Soft tissue sarcoma: adding diffusion-weighted imaging improves MR imaging evaluation of tumor margin infiltration.

Area of Science:

• Radiology
• Oncology
• Orthopedic Surgery

Background:

• Soft tissue sarcomas (STS) are malignant tumors requiring precise assessment of tumor margins for effective treatment.
• Conventional magnetic resonance (MR) imaging is standard for evaluating STS, but assessing tumor infiltration can be challenging.

Purpose of the Study:

• To evaluate the added diagnostic value of diffusion-weighted imaging (DWI) to conventional 3 Tesla (3T) MR imaging in determining tumor margin infiltration in STS.
• To compare the diagnostic performance of conventional MR imaging alone versus combined with DWI for STS margin assessment.

Main Methods:

• A retrospective analysis of 45 patients with pathologically confirmed STS who underwent 3T MR imaging, including DWI.
• Two radiologists assessed tumor margin infiltration using conventional MR imaging alone and then with the addition of DWI.
• Diagnostic performance was evaluated using receiver-operating characteristic (ROC) curve analysis, and interobserver agreement was assessed using kappa statistics.

Main Results:

• The combination of conventional MR imaging and DWI showed significantly higher areas under the curve (AUCs) compared to conventional MR imaging alone (0.890 vs. 0.678 and 0.846 vs. 0.640).
• The addition of DWI improved specificity in assessing tumor margin infiltration, with sensitivity, specificity, and accuracy ranging from 94-100%, 42-67%, and 80-87% respectively.
• Interobserver agreement for margin assessment was moderate to substantial with both methods.

Conclusions:

• Diffusion-weighted imaging (DWI) provides added value in assessing tumor margin infiltration in soft tissue sarcoma (STS) at 3T.
• The integration of DWI with conventional MR imaging enhances diagnostic specificity, potentially improving surgical planning for resection margins.