Abstract
BACKGROUND: To explore the correlation between effective dose to immune cells (EDIC) and vertebral bone marrow dose and hematologic toxicity (HT) for esophageal squamous cell carcinoma (ESCC) during neoadjuvant chemoradiotherapy (nCRT). METHODS: The study included 106 ESCC patients treated with nCRT. We collected dosimetric parameters, including vertebral body volumes receiving 10-40 Gy (V10, V20, V30, V40) and EDIC and complete blood counts. Associations of the cell nadir and dosimetric parameters were examined by linear and logistic regression analysis. The receiver operating characteristic (ROC) curves were used to determine the cutoff values for the dosimetric parameters. RESULTS: During nCRT, the incidence of grade 3-4 lymphopenia, leukopenia, and neutropenia was 76.4%, 37.3%, and 37.3%, respectively. Patients with EDIC ≤ 4.63 Gy plus V10 ≤ 140.3 ml were strongly associated with lower risk of grade 3-4 lymphopenia (OR, 0.050; P < 0.001), and patients with EDIC ≤ 4.53 Gy plus V10 ≤ 100.9 ml were strongly associated with lower risk of grade 3-4 leukopenia (OR, 0.177; P = 0.011), and patients with EDIC ≤ 5.79 Gy were strongly associated with lower risk of grade 3-4 neutropenia (OR, 0.401; P = 0.031). Kaplan-Meier analysis showed that there was a significant difference among all groups for grade 3-4 lymphopenia, leukopenia, and neutropenia (P < 0.05). CONCLUSION: The dose of vertebral bone marrow irradiation and EDIC were significantly correlated with grade 3-4 leukopenia and lymphopenia, and EDIC was significantly correlated with grade 3-4 neutropenia. Reducing vertebral bone marrow irradiation and EDIC effectively reduce the incidence of HT.