Risk Factors Associated with Hematologic Toxicity in Concurrent Chemoradiotherapy and IMRT for Cervical Cancer

Objective To investigate the risk factors associated with hematologic toxicity (HT) in the treatment of concurrent chemotherapy and intensity modulated radiotherapy (IMRT) for cervical cancer. Methods We analyzed 126 cervical cancer patients treated with concurrent chemotherapy and pelvic IMRT. Univariate and multivariate analysis were performed to evaluate the known and hypothesized factors associated with HT. Results Univariate analysis showed that mean dose to pelvic bone marrow (PBM), the volume of PBM receiving 20, 40, and 50 Gy (V20, V40, and V50), initial serum creatinine, chemotherapy before concurrent chemoradiotherapy (CCRT), and BM suppression before CCRT were associated with the incidence of severe HT (P<0.05). By multivariate analysis, the mean dose to PBM (OR: 1.004, 95%CI: 1.002-1.007),V40 (<41% vs. ≥41%, OR: 0.040, 95%CI: 0.007-0.235), V50 (<9% vs. ≥ 9%, OR: 0.040, 95%CI: 0.011-0.152), and initial serum creatinine (<65μmol/L vs.≥65μmol/L, OR: 0.116, 95%CI: 0.030-0.441) were the factors significantly correlated with grades 3~4 HT. Conclusion Initial serum creatinine <65μmol/L, V40<41%, and V50<9% are the factors associated with low incidence of grades 3~4 HT in the treatment of concurrent chemotherapy and IMRT for cervical cancer patients. As the mean dose to bone marrow increases, the incidence of grades 3~4 HT grows. Evaluating initial serum creatinine is needed before CCRT. Strictly controlling the irradiated volume of PBM and the dose to PBM treated with IMRT which can reduce the incidence of HT is warranted in cervical patients receiving CCRT.