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Robert M. Starke, John A. Jane Jr., Ashok R. Asthagiri and John A. Jane Sr.

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Russell R. Lonser, John A. Butman, Kristin Huntoon, Ashok R. Asthagiri, Tianxia Wu, Kamran D. Bakhtian, Emily Y. Chew, Zhengping Zhuang, W. Marston Linehan and Edward H. Oldfield

Object

The tumors most frequently associated with von Hippel-Lindau (VHL) disease are hemangioblastomas. While they are associated with significant neurological impairment and mortality, their natural history and optimal management have not been fully defined.

Methods

Patients with VHL were enrolled in a prospective study designed to define the natural history of CNS hemangioblastomas. In the present analysis, serial imaging, laboratory, genetic, and clinical data were evaluated in those with at least 2 years of follow-up data.

Results

At study entrance 225 patients (111 males, 114 females) harbored 1921 CNS hemangioblastomas in the supratentorial compartment (21 tumors [1%]), cerebellum (865 [45%]), brainstem (129 [7%]), spinal cord (689 [36%]), cauda equina (212 [11%]), and nerve roots (5 [0.3%]; follow-up 15,819 hemangioblastoma-years). Increased tumor burden was associated with partial deletions in the VHL gene (p = 0.005) and male sex (p = 0.002). Hemangioblastoma development (median 0.3 new tumors/year) was associated with younger age (p < 0.0001) and more tumors at study entrance (p < 0.0001). While 1278 hemangioblastomas (51%) did not grow, 1227 hemangioblastomas (49%) grew in a saltatory (886 [72%]), linear (76 [6%]), or exponential (264 [22%]) pattern. Faster tumor growth was associated with male sex (p = 0.001), symptomatic tumors (p < 0.0001), and tumors associated with cysts (p < 0.0001). Location-dependent tumor size was the primary predictor of eventual symptom formation (159 symptomatic tumors [6.3%]; area under the curve > 0.9).

Conclusions

Central nervous system hemangioblastoma burden in VHL is associated with partial germline deletions and male sex. Unpredictable growth of hemangioblastomas compromises assessment of nonsurgical therapies. The judicious treatment of symptom-producing hemangioblastomas, while avoiding unnecessary treatment of asymptomatic tumors that may not progress, can provide clinical stability. Clinical trial registration no.: NCT00005902 (ClinicalTrials.gov).

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Carlijn Frantzen, Sophie J. van Asselt, Roeliene C. Kruizinga, Caroline Abadie, Isabelle Coupier, Stéphane Richard, Gerhard Alsmeier, Joyce W. Graff, Mariëlle G. van Pampus, Rachel H. Giles and Thera P. Links

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Andrew Shaw and E. Antonio Chiocca

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Donald Y. Ye, Kamran D. Bakhtian, Ashok R. Asthagiri and Russell R. Lonser

Object

Prior cases suggest that pregnancy increases the development and progression of CNS hemangioblastomas and/or peritumoral cysts. To determine the effect of pregnancy on CNS hemangioblastomas and peritumoral cysts, the authors prospectively evaluated serial clinical and imaging findings in patients with von Hippel-Lindau (VHL) disease who became pregnant and compared findings during pregnancy to findings in the same patients when they were not pregnant as well as to findings from a cohort of VHL patients who did not become pregnant.

Methods

Female VHL disease patients enrolled in a prospective natural history study who were of reproductive age (16–35 years at study entrance) were included. Analysis of serial clinical and imaging findings was performed.

Results

Thirty-six consecutive female VHL disease patients harboring 177 hemangioblastomas were included (mean follow-up [± SD] 7.5 ± 2.3 years). Nine patients (25%) became pregnant (pregnancy cohort). The mean rates of development of new hemangioblastomas and peritumoral cysts in these women during pregnancy (0.4 ± 0.4 tumors/year; 0.1 ± 0.2 cysts/year) did not differ significantly (p > 0.05) from the mean rates in the same group during nonpregnant periods (0.3 ± 0.4 tumors/year; 0.1 ± −0.1 cysts/year) or from the rate in the 27 patients who did not become pregnant (the no-pregnancy cohort: 0.3 ± 0.5 tumors/year; 0.1 ± 0.2 cysts/year). Hemangioblastoma growth rates were similar (p > 0.05) during pregnancy (mean 29.8% ± 42.7% increase in volume per year) compared with during nonpregnant periods (41.4% ± 51.4%) in the pregnancy cohort and the no-pregnancy cohort (34.3% ± 55.3%). Peritumoral cyst growth rates during pregnancy (571.0% ± 887.4%) were similar (p > 0.05) to those of the no-pregnancy cohort (483.9% ± 493.9%), but the rates were significantly higher for women in the pregnancy cohort during nonpregnant periods (2373.6% ± 3392.9%; p < 0.05 for comparison with no-pregnancy cohort). There was no significant difference (p > 0.05) in the need for resection or the mean age at resection between the pregnancy (28% of hemangioblastomas in cohort; mean patient age at resection 30.2 ± 2.6 years) and no-pregnancy cohorts (19%; 32.3 ± 5.6 years).

Conclusions

Pregnancy is not associated with increased hemangioblastoma or peritumoral cyst development or progression in patients with VHL disease.

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Alexander Ksendzovsky, Stuart Walbridge, Richard C. Saunders, Ashok R. Asthagiri, John D. Heiss and Russell R. Lonser

Object

Recent studies indicate that M13 bacteriophage, a very large nanoparticle, binds to β-amyloid and α-synuclein proteins, leading to plaque disaggregation in models of Alzheimer and Parkinson disease. To determine the feasibility, safety, and characteristics of convection-enhanced delivery (CED) of M13 bacteriophage to the brain, the authors perfused primate brains with bacteriophage.

Methods

Four nonhuman primates underwent CED of M13 bacteriophage (900 nm) to thalamic gray matter (4 infusions) and frontal white matter (3 infusions). Bacteriophage was coinfused with Gd-DTPA (1 mM), and serial MRI studies were performed during infusion. Animals were monitored for neurological deficits and were killed 3 days after infusion. Tissues were analyzed for bacteriophage distribution.

Results

Real-time T1-weighted MRI studies of coinfused Gd-DTPA during infusion demonstrated a discrete region of perfusion in both thalamic gray and frontal white matter. An MRI-volumetric analysis revealed that the mean volume of distribution (Vd) to volume of infusion (Vi) ratio of M13 bacteriophage was 2.3 ± 0.2 in gray matter and 1.9 ± 0.3 in white matter. The mean values are expressed ± SD. Immunohistochemical analysis demonstrated mean Vd:Vi ratios of 2.9 ± 0.2 in gray matter and 2.1 ± 0.3 in white matter. The Gd-DTPA accurately tracked M13 bacteriophage distribution (the mean difference between imaging and actual bacteriophage Vd was insignificant [p > 0.05], and was –2.2% ± 9.9% in thalamic gray matter and 9.1% ± 9.5% in frontal white matter). Immunohistochemical analysis revealed evidence of additional spread from the initial delivery site in white matter (mean Vd:Vi, 16.1 ± 9.1). All animals remained neurologically intact after infusion during the observation period, and histological studies revealed no evidence of toxicity.

Conclusions

The CED method can be used successfully and safely to distribute M13 bacteriophage in the brain. Furthermore, additional white matter spread after infusion cessation enhances distribution of this large nanoparticle. Real-time MRI studies of coinfused Gd-DTPA (1 mM) can be used for accurate tracking of distribution during infusion of M13 bacteriophage.

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J. Bradley Elder and E. Antonio Chiocca

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Michael S. Dirks, John A. Butman, H. Jeffrey Kim, Tianxia Wu, Keaton Morgan, Anne P. Tran, Russell R. Lonser and Ashok R. Asthagiri

Object

Neurofibromatosis Type 2 (NF2) is a heritable tumor predisposition syndrome that leads to the development of multiple intracranial tumors, including meningiomas and schwannomas. Because the natural history of these tumors has not been determined, their optimal management has not been established. To define the natural history of NF2-associated intracranial tumors and to optimize management strategies, the authors evaluated long-term clinical and radiographic data in patients with NF2.

Methods

Consecutive NF2 patients with a minimum of 4 years of serial clinical and MRI follow-up were analyzed.

Results

Seventeen patients, 9 males and 8 females, were included in this analysis (mean follow-up 9.5 ± 4.8 years, range 4.0–20.7 years). The mean age at initial evaluation was 33.2 ± 15.5 years (range 12.3–57.6 years). Patients harbored 182 intracranial neoplasms, 164 of which were assessable for growth rate analysis (18 vestibular schwannomas [VSs], 11 nonvestibular cranial nerve [CN] schwannomas, and 135 meningiomas) and 152 of which were assessable for growth pattern analysis (15 VSs, 9 nonvestibular CN schwannomas, and 128 meningiomas). New tumors developed in patients over the course of the imaging follow-up: 66 meningiomas, 2 VSs, and 2 nonvestibular CN schwannomas. Overall, 45 tumors (29.6%) exhibited linear growth, 17 tumors (11.2%) exhibited exponential growth, and 90 tumors (59.2%) displayed a saltatory growth pattern characterized by alternating periods of growth and quiescence (mean quiescent period 2.3 ± 2.1 years, range 0.4–11.7 years). Further, the saltatory pattern was the most frequently identified growth pattern for each tumor type: meningiomas 60.9%, VSs 46.7%, and nonvestibular schwannoma 55.6%. A younger age at the onset of NF2-related symptoms (p = 0.01) and female sex (p = 0.05) were associated with an increased growth rate in meningiomas. The identification of saltatory growth in meningiomas increased with the duration of follow-up (p = 0.01).

Conclusions

Neurofibromatosis Type 2–associated intracranial tumors most frequently demonstrated a saltatory growth pattern. Because new tumors can develop in NF2 patients over their lifetime and because radiographic progression and symptom formation are unpredictable, resection may be best reserved for symptom-producing tumors. Moreover, establishing the efficacy of nonsurgical therapeutic interventions must be based on long-term follow-up (several years).