Abstract Details

Title Long-term follow-up of schwannoma growth behavior in adult neurofibromatosis type 2 and schwannomatosis patients using whole-body MRI

Topic Neuro-oncology

Presentation(s) S16 - Neuro-oncology (4:32 PM-4:40 PM)

Poster/Presentation
Number 004

Background NF2 and SWN are related genetic tumor predisposition syndromes caused by distinct germline pathogenic variants on chromosome 22, and are characterized by the presence of cranial, peripheral, and/or spinal nerve schwannomas. The long-term growth behavior of schwannomas is unknown but knowledge thereof would help guide patient surveillance and selection for treatment. Whole-body MRI (WBMRI) can detect whole-body schwannoma burden.

Objective To characterize the long-term growth behavior of schwannomas in adults with neurofibromatosis type 2 (NF2) and schwannomatosis (SWN).

Design/Methods

12 NF2 and 10 SWN patients who underwent a WBMRI between 2007-2010 underwent a repeat WBMRI between 2018-2019. Schwannomas were segmented on short tau inversion recovery (STIR) sequences. Tumor volume was calculated using a three-dimensional tumor quantification software (3DQI). Tumor growth and shrinkage were defined as a volume change ≥20% over the entire study period.

Results Median time between scans was 10 years. A total of 103 schwannomas (46 NF2-associated, 57 SWN-associated) were analyzed. In both NF2 and SWN, 50% of tumors grew. Median growth was 88.3% in NF2 and 100.4% in SWN. All growing NF2-associated schwannomas grew in the setting of exposure to systemic therapy whereas only one growing SWN-associated tumor had been treated systemically. Excluding resected tumors, 19.4% of schwannomas shrank. Median shrinkage was 48.5% in NF2 and 37.4% in SWN. All shrinking NF2-associated tumors had been treated with systemic therapy whereas none of the shrinking SWN-associated tumors had been. 19 new tumors (7 NF2-associated, 12 SWN-associated) developed in 8 patients.

Conclusions

Half of NF2- and SWN-associated schwannomas grow significantly over a decade. In NF2 patients, growth occurs despite systemic treatment whereas, in SWN patients, schwannomas may shrink spontaneously without treatment. These findings suggest a more aggressive tumor phenotype in NF2 patients. Continued patient enrollment and correlation of MRI findings with functional outcomes and hormone exposure history are ongoing.

Authors/Disclosures
Ina Ly, MD (Pappas Center for Neuro-Oncology) PRESENTER	An immediate family member of Dr. Ly has received personal compensation for serving as an employee of Enanta Pharmaceuticals. Dr. Ly has received research support from Department of Defense. An immediate family member of Dr. Ly has received intellectual property interests from a discovery or technology relating to health care.
Raquel D. Thalheimer	Raquel D. Thalheimer has received personal compensation for serving as an employee of Jhpeigo.
	No disclosure on file
	No disclosure on file
Alona Muzikansky	No disclosure on file
Vanessa Merker (Massachusetts General Hospital)	The institution of Vanessa Merker has received research support from Children's Tumor Foundation . The institution of Vanessa Merker has received research support from NF Northeast. The institution of Vanessa Merker has received research support from Patient Centered Outcomes Research Institute. The institution of Vanessa Merker has received research support from U.S. Department of Defense . The institution of Vanessa Merker has received research support from Neurofibromatosis Therapeutic Accleration Project. Vanessa Merker has received personal compensation in the range of $10,000-$49,999 for serving as a Science Writer with Neurofibromatosis Network.
	No disclosure on file
Jennifer Da (Massachusetts General Hospital)	No disclosure on file
	No disclosure on file
Scott R. Plotkin, MD, PhD, FAAN (Mass General Cancer Center)	Dr. Plotkin has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for NFlection Therapeutics. Dr. Plotkin has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Akouos. Dr. Plotkin has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for SonALAsense. Dr. Plotkin has stock in NFlection Therapeutics. Dr. Plotkin has stock in NF2 Therapeutics. Dr. Plotkin has stock in SonALAsense. Dr. Plotkin has received research support from Children's Tumor Foundation. Dr. Plotkin has received research support from Department of Defense. Dr. Plotkin has received research support from National Institutes of Health. Dr. Plotkin has received intellectual property interests from a discovery or technology relating to health care.
Justin T. Jordan, MD, MPH, FAAN (Massachusetts General Hospital)	Dr. Jordan has received personal compensation for serving as an employee of City of Beverly. An immediate family member of Dr. Jordan has received personal compensation for serving as an employee of Dietitians on Demand. An immediate family member of Dr. Jordan has received personal compensation for serving as an employee of Genesis HR Solutions. An immediate family member of Dr. Jordan has received personal compensation for serving as an employee of Harborlight Montesorri. Dr. Jordan has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Navio Theragnostics. Dr. Jordan has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Recursion Pharmaceuticals, Inc. Dr. Jordan has received personal compensation in the range of $500-$4,999 for serving as a Consultant for BCD Meetings. Dr. Jordan has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Shepherd Therapeutics. Dr. Jordan has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Alexion Pharmaceuticals. Dr. Jordan has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Akeila Bio. Dr. Jordan has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Springworks Therapeutics. Dr. Jordan has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Continental Casualty Company. Dr. Jordan has stock in Navio Theragnostics. Dr. Jordan has stock in The Doctor Lounge. An immediate family member of Dr. Jordan has stock in OldGate. Dr. Jordan has stock in Akeila Bio. The institution of Dr. Jordan has received research support from NIH. The institution of Dr. Jordan has received research support from Department of Defense. The institution of Dr. Jordan has received research support from PCORI. Dr. Jordan has received publishing royalties from a publication relating to health care. Dr. Jordan has received personal compensation in the range of $500-$4,999 for serving as a Reimbursement for potential consultant role that was aborted with Magnet Biomedicine. Dr. Jordan has a non-compensated relationship as a board member with United Council for Neurologic Subspecialties that is relevant to AAN interests or activities.