Radiation treatment of benign tumors in NF2-related-schwannomatosis: A national study of 266 irradiated patients showing a significant increase in malignancy/malignant progression.

Background: Radiation treatment of benign tumors in tumor predisposition syndromes is controversial, but short-term studies from treatment centers suggest safety despite apparent radiation-associated malignancy being reported. We determined whether radiation treatment in NF2-related schwannomatosis patients is associated with increased rates of subsequent malignancy (M)/malignant progression (MP). Methods: All UK patients with NF2 were eligible if they had a clinical/molecular diagnosis. Cases were NF2 patients treated with radiation for benign tumors. Controls were matched for treatment location with surgical/medical treatments based on age and year of treatment. Prospective data collection began in 1990 with addition of retrospective cases in 1969. Kaplan-Meier analysis was performed for malignancy incidence and survival. Outcomes were central nervous system (CNS) M/MP (2cm annualized diameter growth) and survival from index tumor treatment. Results: In total, 1345 NF2 patients, 266 (133-Male) underwent radiation treatments between 1969 and 2021 with median first radiotherapy age of 32.9 (IQR = 22.4-46.0). Nine subsequent CNS malignancies/MPs were identified in cases with only 4 in 1079 untreated (P < .001). Lifetime and 20-year CNS M/MP was ~6% in all irradiated patients-(4.9% for vestibular schwannomas [VS] radiotherapy) versus <1% in the non-irradiated population (P < .001/.01). Controls were well matched for age at NF2 diagnosis and treatment (Males = 133%-50%) and had no M/MP in the CNS post-index tumor treatment (P = .0016). Thirty-year survival from index tumor treatment was 45.62% (95% CI = 34.0-56.5) for cases and 66.4% (57.3-74.0) for controls (P = .02), but was nonsignificantly worse for VS radiotherapy. Conclusion: NF2 patients should not be offered radiotherapy as first-line treatment of benign tumors and should be given a frank discussion of the potential 5% excess absolute risk of M/MP.

High-Grade Glioma is not a Feature of Neurofibromatosis Type 2 in the Unirradiated Patient.

BACKGROUND: The Manchester criteria for neurofibromatosis type 2 (NF2) include a range of tumors, and gliomas were incorporated in the original description. The gliomas are now widely accepted to be predominantly spinal cord ependymomas. OBJECTIVE: To determine whether these gliomas include any cases of malignant glioma (WHO grade III and IV) through a database review. METHODS: The prospective database consists of 1253 patients with NF2. 1009 are known to be alive at last follow-up. RESULTS: There was a single case of glioblastoma multiforme (GBM; World Health Organization grade IV) in the series and no WHO grade III gliomas. The GBM was in a patient who had previously undergone stereotactic radiosurgery for a vestibular schwannoma. CONCLUSION: High-grade gliomas are not a feature of NF2 in the unirradiated patient and should be excluded from the diagnostic criteria.

Cochlear implantation in early deafened, late implanted adults: Do they benefit?

OBJECTIVES: The aim of this study was to quantify the benefit gained from cochlear implantation in pre- or peri-lingually deafened patients who were implanted as adults Methods: This was a retrospective case-control study. Auditory (BKB/CUNY/3AFC/Environmental sounds), quality of life (GBI/HUI3) and cognitive (customized questionnaire) outcomes in 26 late implanted pre- or peri-lingually deafened adults were compared to those of 30 matched post-lingually deafened, traditional cochlear implant users. RESULTS: There was a statistically significant improvement in all scores in the study group following cochlear implantation. BKB scores for cases was 49.8% compared to 83.6% for controls (p=0.037). CUNY scores for cases was 61.7% compared to 90.3% for controls (p=0.022). The 3AFC and environmental sounds scores were also better in controls compared to cases but the difference was not statistically significant. Quality of life scores improved following implantation in cases and controls but the improvement was only statistically significant in the controls. There was a 7.7% non-user rate in the cases. There were no non-users in the control group. DISCUSSION: Early deafened,,late implanted patients can benefit audiologically from cochlear implantation and in this study the improvement in speech discrimination scores was greater than expected perhaps reflecting careful selection of patients. Nevertheless, audiological benefits are limited compared to traditional cochlear implant recipients with the implant acting as an aid to lip reading in most cases. CONCLUSION: With careful selection of candidates, cochlear implantation is beneficial in early deafened, late implanted patients.