3110 - Assessment of Neutrophil-to-Lymphocyte Ratio Changes in Meningiomas after Conventional Radiotherapy or Radiosurgery
Presenter(s)
S. Mishra1, T. Kroymann1, S. Pandey1, L. Golden1, N. Sando1, C. W. Song1, J. Lawrence1,2, S. Puri3, L. R. Kleinberg4, J. Yuan1, E. Neil5, A. Venteicher6, J. Moore1, S. A. Terezakis1, and L. Sloan1; 1University of Minnesota: Department of Radiation Oncology, Minneapolis, MN, 2Department of Surgical and Radiological Sciences: University of California, Davis, Davis, CA, 3Oregon Health Science University, Portland, OR, 4Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 5University of Minnesota: Department of Neurology, Minneapolis, MN, 6University of Minnesota: Department of Neurosurgery, Minneapolis, MN
Purpose/Objective(s): Neutrophil-to-lymphocyte ratio (NLR) is a biomarker of systemic inflammation linked to increased progression and recurrence in meningiomas. Radiotherapy (RT) may be prescribed for unresectable or recurrent meningiomas and can be delivered via conventional fractionated radiotherapy (CFRT) or stereotactic radiosurgery (SRS). The impact of RT on NLR remains unclear; therefore, we evaluated NLR changes in meningioma patients treated with CFRT or SRS. Because SRS induces antigen release to stimulate anti-tumor immune responses, we hypothesized that NLR would increase after CFRT or SRS, with a greater increase following SRS.
Materials/Methods: In this single-institution, IRB-approved study, all adult meningioma patients treated with CFRT or SRS between 2009 and 2023 who had =2 complete blood counts (CBCs) within two years of RT consultation were included and stratified by treatment modality. Of 72 identified patients, 29 were excluded due to lack of CBC differential or baseline data (n = 20) or inaccurate ICD-10 codes (n = 9), leaving 43 patients. CBCs were analyzed at baseline, ~3 months, and ~12 months post-RT. Absolute NLR changes from baseline were calculated, along with changes in white blood cell (WBC) count, hemoglobin, and platelet count. Statistical comparisons were performed using paired t-tests, with significance set at p < 0.05.
Results: Forty-three patients (12 males and 31 females) were evaluated. The mean age was 62.06 ± 15.26 years, and most were white (n = 38; 4 black, 1 Asian). Twenty-one patients received SRS and 22 received CFRT. There were no significant differences in age, gender, or ethnicity between treatment groups. In the SRS group, a median dose of 13 Gy in 1 fraction was delivered (range: 12.5–25 Gy in 1–5 fractions); in the CFRT group, the median dose was 51.3 Gy in 28 fractions (range: 46.8–60 Gy in 26–30 fractions). In the SRS group, 3 tumors were grade 1 and 18 were not biopsy-confirmed; in the CFRT group, 5 tumors were grade 1, 7 were grade 2, 1 was grade 3, and 9 were not biopsy-confirmed. Overall, mean NLR increased significantly from 2.51 ± 1.68 at baseline to 3.49 ± 2.76 at 3 months (n = 31, p = 0.029). There were no significant changes in hemoglobin, platelet, or WBC counts at 3 months. At 1 year, mean NLR was 2.97 ± 1.72 versus 2.56 ± 1.49 at baseline (n = 30, p = 0.141), with WBC counts significantly decreased (7.25 ± 2.79 vs. 6.46 ± 1.81, p = 0.036). When stratified, CFRT resulted in an NLR increase from 2.33 ± 1.03 to 3.40 ± 3.14 (p = 0.082) and SRS from 2.72 ± 2.20 to 3.61 ± 2.31 (p = 0.110) at 3 months.
Conclusion: RT in patients with meningiomas is associated with a transient yet significant increase in NLR at 3 months but improving over a year, potentially reflecting an acute radiation related immune response. Although both CFRT and SRS trended toward increased NLR, differences between modalities were not statistically significant. We plan further study of the radioimmunological effects of RT in meningioma.