Association between Pelvic Dosimetric Parameters and Acute Bone Marrow Suppression in Cervical Cancer Patients Receiving Intensity Modulated Radiation Therapy

doi:10.3969/j.issn.1004—5511.2019.02.007

Abstract：Objective To identify association between pelvic dosimetric parameters and acute bone marrow sup—pression in intensity modulated radiation therapy(IMRT)for cervical cancer,and provide references for clinical radio—therapy planning. Methods 210 patients receiving IMRT for cervical cancer were enrolled in this study. The pelvic was contoured for each patient in radiotherapy treatment planning system. The pelvic dose-volume parameters inclu—ding V10 ,V20 ,V30 ,V40 ,V45 and V50 were analyzed using univariate analysis( Chi-Square and test)and multivariate analysis(Logistic regression model). Results The percentage of patients that developed acute bone marrow suppres—sion(≥grade 2)was 82. 86%(174∕210). Compared to patients undergoing radiotherapy alone,patients received con—current chemotherapy were more likely to develop acute bone marrow suppression(≥grade 2). The univariate analysis revealed that pelvic V10 ,V20 and V30 of 94 patients received radiotherapy alone with≥grade 2 acute bone marrow sup—pression were higher than those 〈grade 2 patients(t﹦ -2. 03,-3. 237,-2. 626,P﹦0. 045,0. 002,0. 010). Multi—variate analysis demonstrated that V20 was the independent factor affecting≥grade 2 bone marrow suppression(OR﹦5. 285,P﹦0. 012). There was no significant difference on effects of pelvic dosimetric parameters and≥grade 2 acute bone marrow suppression(P〉0. 05). The threshold of pelvic V20 was 84% as determined by receiver operating curve (ROC). Conclusion There is a correlation between pelvic V20 and ≥grade 2 acute bone marrow suppression. To better predict and control≥grade 2 acute bone marrow suppression,pelvic V20 should be carefully controlled below 84% in the treatment plan for cervical cancer patients.