Correlation Between Dosimetric Parameters and Hematologic Toxicity in Cervical Cancer Patients Undergoing...

Objective: This study aimed to elucidate the association between hematologic toxicity (HT) and pelvic bone marrow (PBM) dosimetric parameters in patients with cervical cancer (CC) undergoing radiotherapy (RT) combined with artificial intelligence (AI)-assisted organ at risk (OAR) delineation (Software Copyright Registration Number 2023SR0150365). Accurate delineation of bone marrow (BM) regions and analysis of radiation doses may provide a theoretical foundation for the application of AI in predicting HT. Methods: This retrospective study included 141 patients with CC who received chemotherapy (sequential or concurrent) and/or pelvic volumetric modulated arc therapy (VMAT) at the Department of Gynecology, Cancer Hospital of the Chinese Academy of Medical Sciences, between March 2019 and December 2019. PBM and its subregions (ilium, lower pelvis, lumbosacral spine, and femoral heads) were delineated using AI-based automatic segmentation of CT images. The volumes receiving 10-40 Gy (V10, V20, V30, V40) were calculated, and baseline clinical characteristics were assessed. HT endpoints included grade ≥ 2 (HT2+) and grade ≥ 3 (HT3+) leukopenia, neutropenia, anemia, or thrombocytopenia. Associations between dosimetric parameters and HT were evaluated using logistic regression models. Results: Of the 141 patients, 107 (75.8%) developed HT2+ and 33 (23.4%) developed HT3+. Univariate analysis showed that chemotherapy and age were correlated with HT2+. Multivariate analysis identified femoral head V30, femoral head V40, and chemotherapy as independent predictors of HT3+. Conclusions: This study highlights the potential of AI-based OAR delineation for assessing PBM dosimetric parameters in patients with CC. Optimizing RT to minimize BM dose and volume may mitigate HT and enhance treatment tolerance. In our cohort, receipt of combined neoadjuvant and concurrent chemotherapy (NACT+CCRT) was a stronger predictor of HT than most BM dosimetric parameters, suggesting that the systemic effect of chemotherapy may dominate the hematologic toxicity profile in this setting. Consequently, patients receiving this combined modality treatment are at particularly high risk for HT and warrant close hematologic monitoring.