ESTRO 2024 - Abstract Book

S933

Clinical - CNS

ESTRO 2024

Eight patients (33.3%) had gap in radiation treatment. All gaps were in weeks 5 and week 6 of radiation. Grade 4 thrombocytopenia occurred in three patients, and grade 3 and grade 2 thrombocytopenia in one patient each. The mean slope of data points from baseline to week 3 was 1161 for patients without treatment gap, and -794.6 for patients with treatment gap (statistically nonsignificant). These values for baseline to week 4 were 555.2 (Standard Deviation 1190) and -1883.8 (Standard Deviation 2936.4), respectively, and this difference was statistically significant, with a two-tailed p value of 0.0078. Considering 2 standard deviations to accommodate 95% of data values, the lower limit of slope for patients without treatment completion is calculated as -1825.2.

Conclusion:

A Baseline to Week 4 slope of -1825.2 or lesser, even with the absolute value of platelet count being greater than 100,000/cmm, may indicate the likelihood of severe thrombocytopenia necessitating treatment interruption in the coming weeks of radiation. Initiation of platelet boosting strategies after checking week 4 platelet count may benefit such patients by preventing undue treatment gaps.

Keywords: Thrombocytopenia, Radiation interruption, Gliomas

References:

1.Survival impact of prolonged postoperative radiation therapy for patients with glioblastoma treated with combined-modality therapy. Mehran B Yusuf,Jeremy Gaskins, Mark J. Amsbaugh, Shiao Woo, and Eric Burton. 6(2), 112 – 123, 2019; doi:10.1093/nop/npy027