Dosimetric correlation of bone marrow irradiation with acute hematological toxicity in concurrent chemoradiation of cervical carcinoma patients

Background: Many acute toxicities are associated with concurrent chemoradiation in cervical carcinoma, which includes burning micturition, burning defecation, pain lower abdomen, increased frequency of stools along with Acute Hematological Toxicity (AHT). AHT is often an expected adverse effect, which can lead to treatment interruptions and decreased response rates. The purpose of this study is to analyze if there are any dosimetric constraints on the volume of bone marrow irradiated with AHT in cervical carcinoma patients treated with concurrent chemoradiation. Material and Methods: In this retrospective study of 215 patients, a total of 180 patients were eligible for analysis. Multiple parameters of bone marrow volumes (whole pelvis bone marrow and its sub-volumes--ilium, lower pelvis, and lumbosacral spine) which were contoured individually for all patients were assessed to have any statistically significant association with AHT. Results: The median age of the cohort was 57 years and majority of cases were locally advanced (stage IIB-IVA: 88.3%). Grade I, II, III leukopenia was seen in 44, 25, and 6 patients, respectively. A statistically significant correlation between grade 2+ and 3+ leukopenia was seen if bone marrow V10, V20, V30, and V40 were more than 95%, 82%, 62%, and 38%, respectively. In subvolume analysis, volumes of lumbosacral spine V20, V30, and V40 more than 95%, 90%, and 65%, respectively, were statistically significant for AHT. Conclusion: Bone marrow volumes should also be given a constraint and should be tried to be achieved so that it leads to minimal treatment breaks due to AHT.