Evaluation Of Magnetic Resonance DWI-ADC Value In Assessing The Early Efficacy Of Neoadjuvant Chemotherapy For Conventional Osteosarcoma

Objective: To investigate the value of different apparent diffusion coefficients of magnetic resonance and their rates of change in assessing the early efficacy of neoadjuvant chemotherapy for osteosarcoma.Materials and Methods: Twenty-three patients with osteosarcoma undergoing neoadjuvant chemotherapy（NAC）at The Affiliated Tumour Hospital of Xinjiang Medical University between January 2019 and March 2022 were collected,and conventional MRI and DWI were performed before NAC and after 4 cycles of chemotherapy to obtain different apparent diffusion coefficients（ADC）and its rate of change were obtained.Patients were divided into good histological response group and poor histological response group according to the pathological histological Huvos grading method of chemotherapy,and the statistical differences of different apparent diffusion coefficients and their change rates between the two groups were compared.Results: The differences in ADC_mean,ADC_min,ADC_mean/volume,ADC_min/volume before and after chemotherapy in the good histological response group were statistically significant,all P<0.05（P values were 0.024,<0.001,0.018,0.046,respectively）.The differences in ADC_mean,ADC_min,ADC_min/volume before and after chemotherapy were statistically significant in the poor histological response group,all P<0.05（P values were 0.005,<0.001,0.020,respectively）,while the differences in ADC_mean/volume were not statistically significant（P=0.071,P>0.05）.The differences in the rates of change of different apparent diffusion coefficients ADC_mean,ADC_min,ADC_mean/volume,and ADC_min/volume between the two groups were statistically significant（P=0.047,0.006,0.039,0.015,all P<0.05）.The area under the curve of ADC_min rate of change by ROC curve analysis was 0.938,which was higher than the rates of change of ADC_mean,ADC_min/volume,and ADC_mean/volume（0.783,0.767,and 0.813,respectively）.Conclusion: Different apparent diffusion coefficients and their rates of change are of great value in the early assessment of the efficacy of osteosarcoma,and the ADC_minrate of change has significant advantages in predicting the efficacy of osteosarcoma.