title: Renal remodeling after abdominal radiation therapy: parenchymal and functional changes.
abstract: OBJECTIVE
  The purpose of this study was to quantify changes in renal length, volume, and function over time after upper abdominal radiation therapy.
  
  
  METHODS
  Imaging and clinical data were retrospectively reviewed for 27 adults with abdominal radiation therapy between 2001 and 2012. All had two kidneys, radiation exposure to one kidney, and survival of at least 1 year after therapy. Mean prescribed dose was 52 ± 9 Gy to extrarenal targets. Length and volume of exposed and unexposed kidneys were measured on CT scans before treatment (baseline) and at intervals 0-3, 3-6, 6-12, 12-24, 24-36, and more than 36 months after completion of radiotherapy. Serum creatinine was correlated at each interval. Mixed-models ANOVA was used to test renal length and volume, serum creatinine, and time against multiple models to assess for temporal effects; specific time intervals were compared in pairwise manner.
  
  
  RESULTS
  Mean follow-up duration was 35 months (range, 5-94 months). Exposed kidney length and volume progressively decreased from baseline throughout follow-up, with mean loss of 23% (p < 0.001) and 47% (p < 0.001), respectively. Slight increase in unexposed kidney length was not significant. Mean serum creatinine increased from 0.86 ± 0.18 mg/dL at baseline to 1.12 ± 0.27 mg/dL at 12-24 months (p < 0.001), then stabilized.
  
  
  CONCLUSIONS
  Kidneys exposed to radiation during therapy of adjacent malignancies exhibited continuous progressive atrophy for the entire follow-up period, nearly 8 years. Volume changes were twice as great as length changes. Renal function also declined. To accurately interpret follow-up studies in cancer survivors, radiologists should be aware of the potential for progressive renal atrophy, even many years after radiation therapy.
authors: 1 University of Michigan Medical School, M4101 Medical Science Bldg, I-C Wing, 1301 Catherine Rd, Ann Arbor, MI 48109-5624.
authors: Linda K
authors: LK
authors: Tran
authors: Katherine E
authors: KE
authors: Maturen
authors: Mary U
authors: MU
authors: Feng
authors: Eric J
authors: EJ
authors: Wizauer
authors: Kuanwong
authors: K
authors: Watcharotone
authors: Robert A
authors: RA
authors: Parker
authors: James H
authors: JH
authors: Ellis
mesh_terms: D000328:Adult; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D006801:Humans; D007668:Kidney / Q000528:radiation effects*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000000981:diagnostic imaging* / Q000209:etiology*; D011836:Radiation Tolerance; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media
keywords: abnormalities; radiation induced; radiation therapy; renal atrophy; side effects