title: Prognostic value of saturated prostate cryoablation for localized prostate cancer.
abstract: OBJECTIVE
  To evaluate the oncological outcomes and complications of patients with saturated prostate cryoablation.
  
  
  METHODS
  A cohort of 208 patients cumulatively treated between June 2008 and December 2012 qualified for study inclusion, each undergoing total-gland cryoablation for prostate cancer. The degree of saturated prostate cryoablation was defined as the average prostate volume per cryoprobe (APVC), and divided into four groups (groups 1-4: <3 ml, 3 to <4 ml, 4 to <5 ml, ≧5 ml, respectively). Post-ablative complications were measured prospectively at weeks 1, 2, 4, 8, 12, and 24 by using the Common Terminology Criteria for Adverse Events. Biochemical failure was gauged by Phoenix criterion. The Kruskal-Wallis rank sum test and Chi-square test were used to compare clinical characteristics of therapeutic subsets. The Cox proportional hazard model was applied for comparison of recurrence risk between groups.
  
  
  RESULTS
  APVC group 1 had the highest pre-operative PSA value and smallest prostate size among the groups. Multivariate analysis of risks of biochemical failures revealed that the larger the APVC, the higher the hazard (p for trend = 0.01). Compared to the group 1 patients, the hazard ratios of biochemical failures in groups 2-4 were 4.4 (confidence interval (CI): 0.5-37), 8.8 (CI 1.1-73), and 9.4 (CI 1.1-78), respectively. Nevertheless, the complication rate of APVC group 1 patients was similar to the other three groups.
  
  
  CONCLUSIONS
  Saturated prostate cryoablation by reducing APVC would be beneficial for cancer control without compromising patient safety.
authors.affiliation: Department of Urology, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.
authors.forename: Chung-Hsin
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Urology, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan.
authors.forename: Yi-Sheng
authors.initials: YS
authors.lastname: Tai
authors.affiliation: Department of Urology, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan. yspu@ntu.edu.tw.
authors.forename: Yeong-Shiau
authors.initials: YS
authors.lastname: Pu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D003452:Cryosurgery / Q000379:methods*; D019160:Endosonography; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D009367:Neoplasm Staging / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D012007:Rectum; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013624:Taiwan / Q000453:epidemiology; D047368:Tumor Burden
keywords: Complication; Cryosurgery; Cryotherapy; Prostate tumor; Prostate volume