ESTRO 2024 - Abstract Book

S784

Clinical - CNS

ESTRO 2024

Figure. Temporal changes in total lymphocyte count (TLC) after brain radiotherapy

Ninety and 38 patients received WBRT and SRS/SRT, respectively, as the first course of RT for brain metastases. The median potential follow-up according to the reverse Kaplan-Meier method was 23.1 and 31.1 months, respectively. Persistent lymphopenia was observed in 26 (29%) and 3 (8%) patients in the WBRT and SRS/SRT groups, respectively. In the WBRT group, OS was significantly worse in patients with persistent lymphopenia compared to those without, with median survival time of 2.6 and 6.1 months, respectively (p<0.001). The median survival time in the SRS/SRT group was 7.2 months for those with persistent lymphopenia and 11.7 months for those without (p=0.599).

Conclusion:

Lymphopenia was observed after WBRT and persisted for more than 4 weeks after completion of RT. Persistent lymphopenia after WBRT was associated with a poor prognosis. The results from this retrospective study suggest that SRS/SRT may be preferable for patients with brain metastases in terms of lymphocyte preservation.

Keywords: Radiation-induced lymphopenia, brain radiotherapy

References:

1. Damen PJJ, Kroese TE, van Hillegersberg R et al. The Influence of Severe Radiation-Induced Lymphopenia on Overall Survival in Solid Tumors: A Systematic Review and Meta-Analysis. Int J Radiat Oncol Biol Phys. 2021;111:936 48.