title: Diagnostic radiation exposure during surveillance in patients with pT1a renal cell carcinoma.
abstract: OBJECTIVE
  To determine the pattern of postoperative radiographic surveillance in patients with pT1a renal cell carcinoma (RCC) at a tertiary care hospital.
  
  
  METHODS
  An institutionally approved urologic oncology database was used to retrospectively identify patients who underwent partial or radical nephrectomy for pT1a RCC from 1990 to 2010 at a tertiary care center. Baseline characteristics were reviewed, and postoperative imaging for the indication of RCC surveillance was recorded. Radiation exposure was calculated using the effective dose according to imaging modality. Relative risks of the development of solid malignancies and leukemia were calculated from the dose of radiation exposure. RCC recurrence, defined as radiologic evidence of local recurrence or distant metastases, was noted.
  
  
  RESULTS
  A total of 1708 patients had undergone partial or radical nephrectomy for a renal mass. Of these, 315 patients had pT1a RCC with postsurgical follow-up, and 252 (80%) of these patients were exposed to ionizing radiation during postoperative surveillance. Mean radiation doses in years 1, 2 to 5, and ≥6 after surgery were 11.4, 47.0, and 13.8 mSv, respectively. Relative risks of radiation-induced solid cancers and leukemia were 1.05 and 1.12, respectively. There were 8 (2.5%) total recurrences.
  
  
  CONCLUSIONS
  During the past 20 years, 80% of patients undergoing surgery for pT1a RCC were monitored with radiation-based imaging during postoperative surveillance. Given the low rate of cancer recurrence in this population, expanded efforts in counseling physicians regarding the risk of ionizing radiation in imaging should be encouraged.
authors.affiliation: Department of Urology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lipsky
authors.forename: Edan Y
authors.initials: EY
authors.lastname: Shapiro
authors.forename: Greg W
authors.initials: GW
authors.lastname: Hruby
authors.forename: James M
authors.initials: JM
authors.lastname: McKiernan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D007953:Leukemia, Radiation-Induced / Q000453:epidemiology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D009392:Nephrectomy; D011159:Population Surveillance; D011184:Postoperative Period; D011829:Radiation Dosage; D012189:Retrospective Studies; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed / Q000009:adverse effects; D055815:Young Adult