title: Cryotherapy precision. Clinician's estimate of cryosurgical iceball lateral spread of freeze.
abstract: OBJECTIVE
  To examine physicians' ability to estimate the lateral spread of freeze (LSF) of a cryosurgical iceball using three techniques.
  
  
  METHODS
  A nonrandomized control trial of in vitro nitrous oxide cryosurgical procedures.
  
  
  METHODS
  Primary care residency training programs.
  
  
  METHODS
  A convenience sample of 80 resident and faculty physicians from four family practice residency programs and one obstetrics and gynecology residency program.
  
  
  METHODS
  After performing cryosurgery with standard naked-eye and colposcopic-assisted techniques, subjects used a new experimental cryosurgical iceball gauge (CIG) to estimate the LSF during cryotherapy.
  
  
  METHODS
  LSF estimations reported physicians were compared simultaneously with those measured by an observer.
  
  
  RESULTS
  The mean (+/- SD) LSF estimation errors at the termination of freeze were as follows: 2.62 +/- 2.42 mm for the colposcopy technique, 2.00 +/- 2.16 mm for the naked-eye method, and 1.28 +/- 0.87 mm for the CIG technique. The range of maximum error was 6.5 to 11 mm for the colposcopic technique, 5.5 to 12.5 mm for the naked-eye method, and 3.0 to 4.0 mm for the CIG technique.
  
  
  CONCLUSIONS
  Overestimation of the LSF, which increases the risk of undertreatment and residual disease, was more common than underestimation. The CIG minimized perceptual error and provided the best cryosurgical precision.
authors.affiliation: Department of Family Medicine, Medical College of Georgia, Augusta.
authors.forename: D G
authors.initials: DG
authors.lastname: Ferris
authors.forename: G R
authors.initials: GR
authors.lastname: Crawley
authors.forename: E G
authors.initials: EG
authors.lastname: Baxley
authors.forename: R
authors.initials: R
authors.lastname: Line
authors.forename: K
authors.initials: K
authors.lastname: Ellis
authors.forename: P
authors.initials: P
authors.lastname: Wagner
mesh_terms: D002138:Calibration; D002983:Clinical Competence; D020681:Colposcopes; D003452:Cryosurgery / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D004867:Equipment Design; D005194:Family Practice / Q000193:education; D005260:Female; D005615:Freezing; D006176:Gynecology / Q000193:education; D006801:Humans; D007396:Internship and Residency; D008961:Models, Structural; D015588:Observer Variation; D009774:Obstetrics / Q000193:education; D013997:Time Factors; D014621:Vagina / Q000473:pathology / Q000601:surgery*