A CT-Based Tumoral and Mini-Peritumoral Radiomics Approach: Differentiate Fat-Poor Angiomyolipoma from Clear Cell Renal Cell Carcinoma

Figures & data

Figure 1 (A) showed the VOI of tumor. (B) was the VOI of mini-peritumor, which automatically expanded 2-mm from the margin of the lesion with “A.K.” software. (C and D) was the manually divided Pr/Pf-VOI based on the mini-peritumoral VOI. (E) demonstrated that the Pr-VOI did not include blood vessels and fat in renal hilar region. (F) illustrated that if the Pf-VOI affected by the surrounding structures (such as intestine, liver, adjacent muscle, and so on), this portion was manually removed.

Figure 2 The program flowchart of CT-based radiomics analysis.

Table 1 Patients’ General Characteristics

	fp-AML	ccRCC	P
Gender (female/male)	38 (65.5%)/20 (34.5%)	59 (34.3%)/113 (65.7%)	<0.001
Age	48.4±11.9	61.3±13.2	<0.001
Location (right/left)	27 (46.6%)/31 (53.4%)	82 (47.7%)/90 (52.3%)	0.882
Size (mm)	27.1±15.5	34.9±12.9	<0.001

Notes: The gender and location were analyzed by Chi-square test, while the age and size were dealt with independent-samples t-test. A P-value <0.05 showed statistical significance.

Figure 3 The ROC curves of mini-peritumoral radiomics models of CMP and NP. The AUCs of NP were higher than those of CMP in both the training (A) and validation (B) sets.

Table 2 The AUCs of Tumoral and Mini-Peritumoral Radiomics Models in NP

	Training Set	P value	Validation Set	P value
Ra-Peritumoral
Ra-Pr	0.745 (0.670–0.810)	<0.001	0.700 (0.578–0.804)	0.007
Ra-Pf	0.683 (0.605–0.754)	<0.001	0.608 (0.484–0.723)	0.172
Ra-tumor	0.841 (0.775–0.894)	<0.001	0.778 (0.663–0.868)	<0.001
Ra-tumor+Pr	0.912 (0.857–0.951)	<0.001	0.843 (0.736–0.919)	<0.001

Notes: The AUCs of tumoral and mini-peritumoral radiomics models were calculated from ROC curves by DeLong test. A P-value <0.05 was defined to be statistical significance.

Figure 4 The heat map of Ra-Pr to distinguish fp-AML from ccRCC. There were five optimal radiomics features left in Ra-Pr. And zero presented the ccRCC, one presented the fp-AML.

Table 3 The Cohort of Ra-Tumor, Ra-Peritumor, and Ra-tumor+Pr Models

	AUC	95% CI	Sensitivity	Specificity	P
Ra-tumor	0.820	0.764–0.867	65.52%	84.88%	<0.001
Ra-peritumor	0.742	0.680–0.797	67.24%	76.16%	<0.001
Ra-tumor+Pr	0.890	0.842–0.927	79.31%	85.47%	<0.001

Notes: The AUCs of Ra-tumor, Ra-peritumor, and Ra-tumor+Pr models were calculated from ROC curves by DeLong test based on the cohort. A P-value <0.05 was defined to be statistical significance.

Figure 5 The calibration curves of training and validation set of Ra-tumor+Pr (A and B).