MP11-12 DEVELOPMENT AND VALIDATION OF A NOVEL PREDICTION MODEL FOR FAT-POOR ANGIOMYOLIPOMA IN SMALL RENAL MASSES BASED ON RADIOLOGICAL AND CLINICAL FEATURES

Abstract

You have accessJournal of UrologyImaging/Radiology: Uroradiology II1 Apr 2015MP11-12 DEVELOPMENT AND VALIDATION OF A NOVEL PREDICTION MODEL FOR FAT-POOR ANGIOMYOLIPOMA IN SMALL RENAL MASSES BASED ON RADIOLOGICAL AND CLINICAL FEATURES Hajime Tanaka, Yasuhisa Fujii, Masaya Ito, Manabu Tatokoro, Soichiro Yoshida, Minato Yokoyama, Junichiro Ishioka, Yoh Matsuoka, Noboru Numao, Kazutaka Saito, Junji Yonese, and Kazunori Kihara Hajime TanakaHajime Tanaka More articles by this author , Yasuhisa FujiiYasuhisa Fujii More articles by this author , Masaya ItoMasaya Ito More articles by this author , Manabu TatokoroManabu Tatokoro More articles by this author , Soichiro YoshidaSoichiro Yoshida More articles by this author , Minato YokoyamaMinato Yokoyama More articles by this author , Junichiro IshiokaJunichiro Ishioka More articles by this author , Yoh MatsuokaYoh Matsuoka More articles by this author , Noboru NumaoNoboru Numao More articles by this author , Kazutaka SaitoKazutaka Saito More articles by this author , Junji YoneseJunji Yonese More articles by this author , and Kazunori KiharaKazunori Kihara More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.393AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recent studies have shown that about 20% of small renal masses (SRMs) with presumed renal cell carcinomas (RCCs) are pathologically benign. In Asian patients, fat-poor angiomyolipoma (fp-AML) accounts for most of the benign lesions, because of the low incidence of oncocytoma. Renal mass biopsy (RMB) is being used increasingly, but considerable complications have been reported. The aim of this study is to develop a practical prediction model of fp-AML based on radiological and clinical features for appropriate SRM management. METHODS This retrospective study included patients with 153 solid renal tumors <4 cm, without an apparent fat component as assessed using unenhanced CT, and which were surgically removed (N=148) or biopsied (N=5) after dynamic contrast-enhanced CT (DCE-CT) and MRI. Pathologically, 18, 135 and 0 tumors were fp-AMLs, RCCs (111 clear cell RCCs and 24 others), and oncocytomas, respectively. Preoperative CT/MRI findings were reviewed, and the radiological and clinical features were statistically analyzed using multivariate analysis to determine independent predictors of fp-AML. A scoring model for prediction of fp-AML was developed and was validated using another cohort of 61 SRMs, which included 7 fp-AMLs. RESULTS Independent predictors of fp-AML were female <50 years old, high attenuation on unenhanced CT, less enhancement than normal renal cortex on corticomedullary phase of DCE-CT, low signal intensity on T2W-MRI, and absence of pseudocapsule on T2W-MRI (p=0.001, 0.037, 0.027, 0.009, and 0.009, respectively). “Female <50 years old” was scored as 2 points and the other 4 factors were scored as 1 point each (Fig. 1). The original cohort was stratified into high (total score 4–6), intermediate (2–3), and low (0–1) AML-probability groups, and the incidence of AML was 93% (13/14 tumors), 25% (5/20 tumors), and 0% (0/119 tumors), respectively (AUC=0.98). In the validation cohort, it was 75% (3/4 tumors), 24% (4/17 tumors), and 0% (0/40 tumors), respectively (AUC=0.92). CONCLUSIONS Our novel prediction model differentiated fp-AML from RCC with high accuracy. Patients in the low, intermediate, and high AML-probability groups could be considered to be good candidates for immediate operation, RMB, and initial surveillance, respectively. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e123-e124 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hajime Tanaka More articles by this author Yasuhisa Fujii More articles by this author Masaya Ito More articles by this author Manabu Tatokoro More articles by this author Soichiro Yoshida More articles by this author Minato Yokoyama More articles by this author Junichiro Ishioka More articles by this author Yoh Matsuoka More articles by this author Noboru Numao More articles by this author Kazutaka Saito More articles by this author Junji Yonese More articles by this author Kazunori Kihara More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...