Quantitative diffusion-weighted magnetic resonance imaging assessment of chemotherapy treatment response of pediatric osteosarcoma and Ewing sarcoma malignant bone tumors.

Objective: Assessment of tumor response to chemotherapy is essential in managing malignant pediatric bone tumors prior to resection.

Subjects And Methods: Pre-chemotherapy and post-chemotherapy osteosarcoma and Ewing sarcoma cases (n=18) were analyzed with apparent diffusion coefficient (ADC) values measured by two readers.

Results: Treated tumors demonstrated significantly greater ADC values compared to untreated tumors (p<0.001). Intraclass correlation coefficients ranged between 0.858 and 0.935. No significant tumor volume differences were observed. Regression analysis demonstrated average ADC as the best predictor of treatment.

Conclusions: Our study suggests that ADC values may be useful for evaluating chemotherapeutic response of malignant pediatric bone tumors.