Figure 1:

MR images (postcontrast T1 with fat suppression, coronal plane [patient 1], and sagittal plane [patients 2 and 3]) in three different patients treated for osteosarcoma with neoadjuvant chemotherapy (NAC) and surgery at different timepoints (before surgery; after the administration of methotrexate, ifosfamide, and etoposide; and at the end of NAC). Patient 1 (male, aged 14 years) had a stable tumor volume throughout follow-up, with the disappearance of bone edema from the first MRI control. After surgery, histologic evaluation showed less than 1% viable cells (Huvos 4). Both patients 2 (female, aged 15 years) and 3 (female, aged 12 years) showed an increase in tumor volume in the first control followed by a decrease. However, histologic evaluation showed more than 60% viable cells for patient 2 (Huvos 2) and less than 1% (Huvos 1) for patient 3.