The Measurement of Apparent Diffusion Coefficient using Diffusion-Weighted MR Imaging in Differentiation between Benign and Malignant Musculoskeletal Soft Tissue Tumors

Abstract

Objective: The objective of this study were to assess the Apparent Diffusion Coefficient (ADC) values in benign and malignant musculoskeletal soft tissue tumors and determine the ADC threshold for discriminating the benign from the malignant lesions.

Materials and Methods: From December 2013 to August 2015, the retrospective descriptive study was performed in the 21 non-treated musculoskeletal soft tissue tumors with proven pathology (11 benign and 10 malignant tumors) in Srinagarind hospital by using diffusion-weighted magnetic resonance images.  The receiver operating characteristic (ROC) analysis was used to determine the threshold ADC value for discriminating malignant from benign tumors.

Results: The mean ADC value of malignant soft tissue tumors (1.075 ± 0.392x10^-3mm²/s) was significantly lower than that of benign soft tissue tumors (1.594±0.494x10^-3mm²/s) with a p£ 0.05. The mean ADC value of malignant non-myxoid soft tissue tumors lowered to 0.937±0.247x10^-3mm²/s and was significantly lower than that of benign non-myxoid soft tissue tumors (1.597±0.413x10^-3mm²/s) p < 0.05. ROC analysis showed a threshold ADC value at 1.316x10^-3mm²/s, used for discriminating  benign from malignant soft tissue tumors with 82% sensitivity, 90% specificity o and AUC of 0.8636.

Conclusion: The mean ADC value of malignant soft tissue tumors was significantly lower than that of benign soft tissue tumors. A threshold ADC value of 1.316x10^-3mm²/s. is recommended for differentiating benign and malignant musculoskeletal soft tissue tumors.