Purpose. To investigate the value of intravoxel incoherent motion (IVIM) magnetic resonance imaging in the evaluation of the osteosarcoma (OS) response to preoperative neoadjuvant chemotherapy (NAC) in teens. Methods. Eighteen consecutive osteosarcoma patients (12 males and 6 females) diagnosed by histopathology were enrolled. All enrolled patients received NAC and underwent MRI examinations before and after 2 cycles of NAC. The volume (V), apparent diffusion coefficient (ADC), (slow) diffusion coefficient (D), pseudo-perfusion (fast) diffusion coefficient (D⁎or D star), and perfusion fractions (f) of the OS before and after NAC were measured and analysed. The sensitivity and the specificity of the ADC, D, D⁎ and f values and the correlation between changes in volume (ΔV) and the IVIM-derived parameters (ΔADC, ΔD, ΔD⁎ and Δf) were also calculated and analysed. Paired Student’s t-tests, receiver operating characteristic (ROC) curves, and Spearman correlation analyses were used. Results. The mean volume of the OS after NAC decreased significantly (61.55±9.3 cm3 vs 40.26±4.1 cm3) (P<0.05). After NAC, the ADC (1.21±0.09 × 10-3 mm2/s vs 1.73±0.11 × 10-3 mm2/s) and D (1.14±0.09 × 10-3 mm2/s vs 1.63±0.1 × 10-3 mm2/s) values increased and f (28.58±1.37% vs 20.93±1.16%) values decreased significantly (P<0.05), while D⁎ (9.17±0.98 × 10-3 mm2/s vs 8.94±0.13 × 10-3 mm2/s) values changed slightly (P>0.05). The AUC values of ADC (0.938) and D (0.943) were higher than those of D⁎ (0.574) and f (0.765). The sensitivity and specificity of ADC (0.778, 1) and D (0.944, 0.833) values were superior to those of D⁎ (0.278, 0.722) and f (0.5, 0.944) values. No significant correlations were found between the ΔV and ΔADC, ΔD, ΔD⁎ and Δf values (P>0.05). Conclusion. IVIM-derived parameters ADC and D have the potential to be imaging biomarkers for evaluation of the therapeutic response to NAC in OS patients.
Intravoxel Incoherent Motion-Magnetic Resonance Imaging as an Early Predictor of Treatment Response to Neoadjuvant Chemotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma
