Grading Clear Cell Renal Cell Carcinoma Grade Using Diffusion Relaxation Correlated MR Spectroscopic Imaging

• Published in: Journal of magnetic resonance imaging Vol. 59; no. 2; pp. 699 - 710
• Main Authors: Dai, Yongming, Hu, Wentao, Wu, Guangyu, Wu, Dongmei, Zhu, Mengying, Luo, Yuansheng, Wang, Jieying, Zhou, Yan, Hu, Peng
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.02.2024; Wiley Subscription Services, Inc
• Subjects: Aged; Biopsy; Carcinoma, Renal Cell - diagnostic imaging; Carcinoma, Renal Cell - pathology; clear cell renal cell carcinoma; Clear cell-type renal cell carcinoma; Correlation; Diffusion coefficient; Diffusion Magnetic Resonance Imaging - methods; diffusion weighted imaging; Field strength; Histopathology; Humans; Kidney cancer; Kidney Neoplasms - diagnostic imaging; Kidney Neoplasms - pathology; Magnetic Resonance Imaging; Male; Medical imaging; Middle Aged; multidimensional correlation MRI; Neoplasm Grading; Performance assessment; Prospective Studies; Regression analysis; Retrospective Studies; Segmentation; Solid tumors; Statistical analysis; Statistical tests; T2 relaxation time; tumor heterogeneity; Tumors; Variance analysis; clear cell renal cell carcinoma; diffusion weighted imaging; T2 relaxation time; multidimensional correlation MRI; tumor heterogeneity
• ISSN: 1053-1807; 1522-2586; 1522-2586
• DOI: 10.1002/jmri.28777

Background Clear cell renal cell carcinoma (ccRCC) is the most common subtype of RCC, and accurate grading is crucial for prognosis and treatment selection. Biopsy is the reference standard for grading, but MRI methods can improve and complement the grading procedure. Purpose Assess the performance of diffusion relaxation correlation spectroscopic imaging (DR‐CSI) in grading ccRCC. Study Type Prospective. Subjects 79 patients (age: 58.1 +/− 11.5 years; 55 male) with ccRCC confirmed by histopathology (grade 1, 7; grade 2, 45; grade 3, 18; grade 4, 9) following surgery. Field Strength/Sequence 3.0 T MRI scanner. DR‐CSI with a diffusion‐weighted echo‐planar imaging sequence and T2‐mapping with a multi‐echo spin echo sequence. Assessment DR‐CSI results were analyzed for the solid tumor regions of interest using spectrum segmentation with five sub‐region volume fraction metrics (VA, VB, VC, VD, and VE). The regulations for spectrum segmentation were determined based on the D‐T2 spectra of distinct macro‐components. Tumor size, voxel‐wise T2, and apparent diffusion coefficient (ADC) values were obtained. Histopathology assessed tumor grade (G1–G4) for each case. Statistical Tests One‐way ANOVA or Kruskal–Wallis test, Spearman's correlation (coefficient, rho), multivariable logistic regression analysis, receiver operating characteristic curve analysis, and DeLong's test. Significance criteria: P < 0.05. Results Significant differences were found in ADC, T2, DR‐CSI VB, and VD among the ccRCC grades. Correlations were found for ccRCC grade to tumor size (rho = 0.419), age (rho = 0.253), VB (rho = 0.553) and VD (rho = −0.378). AUC of VB was slightly larger than ADC in distinguishing low‐grade (G1‐G2) from high‐grade (G3‐G4) ccRCC (0.801 vs. 0.762, P = 0.406) and G1 from G2 to G4 (0.796 vs. 0.647, P = 0.175), although not significant. Combining VB, VD, and VE had better diagnostic performance than combining ADC and T2 for differentiating G1 from G2‐G4 (AUC: 0.814 vs 0.643). Data Conclusion DR‐CSI parameters are correlated with ccRCC grades, and may help to differentiate ccRCC grades. Evidence Level 2 Technical Efficacy Stage 2