Osseous Tumor Reporting and Data System—Multireader Validation Study

Abstract

To develop and validate an Osseous Tumor Reporting and Data System (OT-RADS) with the hypothesis that the proposed guideline is reliable and assists in separating benign from malignant osseous tumors with a good area under the curve, and that could assist further patient management. Methods:In this multireader cross-sectional validation study, an agreement was reached for OT-RADS categories based on previously described magnetic resonance imaging features and consensus of expert musculoskeletal radiologists. World Health Organization classification was used, and a wide spectrum of benign and malignant osseous tumors was evaluated. Magnetic resonance imaging categories were as follows: OT-RADS 0-incomplete imaging; OT-RADS I-negative; OT-RADS IIdefinitely benign; OT-RADS III-probably benign; OT-RADS IVsuspicious for malignancy or indeterminate; OT-RADS V-highly suggestive of malignancy; and OT-RADS VI-known biopsy-proven malignancy or recurrent malignancy in the tumor bed. Four blinded readers categorized each tumor according to OT-RADS classification. Intraclass correlation (ICC) and Conger κ were used. Diagnostic performance measures including area under the receiver operating curve were reported. Osseous Tumor Reporting and Data System was dichotomized as benign (I-III) and malignant (IV and V) for calculating sensitivity and specificity.Results: Interreader agreement for OT-RADS (ICC = 0.78) and binary distinction of benign versus malignant (κ = 0.67) were good to excellent, while agreement for individual tumor feature characteristics were poor to fair (ICC = 0.25-0.36; κ = 0.16-0.39). The sensitivities, specificities, and area under the receiver operating curve of the readers ranged from 0.93-1.0, 0.71-0.86, and 0.92-0.97, respectively.Conclusions: Osseous Tumor Reporting and Data System lexicon is reliable and helps stratify tumors into benign and malignant categories. It can be practically used by radiologists to guide patient management, improve multidisciplinary communications, and potentially impact outcomes.

Osseous-Tissue Tumor Reporting and Data System With Diffusion-Weighted Imaging of Bone Tumors—An Interreader Analysis and Whether It Adds Incremental Value on Tumor Grading Over Conventional Magnetic Resonance Imaging

“…The OT-RADS classifications used by readers were on a range of II to V and included the following categories of: definitely benign (II), probably benign (III), suspicious for malignancy (IV), and highly suggestive of malignancy (V). These categories were differentiated by the likelihood of malignancy, which was essentially 0%, less than or equal to 2%, between 2% and 50%, and more than or equal to 50%, respectively, as in previous study 18 . During round 2 of readings conducted 6 months after round 1 to mitigate memory bias, the readers were asked to interpret conventional MR images in conjunction with DW images of each scan.…”

“…Area under the ROC curve between rounds 1 and 2 were compared using the DeLong test 20 for each reader respectively. For calculating diagnostic performance such as sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), OT-RADS scores were dichotomized—with OT-RADS scores I to III classified as benign tumors and scores IV to V as malignant as defined in the previous study 18 . In addition, AUC, sensitivity, specificity, positive predictive value and negative predictive value were also pooled from all readers and compared between round 1 and 2 using generalized linear mixed models.…”

Response to the letter to the editor in reference to OT-RADS

“…We appreciate the letter to the editor clarifying that radiographs or CT in addition to MR was available to the readers of the OT-RADS, published by Chhabra A et al [1]. The authors indeed provide that information in the "demographics" session.…”

Imaging report and data system (RADS) for bone tumors: where do we stand and future directions

“…Since 2021, three different imaging RADS for focal bone lesions have been proposed, which underscores the interest in this approach but may also lead to confusion as there is no indication of which system is more efficient [2][3][4]. Also, probably none of these systems is sufficiently mature for clinical use.…”

“…The third system, the Bone reporting and data system (Bone-RADS) [3] by Chang et al, supported by the Society of Skeletal Radiology (SSR) in 2022, proposed four algorithms for the diagnosis management of solitary bone lesions incidentally encountered on CT or MRI studies in adults. An ad hoc white paper committee was created, composed of 12 SSR members and one orthopedic oncologist with expertise in bone tumor imaging.…”