The additional utility of apparent diffusion coefficient values of clear-cell renal cell carcinoma for predicting metastasis during clinical staging

• Published in: Acta Radiologica Open Vol. 6; no. 1; p. 2058460116687174
• Main Authors: Yoshida, Rika, Yoshizako, Takeshi, Hisatoshi, Araki, Mori, Hiroshi, Tamaki, Yukihisa, Ishikawa, Noriyoshi, Kitagaki, Hajime
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.01.2017; Sage Publications Ltd; SAGE Publishing
• Subjects: Clear cell-type renal cell carcinoma; Diffusion coefficient; Kidney cancer; Lymph nodes; Magnetic resonance imaging; Medical physics. Medical radiology. Nuclear medicine; Metastases; Metastasis; R895-920; Statistical analysis; Tumors; ADC value; Clear-cell renal cell carcinoma (RCC); diffusion-weighted imaging (DWI); 1.5 T magnetic resonance imaging (MRI)
• ISSN: 2058-4601; 2058-4601
• DOI: 10.1177/2058460116687174

Background The apparent diffusion coefficient (ADC) value is known to be an indicator of tumor activity. The ADC value of high-grade clear-cell renal cell carcinoma (RCC) is significantly lower than that of low-grade clear-cell RCC. Purpose To investigate the utility of ADC values of clear-cell RCC by comparing ADC values between groups with T1a RCC (tumor size ≤ 4 cm) without metastasis and the group with metastasis. Material and Methods A retrospective review was performed on 51 patients with 51 RCCs who underwent 1.5 T magnetic resonance imaging (MRI) for evaluating a renal mass confirmed pathologically to be clear-cell RCC between January 2010 and August 2014. We compared ADC values between group A (T1a RCC without metastasis, T1aN0M0) and group B (RCC with metastasis) using the Mann–Whitney U test. Results The patients were divided into group A (n = 30; tumor size: median, 24.5 mm; range, 8–40 mm; ADC value [×10−3 mm2/s]: median, 1.71; range, 1.23–2.24) and group B (n = 21; tumor size: median, 87.5 mm; range, 18–150 mm; ADC value [×10−3 mm2/s]: median, 1.35; range, 0.91–1.94). The ADC value differed significantly between the two groups. The area under the receiver operating characteristic curve was 0.869. Using the optimum cutoff value (1.552 × 10−3 mm2/s), ADC had a sensitivity of 80.0% and specificity of 81.0%. Conclusion There was a statistically significant difference in the ADC between group A (T1a clear-cell RCC without distant metastasis) and group B (advanced clear-cell RCC with lymph node metastasis or distant metastasis).