Abstract
Objectives
To develop and validate a radiomics nomogram for preoperative differentiating renal angiomyolipoma without visible fat (AML.wovf) from homogeneous clear cell renal cell carcinoma (hm-ccRCC).
Methods
Ninety-nine patients with AML.wovf (n = 36) and hm-ccRCC (n = 63) were divided into a training set (n = 80) and a validation set (n = 19). Radiomics features were extracted from corticomedullary phase and nephrographic phase CT images. A radiomics signature was constructed and a radiomics score (Rad-score) was calculated. Demographics and CT findings were assessed to build a clinical factors model. Combined with the Rad-score and independent clinical factors, a radiomics nomogram was constructed. Nomogram performance was assessed with respect to calibration, discrimination, and clinical usefulness.
Results
Fourteen features were used to build the radiomics signature. The radiomics signature showed good discrimination in the training set (AUC [area under the curve], 0.879; 95%; confidence interval [CI], 0.793–0.966) and the validation set (AUC, 0.846; 95% CI, 0.643–1.000). The radiomics nomogram showed good calibration and discrimination in the training set (AUC, 0.896; 95% CI, 0.810–0.983) and the validation set (AUC, 0.949; 95% CI, 0.856–1.000) and showed better discrimination capability (p < 0.05) compared with the clinical factor model (AUC, 0.788; 95% CI, 0.683–0.893) in the training set. Decision curve analysis demonstrated the nomogram outperformed the clinical factors model and radiomics signature in terms of clinical usefulness.
Conclusions
The CT-based radiomics nomogram, a noninvasive preoperative prediction tool that incorporates the Rad-score and clinical factors, shows favorable predictive efficacy for differentiating AML.wovf from hm-ccRCC, which might assist clinicians in tailoring precise therapy.
Key Points
• Differential diagnosis between AML.wovf and hm-ccRCC is rather difficult by conventional imaging modalities.
• A radiomics nomogram integrated with the radiomics signature, demographics, and CT findings facilitates differentiation of AML.wovf from hm-ccRCC with improved diagnostic efficacy.
• The CT-based radiomics nomogram might spare unnecessary surgery for AML.wovf.
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Abbreviations
- 3-D:
-
Three-dimensional
- AML:
-
Angiomyolipoma
- AML.wovf:
-
AML without visible fat
- ANOVA:
-
Analysis of variance
- AUC:
-
Area under the curve
- BMI:
-
Body mass index
- ccRCC:
-
Clear cell renal cell carcinoma
- CI:
-
Confidence interval
- CMP:
-
Corticomedullary phase
- DCA:
-
Decision curve analysis
- EP:
-
Excretory phase
- GLCM:
-
Gray level co-occurrence matrix
- GLRLM:
-
Gray level run length matrix
- GLSZM:
-
Gray level size zone matrix
- Hm-ccRCC:
-
Homogeneous ccRCC
- ICC:
-
Inter-/intra- class correlation coefficient
- LASSO:
-
Least absolute shrinkage and selection operator
- Nomo-score:
-
Nomogram score
- NP:
-
Nephrographic phase
- OR:
-
Odds ratio
- PACS:
-
Picture archiving and communication system
- PEC:
-
Perivascular epithelioid cell
- Rad-score:
-
Radiomics score
- ROC:
-
Receiver operator characteristic
- ROI:
-
Region of interest
- SVM:
-
Support vector machine
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Funding
This study has received funding by the National Natural Science Foundation of China (81701688 and 81601527); the Natural Science Foundation of Shandong Province (ZR2017BH096 and ZR2017MH036); the Key Research and Development Project of Shandong Province (2018GSF118078); and the Postdoctoral Science Foundation of China (2018M642617). None of these funding sources had any role in study design, the collection, analysis and interpretation of data, the writing of the report, or the decision to submit the paper for publication.
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The scientific guarantor of this publication is Zhenguang Wang.
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The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
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One of the authors (Guangjie Yang) has significant statistical expertise.
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Written informed consent was waived by the Institutional Review Board.
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• retrospective
• case-control study
• performed at one institution
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Nie, P., Yang, G., Wang, Z. et al. A CT-based radiomics nomogram for differentiation of renal angiomyolipoma without visible fat from homogeneous clear cell renal cell carcinoma. Eur Radiol 30, 1274–1284 (2020). https://doi.org/10.1007/s00330-019-06427-x
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DOI: https://doi.org/10.1007/s00330-019-06427-x