Abstract：
OBJECTIVE: This study aimed to externally validate the Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP) recommendations for differentiation/follow-up of central cartilage tumours (CCTs) of the proximal humerus, distal femur, and proximal tibia and to propose BACTIP adaptations if the results provide new insights.
METHODS: MRIs of 123 patients (45 ± 11 years, 37 men) with an untreated CCT with MRI follow-up (n = 62) or histopathological confirmation (n = 61) were retrospectively/consecutively included and categorised following the BACTIP (2003-2020 / Ghent University Hospital/Belgium). Tumour length and endosteal scalloping differences between enchondroma, atypical cartilaginous tumour (ACT), and high-grade chondrosarcoma (CS II/III/dedifferentiated) were evaluated. ROC-curve analysis for differentiating benign from malignant CCTs and for evaluating the BACTIP was performed.
RESULTS: For lesion length and endosteal scalloping, ROC-AUCs were poor and fair-excellent, respectively, for differentiating different CCT groups (0.59-0.69 versus 0.73-0.91). The diagnostic performance of endosteal scalloping and the BACTIP was higher than that of lesion length. A 1° endosteal scalloping cut-off differentiated enchondroma from ACT + high-grade chondrosarcoma with a sensitivity of 90%, reducing the potential diagnostic delay. However, the specificity was 29%, inducing overmedicalisation (excessive follow-up). ROC-AUC of the BACTIP was poor for differentiating enchondroma from ACT (ROC-AUC = 0.69; 95%CI = 0.51-0.87; p = 0.041) and fair-good for differentiation between other CCT groups (ROC-AUC = 0.72-0.81). BACTIP recommendations were incorrect/unsafe in five ACTs and one CSII, potentially inducing diagnostic delay. Eleven enchondromas received unnecessary referrals/follow-up.
CONCLUSIONS: Although promising as a useful tool for management/follow-up of CCTs of the proximal humerus, distal femur, and proximal tibia, five ACTs and one chondrosarcoma grade II were discharged, potentially inducing diagnostic delay, which could be reduced by adapting BACTIP cut-off values.
CONCLUSIONS: Mostly, Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP) assesses central cartilage tumours of the proximal humerus and the knee correctly. Both when using the BACTIP and when adapting cut-offs, caution should be taken for the trade-off between underdiagnosis/potential diagnostic delay in chondrosarcomas and overmedicalisation in enchondromas.
CONCLUSIONS: • This retrospective external validation confirms the Birmingham Atypical Cartilage Tumour Imaging Protocol as a useful tool for initial assessment and follow-up recommendation of central cartilage tumours in the proximal humerus and around the knee in the majority of cases. • Using only the Birmingham Atypical Cartilage Tumour Imaging Protocol, both atypical cartilaginous tumours and high-grade chondrosarcomas (grade II, grade III, and dedifferentiated chondrosarcomas) can be misdiagnosed, excluding them from specialist referral and further follow-up, thus creating a potential risk of delayed diagnosis and worse prognosis. • Adapted cut-offs to maximise detection of atypical cartilaginous tumours and high-grade chondrosarcomas, minimise underdiagnosis and reduce potential diagnostic delay in malignant tumours but increase unnecessary referral and follow-up of benign tumours.
METHODS: MRIs of 123 patients (45 ± 11 years, 37 men) with an untreated CCT with MRI follow-up (n = 62) or histopathological confirmation (n = 61) were retrospectively/consecutively included and categorised following the BACTIP (2003-2020 / Ghent University Hospital/Belgium). Tumour length and endosteal scalloping differences between enchondroma, atypical cartilaginous tumour (ACT), and high-grade chondrosarcoma (CS II/III/dedifferentiated) were evaluated. ROC-curve analysis for differentiating benign from malignant CCTs and for evaluating the BACTIP was performed.
RESULTS: For lesion length and endosteal scalloping, ROC-AUCs were poor and fair-excellent, respectively, for differentiating different CCT groups (0.59-0.69 versus 0.73-0.91). The diagnostic performance of endosteal scalloping and the BACTIP was higher than that of lesion length. A 1° endosteal scalloping cut-off differentiated enchondroma from ACT + high-grade chondrosarcoma with a sensitivity of 90%, reducing the potential diagnostic delay. However, the specificity was 29%, inducing overmedicalisation (excessive follow-up). ROC-AUC of the BACTIP was poor for differentiating enchondroma from ACT (ROC-AUC = 0.69; 95%CI = 0.51-0.87; p = 0.041) and fair-good for differentiation between other CCT groups (ROC-AUC = 0.72-0.81). BACTIP recommendations were incorrect/unsafe in five ACTs and one CSII, potentially inducing diagnostic delay. Eleven enchondromas received unnecessary referrals/follow-up.
CONCLUSIONS: Although promising as a useful tool for management/follow-up of CCTs of the proximal humerus, distal femur, and proximal tibia, five ACTs and one chondrosarcoma grade II were discharged, potentially inducing diagnostic delay, which could be reduced by adapting BACTIP cut-off values.
CONCLUSIONS: Mostly, Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP) assesses central cartilage tumours of the proximal humerus and the knee correctly. Both when using the BACTIP and when adapting cut-offs, caution should be taken for the trade-off between underdiagnosis/potential diagnostic delay in chondrosarcomas and overmedicalisation in enchondromas.
CONCLUSIONS: • This retrospective external validation confirms the Birmingham Atypical Cartilage Tumour Imaging Protocol as a useful tool for initial assessment and follow-up recommendation of central cartilage tumours in the proximal humerus and around the knee in the majority of cases. • Using only the Birmingham Atypical Cartilage Tumour Imaging Protocol, both atypical cartilaginous tumours and high-grade chondrosarcomas (grade II, grade III, and dedifferentiated chondrosarcomas) can be misdiagnosed, excluding them from specialist referral and further follow-up, thus creating a potential risk of delayed diagnosis and worse prognosis. • Adapted cut-offs to maximise detection of atypical cartilaginous tumours and high-grade chondrosarcomas, minimise underdiagnosis and reduce potential diagnostic delay in malignant tumours but increase unnecessary referral and follow-up of benign tumours.
摘要：
目的：本研究旨在外部验证伯明翰非典型软骨肿瘤成像方案（BACTIP）对肱骨近端中央软骨肿瘤（CCT）的鉴别/随访建议，股骨远端,和胫骨近端，并提出BACTIP适应性，如果结果提供新的见解。
方法：123例患者（45±11岁，在BACTIP（2003-2020/根特大学医院/比利时）之后，回顾性/连续地纳入了未经治疗的CCT并进行了MRI随访（n=62）或组织病理学确认（n=61）。内生软骨瘤之间的肿瘤长度和骨内膜扇贝差异，非典型软骨肿瘤（ACT），和高级别软骨肉瘤（CSII/III/去分化）进行评估。进行ROC曲线分析以区分良性和恶性CCT并评估BACTIP。
结果：对于病变长度和骨内膜扇贝，ROC-AUC很差，相当优秀，分别,用于区分不同的CCT组（0.59-0.69对0.73-0.91）。骨内膜扇贝和BACTIP的诊断性能高于病变长度。来自ACT+高级别软骨肉瘤的1°骨内膜扇贝切断术分化内生软骨瘤，敏感性为90％，减少潜在的诊断延迟。然而,特异性为29%，导致过度医疗(过度随访)。BACTIP的ROC-AUC对于区分内软骨瘤与ACT较差（ROC-AUC=0.69;95CI=0.51-0.87;p=0.041），并且对于其他CCT组之间的区分相当好（ROC-AUC=0.72-0.81）。BACTIP建议在五个ACT和一个CSII中不正确/不安全，可能导致诊断延迟。11个中成虫接受了不必要的转诊/随访。
结论：尽管有望成为肱骨近端CCT管理/随访的有用工具，股骨远端,和胫骨近端,5例ACTs和1例II级软骨肉瘤出院,可能导致诊断延迟，可以通过调整BACTIP截止值来降低。
结论：大多数情况下，伯明翰非典型软骨肿瘤成像方案（BACTIP）正确评估肱骨近端和膝盖的中央软骨肿瘤。无论是在使用BACTIP时，还是在调整切断时，应谨慎权衡软骨肉瘤的诊断不足/潜在诊断延迟与软骨瘤的过度医疗。
结论：•这种回顾性外部验证证实了伯明翰非典型软骨肿瘤成像方案是一种有用的工具，用于初始评估和随访建议大多数病例中肱骨近端和膝关节周围的中央软骨肿瘤。•仅使用伯明翰非典型软骨肿瘤成像方案，非典型软骨肿瘤和高级别软骨肉瘤（II级，三级,和去分化软骨肉瘤）可以误诊，将他们排除在专家转诊和进一步随访之外，从而造成延迟诊断和预后恶化的潜在风险.•适应截止，以最大限度地检测非典型软骨肿瘤和高级别软骨肉瘤，减少恶性肿瘤的诊断不足并减少潜在的诊断延迟，但增加良性肿瘤的不必要转诊和随访。
方法：123例患者（45±11岁，在BACTIP（2003-2020/根特大学医院/比利时）之后，回顾性/连续地纳入了未经治疗的CCT并进行了MRI随访（n=62）或组织病理学确认（n=61）。内生软骨瘤之间的肿瘤长度和骨内膜扇贝差异，非典型软骨肿瘤（ACT），和高级别软骨肉瘤（CSII/III/去分化）进行评估。进行ROC曲线分析以区分良性和恶性CCT并评估BACTIP。
结果：对于病变长度和骨内膜扇贝，ROC-AUC很差，相当优秀，分别,用于区分不同的CCT组（0.59-0.69对0.73-0.91）。骨内膜扇贝和BACTIP的诊断性能高于病变长度。来自ACT+高级别软骨肉瘤的1°骨内膜扇贝切断术分化内生软骨瘤，敏感性为90％，减少潜在的诊断延迟。然而,特异性为29%，导致过度医疗(过度随访)。BACTIP的ROC-AUC对于区分内软骨瘤与ACT较差（ROC-AUC=0.69;95CI=0.51-0.87;p=0.041），并且对于其他CCT组之间的区分相当好（ROC-AUC=0.72-0.81）。BACTIP建议在五个ACT和一个CSII中不正确/不安全，可能导致诊断延迟。11个中成虫接受了不必要的转诊/随访。
结论：尽管有望成为肱骨近端CCT管理/随访的有用工具，股骨远端,和胫骨近端,5例ACTs和1例II级软骨肉瘤出院,可能导致诊断延迟，可以通过调整BACTIP截止值来降低。
结论：大多数情况下，伯明翰非典型软骨肿瘤成像方案（BACTIP）正确评估肱骨近端和膝盖的中央软骨肿瘤。无论是在使用BACTIP时，还是在调整切断时，应谨慎权衡软骨肉瘤的诊断不足/潜在诊断延迟与软骨瘤的过度医疗。
结论：•这种回顾性外部验证证实了伯明翰非典型软骨肿瘤成像方案是一种有用的工具，用于初始评估和随访建议大多数病例中肱骨近端和膝关节周围的中央软骨肿瘤。•仅使用伯明翰非典型软骨肿瘤成像方案，非典型软骨肿瘤和高级别软骨肉瘤（II级，三级,和去分化软骨肉瘤）可以误诊，将他们排除在专家转诊和进一步随访之外，从而造成延迟诊断和预后恶化的潜在风险.•适应截止，以最大限度地检测非典型软骨肿瘤和高级别软骨肉瘤，减少恶性肿瘤的诊断不足并减少潜在的诊断延迟，但增加良性肿瘤的不必要转诊和随访。
