. PATIENTS: Fifty-one consecutive patients with a giant adenoma (39 endocrine-inactive, 12 endocrine-active; mean tumour diameter 45 mm) treated over 10 years by an endonasal transsphenoidal approach were included. All patients had surgical resection followed by radiotherapy and/or medical therapy as judged necessary. MEASUREMENTS: Hormonal and visual status, extent of resection, tumour control rates, complications and use of medical and radiotherapy were evaluated. RESULTS: Surgery resulted in gross total, near total and subtotal removal in21 (41%), 10 (20%) and 20 (39%) patients respectively. Complete tumour removal was associated with absence of cavernous sinus invasion (P < 0.001). Long-term endocrine function improved in 49% of patients and new endocrinopathy occurred in 14.6%; 76% required long-term hormone replacement therapy. Vision improved in 81.5% of the patients and there was no visual worsening. At the last follow up (median 30 months), tumour control was achieved in 96% of patients: 59% with surgery alone, 20% with surgery plus focussed radiotherapy, 18% with surgery and medical therapy and two with all three modalities. CONCLUSIONS: Endonasal surgery provides effective initial treatment for patients with giant adenomas. Multimodality therapy was needed in almost 50% of patients and this rate will likely increase with longer follow up. Close collaboration of neurosurgeons with endocrinologists and radiation oncologists is essential for optimal treatment of patients with these challenging tumours.

Electrical stimulation of the anterior nucleus of thalamus for treatment of refractory epilepsy.

PURPOSE: We report a multicenter, double-blind, randomized trial of bilateral stimulation of the anterior nuclei of the thalamus for localization-related epilepsy. METHODS: Participants were adults with medically refractory partial seizures, including secondarily generalized seizures. Half received stimulation and half no stimulation during a 3-month blinded phase; then all received unblinded stimulation. RESULTS: One hundred ten participants were randomized. Baseline monthly median seizure frequency was 19.5. In the last month of the blinded phase the stimulated group had a 29% greater reduction in seizures compared with the control group, as estimated by a generalized estimating equations (GEE) model (p = 0.002). Unadjusted median declines at the end of the blinded phase were 14.5% in the control group and 40.4% in the stimulated group. Complex partial and "most severe" seizures were significantly reduced by stimulation. By 2 years, there was a 56% median percent reduction in seizure frequency; 54% of patients had a seizure reduction of at least 50%, and 14 patients were seizure-free for at least 6 months. Five deaths occurred and none were from implantation or stimulation. No participant had symptomatic hemorrhage or brain infection. Two participants had acute, transient stimulation-associated seizures. Cognition and mood showed no group differences, but participants in the stimulated group were more likely to report depression or memory problems as adverse events. DISCUSSION: Bilateral stimulation of the anterior nuclei of the thalamus reduces seizures. Benefit persisted for 2 years of study. Complication rates were modest. Deep brain stimulation of the anterior thalamus is useful for some people with medically refractory partial and secondarily generalized seizures.

Diffusion tensor imaging (DTI) and colored fractional anisotropy (FA) mapping of the subthalamic nucleus (STN) and the globus pallidus interna (GPi).

INTRODUCTION: The subthalamic nucleus (STN) and the globus pallidus internus (GPi) are the most common surgical targets for the treatment of Parkinson's disease. We studied directionally colored fractional anisotropy (FA) and diffusion tensor imaging (DTI) sequences to better target these anatomical regions. METHODS: Four patients undergoing stereotactic surgery for movement disorders were studied. Stereotactic targets and fiber tractography were determined on MRIs using the Schaltenbrand-Wahren atlas for definition in the iPlan software. In addition, post-operative imaging was fused to preoperative FA sequences for end-result identification. Axial, sagittal, and coronal images of the FA sequence were studied. DTI parameters used ranged from 2 to 4 mm for voxel size in the x/y/z planes, fiber length was kept constant at 15 mm and FA threshold of 0.25. RESULTS: Colored FA maps resulted in a key signature in and around the STN and GPi. Regions identified include, but were not limited to: the internal capsule, nigral projections, the thalamic fasciculus, Forel's fields H1 and H2, zona incerta, suthalamic fasciculus, tegmental tracts, and cerebello-rubro-thalamic tract. CONCLUSIONS: Colored FA maps allow a potential method to identify the STN and GPi accurately. DTI has proven to be a powerful tool that can be used to augment identification of the STN nucleus and GPi used for stereotactic surgery.

Stereotactic coordinates associated with facial musculature contraction during high-frequency stimulation of the subthalamic nucleus.

OBJECT: High-frequency stimulation of the subthalamic nucleus (STN) in patients with parkinsonian symptoms is often used to ameliorate debilitating motor symptoms associated with this condition. However, individual variability in the shape and orientation of this relatively small nucleus results in multiple side effects related to the spread of electrical current to surrounding structures. Specifically, contraction of the muscles of facial expression is noted in a small percentage of patients, although the precise mechanism remains poorly understood. METHODS: Facial muscle contraction was triggered by high-frequency stimulation of 49 contacts in 18 patients undergoing deep brain stimulation of the STN. The mean coordinates of these individual contacts relative to the anterior commissure-posterior commissure midpoint (also called the midcommissural point) were calculated to determine the location or structure(s) most often associated with facial contraction during physiological macrostimulation. RESULTS: The x, y, and z coordinates associated with contraction of the facial musculature were found to be 11.52, 1.29, and 1.15 mm lateral, posterior, and inferior to the midcommissural point, respectively. This location, along the lateral-anterior-superior border of the STN, may allow for the spread of electrical current to the fields of Forel, zona incerta, and/or descending corticospinal/corticobulbar tracts. Because stimulation of corticobulbar tracts produces similar findings, these results are best explained by the spread of electrical current to nearby internal capsule axons coursing lateral to the STN. CONCLUSIONS: Thus, if intraoperative deep brain stimulation lead testing results in facial musculature contraction, placement of the electrode in a more medial, posterior position may reduce the amount of current spread to corticobulbar fibers and resolve this side effect.

Image-guided radiosurgery for spinal tumors: methods, accuracy and patient intrafraction motion.

Image-guided frameless extracranial radiosurgery has become an established treatment option; however, without a frame to restrict patient movements, intrafraction field mispositioning becomes more probable. The primary aim of this study is to determine the intrafraction motion of spinal radiosurgery patients. This aim was approached in two steps. First, a phantom study demonstrated that the system can detect movements accurately within 0.1 mm and rotational changes within 0.2 degrees. Second, patient positioning and monitoring were carried out for a group of 15 patients with 20 treatment sites. For the patient pool in the study, vertebral anatomy movement was observed to vary as much as 3 mm between sequential measurements and could occur in as little as 5 min. These results suggest a need for intrafraction patient monitoring and correctional shifts, even for patients whose overall treatment times are expected to be relatively short. Small relative rotations with standard deviations of less than 1.5 degrees were observed. The small relative rotational movements observed do not, alone, justify patient monitoring using the image-guidance system during the treatments of generally small radiosurgical targets.

Potential surgical targets for deep brain stimulation in treatment-resistant depression.

OBJECT: The goal of this study was to evaluate the definition of treatment-resistant depression (TRD), review the literature regarding deep brain stimulation (DBS) for TRD, and identify potential anatomical and functional targets for future widespread clinical application. METHODS: A comprehensive literature review was performed to determine the current status of DBS for TRD, with an emphasis on the scientific support for various implantation sites. RESULTS: The definition of TRD is presented, as is its management scheme. The rationale behind using DBS for depression is reviewed. Five potential targets have been identified in the literature: ventral striatum/nucleus accumbens, subgenual cingulate cortex (area 25), inferior thalamic peduncle, rostral cingulate cortex (area 24a), and lateral habenula. Deep brain stimulation electrodes thus far have been implanted and activated in only the first 3 of these structures in humans. These targets have proven to be safe and effective, albeit in a small number of cases. CONCLUSIONS: Surgical intervention for TRD in the form of DBS is emerging as a viable treatment alternative to existing modalities. Although the studies reported thus far have small sample sizes, the results appear to be promising. Various surgical targets, such as the subgenual cingulate cortex, inferior thalamic peduncle, and nucleus accumbens, have been shown to be safe and to lead to beneficial effects with various stimulation parameters. Further studies with larger patient groups are required to adequately assess the safety and efficacy of these targets, as well as the optimal stimulation parameters and long-term effects.

Stereotactic Radiosurgery for Benign (World Health Organization Grade I) Cavernous Sinus Meningiomas-International Stereotactic Radiosurgery Society (ISRS) Practice Guideline: A Systematic Review.

BACKGROUND: Stereotactic radiosurgery (SRS) has become popular as a standard treatment for cavernous sinus (CS) meningiomas. OBJECTIVE: To summarize the published literature specific to the treatment of CS meningioma with SRS found through a systematic review, and to create recommendations on behalf of the International Stereotactic Radiosurgery Society. METHODS: Articles published from January 1963 to December 2014 were systemically reviewed. Three electronic databases, PubMed, EMBASE, and The Cochrane Central Register of Controlled Trials, were searched. Publications in English with at least 10 patients (each arm) were included. RESULTS: Of 569 screened abstracts, a total of 49 full-text articles were included in the analysis. All studies were retrospective. Most of the reports had favorable outcomes with 5-yr progression-free survival (PFS) rates ranging from 86% to 99%, and 10-yr PFS rates ranging from 69% to 97%. The post-SRS neurological preservation rate ranged from 80% to 100%. Resection can be considered for the treatment of larger (>3 cm in diameter) and symptomatic CS meningioma in patients both receptive to and medically eligible for open surgery. Adjuvant or salvage SRS for residual or recurrent tumor can be utilized depending on factors such as tumor volume and proximity to adjacent critical organs at risk. CONCLUSION: The literature is limited to level III evidence with respect to outcomes of SRS in patients with CS meningioma. Based on the observed results, SRS offers a favorable benefit to risk profile for patients with CS meningioma.

Contralateral conjugate eye deviation during deep brain stimulation of the subthalamic nucleus.

OBJECT: Deep brain stimulation of the subthalamic nucleus (STN) in patients with Parkinson disease is often very effective for treatment of debilitating motor symptoms. Nevertheless, the small size of the STN and its proximity to axonal projections results in multiple side effects during high-frequency stimulation. Contralateral eye deviation is produced in a small percentage of patients, but the precise mechanism of this side effect is at present poorly understood. METHODS: Contralateral eye deviation was produced by high-frequency stimulation of 22 contact sites in nine patients undergoing deep brain stimulation of the STN. The precise locations of these contacts were calculated and compiled in order to locate the stimulated structure responsible for eye deviation. RESULTS: The mean x, y, and z coordinates associated with contralateral eye deviation were found to be 11.57, 2.03, and 3.83 mm lateral, posterior, and inferior to the anterior commissure-posterior commissure midpoint, respectively. The point described by these coordinates is located within the lateral anterosuperior border of the STN. CONCLUSIONS: Given that stimulation of frontal eye field cortical regions produces similar contralateral conjugate eye deviation, these results are best explained by electrical current spread to nearby frontal eye field axons coursing lateral to the STN within the internal capsule. Thus, placement of the implanted electrode in a more medial, posterior, and inferior position may bring resolution of these symptoms by reducing the amount of current spread to internal capsule ax-

Radiosurgery for Secondary Trigeminal Neuralgia: Revisiting the Treatment Paradigm.

BACKGROUND: The mechanisms by which surgery and radiation elicit pain relief in trigeminal neuralgia (TN) secondary to mass lesions vary widely. We aimed to evaluate the outcomes of radiation to the nerve rather than to the lesion in the treatment of secondary TN. METHODS: We retrospectively reviewed all patients who underwent radiation at the University of California, Los Angeles for TN secondary to tumors. The Barrow Neurological Institute (BNI) pain score was used to evaluate pain outcomes. RESULTS: Twelve patients were identified; 4 were male and 8 were female. Their mean age at treatment was 59.8 years (range, 47.7-84.7 years). Tumor pathologies included meningioma (n = 8), squamous cell carcinoma (n = 2), vestibular schwannoma (n = 1), and hemangiopericytoma (n = 1). No patient suffered from multiple sclerosis. Ten patients underwent initial radiation targeting their tumors-radiosurgery in 3 and fractionated radiation therapy in 7 others. Only 6 among these 10 experienced at least partial relief, which lasted a mean 6 months. Radiosurgery targeting the trigeminal nerve was eventually performed. Overall, 10 of 12 (83.3%) patients experienced good initial pain relief, complete in 6 (50%) patients. Pain recurred in 6 (60%) patients, at a mean 41 months after radiosurgery to the trigeminal nerve. Three patients experienced facial sensory dysfunction postprocedurally at a mean follow-up duration of 57 months. CONCLUSION: In contrast to tumor radiation, radiosurgery to the trigeminal nerve root resulted in reasonable and longer pain reduction, on par with the literature regarding surgical resection, with low risk of additional complications.

Lateralization of the Subthalamic Nucleus with Age in Parkinson's Disease.

Age-related changes in subthalamic nucleus (STN) position have not been well characterized in patients with Parkinson's disease (PD). We report a systematic retrospective analysis of age-related changes in radiographic and final deep brain stimulator (DBS) STN coordinates in PD patients. The charts of 134 PD patients (97 males, 28-84 years) representing 255 STN were reviewed. Multiple linear regression, stepwise regression, and relative importance of regressors analysis was performed to determine the significance of the relationship between STN position and age. Across all subjects, both radiographic STN localization and final DBS position within the STN showed a lateralization of the STN target with age (R2=0.1096,p=6.9×10-8 and R2=0.0433,p=8.7×10-4, respectively). Lateralization with age was observed regardless of MR field strength (1.5T and 3.0T) (R2=0.0946,p=7.6×10-6 and R2=0.2687,p=9.2×10-5, respectively). No other consistent or clinically significant age-related changes were identified. Multiple linear regression revealed that the third ventricle width and age are statistically significant predictors of radiographic STN lateralization (R2 = 0.2404, p = 1.51×10-5 and p = .00784 respectively). Step-wise regression demonstrated that age is a non-redundant predictor of STN lateralization relative to third ventricle width. Similar to healthy controls, STN position appears to shift laterally with age in PD. This highlights limitations of indirect targeting and atlas-based stereotactic surgery and argues for reliance on patient specific anatomy since factors such as age and 3rd ventricular width can contribute to patient-specific variability in STN localization.

Adjuvant Stereotactic Radiosurgery and Radiation Therapy for the Treatment of Intracranial Chordomas.

Objective Chordomas are locally aggressive, highly recurrent tumors requiring adjuvant radiotherapy following resection for successful management. We retrospectively reviewed patients treated for intracranial chordomas with adjuvant stereotactic radiosurgery (SRS) and stereotactic radiation therapy (SRT). Methods A total of 57 patients underwent 83 treatments at the UCLA Medical Center between February 1990 and August 2011. Mean follow-up was 57.8 months. Mean tumor diameter was 3.36 cm. Overall, 8 and 34 patients received adjuvant SRS and SRT, and the mean maximal dose of radiation therapy was 1783.3 cGy and 6339 cGy, respectively. Results Overall rate of recurrence was 51.8%, and 1- and 5-year progression-free survival (PFS) was 88.2% and 35.2%, respectively. Gross total resection was achieved in 30.9% of patients. Adjuvant radiotherapy improved outcomes following subtotal resection (5-year PFS 62.5% versus 20.1%; p = 0.036). SRS and SRT produced comparable rates of tumor control (p = 0.28). Higher dose SRT (> 6,000 cGy) (p = 0.013) and younger age (< 45 years) (p = 0.03) was associated with improved rates of tumor control. Conclusion Adjuvant radiotherapy is critical following subtotal resection of intracranial chordomas. Adjuvant SRT and SRS were safe and improved PFS following subtotal resection. Higher total doses of SRT and younger patient age were associated with improved rates of tumor control.

The extended direct endonasal transsphenoidal approach for nonadenomatous suprasellar tumors.

OBJECT: The extended transsphenoidal approach, which requires a bone and dural opening through the tuberculum sellae and posterior planum sphenoidale, is increasingly used for the treatment of nonadenomatous suprasellar tumors. The authors present their experiences in using the direct endonasal approach in patients with nonadenomatous suprasellar tumors. METHODS: Surgery was performed with the aid of an operating microscope and angled endoscopes were used to assess the completeness of resection. Bone and dural defects were repaired using abdominal fat, collagen sponge, titanium mesh, and, in most cases, lumbar drainage of cerebrospinal fluid (CSF). Twenty-six procedures for tumor removal were performed in 24 patients (ages 9-79 years), including two repeated operations for residual tumor. Gross-total removal could be accomplished in only 46% of patients, with near-gross-total removal or better in 74% of 23 patients (five of eight with craniopharyngiomas, six of seven with meningiomas, five of six with Rathke cleft cysts, and one of two with a dermoid or epidermoid cyst); a patient with a lymphoma only underwent biopsy. Of 13 patients with tumor-related visual loss, 85% improved postoperatively. The complications that occurred included five patients (21%) with postoperative CSF leaks, one patient (4%) with bacterial meningitis; five patients (21%) with new endocrinopathy; and two patients (8%) who needed to undergo repeated operations to downsize suprasellar fat grafts. The only permanent neurological deficit was anosmia in one patient; there were no intracranial vascular injuries. CONCLUSIONS: The direct endonasal skull-base approach provides an effective minimally invasive means for resecting or debulking nonadenomatous suprasellar tumors that have traditionally been approached through a sublabial or transcranial route. Procedures in the supraglandular space can be performed effectively with excellent visualization of the optic apparatus while preserving pituitary function in most cases. The major challenge remains developing consistently effective techniques to prevent postoperative CSF leaks.

Predictors of recurrence following resection of intracranial chordomas.

Management of intracranial chordomas remains challenging, despite improvements in microsurgical techniques and radiotherapy. Here, we analyzed the prognostic factors associated with improved rates of tumor control in patients with intracranial chordomas, who received either gross (GTR) or subtotal resections (STR). A retrospective review was performed to identify all patients who were undergoing resection of their intracranial chordomas at the Ronald Reagan University of California Los Angeles Medical Center from 1990 to 2011. In total, 57 patients undergoing 81 resections were included. There were 24 females and 33 males with a mean age of 44.6 years, and the mean tumor diameter was 3.36 cm. The extent of resection was not associated with recurrence. For all 81 operations, the 1 and 5 year progression free survival (PFS) was 87.5 and 40.4%, and 88.0 and 33.6% for STR and GTR, respectively (p=0.90). Adjuvant radiotherapy was associated with improved rates of PFS (hazard ratio [HR] 0.20; p=0.009). Additionally, age >45 years (HR 5.88; p=0.01) and the presence of visual deficits (HR 7.59; p=0.03) were associated with worse rates of tumor control. Tumor size, sex, tumor histology, and recurrent tumors were not predictors of recurrence. Younger age, lack of visual symptoms on presentation and adjuvant radiotherapy were associated with improved rates of tumor control following surgery. However, GTR and STR produced comparable rates of tumor control. The surgical management of intracranial chordomas should take a conservative approach, with the aim of maximal but safe cytoreductive resection with adjuvant radiation therapy, and a major focus on quality of life.

Stereotactic radiotherapy for treatment of cavernous sinus meningiomas.

PURPOSE: To assess the safety and efficacy of stereotactic radiotherapy (SRT) using a linear accelerator equipped with a micromultileaf collimator for cavernous sinus meningiomas. METHODS AND MATERIALS: Forty-five patients with benign cavernous sinus meningiomas were treated with SRT between November 1997 and April 2002. Sixteen patients received definitive treatment on the basis of imaging characteristics of the cavernous sinus tumor. Twenty-nine patients received SRT either as immediate adjuvant treatment after incomplete resection or at documented recurrence. Treatment planning in all patients included CT-MRI image fusion and beam shaping using a micromultileaf collimator. The primary tumor volume varied from 1.41 to 65.66 cm(3) (median, 14.5 cm(3)). The tumor diameter varied from 1.4 to 7.4 cm (median, 3.8 cm). Tumor compressed the optic chiasm or optic nerve in 30 patients. All tumors were treated with a single isocenter plus a margin of normal parenchyma varying from 1 to 5 mm (median, 2.5 mm). The prescribed dose varied from 4250 to 5400 cGy (median, 5040 cGy). The prescription isodose varied from 87% to 95% (median, 90%). The maximal tumor dose varied from 5000 to 6000 cGy (median, 5600 cGy). The follow-up varied from 12 to 53 months (median, 36 months). RESULTS: The actuarial 3-year overall and progression-free survival rate was 100% and 97.4%, respectively. One patient (2%) developed local relapsed at 18 months. A partial imaging response occurred in 18% of patients, and the tumor was stable in the remaining 80%. Preexisting neurologic complaints improved in 20% of patients and were stable in the remainder. No patient, tumor, or treatment factors were found to be predictive of imaging or clinical response. Transient acute morbidities included headache responsive to nonnarcotic analgesics in 4 patients, fatigue in 3 patients, and retroorbital pain in 1 patient. No treatment-induced peritumoral edema, cranial neuropathy, endocrine dysfunction, cognitive decline, or second malignancy occurred. One patient had an ipsilateral cerebrovascular accident 6 months after SRT. CONCLUSION: Stereotactic radiotherapy is both safe and effective for patients with cavernous sinus meningiomas. Field shaping using a micromultileaf collimator allows conformal and homogeneous radiation of cavernous sinus meningiomas that may not be amenable to single-fraction stereotactic radiosurgery because of tumor size or location. Additional clinical experience is necessary to determine the position of SRT among the available innovative fractionated RT options for challenging skull base meningiomas.

Initial clinical results of stereotactic radiotherapy for the treatment of craniopharyngiomas.

The efficacy and toxicity of stereotactic radiotherapy (SRT) for the treatment of craniopharyngioma has been retrospectively evaluated in 16 patients. The median tumor diameter was 2.8 cm (range 1.5-6.1) and the median tumor volume was 7.7 cc (range 0.7-62.8). SRT was delivered to a single isocenter using a dedicated 6 MV linear accelerator to patients immobilized with a relocatable stereotactic head frame. The three-year actuarial overall survival was 93% and the rate of survival free of any imaging evidence of progressive disease was 75%. The three-year actuarial survival rates free of solid tumor growth or cyst enlargement were 94% and 81% respectively. Our results suggest that SRT is a safe and effective treatment approach for patients with craniopharyngioma. Long-term follow-up is required to determine whether the normal tissue-sparing inherent with SRT results in reduction of the neurocognitive effects of conventional radiotherapy for craniopharyngioma. SRT can be delivered to craniopharyngioma that may be difficult to treat with stereotactic radiosurgery due to proximity of the optic chiasm. Further clinical experience is necessary to determine the clinical utility of beam shaping in the setting of SRT.

Linear accelerator radiosurgery using 90 gray for essential trigeminal neuralgia: results and dose volume histogram analysis.

OBJECTIVE: To evaluate treatment of essential trigeminal neuralgia with 90 Gy delivered by a linear accelerator dedicated to radiosurgery. METHODS: This is a retrospective case series of 25 patients with essential trigeminal neuralgia treated from March 1999 to March 2001. All were treated with 90 Gy by means of a 5-mm collimator directed to the nerve root entry zone. Patient follow-up (range, 8-52 mo; median, 18 mo) was completed by an uninvolved party. Dose volume histograms of the brainstem were developed for the 20, 30, and 50% isodose lines by means of radiosurgery planning software. RESULTS: All patients obtained good to excellent pain relief with treatment. Nineteen (76%) of 25 patients achieved excellent pain relief (pain-free without medication). Six patients (24%) achieved good pain relief (50-90% reduction of pain with or without medication). Median time to pain relief was 2 months. Eight patients (32%) experienced relapse 4 to 13 months after treatment. Eight patients (32%) developed facial numbness, but none developed painful numbness. Mean brainstem volume within the 50% isodose line and occurrence of numbness was statistically significant (P = 0.03). There was no correlation between brainstem volume treated and outcome. CONCLUSION: Dedicated linear accelerator-based stereotactic radiosurgery that uses a 5-mm collimator to deliver 90 Gy to the nerve root entry zone is a safe and effective method for the treatment of essential trigeminal neuralgia. Care should be taken to limit brainstem volume included in the 50% isodose line in the treatment plan to avoid facial numbness.

Stereotactic radiotherapy for the treatment of acoustic neuromas.

OBJECT: The authors sought to assess the safety and efficacy of stereotactic radiotherapy when using a linear accelerator equipped with a micromultileaf collimator for the treatment of patients with acoustic neuromas. METHODS: Fifty patients harboring acoustic neuromas were treated with stereotactic radiotherapy between September 1997 and June 2003. Two patients were lost to follow-up review. Patient age ranged from 20 to 76 years (median 59 years), and none had neurofibromatosis. Forty-two patients had useful hearing prior to stereotactic radiotherapy. The fifth and seventh cranial nerve functions were normal in 44 and 46 patients, respectively. Tumor volume ranged from 0.3 to 19.25 ml (median 2.51 ml). The largest tumor dimension varied from 0.6 to 4 cm (median 2.2 cm). Treatment planning in all patients included computerized tomography and magnetic resonance image fusion and beam shaping by using a micromultileaf collimator. The planning target volume included the contrast-enhancing tumor mass and a margin of normal tissue varying from 1 to 3 mm (median 2 mm). All tumors were treated with 6-MV photons and received 54 Gy prescribed at the 90% isodose line encompassing the planning target volume. A sustained increase greater than 2 mm in any tumor dimension was defined as local relapse. The follow-up duration varied from 6 to 74 months (median 36 months). The local tumor control rate in the 48 patients available for follow up was 100%. Central tumor hypodensity occurred in 32 patients (67%) at a median of 6 months following stereotactic radiotherapy. In 12 patients (25%), tumor size increased 1 to 2 mm at a median of 6 months following stereotactic radiotherapy. Increased tumor size in six of these patients was transient. In 13 patients (27%), tumor size decreased 1 to 14 mm at a median of 6 months after treatment. Useful hearing was preserved in 39 patients (93%). New facial numbness occurred in one patient (2.2%) with normal fifth cranial nerve function prior to stereotactic radiotherapy. New facial palsy occurred in one patient (2.1 %) with normal seventh cranial nerve function prior to treatment. No patient's pretreatment dysfunction of the fifth or seventh cranial nerve worsened after stereotactic radiotherapy. Tinnitus improved in six patients and worsened in two. CONCLUSIONS: Stereotactic radiotherapy using field shaping for the treatment of acoustic neuromas achieves high rates of tumor control and preservation of useful hearing. The technique produces low rates of damage to the fifth and seventh cranial nerves. Long-term follow-up studies are necessary to confirm these findings.