Predicting severe hematologic toxicity from extended-field chemoradiation of para-aortic nodal metastases from cervical cancer.

ABSTRACT

PURPOSE: The purpose of this study was to determine factors predictive for severe hematologic toxicity (HT) in cervical cancer patients with para-aortic lymph node metastasis treated with concurrent cisplatin chemoradiation to an extended field (EFCRT). METHODS AND MATERIALS Thirty-eight patients with cervical cancer and para-aortic lymph node metastasis who underwent EFCRT were analyzed. Active bone marrow was defined as the region within irradiated total bone marrow (BMTOT) with a standard uptake value on 18F-fluorodeoxyglucose positron emission tomography/computed tomography greater than the mean standard uptake value for BMTOT. Serial weekly blood counts from the beginning to the end of radiation treatment were evaluated for HT using Common Terminology Criteria for Adverse Events, version 4.0. RESULTS: Nineteen patients had grade 3 or higher hematologic toxicity (HT3+), not including lymphocyte toxicity. Obese patients (n = 12) were less likely to get HT3+ (P = .03) despite getting equivalent doses of chemotherapy. Volumes of BMTOT and active bone marrow receiving doses of 20, 30, and 45 Gy and body mass index significantly predicted HT3+. Patients who had HT3+ had prolonged treatment time (62 vs 53 days, P < .001). CONCLUSIONS: For patients receiving EFCRT, bone marrow irradiation parameters and patient body mass index were associated with HT3+. A simplified nomogram has been created to predict HT3+ in these patients, allowing the potential to explore bone marrow-sparing delivery techniques.