ESTRO 2024 - Abstract Book

S806

Clinical - CNS

ESTRO 2024

972

Mini-Oral

Proton therapy for patients with meningioma — Long-term outcomes from ProReg and KiProReg study

Yeshan Chen 1,2 , Christine Hansel 1 , Dalia Ahmad Khalil 1 , Sarah Peters 1 , Sandija Plaude 1 , Stephan Tippelt 3 , Martin Glas 4 , Ulrich Sure 5 , Rolf-Dieter Kortmann 1 , Beate Timmermann 1 1 Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Center Essen (WPE), West German Cancer Center (WTZ), Essen, Germany. 2 Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. 3 Department of Pediatrics III, University Hospital Essen, Essen, Germany. 4 Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Division of Clinical Neurooncology, University Medicine Essen, University Duisburg-Essen, Essen, Germany. 5 Department of Neurosurgery and Spine Surgery, University Hospital Essen, Essen, Germany

Purpose/Objective:

Proton beam therapy (PBT) has become a favorable treatment modality by sparing critical normal structures and reducing the risk of secondary malignancies for low-grade meningioma and highly aggressive cases that are large, irregularly shaped and/or close to vulnerable neurocritical organs. However, few reports on the long-term outcomes and toxicities of all grades meningioma treated with PBT exist. The purpose of this study was to investigate the 5-year survival, recurrence pattern and radiation-related toxicities in a large cohort of meningioma treated with proton therapy.

Material/Methods:

The study cohort consisted of patients diagnosed with meningiomas and enrolled in one of the prospective observational registry studies ProReg (DRKS00004384) and KiProReg (DRKS00005363). Patients were treated between 07/2013 and 12/2022 at our institution. Information on demographics, treatment, tumor characteristics as well as toxicities and outcomes were analyzed. The diagnosis of meningioma was based on pathological (n=121) or radiological (n=32) reports, the latter of which required agreement by at least two experienced radiologists. Patients’ recurrence pattern was determined by comparing the location of relapses on MRI with respect to the dose coverage after co-registration with the treatment plan. Toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0.

Results:

A total of 153 patients treated with PBT between 2013 and 2022 were included, of which 143 were adults (in ProReg study) and 10 were children (in KiProReg study). The median age was 51.0 years (range, 2-82 years) for the study cohort, of whom 49.7% were benign (WHO grade I, n=76), 29.4% (38 of WHO grade II and 7 of WHO grade III) were non-benign and 20.9% (n=32) were radiologically diagnosed meningioma. Twenty-six patients (17%) underwent gross total resection (GTR) and 95 (62.1%) were subtotally resected (STR), while 32 (20.9%) received PBT alone. 102 patients (66.7%) treated with PBT at initial diagnosis and 51 patients (33.3%) treated for recurrence or disease