Abstract
Background:
Bone-RADS (Bone Reporting and Data System) is a consensus guideline by the American College of Radiology to assist in the risk stratification of lytic bone lesions. A score is calculated using 5 radiographic factors and a history of primary malignancy. The purpose of this study was to externally validate the Bone-RADS scoring system.
Methods:
This retrospective review examined radiographs from January 1, 2021, to December 31, 2021. Radiographs were identified via a keyword search for “lucent,” “osteolytic,” or “lytic” in extremity radiograph reports. All radiographs were initially read by a musculoskeletal radiologist. Radiographs of skeletally immature patients, lesions in a bone other than a long bone, primary soft-tissue masses, and negative/normal radiographs were excluded. Radiographs were independently scored on the basis of the Bone-RADS system by 4 reviewers. In the absence of a biopsy, a lesion was considered benign if it remained stable for 2 years on radiographs. Scores were correlated with final diagnoses to calculate the rates of malignancy and malignant transformation.
Results:
Of 1,108 screened radiographs, 423 were eligible. The mean age of the patients was 62 years and 49% were male. A higher Bone-RADS score was associated with a malignant diagnosis (p
Conclusions:
The Bone-RADS scoring system demonstrated moderate diagnostic performance for malignancy risk stratification of lytic bone lesions, with high sensitivity and reproducible binary classification of possibly benign versus malignant. Although inter-rater agreement for the 4-tier score was only moderate, clinically relevant benign-versus-malignant categorization demonstrated higher inter- and intra-rater agreement. These findings support Bone-RADS as a practical triage framework based on musculoskeletal imaging of lytic bone lesions.
Level of Evidence:
Diagnostic
Level III
. See Instructions for Authors for a complete description of levels of evidence.