The Relationship Between the Radiation Dose of Different Anatomic Bony Sites and Neutrophil Toxicity in Concurrent Chemoradiotherapy for Cervical Cancer

Abstract Background: The purpose of this study was to verify the radiation dose of the pelvic bone marrow of different anatomical bony sitesand the incidence of neutrophil toxicity during the concurrent chemoradiotherapy for cervical cancer.Methods: There were 117 cervical cancer patients who received concurrent chemoradiotherapy included in this research. The radiotherapy includedexternal-beam radiation therapy (EBRT) and the brachytherapy. The dosimetric parameters included V5, V10, V20, V30, V40, V50, and Dmean. The final neutrophil count was defined as the lowest neutrophil count after 2 circles of concurrent chemotherapy, during or within 1 month after the treatment. The correlation between the dosimetric parameters and the lowest neutrophil count were analyzed by linear regression, the cutoff values of the dosimetric parameters were obtained using the ROC curves,the patients were divided into subgroups based on the cutoff values. The clinicopathologic features and the dosimetric parameters were included into the multivariate regression analysis model to further prove the correlation between the dosimetric parameters and the neutrophil toxicity. Data were assessed with IBM-SPSS software version 22.0, and all values of p<0.05were considered statistically significant.Results:The neutrophil toxicity (grade 1-4) rate was 58.97%. The linear regression showed the Dmean and V50 of Lumbosacral vertebrae(LS), the Dmean, V5, V10, V20, V30, V40 and V50 of the ilium correlated with the lowest neutrophil count, while none of the dosimetric parameters of the femoral correlated with the lowest neutrophil count.The multivariate analysis showed the V20, V30 and V50 of the LS, the Dmean, V5, V10, V20 and V30 of the ilium correlated well with the neutrophil toxicity; none of the dosimetric parameters of the femoral correlated with the neutrophil toxicity.Conclusion:During the process of concurrent chemoradiotherapy for cervical cancer, the volume of medium and high dose of LS and the volume of low and medium dose of ilium should be strictly limitedto reduce the risk of neutrophil toxicity, the Dmean of the ilium should also be taken into consideration. The dosimetric parameters of the femur could be ignored.Trial registration:This is a retrospective research, and it will be retrospectively registered.