Single‐photon emission computed tomography‐defined active bone marrow‐sparing volumetric‐modulated arc therapy reduces the incidence of acute hematologic toxicity in locally advanced cervical cancer patients who receive chemoradiotherapy: A single‐center prospective randomized controlled trial

Abstract

AbstractBackgroundThis study aims to test the efficacy of single‐photon emission computed tomography (SPECT)‐defined active bone marrow‐sparing (ABMS) volumetric‐modulated arc therapy (VMAT) in reducing grade 3+ acute hematologic toxicity (HT) in locally advanced cervical cancer patients treated with chemoradiotherapy.MethodsThis was a prospective, single‐center, open label, randomized clinical trial that enrolled locally advanced cervical cancer patients. Participants were randomized to the 99mTc sulfur colloid SPECT‐defined ABMS VMAT (ABMS group) or control group, who received weekly cisplatin concurrently with VMAT followed by high–dose‐rate intracavitary brachytherapy. The ABMS group additionally received SPECT‐defined ABM dose constraints. The primary end point was the incidence of grade 3+ acute HT.ResultsA total of 192 Federation of Gynaecology and Obstetrics stage IB‐IIIB patients were randomly treated (96 each in the ABMS control groups). The median follow‐up was 24.0 months. The incidence of grade 3+ acute HT in the ABMS group was significantly lower than that in the control group (32.3% vs. 53.1%, p < .01). The number of patients completing five cycles of cisplatin was 88.5% in the ABMS group and 75% in the control group, and the difference was significant (p = .02). There were no differences in planning target value coverage, organs at risk dosimetric parameters, 2‐year progression‐free survival, or 2‐year overall survival between the two groups. Patients in the control group had nonsignificantly worse 2‐year distant metastasis than patients in the ABMS group (17.8% vs. 11.1%, p = .19).ConclusionsABMS VMAT significantly reduced grade 3+ acute HT and improved chemotherapy delivery compared with the control treatment. We found weak evidence of the effect of ABMS VMAT on distant metastasis.