The application value of apparent diffusion coefficient in monitoring the response to chemotherapy of primary bone lymphoma / 中华放射学杂志

ABSTRACT

Objective To investigate the application value of apparent diffusion coefficient (ADC) in monitoring the response to chemotherapy of primary bone lymphoma(PBL). Methods Sixteen consecutive patients with PBL confirmed by pathology were enrolled in this retrospective study.All patients underwent a controlled MRI including a DWI sequence before chemotherapy and after the first chemotherapy session. The ADC values of PBL lesions were measured before and after the first chemotherapy session. All patients were divided into responders and non-responders groups according to the combined response assessment criteria. The difference in ADC values between the responders and non-responders groups before and after chemotherapy and the rate of change of ADC values were compared using Wilcoxon test. The paired t test was used to compare ADC values before and after chemotherapy in each group. Results Twenty-three cases of PBL lesions were diagnosed in 16 patients before the chemotherapy. After the first chemotherapy session, 10 patients (12 lesions) and 6 patients (11 lesions) were categorized into the responder and non-responder group, respectively. The mean pre-treatment ADC value of the responder group and non-responder group were 737.1(301.7,928.4)× 10-6mm2/s and 749.2(624.4, 1186.5)× 10-6mm2/s, which had no statistically significant difference (Z=1.51,P=0.132). The mean post-treatment ADC value of the responder group and non-responder group were 1843.0(721.5,2745.8)× 10-6mm2/s and 1026.3(382.8,2100.8)× 10-6mm2/s, which had no statistically significant difference (Z=-1.75,P=0.079). The post-treatment ADC value of the responder group significantly increased [156.7(60.9,227.5)%] while the post-treatment ADC value of the non-responder group slightly increased [31.7(-44.7,147.4)%]. The difference in the percentage changes of ADC values in the responder and non-responder groups before and after the treatment was statistically significant(Z=-3.66,P<0.001). Conclusion The measurement of the percentage changes of ADC values enable a good short-term response evaluation for PBL.