Faculty Bibliography

Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, has shown promise in treating recurrent adult high-grade glioma (HGG). However, there is very little data on recurrent or progressive pediatric HGG treated with bevacizumab. We report the results of a single institution experience using bevacizumab and irinotecan in children who relapsed or progressed following standard therapy. Twelve pediatric patients with recurrent or progressive HGG received bevacizumab at 10 mg/kg every 2 weeks with irinotecan at 125 mg/m(2). Magnetic resonance imaging (MRI) was performed prior to therapy and every 8 weeks subsequently. Ten patients had supratentorial HGG; 2 had DIPG. Radiological responses were defined according to MacDonald's criteria. Progression-free survival (PFS), overall survival (OS), and toxicities were analyzed. Ten (83.3%) patients tolerated bevacizumab without serious toxicity. Therapy was discontinued in 1 patient because of anaphylaxis. Another patient developed grade III delayed wound healing and deep vein thrombosis. Two patients (16.7%) experienced a partial response after the first MRI. No complete radiographic responses were seen. Stable disease was noted in 4 (33.3%) patients. The median PFS and OS were 2.25 and 6.25 months, respectively. A diffuse invasive recurrence pattern was noted in 5 (45.5%) patients. Treatment tolerance, toxicity, and recurrence profiles were comparable to adult HGG patients treated with bevacizumab. However, the radiological response rate, response duration, and survival appeared inferior in pediatric patients. Genetic differences in pediatric gliomas might account for this difference

OBJECT: Fusiform dilation of the supraclinoid internal carotid artery (FDCA) is a reported occurrence following surgery for suprasellar tumors, in particular craniopharyngiomas. We report our experience of the incidence and natural history of FDCA following aggressive surgical resection of craniopharyngiomas in children. METHODS: Between 1986 and 2006, 86 patients under the age of 21 underwent radical resection of craniopharyngiomas at our institution. Ten cases with < 1 year of follow-up imaging (6), perioperative death (3), or nonsuprasellar tumors (1) were excluded. Data were retrospectively collected on the remaining 76 patients (43 male, 33 female; mean age 9.5 years; mean tumor size 3.3 cm) to determine the risk factors for and the rate and clinical significance of FDCA. RESULTS: Fifty patients had primary tumors and 26 patients received treatment before referral to our center. Sixty-six children (87%) had gross-total resection. At a mean follow-up time of 9.9 years, FDCA had developed in 7 patients (9.2%), all of whom had primary tumors and gross-total resection. The mean time to onset of FDCA was 6.8 months (range 3-11 months) with stabilization occurring at mean of 17.7 months (range 9-29.5 months). The mean size of the aneurysms was 9.1 mm (range 7.1-12 mm). After arrest, no lesions showed continued growth on serial imaging or produced symptoms or required treatment. There were no significant differences in age, sex, tumor size, pre- or retrochiasmatic location, extent of resection, or surgical approach (p > 0.05) between patients with and without FDCA. CONCLUSIONS: Fusiform dilation of the supraclinoid internal carotid artery occurred in almost 10% of children following radical resection of craniopharyngiomas. In agreement with other reports, the authors concluded that FDCA probably occurs as a result of surgical manipulation of the supraclinoid carotid artery and should be managed conservatively because very few patients exhibit continued symptoms or experience growth or rupture of the lesion

OBJECT: Controversy persists concerning the optimal treatment of craniopharyngiomas in children, and no standard outcome metric exists for comparison across treatment modalities, nor is there one that adequately reflects the multisystem dysfunction that may arise. METHODS: The authors retrospectively analyzed the records of 86 consecutive children who underwent a uniform treatment paradigm of attempted radical resection performed by a single surgeon. Excluding 3 perioperative deaths and 3 patients with inadequate follow-up, 80 children (34 girls and 46 boys; mean age 9.56 years; mean follow-up 9.6 years) composed the study group (53 primary and 27 previously treated/recurrent tumors). Building on existing classification schemes proposed by De Vile for hypothalamic dysfunction and Wen for overall functional outcome, the authors devised a more nuanced classification system (Craniopharyngioma Clinical Status Scale [CCSS]) that assesses outcome across 5 axes, including neurological examination, visual status, pituitary function, hypothalamic dysfunction, and educational/occupational status at last follow-up (there is a 4-tiered grading scale in each domain, with increasing values reflecting greater dysfunction). RESULTS: There was a significant increase in pituitary dysfunction following treatment-consistent with the high rates of diabetes insipidus and hypopituitarism common to the surgical management of craniopharyngiomas-and less dramatic deterioration in hypothalamic function or cognitive domains. Significant improvement in vision was also demonstrated, with no significant overall change in neurological status. Preoperative CCSS scores predicted postoperative outcome better than clinical characteristics like patient age, sex, tumor size, and the location or presence of hydrocephalus. CONCLUSIONS: Preoperative CCSS scores predicted outcome with higher accuracy than clinical or imaging characteristics. In lieu of randomized trials, the CCSS may provide a useful outcome assessment tool for comparison across treatment paradigms and surgical approaches. Long-term follow-up is critical to the analysis of outcomes of craniopharyngioma treatment, given the often-delayed sequelae of all therapies and the high recurrence rates of these tumors

BACKGROUND: The treatment of central nervous system (CNS) germ cell tumors (GCT) remains controversial. The purpose of this study was to demonstrate efficacy of a chemotherapy only strategy, with less morbidity, when compared to regimens with irradiation. METHODS: Between January 2001 and December 2004 newly diagnosed patients with CNS GCT were treated with one of two risk-tailored chemotherapy regimens. Twenty-five patients aged 4 months to 24.5 years were stratified: Regimen A consisted of 4-6 cycles of carboplatin/etoposide alternating with cyclophosphamide/etoposide for low risk (LR) localized germinoma with normal cerebrospinal fluid (CSF) and serum tumor markers. Regimen B consisted of 4-6 cycles of carboplatin/cyclophosphamide/etoposide for intermediate-risk (IR) germinoma with positive human chorionic gonadotrophin-beta (HCGbeta) and/or CSF HCGbeta <50 mIU/ml and high-risk (HR) biopsy-proven non-germinomatous malignant elements (MMGCT) or elevated serum/CSF alpha-fetoprotein and/or HCGbeta serum/CSF >50 mIU/ml. RESULTS: Eleven patients were classified as LR, 2 IR, and 12 HR. Seventeen (68%) patients achieved complete radiographic and marker responses after two courses and 19 (76%) after four courses of chemotherapy. Eleven patients relapsed at a mean of 30.8 months; eight of them subsequently received irradiation. The 6-year event free and overall survival for the 25 patients was 45.6% and 75.3%, respectively. CONCLUSION: These intensive chemotherapy regimens proved less effective than irradiation containing regimens. Our results indicate that, at the present time, standard treatment for CNS GCT continues to include irradiation either alone or combined with chemotherapy for pure germinomas and with chemotherapy for those with MMGCT

OBJECT: Optimal treatment of primary and recurrent craniopharyngiomas remains controversial. Radical resection and limited resection plus radiation therapy yield similar rates of disease control and overall survival. The data are much less clear for recurrent tumors. The authors report their experience with radical resection of both primary and recurrent craniopharyngiomas in children and compare the outcomes between the 2 groups. METHODS: A retrospective analysis was performed in 86 children younger than 21 years of age who underwent a total of 103 operations for craniopharyngioma between 1986 and 2008; these were performed by the senior author. The goal was resection with curative intent in all patients. Two patients were lost to follow-up and were excluded from analysis. The mean age at the time of surgery was 9.6 years, and the mean follow-up was 9.0 years. RESULTS: All 57 children with primary tumors underwent gross-total resection (GTR). A GTR was achieved in significantly fewer children with recurrent tumors (18 [62%] of 29). There were 3 perioperative deaths (3%). Tumor recurred after GTR in 14 (20%) of 71 patients. Overall survival and progression-free survival were significantly better in patients with primary tumors at time of presentation to the authors' institution. There were no significant differences in the neurological, endocrinological, visual, or functional outcomes between patients with primary and those with recurrent tumors. Factors negatively affecting overall survival and progression-free survival include subtotal resection (recurrent tumors only), tumor size >or= 5 cm, or presence of hydrocephalus or a ventriculoperitoneal shunt. Prior radiation therapy and increasing tumor size were both risk factors for incomplete resection at reoperation. CONCLUSIONS: In the hands of surgeons with experience with craniopharyngiomas, the authors believe that radical resection at presentation offers the best chance of disease control and potential cure with acceptable morbidity. While GTR does not preclude recurrence and is more difficult to achieve in recurrent tumors, especially large and previously irradiated tumors, radical resection is still possible in patients with recurrent craniopharyngiomas with morbidity similar to that of primary tumors

A choroid plexus papilloma is a rare CNS neoplasm arising from the neuroepithelial lining of the choroid plexus. A third ventricular location of a choroid plexus papilloma is rare compared with the more common sites in the lateral and fourth ventricles. Cystic choroid plexus papilloma represents an infrequent subtype that may present diagnostic ambiguity. The authors present a case of cystic choroid plexus papilloma within a cavum septum pellucidum that radiographically mimicked neurocysticercosis

OBJECT: The choice of surgical approach during resection of a thalamic juvenile pilocytic astrocytoma (JPA) is dictated by the location of the displaced normal thalamus and posterior limb of the internal capsule (PLIC). Diffusion tensor (DT) imaging and white matter tractography can identify the location of the PLIC in relation to the tumor and may be useful in planning the operative trajectory. METHODS: Diffusion tensor imaging was used to localize the PLIC on preoperative MR imaging in 6 children undergoing resection of thalamic JPAs. After review of the standard T2-weighted MR imaging sequences, the anticipated position of the PLIC was determined. This result was compared with the location of the PLIC determined by a blinded radiologist with the use of DT imaging. The utility of DT imaging in determining the surgical approach to a thalamic JPA, degree of resection, and neurological outcomes were all evaluated. RESULTS: Diffusion tensor imaging confirmed the expected location of the PLIC as approximated on conventional T2-weighted images in all 6 cases. In 1 patient in particular, unexpected medial deviation of the PLIC was identified, and this proved useful in tailoring the approach to a more lateral trajectory. Gross-total resection of all cystic and solid tumor components was confirmed on postoperative imaging in all cases. All patients experienced mild to moderate worsening of neurological status immediately following resection, but 4 of 6 patients were back to their preoperative baseline at 6-month follow-up. CONCLUSIONS: Diffusion tensor imaging and white matter tractography successfully identified the white matter fibers emanating from the precentral gyrus within the PLIC in children with thalamic JPAs prior to surgery. Diffusion tensor imaging served as a valuable tool for stereotactic planning of operative approaches to thalamic JPAs. Localizing the position of the PLIC helped minimize potential neurological morbidity and facilitated gross-total resection