Soft Tissue-RADS: An ACR Work-in-Progress Framework for Standardized Reporting of Soft-Tissue Lesions on MRI

Abstract

Soft-tissue tumors and tumorlike lesions are commonly identified on imaging and encompass a wide spectrum of entities. For lesions lacking classic features of a particular benign diagnosis, the radiologist must carefully assess its likelihood of representing an aggressive or malignant entity. However, in the absence of classic features, this determination is challenging. In 2023, the American College of Radiology (ACR) launched the development of Soft Tissue-RADS to serve as a unified framework for approaching these lesions. Soft Tissue-RADS, currently designated by the ACR as a work in progress, provides a standardized classification for soft-tissue tumors and tumorlike lesions encountered on MRI, incorporating seven categories (0 through 6), each with linked management recommendations, and diagnostic algorithms presented as flowcharts for guiding category selection. This Clinical Perspective provides an overview of Soft Tissue-RADS. We present the proposed risk categories and associated diagnostic algorithms, provide a structured report template, and show numerous case examples. The proposed system seeks to assist radiologists in differentiating benign soft-tissue tumors and tumorlike lesions from aggressive or malignant tumors, improve the clarity of radiology reports through succinct communication of malignancy risk, guide appropriate management recommendations, facilitate assessment of radiologic-pathologic concordance, refine posttreatment evaluation, and streamline data-informed approaches to sarcoma care.