To systematically review the literature on the Bosniak classification system in CT to determine its diagnostic performance to diagnose malignant cystic lesions and the prevalence of malignancy in Bosniak categories.
A predefined database search was performed from 1 January 1986 to 18 January 2016. Two independent reviewers extracted data on malignancy rates in Bosniak categories and several covariates using predefined criteria. Study quality was assessed using QUADAS-2. Meta-analysis included data pooling, subgroup analyses, meta-regression and investigation of publication bias.
A total of 35 studies, which included 2,578 lesions, were investigated. Data on observer experience, inter-observer variation and technical CT standards were insufficiently reported. The pooled rate of malignancy increased from Bosniak I (3.2 %, 95 % CI 0-6.8, I(2) = 5 %) to Bosniak II (6 %, 95 % CI 2.7-9.3, I(2) = 32 %), IIF (6.7 %, 95 % CI 5-8.4, I(2) = 0 %), III (55.1 %, 95 % CI 45.7-64.5, I(2) = 89 %) and IV (91 %, 95 % CI 87.7-94.2, I(2) = 36). Several study design-related influences on malignancy rates and subsequent diagnostic performance indices were identified.
The Bosniak classification is an accurate tool with which to stratify the risk of malignancy in renal cystic lesions.
• The Bosniak classification can accurately rule out malignancy. • Specificity remains moderate at 74 % (95 % CI 64-82). • Follow-up examinations should be considered in Bosniak IIF and Bosniak II cysts. • Data on the influence of reader experience and inter-reader variability are insufficient. • Technical CT standards and publication year did not influence diagnostic performance.
European radiology. 2016 Oct 19 [Epub ahead of print]
Sabina Sevcenco, Claudio Spick, Thomas H Helbich, Gertraud Heinz, Shahrokh F Shariat, Hans C Klingler, Michael Rauchenwald, Pascal A Baltzer
Department of Urology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria., Department of Biomedical Imaging and Image-guided Therapy, General Hospital Vienna, Medical University of Vienna, Währinger Gürtel 18-20, A-1090, Vienna, Austria., Department of Radiology, University Hospital of Sankt-Pölten, Propst-Führer-Straße 4, 3100 St., Pölten, Austria., Department of Urology, Wilhelminenspital, Montleartstraße 37, 1160, Vienna, Austria., Department of Urology, Donauspital, Langobardenstraße 122, 1220, Vienna, Austria., Department of Biomedical Imaging and Image-guided Therapy, General Hospital Vienna, Medical University of Vienna, Währinger Gürtel 18-20, A-1090, Vienna, Austria. .