Article Abstract

Dosimetric predictors of acute hematologic toxicity due to intensity-modulated pelvic radiotherapy with concurrent chemotherapy for pelvic cancer patients

Authors: Yongqiang Yang, Wenjing Li, Jianjun Qian, Junjun Zhang, Yuntian Shen, Ye Tian


Background: Hematologic toxicity is a major common side effect after chemoradiotherapy in pelvic cancer patients. Here, we investigate the clinical and dosimetric factors associated with acute hematologic toxicity in Chinese cervical and rectal cancer patients treated with pelvic intensity-modulated radiotherapy with concurrent chemotherapy.
Methods: We retrospectively analyzed 171 patients receiving concurrent chemoradiotherapy or pelvic radiotherapy alone. The volume of pelvic bone marrow receiving 5, 10, 20, 30, 40, and 50 Gy and the patient baseline clinical characteristics were calculated. The χ2 test and univariate and multiple logistic regression analyses were used to evaluate associations between the dosimetric parameters and grade ≥2 acute hematologic toxicity.
Results: One hundred sixty-seven patients were eligible for analysis, and of these patients, 105 (62.9%) had grade ≥2 acute HT. Patients treated with chemoradiotherapy with V10 ≥90%, V20 ≥75%, V30 ≥59.2%, and V40 ≥37% had higher rates of grade ≥2 hematologic toxicity than those with V10 <90%, V20 <75%, V30 <59.2%, and V40 <37% (85.2% vs. 60.4%, P=0.004; 78.9% vs. 58.1%, P=0.027; 83.3% vs. 60.8%, P=0.010; 82.3% vs. 60.0%, P=0.011; respectively). Multiple logistic regression analysis showed that increased pelvic bone marrow V10 and pelvic bone marrow V40 were associated with increased grade 2 or worse hematologic toxicity for patients treated with chemoradiotherapy [odds ratio (OR), 4.07; 95% confidence interval (CI), 1.38–11.96; P=0.011; OR, 3.41; 95% CI, 1.20–9.69; P=0.022; respectively].
Conclusions: Increased pelvic bone marrow V10 and V40 were associated with hematologic toxicity in cervical and rectal cancer patients undergoing concurrent chemoradiotherapy. We suggest that pelvic bone marrow should be routinely considered to be an at-risk organ in cervical and rectal cancer patients treated with pelvic radiotherapy.