title: Cryotherapy of Renal Lesions: Enhancement on Contrast-Enhanced Sonography on Postoperative Day 1 Does Not Imply Viable Tissue Persistence.
abstract: OBJECTIVE
  To investigate whether persistent enhancement detected on contrast-enhanced sonography at postoperative day 1 (early contrast-enhanced sonography) after cryoablation of renal tumors implies the presence of residual viable tumor tissue, defined as residual enhancing tissue on reference imaging (computed tomography or magnetic resonance imaging) performed 6 months after the procedure.
  
  
  METHODS
  Seventy-four patients with percutaneous cryoablation of renal tumors had early contrast-enhanced sonography from November 2011 to August 2015. Two independent readers evaluated early contrast-enhanced sonographic findings and contrast-enhanced sonographic investigations performed 1 month after cryoablation of lesions that displayed enhancement on early contrast-enhanced sonography. They scored intralesional enhancement in 4 groups: no enhancement, few intralesional vessels, focal enhancing areas, and diffuse enhancement. Inter-reader agreement in evaluating lesion vascularity on early contrast-enhanced sonography was assessed with weighted κ statistics. Computed tomography or magnetic resonance imaging performed 6 months after the treatment was the reference procedure for assessing the absence or presence of residual disease.
  
  
  RESULTS
  Inter-reader agreement in assessing intratumoral vascularization on early contrast-enhanced sonography was very good (κ = 0.90). Enhancement was absent for both readers in 33 of 74 cases; only a few intralesional vessels were visible in 21; whereas diffuse or focal enhancement was present in 13. In the remaining 7 patients, there were differences. Four lesions with focal enhancement on early contrast-enhanced sonography and 1 that was considered avascular had residual tumors on reference imaging. Ablation was successful in the remaining 69 of 74 patients (93%).
  
  
  CONCLUSIONS
  After cryoablation, intratumoral enhancement on early contrast-enhanced sonography does not imply tumor cell viability.
authors.affiliation: Department of Radiology, University of Trieste, Ospedale di Cattinara, Trieste, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Bertolotto
authors.affiliation: Department of Urology, University of Verona, Policlinico G. B. Rossi, Verona, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Siracusano
authors.affiliation: Department of Radiology, Ospedale San Bassiano, Bassano del Grappa, Italy.
authors.forename: Calogero
authors.initials: C
authors.lastname: Cicero
authors.affiliation: Department of Radiology, University of Trieste, Ospedale di Cattinara, Trieste, Italy.
authors.forename: Mariano
authors.initials: M
authors.lastname: Iannelli
authors.affiliation: Department of Urology, University of Trieste, Ospedale di Cattinara, Trieste, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Silvestri
authors.affiliation: Department of Urology, Ospedale San Bassiano, Bassano del Grappa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Celia
authors.affiliation: Department of Radiology, Ospedale San Bassiano, Bassano del Grappa, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Guarise
authors.affiliation: S. C. Radiologia Ospedale Maggiore, Azienda Ospedaliero-Universitaria Ospedali Riuniti di Trieste, Trieste, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Stacul
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D017679:Cryotherapy; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007668:Kidney / Q000000981:diagnostic imaging; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D014463:Ultrasonography
chemical_list: D003287:Contrast Media
keywords: contrast-enhanced sonography; cryoablation; genitourinary ultrasound; imaging; microbubbles; outcomes; percutaneous cryoablation; renal tumors; sonography