Value of diffusion-weighted images in differentiating mid-course responders to chemotherapy for osteosarcoma compared to the histological response: preliminary results

• DOI: 10.1007/s00256-012-1360-2
• Publication Date: 2012-02-08T10:48:12Z
• Authors: C. Baunin; G. Schmidt; K. Baumstarck; C. Bouvier; J. C. Gentet; A. Aschero; A. Ruocco; B. Bourlière; G. Gorincour; C. Desvignes; N. Colavolpe; G. Bollini; P. Auqier; P. Petit
• Keywords: Male; Osteosarcoma; Adolescent; Reproducibility of Results; Antineoplastic Agents; Bone Neoplasms; Pilot Projects; Prognosis; Sensitivity and Specificity; 3. Good health; Diagnosis, Differential; 03 medical and health sciences; Diffusion Magnetic Resonance Imaging; Treatment Outcome; 0302 clinical medicine; Child, Preschool; Humans; Female; Child

Preoperative diffusion-weighted MRI (DW-MRI) has been described as an efficient method to differentiate good and poor responders to chemotherapy in osteosarcoma patients. A DW-MRI performed earlier during treatment could be helpful in monitoring chemotherapy.To assess the accuracy of DW-MRI in evaluating response to chemotherapy in the treatment of osteosarcoma, more specifically at mid-course of treatment.This study was carried out on a prospective series of adolescents treated for long-bone osteosarcoma. MR examinations were performed at diagnosis (MRI-1), at mid-course of chemotherapy (MRI-2), and immediately before surgery (MRI-3). A DW sequence was performed using diffusion gradients of b0 and b900. The apparent diffusion coefficients (ADC1, ADC2, ADC3, respectively), their differentials (ADC2 - ADC1 and ADC3 - ADC1), and their variation (ADC2 - ADC1/ADC1 and ADC3 - ADC1/ADC1) were calculated for each of these three time points.Fifteen patients were included. Patients with no increase in ADC showed a poor response to chemotherapy on their histology results. At mid-course, the three calculated values were significantly different between good and poor responders. ADC2 - ADC1 enabled us to detect, with 100% specificity, four out of seven of the poor responders. There was no significant difference in the values at MRI-3 between the two groups.DW-MRI performed both at baseline and mid-course of neoadjuvant chemotherapy is an efficient method to predict further histological response of osteosarcoma. This method could be used as an early prognostic factor to monitor preoperative chemotherapy.