title: Differentiating radiological features of rapid- and slow-growing renal cell carcinoma using multidetector computed tomography.
abstract: OBJECTIVE
  This study aimed to retrospectively evaluate the radiological features between rapid- and slow-growing renal cell carcinoma (RCC).
  
  
  METHODS
  Twenty-five pathologically proven RCCs were reviewed with computed tomography (CT). Each tumor underwent at least 2 CT sessions. Growth rate was evaluated in terms of its maximal diameter and volume change with the serial CT scan. We reviewed 8 reports from 8 single-institution series in the world literature regarding growth rate of RCCs and determined mean growth rate. Slow- and rapid-growing RCCs were compared in relation to several radiological factors (tumor shape, initial size, initial volume, initial location, enhancement pattern, and cystic change). In addition, we evaluated differences in growth rate between asymptomatic and symptomatic RCCs.
  
  
  RESULTS
  The mean diameter growth rate of RCC was determined as 0.49 cm/y (8 studies, 126 cases). There were 14 cases of rapid-growing RCCs (mean growth rate, 1.3 cm/y) and 11 cases of slow-growing RCCs (mean growth rate, 0.1 cm/y). The slow-growing tumors showed round shape, small initial size, small initial volume, and outer location of the kidney compared with the rapid-growing tumors. Sixteen patients (64%) were treated for incidental and 9 patients (36%) were treated for symptomatic RCCs. The asymptomatic RCCs grew at a slow rate both diametrically (P = 0.007) and volumetrically (P = 0.003).
  
  
  CONCLUSIONS
  Rapid- and slow-growing RCCs tend to show some different radiological features with respect to tumor shape, initial size, initial volume, and location. Radiological features may be helpful to predict growth rate.
authors.affiliation: Department of Radiology, Gachon University Gil Hospital, Incheon, Korea.
authors.forename: Seung Joon
authors.initials: SJ
authors.lastname: Choi
authors.forename: Hyung-Sik
authors.initials: HS
authors.lastname: Kim
authors.forename: Su-Joa
authors.initials: SJ
authors.lastname: Ahn
authors.forename: Yulri
authors.initials: Y
authors.lastname: Park
authors.forename: Hye-Young
authors.initials: HY
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging*; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D007668:Kidney / Q000000981:diagnostic imaging; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D015996:Survival Rate
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide