IRCCS Istituto Ortopedico Galeazzi, Milan, Italy; Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan, Italy.
Nuclear Medicine Unit, IRCCS Regina Elena National Cancer Institute, Rome, Italy.
EBioMedicine. 2024 Mar;101:105018. doi: 10.1016/j.ebiom.2024.105018. Epub 2024 Feb 19.
Atypical cartilaginous tumour (ACT) and high-grade chondrosarcoma (CS) of long bones are respectively managed with active surveillance or curettage and wide resection. Our aim was to determine diagnostic performance of X-rays radiomics-based machine learning for classification of ACT and high-grade CS of long bones.
This retrospective, IRB-approved study included 150 patients with surgically treated and histology-proven lesions at two tertiary bone sarcoma centres. At centre 1, the dataset was split into training (n = 71 ACT, n = 24 high-grade CS) and internal test (n = 19 ACT, n = 6 high-grade CS) cohorts, respectively, based on the date of surgery. At centre 2, the dataset constituted the external test cohort (n = 12 ACT, n = 18 high-grade CS). Manual segmentation was performed on frontal view X-rays, using MRI or CT for preliminary identification of lesion margins. After image pre-processing, radiomic features were extracted. Dimensionality reduction included stability, coefficient of variation, and mutual information analyses. In the training cohort, after class balancing, a machine learning classifier (Support Vector Machine) was automatically tuned using nested 10-fold cross-validation. Then, it was tested on both the test cohorts and compared to two musculoskeletal radiologists' performance using McNemar's test.
Five radiomic features (3 morphology, 2 texture) passed dimensionality reduction. After tuning on the training cohort (AUC = 0.75), the classifier had 80%, 83%, 79% and 80%, 89%, 67% accuracy, sensitivity, and specificity in the internal (temporally independent) and external (geographically independent) test cohorts, respectively, with no difference compared to the radiologists (p ≥ 0.617).
X-rays radiomics-based machine learning accurately differentiates between ACT and high-grade CS of long bones.
AIRC Investigator Grant.
非典型性软骨肿瘤(ACT)和高级别软骨肉瘤(CS)是长骨中两种不同的疾病,分别采用主动监测或刮除和广泛切除的方法进行治疗。我们的目的是确定基于 X 射线放射组学的机器学习在长骨 ACT 和高级别 CS 分类中的诊断性能。
这是一项回顾性的、经机构审查委员会批准的研究,纳入了在两个三级骨肉瘤中心接受手术治疗和组织学证实的病变的 150 名患者。在中心 1 中,数据集根据手术日期分为训练集(n=71 例 ACT,n=24 例高级别 CS)和内部测试集(n=19 例 ACT,n=6 例高级别 CS)。在中心 2 中,数据集构成了外部测试集(n=12 例 ACT,n=18 例高级别 CS)。在正位 X 射线上手动进行病变分割,使用 MRI 或 CT 对病变边界进行初步识别。在图像预处理后,提取放射组学特征。降维分析包括稳定性、变异系数和互信息分析。在训练集中,在平衡类后,使用嵌套的 10 折交叉验证自动调整机器学习分类器(支持向量机)。然后,在两个测试集上进行测试,并与两位肌肉骨骼放射科医生的表现进行比较,使用 McNemar 检验。
通过降维分析,有 5 个放射组学特征(3 个形态学特征,2 个纹理特征)通过了降维分析。在训练集上进行调整后(AUC=0.75),分类器在内部(时间独立)和外部(地理独立)测试集中的准确率、敏感度和特异性分别为 80%、83%、79%和 80%、89%、67%,与放射科医生的表现无差异(p≥0.617)。
X 射线放射组学的机器学习能够准确地区分长骨的 ACT 和高级别 CS。
AIRC 研究员资助。