Kalamarides, Michel

BACKGROUND AND OBJECTIVES: Surgery in NF2-related schwannomatosis (NF2-SWN) vestibular schwannoma (VS) carries a higher risk of facial nerve damage, hearing loss, and partial resection, than in sporadic cases. Radiosurgery is also associated with higher failure compared with sporadic schwannomas. Nowadays, bevacizumab (BEV) is frequently considered in the NF2-SWN population. However, some patients experience progression despite treatment. Among other surgical risks, in BEV-treated patients, hemorrhage and impaired healing are specific considerations. These concerns have led manufacturers to recommend stopping BEV 6 to 8 weeks preoperatively. The aim of our multicentric study was to assess the perioperative bleeding risk and postoperative outcomes in NF2-SWN patients undergoing VS surgery after preoperative BEV treatment. METHODS: Our retrospective analysis included medical and surgical records along with imaging reviews from 4 high-volume tertiary academic referral centers for NF2-SWN and VS. RESULTS: A total of 21 patients met the inclusion criteria. VS had a mean volume of 13.2 ±7.6 cm 3 corresponding to 1 KOOS III and 20 KOOS IV. BEV was stopped at a mean of 5.8 ± 4.0 months before surgery with a total mean treatment duration of 33.7 ± 20.7 months and a monthly dose of 10.2 ± 4.1 mg/kg. Intraoperatively, the tumor was assessed to be bloody by the operating surgeons in 7 patients. Late BEV discontinuation and high cumulative dose independently predicted perioperative bleeding and longer surgery duration. No other complication such as wound dehiscence was reported. CONCLUSION: Our findings suggest that a higher cumulative BEV dose (∼600 mg/kg) and a longer interval between BEV discontinuation and surgery (∼8 months) are associated with a modest but statistically significant increase in intraoperative bleeding risk. Based on these observations, a BEV-free window between 6 weeks and 6 months (depending on the clinical scenario) before tumor resection seems optimal, particularly for patients with high cumulative exposure.

Objective The objective of the current study was to present the results of an international working group survey identifying perceived limitations of existing facial nerve grading scales to inform the development of a novel grading scale for assessing early postoperative facial paralysis that incorporates regional scoring and is anchored in recovery prognosis and risk of associated complications. Study Design Survey. Setting A working group of 48 multidisciplinary clinicians with expertise in skull base, cerebellopontine angle, temporal bone, or parotid gland surgery. Results House-Brackmann grade is the most widely used system to assess facial nerve function among working group members (81%), although more than half (54%) agreed that the system they currently use does not adequately estimate the risk of associated complications, such as corneal injury, and confidence in interrater and intrarater reliability is generally low. Simplicity was ranked as the most important attribute of a novel postoperative facial nerve grading system to increase the likelihood of adoption, followed by reliability and accuracy. There was widespread consensus (91%) that the eye is the most critical facial region to focus on in the early postoperative setting. Conclusions Members were invited to submit proposed grading systems in alignment with the objectives of the working group for subsequent validation. From these data, we plan to develop a simple, clinically anchored, and reproducible staging system with regional scoring for assessing early postoperative facial nerve function after surgery of the skull base, cerebellopontine angle, temporal bone, or parotid gland.

Abstract Purpose: Neurofibromatosis type 2 (NF2) is a rare autosomal dominant disorder associated primarily with bilateral schwannomas seen on the superior vestibular branches of the eighth cranial nerves. Significant morbidity can result from surgical treatment of these tumors. Meningiomas, ependymomas, and other benign central nervous system tumors are also common in NF2. The lack of effective treatments for NF2 marks an unmet medical need. Experimental Design: Here, we provide recommendations from a workshop, cochaired by Drs. D. Gareth Evans and Marco Giovannini, of 36 international researchers, physicians, representatives of the biotechnology industry, and patient advocates on how to accelerate progress toward NF2 clinical trials. Results: Workshop participants reached a consensus that, based on current knowledge, the time is right to plan and implement NF2 clinical trials. Obstacles impeding NF2 clinical trials and how to address them were discussed, as well as the candidate therapeutic pipeline for NF2. Conclusions: Both phase 0 and phase II NF2 trials are near-term options for NF2 clinical trials. The number of NF2 patients in the population remains limited, and successful recruitment will require ongoing collaboration efforts between NF2 clinics. (Clin Cancer Res 2009;15(16):5032–9)