Background: DWI is beneficial in evaluation of soft tissue sarcomas, thus improving the diagnostic accuracy, characterization and response to treatment.
Purpose: The aim of this study was to evaluate the benefit of using quantitative diffusion weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping in the diagnosis of soft tissue sarcoma, with emphasis on its prognostic value.
Patients and Methods: This study included 50 patients with pathologically proven soft tissue sarcoma. The DWI was obtained with 3 b values, including 0, 400, and 800 s/mm². Calculation of the ADC value of the lesion was done by placing the region of interest (ROI) to include the largest area of the lesion. ADC values were compared with the histopathology.
Results: The most frequent site was thigh (48.0), followed by shoulder, forearm, arm and foot (8.0% for each). The most frequent pathology was synovial sarcoma (32.0%) followed by spindle cell sarcoma (28.0%) then liposarcoma (12.0%). 80% of lesions showed restricted diffusion. Median ADC value was 0.7 and ranged from 0.5 to 2.4. All patients underwent surgery. 48.0% of patients received chemotherapy and 52.0% received radiotherapy. 56.0% of patients showed recurrence. 44.0% showed metastasis. Mean follow up duration was 13 months with standard deviation of 5 months. Median ADC value was significantly higher in patients with no recurrence (0.9) compared to those with recurrence (0.7). P value was 0.016.
Conclusion: DWI with ADC mapping of soft tissue sarcoma has additive role to anatomic sequences for lesion characterization and grading as well as treatment response.