The role of quantitative DCE-MRI and diffusion-weighted imaging in differentiating the grade of soft tissue sarcomas

Abstract

Objective: Tumor grade is critical for prognosis, metastatic risk, and treatment planning in soft tissue sarcomas (STSs). This study evaluated the role of quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters and diffusion-weighted imaging (DWI) in predicting STS grade. Methods: Between March 2022 and February 2023, patients with histopathologically confirmed STS who underwent DCE-MRI and DWI were retrospectively included; those with prior therapy or liposarcoma were excluded. Two musculoskeletal radiologists (3 and 4 years of experience) reviewed the exams. Age, gender, and tumor diameter (LD) were recorded. Dynamic contrast-enhanced magnetic resonance imaging measurements were obtained from Ktrans maps, avoiding hemorrhagic, necrotic, and cystic areas. Regions of interest were placed over the most perfused region (max) and a broader area (mean). Parameters (Ktrans, area under the curve [AUC], Kep, Ve) and enhancement curves were documented. Apparent diffusion coefficient (ADC)min and ADCmean were measured from ADC maps. Soft tissue sarcomas were grouped by pathological grade (1-3) and as low (1-2) vs. high (3). Results: Fourteen patients (3 females, 11 males) were included: 4 grade 1, 2 grade 2, and 8 grade 3. Mean age was 58.07 ± 16.35 years; mean LD 113.36 ± 36.87 mm. Inter-observer agreement was excellent for perfusion max values and ADCmin, and good for perfusion mean and ADCmean. No significant differences were found in age or LD. Apparent diffusion coefficient (ADC)mean (P = .026), ADCmin (P = .029), and AUCmax (P = .047) differed among grades. In low- vs. high-grade comparison, ADCmean, ADCmin, Ktransmax, AUCmax, and Ktransmean were significant. Conclusion: Apparent diffusion coefficient (ADC)min, ADCmean, AUCmax, Ktransmax, and Ktransmean may support STS grading.