To externally validate the Spectrum Score using a modified calculation based on functional parenchymal volumes instead of renal scans. The Spectrum Score quantifies acute ischemic injury in the ipsilateral kidney after partial nephrectomy. However, this metric requires renal split function assessment via renal scans, which may be unavailable in routine practice.
We retrospectively reviewed patients with a solitary renal mass and contralateral kidney who underwent partial nephrectomy at our institution between 2015-2017. Functional parenchymal volumes were calculated using cylindrical volume approximation, and used to quantitate relative renal function. Based on renal split function and parenchyma preserved, we determined: creatinineideal, assuming no ipsilateral kidney ischemic injury; and creatinineworst-case, assuming temporary ipsilateral kidney non-function. Functional parenchymal volume-based Spectrum Score was defined as: (observed peak creatinine-creatinineideal)/(creatinineworst-case-creatinineideal). Functional recovery was defined as: (% function saved)/(% parenchyma preserved). Factors associated with functional parenchymal volume-based Spectrum Score and functional recovery were assessed using linear regression.
We assessed 174 patients with a median renal mass size of 2.7 centimeters (IQR 2.0-3.6), warm ischemia time of 26.0 minutes (IQR 19.0-34.3), and parenchyma preservation of 92.6% (IQR 80.8-100). Preoperative ipsilateral kidney % split function (p=0.003), preoperative ipsilateral kidney glomerular filtration rate (p=0.045), and warm ischemia time (p=0.005) independently associated with functional parenchymal volume-based Spectrum Score. Only functional parenchymal volume-based Spectrum Score (p<0.001) independently associated with functional recovery.
The functional parenchymal volume-based Spectrum Score, which does not require renal scans, quantifies acute ipsilateral renal dysfunction and predicts functional recovery after partial nephrectomy.
Urology. 2018 Jul 28 [Epub ahead of print]
Ziho Lee, Robert Uzzo, Aeen Asghar, Phyllis Parkansky, Mahesh Botejue, Tianyu Li, Rosalia Viterbo, David Yt Chen, Marc Smaldone, Alexander Kutikov
Department of Urology, Temple University School of Medicine, Philadelphia, PA. Electronic address: ., Department of Urologic Oncology, Fox Chase Cancer Center-Temple Health System, Philadelphia, PA., Department of Urology, Temple University School of Medicine, Philadelphia, PA., Department of Biostatistics, Fox Chase Cancer Center, Philadelphia, PA.