2113 - Impact of Aggressive Treatment on Outcomes in IDH-Wildtype Glioblastoma Patients with Leptomeningeal Dissemination (KROG 24-07)

03:00pm - 04:00pm ET

Poster Hall - Exhibit Hall A

Screen: 10

POSTER

Presenter(s)

In Ah Kim, MD, PhD - Seoul National University Bundang Hospital, Seongnamsi, Kyeonggido

I. A. Kim¹, S. H. Jeon², N. Kim³, H. I. Yoon⁴, C. W. Wee⁵, H. Choi⁵, J. H. Im⁶, S. G. Park⁷, J. H. Kim⁷, D. H. Lim⁸, and C. O. Suh⁹; ¹Department of Radiation Oncology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea, Republic of (South), ²Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Korea, Republic of (South), ³Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of (South), ⁴Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea, Republic of (South), ⁵Department of Radiation Oncology, Yonsei Cancer Center, Heavy Ion Therapy Research Institute, Yonsei University College of Medicine, Seoul, Korea, Republic of (South), ⁶Departments of Radiation Oncology, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea, Republic of (South), ⁷Department of Radiation Oncology, Keimyung University School of medicine, Daegu, Korea, Republic of (South), ⁸Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of (South), ⁹Department of Radiation Oncology, Bundang CHA Medical Center, CHA University, Gyeonggi-do, Korea, Republic of (South)

Purpose/Objective(s):

Prognosis of cerebrospinal fluid (CSF) dissemination in IDH-wildtype glioblastoma (GBM) patients is dismal, but prognostic factors and optimal treatment strategy for LMD are still not clearly defined. This multi-institutional study aims to analyze clinical factors that affect the outcomes of GBM patients with LMD.

Materials/Methods:

A total of 221 IDH-wildtype GBM patients with LMD diagnosed between March 2009 and March 2024 in five institutions were analyzed, including 66 primary LMD and 155 recurrent LMD. Prognostic factors for overall survival (OS) and progression-free survival (PFS) were identified using Cox regression model.

Results:

Patients with recurrent LMD had significantly worse OS and PFS compared with those with primary dissemination. Among patients with primary LMD, longer OS was associated with better performance status and younger age, while adjuvant temozolomide more than 3 cycles was also associated with improved PFS. In the recurrent setting,

male sex, MGMT promoter methylation, prophylactic radiotherapy field coverage, and administration of systemic therapy were associated with both OS and PFS, with bevacizumab and non-bevacizumab regimens showed similar survival benefit.

Conclusion:

Our findings highlight differential impacts of clinical and treatment-related factors on outcomes between primary and recurrent LMD. In particular, aggressive intervention, including prophylactic radiotherapy field coverage and systemic therapy, may improve outcomes in patients with IDH-wildtype GBM who develop LMD at recurrence.