MRI in primary bone tumors: therapeutic implications.

Area of Science:

• Radiology
• Oncology
• Orthopedic Surgery

Background:

• Accurate preoperative assessment of primary bone neoplasms is crucial for effective surgical planning and treatment.
• Magnetic Resonance Imaging (MRI) is a key modality for evaluating tumor extent, but its accuracy varies.
• Assessing response to neoadjuvant chemotherapy is vital for tailoring treatment in bone tumors.

Purpose of the Study:

• To evaluate the accuracy of preoperative MRI in determining the intra-osseous extent of primary bone neoplasms.
• To assess the utility of MRI in identifying changes indicative of response to presurgical chemotherapy.
• To determine if MRI meets surgeons' preoperative requirements for local tumor staging and therapy response assessment.

Main Methods:

• Retrospective analysis of preoperative MRI scans in 35 patients with primary bone neoplasms.
• Comparison of intra-osseous tumor extent on MRI with surgical specimen macroslides in 26 cases.
• Evaluation of Spin-Echo (SE) and Short Inversion Time Inversion Recovery (STIR) sequences for tumor delineation.
• Analysis of Signal Intensity (SI) and morphological changes in tumors after neoadjuvant chemotherapy.

Main Results:

• Combined SE and STIR sequences achieved high accuracy in predicting tumor size, with exceptions in two Ewing's sarcomas.
• Chemotherapy-induced changes in SI (reduction) and morphology (homogeneity) correlated with positive cytotoxic therapy response.
• MRI accurately assessed local tumor staging and therapy response for most neoplasms, excluding Ewing's sarcoma.

Conclusions:

• Preoperative MRI, particularly with combined SE and STIR sequences, is highly accurate for staging primary bone neoplasms.
• MRI effectively detects chemotherapy-induced changes, aiding in the assessment of treatment response.
• MRI is a valuable tool for surgeons, fulfilling preoperative requirements for staging and response evaluation, except for Ewing's sarcoma.