Skin-to-Tumor Distance Predicts Treatment Failure of T1a Renal Cell Carcinoma Following Percutaneous Cryoablation

To determine the impact of skin-to-tumor (STT) distance on the risk for treatment failure following PCA.

We retrospectively reviewed patients who underwent PCA with documented T1a recurrent renal cell carcinoma (RCC) at two academic centers between 2005 and 2015. Patient demographics, tumor characteristics, perioperative and post-operative course variables were collected. Additionally, we measured the STT by averaging the distance from the skin to the center of the tumor at 0, 45 and 90 degrees on preoperative computed tomography imaging.

We identified 86 patients with documented T1a RCC. The mean age at the time of surgery was 69 years (range 37 - 91 years), and the mean tumor size was 2.7 cm (range 1.0 - 4.0 cm). With a mean follow up of 24 months (range 3 - 63 months), 11 (12.8%) treatment failures occurred. Patients with treatment failure had significantly higher mean STT than those without: 11.0 cm (range 6.3 - 20.1 cm) compared to 8.4 cm (range 4.4 - 15.2 cm), respectively (p=0.002). STT was an independent predictor of treatment failure (OR 1.32 CI 1.04-1.69, p= 0.029). STT greater than 10 cm had a 4-fold increased risk of tumor treatment failure (OR 4.43, CI 1.19-16.39, p= 0.018). Tumor size, R.E.N.A.L. Nephrometry score, and number of cryoprobes placed were not associated with treatment failure.

STT, an easily measured preoperative variable, may inform the risk of RCC treatment failure following PCA.

Urology. 2017 Jun 23 [Epub ahead of print]

Simone L Vernez, Zhamshid Okhunov, Kamaljot Kaler, Ramy F Youssef, Rahul Dutta, Arkadiy Palvanov, Paras Shah, Kathryn Osann, David N Siegel, Igor Lobko, Louis Kavoussi, Ralph V Clayman, Jaime Landman

Department of Urology, University of California, Irvine., The Arthur Smith Institute of Urology, North Shore LIJ Health System., Department of Urology, University of California, Irvine. Electronic address: .