Characteristics of contrast‐enhanced ultrasound for diagnosis of solid clear cell renal cell carcinomas ≤4 cm: A meta‐analysis

Abstract

Now solid renal tumors ≤4 cm is the most common, especially the subtype of clear cell renal cell carcinoma (ccRCC) of malignant kidney tumors in clinical. However, there is not specific characteristics of contrast‐enhanced ultrasound (CEUS) be recommended by the EFSUMB Guidelines in distinguish the essence of the kidney tumor with different sizes. Therefore, this meta‐analysis aimed to assess the ability of CEUS to diagnose solid ccRCC (sccRCC) ≤4 cm. We comprehensively searched the Cochrane Library, Embase, PubMed, and Web of Science databases from their inception to 28 July 2020, for studies reporting the CEUS features of sccRCC lesions ≤4 cm. Additional articles were identified through the Chinese National Knowledge Infrastructure database. Studies were selected independently by two investigators and the relevant data were extracted. Discrepancies were resolved via discussion with the senior author. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies‐2 tool, and the sensitivity and specificity of each study were determined and plotted as a receiver operating characteristic curve. Ten studies were included in this meta‐analysis. Hyperenhancement showed medium sensitivity (67%–89%) and specificity (42%–75%) for diagnosing sccRCC ≤4 cm, fast‐in contrast agent and heterogeneous enhancement showed high diagnostic abilities (area under curve (AUC) 0.74–0.84), but the presence of a pseudocapsule and fast‐out contrast agent had poor diagnostic ability (AUC <0.70). The combination of hyperenhancement and iso‐enhancement showed high sensitivity (98%) for diagnosing sccRCC ≤4 cm. Hyperenhancement, fast‐in contrast agent, and heterogeneous enhancement may be specific features that could help to identify sccRCC ≤4 cm, while the presence of a pseudocapsule and fast‐out of contrast agent may have low diagnostic values. The combination of multiple indexes may improve the diagnostic value of CEUS for sccRCC ≤4 cm.

Diagnostic Performance of Contrast-Enhanced Ultrasound in the Evaluation of Small Renal Masses: A Systematic Review and Meta-Analysis

“…Interestingly, Liu et al evaluated the usefulness of CEUS features in the evaluation of small clear cell renal cell carcinoma (sccRCC). Although the authors only relied on the incidence of CEUS characteristics, without discerning among potentially benign or malignant renal masses, the most common pattern for sccRCC was hyper-iso-enhancement (94.1%) and fast wash-in (87.5%) [ 27 ].…”

Characteristics of peritumoral pseudocapsule in small renal cell carcinoma and its influencing factors

“…CT imaging features included necrosis/cystic components, homogeneity, enhancement pattern, and boundary. Heterogeneous and homogeneous enhancement were defined as the presence or absence of unenhanced areas in the tumor lesion, respectively 13 . The definition of hyperenhancement and hypoenhancement was based on the degree of tumor lesion enhancement compared with the surrounding renal cortex on corticomedullary phase.…”

“…Heterogeneous and homogeneous enhancement were defined as the presence or absence of unenhanced areas in the tumor lesion, respectively. 13 The definition of hyperenhancement and hypoenhancement was based on the degree of tumor lesion enhancement compared with the surrounding renal cortex on corticomedullary phase. We defined a clear boundary as the regular and distinct low‐attenuation rim at the tumor‐parenchyma interface on the corticomedullary phase images, based on reports from previous studies.…”

Incidence and survival patterns of clear cell renal cell carcinoma from 2000 to 2017, based on A SEER Database

“…Clear cell renal cell carcinoma (ccRCC) accounts for approximately 80% of all RCC, and is the most common histological type of RCC (3). It also has an extremely poor prognosis, with a 5-year survival rate of approximately 96% for early stage ccRCC and < 10% for late-stage ccRCC (4).…”