2102 - Time to Development of Leptomeningeal Disease (LMD) among Metastatic Cancer Patients Who Undergo Stereotactic Radiosurgery (SRS)
Presenter(s)
A. Jambhale1, S. Koduri2, C. M. Liu1, C. Oh3, K. Bernstein2, M. Mureb4, J. S. Silverman2, B. T. Cooper2, B. R. Donahue2, A. Gewirtz5, A. Miller6, J. R. McFaline-Figueroa6, D. Kondziolka7, and J. T. Yang8; 1NYU Grossman School of Medicine, New York, NY, 2Department of Radiation Oncology, NYU Langone Health, New York, NY, 3Biostatistics, Department of Population Health, NYU Langone Health, New York, NY, 4Department of Neurosurgery, Westchester Medical Center, Vahalla, NY, 5Department of Neurology, NYU Grossman Long Island School of Medicine, New York, NY, 6Department of Neurology, NYU Grossman School of Medicine, New York, NY, 7Department of Neurosurgery, NYU Langone Health, New York, NY, 8Department of Radiation Oncology, NYU Grossman School of Medicine, New York, NY
Purpose/Objective(s):
Leptomeningeal Disease (LMD) is a late-stage progression of metastatic cancer to the meningeal membranes surrounding the brain and spinal cord. This retrospective study explores trends among patients who develop LMD after Stereotactic Radiosurgery (SRS) at our institution.Materials/Methods:
Patients who received Gamma Knife Radiosurgery (SRS) between 2008 and 2025 at our institution and then developed LMD were retrospectively reviewed. Treatment history and disease outcomes were obtained. EANO-ESMO staging of LMD was retrospectively recorded. Time from SRS to LMD diagnosis was analyzed using linear regression on log-months with subsequent log-linear regression modeling.Results:
Of the 264 post-SRS LMD patients identified, the median age of LMD diagnosis was 63 (IQR 54-70), with 68% of patients being female and a median Karnofsky Performance Status of 90 (IQR 80-90). The most common primary histologies were non-small cell lung cancer (NSCLC, 47%), breast cancer (24%), and melanoma (15%). 11 patients (4.1%) had positive cerebrospinal fluid studies (EANO-ESMO Type 1 LMD), 214 (81%) were diagnosed based on radiographic and clinical signs (EANO-ESMO Type 2A, 2B, 2C Probable LMD), and 39 (15%) by MRI findings alone (EANO-ESMO Type 2A, 2B, 2C Possible LMD). 99 (38%) patients received immunotherapy. Median time from SRS to LMD was 8.3 months (IQR 4-17), with 76% of patients developing LMD within 1.5 years from SRS. Meanwhile, 82% of NSCLC patients were diagnosed with LMD for up to 2.5 years after SRS. Univariate analysis showed that male sex (ß = -0.4, p = 0.011), greater number of SRS-treated tumors (ß = -0.03 per tumor, p = 0.008), and immunotherapy exposure (ß = -0.45, p = 0.003) were associated with earlier LMD. In contrast, controlled extracranial disease (ß = 0.39, p = 0.02), greater number of SRS treatments (ß = 0.21 per treatment, p < 0.001), history of craniotomy (ß = 0.59, p < 0.001), and greater number of craniotomies (ß = 0.27 per craniotomy, p = 0.003) were associated with delayed LMD. Primary cancer type, LMD MRI pattern, and prior whole brain radiotherapy were not significantly associated with time to LMD. In the multivariate model, only immunotherapy exposure (ß = -0.36, p = 0.014) remained associated with earlier LMD, while a greater number of SRS treatments (ß = 0.19 per treatment, p < 0.001) and history of craniotomy (ß = 0.41, p = 0.008) remained associated with delayed LMD after SRS.Conclusion:
Among patients who developed LMD after SRS, immunotherapy exposure was associated with a 30–35% shorter time to LMD. Our findings suggest close monitoring for development of LMD after SRS for patients that have been treated with immunotherapy. Our data shows that LMD is most likely detected within 1.5 years of SRS with a majority of NSCLC patients developing LMD up to 2.5 years after SRS. Primary cancer type, LMD MRI pattern, prior whole brain radiotherapy, and extracranial disease status were not significantly associated with time to LMD after SRS.