title: Disappearance of Renal Cysts Included in Ice Ball During Cryoablation of Renal-Cell Carcinoma: A Potential Therapy for Symptomatic Renal Cysts?
abstract: OBJECTIVE
  To retrospectively evaluate the effect of cryoablation of renal-cell carcinoma on nearby renal cysts with the goal to investigate the potential for an alternative therapy to treat symptomatic renal cysts.
  
  
  METHODS
  The study population comprised 46 cysts (mean size, 12 mm; range, 5-43 mm) that were within or near the ice ball during cryoablation in 22 patients. Size change of each cyst was evaluated via enhanced CT or MR imaging before and 1, 3, 6, and 12 months after cryoablation. Forty-one cysts were also followed after 12 months. Variables including positional relationship between the cyst and the ice ball were evaluated via linear regression analysis using generalized estimating equation models to determine which factors affected cyst shrinkage rate at 12 months.
  
  
  RESULTS
  Fifteen, 12, and 19 cysts were completely included in, partially included in, or excluded from the ice ball, respectively. The overall shrinkage rate was 62%, and 57% of cysts (26 of 46) had disappeared at 12 months. Only the relationship between the cyst and the ice ball was significantly (P < .001) associated with cyst shrinkage rate. Cyst disappearance rates at 12 months were 100% (15 of 15), 67% (8 of 12), and 16% (3 of 19) for cysts completely included, partially included, and excluded from the ice ball, respectively. Among the 22 cysts that disappeared at 12 months and continued to be followed, none recurred after 12 months.
  
  
  CONCLUSIONS
  All renal cysts that were completely included in the ice ball disappeared after cryoablation, demonstrating the potential utility of cryoablation as an alternative therapy for symptomatic renal cysts.
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Yodoya
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan. Electronic address: takaoh@tc4.so-net.ne.jp.
authors.forename: Takao
authors.initials: T
authors.lastname: Hiraki
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Iguchi
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Fujiwara
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Matsui
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Masaoka
authors.affiliation: Center for Innovative Clinical Medicine, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Sakurai
authors.affiliation: Center for Innovative Clinical Medicine, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Mitsuhashi
authors.affiliation: Division of Medical Informatics, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Gobara
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D003452:Cryosurgery / Q000379:methods*; D003560:Cysts / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome