Pelvic Bone Marrow Sparing Using Different Radiotherapy Techniques in Patients with Cervical Cancer Receiving Concurrent Chemoradiotherapy: A Retrospective Study

Abstract

Purpose: To evaluate the association between pelvic bone marrow irradiation and hematological toxicity in patients with cervical cancer treated with concurrent chemoradiotherapy and to assess whether bone marrow-sparing conformal radiotherapy may reduce treatment-related toxicity.

Materials and Methods: This retrospective study included 44 patients with cervical cancer treated with pelvic external-beam radiotherapy and weekly cisplatin (40 mg/m²) between July and September 2011. Hematological toxicity was assessed according to Common Terminology Criteria. Clinical and dosimetric factors, including age, body mass index, pelvic bone marrow volume, transfusion requirements, and irradiated bone marrow volume, were analyzed. Multivariable regression was used to evaluate the association between bone marrow dose-volume parameters and hematological toxicity.

Results: Hematological toxicity occurred in 24 of 44 patients (54.5%). A pelvic bone marrow volume receiving ≥20 Gy (V20) was significantly associated with hematological toxicity. Patients with V20 >70% had a higher risk of hematological toxicity than those with V20 ≤70% (p=0.008). Five-field conformal radiotherapy was also associated with a lower incidence of hematological toxicity.

Conclusion: Pelvic bone marrow irradiation is associated with hematological toxicity during concurrent chemoradiotherapy for cervical cancer. A pelvic bone marrow V20 of 70% may serve as a useful dosimetric threshold for predicting toxicity. Five-field conformal radiotherapy may provide a practical bone marrow-sparing approach, particularly in resource-limited settings.