Is a radiological score able to predict resection-grade chondrosarcoma in primary intraosseous lesions of the long bones?

Abstract

AimsThe preoperative grading of chondrosarcomas of bone that accurately predicts surgical management is difficult for surgeons, radiologists, and pathologists. There are often discrepancies in grade between the initial biopsy and the final histology. Recent advances in the use of imaging methods have shown promise in the ability to predict the final grade. The most important clinical distinction is between grade 1 chondrosarcomas, which are amenable to curettage, and resection-grade chondrosarcomas (grade 2 and 3) which require en bloc resection. The aim of this study was to evaluate the use of a Radiological Aggressiveness Score (RAS) to predict the grade of primary chondrosarcomas in long bones and thus to guide management.MethodsA total of 113 patients with a primary chondrosarcoma of a long bone presenting between January 2001 and December 2021 were identified on retrospective review of a single oncology centre’s prospectively collected database. The nine-parameter RAS included variables from radiographs and MRI scans. The best cut-off of parameters to predict the final grade of chondrosarcoma after resection was determined using a receiver operating characteristic curve (ROC), and this was correlated with the biopsy grade.ResultsA RAS of ≥ four parameters was 97.9% sensitive and 90.5% specific in predicting resection-grade chondrosarcoma based on a ROC cut-off derived using the Youden index. Cronbach’s α of 0.897 was derived as the interclass correlation for scoring the lesions by four blinded reviewers who were surgeons. Concordance between resection-grade lesions predicted from the RAS and ROC cut-off with the final grade after resection was 96.46%. Concordance between the biopsy grade and the final grade was 63.8%. However, when the patients were analyzed based on surgical management, the initial biopsy was able to differentiate low-grade from resection-grade chondrosarcomas in 82.9% of biopsies.ConclusionThese findings suggest that the RAS is an accurate method for guiding the surgical management of patients with these tumours, particularly when the initial biopsy results are discordant with the clinical presentation.Cite this article: Bone Joint J 2023;105-B(7):808–814.

Oncology

“…In a retrospective review of 113 patients with a primary chondrosarcoma of a long bone, a group from Toronto (Canada) sought to evaluate the use of a Radiological Aggressiveness Score (RAS) to predict the grade of primary chondrosarcomas in long bones and thus guide management using nine radiological parameters from radiographs and MRI scans. 5 The analysis showed that the parameters that most significantly correlated with a higher grade of tumour were complete cortical erosion, periosteal reaction, a soft-tissue component, marrow oedema, and pathological fracture. A RAS of ≥ four parameters was 97.9% sensitive and 90.5% specific in predicting resection-grade chondrosarcoma.…”

Oncology

“…Assessing the extent of the disease and predicting the treatment likely to meet with success is essential, and so a team from Toronto (Canada) has contributed by investigating the predictive capability of a radiological score for resection-grade chondrosarcoma. 9 The research involved the analysis of radiological imaging, including radiographs and MRI scans, from a cohort of patients with these lesions to evaluate whether a radiological score could reliably and effectively identify high-grade chondrosarcomas that require extensive resection. The team showed a concordance between resection-grade lesions predicted by the radiological score of 96.46%, whereas concordance between the biopsy grade and the final grade was 63.8, and the ability of initial biopsy to differentiate low-grade from resection-grade chondrosarcomas was 82.9%.…”