2123 - Wide Dural Radiation Therapy (WDRT) for Meningiomatosis in Patients with Neurofibromatosis Type 2

03:00pm - 04:00pm ET

Poster Hall - Exhibit Hall A

Screen: 1

POSTER

Presenter(s)

Chan Woo Wee, MD, PhD - Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Seoul

J. Lee¹, C. W. Wee^1,2, S. Yeon Do¹, S. Choi¹, J. Oh³, J. H. Chang^2,4, and H. I. Yoon^1,2; ¹Department of Radiation Oncology, Yonsei Cancer Center, Heavy Ion Therapy Research Institute, Yonsei University College of Medicine, Seoul, Korea, Republic of (South), ²Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea, Republic of (South), ³Division of Clinical Genetics, Department of Pediatrics, Yonsei University, College of Medicine, Severance Children's Hospital, Seoul, Korea, Republic of (South), ⁴Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, Republic of (South)

Purpose/Objective(s):

Intracranial meningiomas are the second most common tumors that arise in patients affected by neurofibromatosis type 2 (NF2), and they often present as a form of diffuse meningiomatosis (multiple meningiomas). However, the optimal treatment for patients with meningiomatosis remain unclear mostly due to the long-term clinical course of the disease. In this study, we evaluated the safety and efficacy of wide dural radiation therapy (WDRT) in NF2 patients with meningiomatosis.

Materials/Methods:

A total of 10 NF2 patients presenting with meningiomatosis who were treated with WDRT between March 2018 and December 2022 were reviewed. Local control and progression-free survival (PFS) from the date of WDRT completion and acute toxicity were evaluated. Progressive disease was defined as an increase of tumor diameter over 20% or development of a new lesion.

Results:

The median age at treatment was 41 years (range, 25–53 years) and the median follow-up period was 45.8 months (range, 31.1–89.2 months). All patients initiated WDRT due to growing lesions or aggravating symptoms. The median dose to gross lesions and tumor bed (in resected cases) was 54 Gy in 30 fractions. The median dose to the wide dural field was 48 Gy in 30 fractions. A total of 91 meningiomas sized >5 mm were irradiated with a dose of 48 Gy or higher with no infield progression. The 2-year local control rates was 100%. However, 3 patients (30%) demonstrated outfield progression with a median time to progression of 31.3 months. Two patients developed progression in lesions which were intentionally not treated with purpose of being treated later with either Gamma Knife Radiosurgery (GKRS) or surgery. One patient showed marginal recurrence at the edge of the supratentorial whole dural field.

Conclusion:

WDRT provides excellent local control and adequate safety profiles in NF2 patients with meningiomatosis. Further prospective studies with a predefined target volume is warranted to validate our findings.