title: Effect of Tumor Complexity and Technique on Efficacy and Complications after Percutaneous Microwave Ablation of Stage T1a Renal Cell Carcinoma: A Single-Center, Retrospective Study.
abstract: Purpose To evaluate the effects of tumor complexity and technique on early and midterm oncologic efficacy and rate of complications for 100 consecutive biopsy-proved stage T1a renal cell carcinomas (RCCs) treated with percutaneous microwave ablation. Materials and Methods This HIPAA-compliant, single-center retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. Ninety-six consecutive patients (68 men, 28 women; mean age, 66 years ± 9.4) with 100 stage T1a N0M0 biopsy-proved RCCs (median diameter, 2.6 cm ± 0.8) underwent percutaneous microwave ablation between March 2011 and June 2015. Patient and procedural data were collected, including body mass index, comorbidities, tumor histologic characteristics and grade, RENAL nephrometry score, number of antennas, generator power, and duration of ablation. Technical success, local tumor progression, and presence of complications were assessed at immediate and follow-up imaging. The Kaplan-Meier method was used for survival analyses. Results Technical success was achieved for all 100 tumors (100%), including 47 moderately and five highly complex RCCs. Median clinical and imaging follow-up was 17 months (range, 0-48 months) and 15 months (range, 0-44 months), respectively. No change in estimated glomerular filtration rate was noted after the procedure (P = .49). There were three (3%) procedure-related complications and six (6%) delayed complications, all urinomas. One case of local tumor progression (1%) was identified 25 months after the procedure. Three-year local progression-free survival, cancer-specific survival, and overall survival were 88% (95% confidence interval: 0.52%, 0.97%), 100% (95% confidence interval: 1.0%, 1.0%), and 91% (95% confidence interval: 0.51%, 0.99%), respectively. Conclusion Percutaneous microwave ablation is an effective and safe treatment option for stage T1a RCC, regardless of tumor complexity. Long-term follow-up is needed to establish durable oncologic efficacy and survival relative to competing ablation modalities and surgery.©RSNA, 2017.
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: Marki E
authors.initials: ME
authors.lastname: Klapperich
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: E Jason
authors.initials: EJ
authors.lastname: Abel
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Ziemlewicz
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: Sara
authors.initials: S
authors.lastname: Best
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: Meghan G
authors.initials: MG
authors.lastname: Lubner
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: Stephen Y
authors.initials: SY
authors.lastname: Nakada
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: J Louis
authors.initials: JL
authors.lastname: Hinshaw
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Brace
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: Fred T
authors.initials: FT
authors.lastname: Lee
authors.affiliation: From the School of Medicine and Public Health (M.E.K.) and Departments of Urology (E.J.A., S.B., S.Y.N., J.L.H., C.L.B., F.T.L., S.A.W.), Radiology (T.J.Z., M.G.L., J.L.H., F.T.L.), and Biomedical Engineering (C.L.B., F.T.L.), University of Wisconsin, 600 Highland Ave, E3/376 Clinical Science Center, Madison, WI 53792.
authors.forename: Shane A
authors.initials: SA
authors.lastname: Wells
mesh_terms: D000368:Aged; D001706:Biopsy; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D003287:Contrast Media; D005260:Female; D005466:Fluorocarbons; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D009367:Neoplasm Staging; D011183:Postoperative Complications; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D005466:Fluorocarbons; C042852:perflutren