A potential imaging-based predictor for renal functional outcomes after partial nephrectomy for localized renal masses.

Background: To determine whether postoperative renal parenchymal volume from first post-operative computed tomography (CT) is a significant prognostic factor for chronic kidney disease (CKD) on the long-term follow up after partial nephrectomy (PN).

Methods: This retrospective study included 319 patients who underwent PN for T1 localized renal cell carcinoma (RCC) between September 2006 and December 2020. Kidney volume data of first postoperative CT and preoperative CT was made with a three-dimensional rendering software. Time-dependent cox proportional-hazards regression analysis was used to find important risk factors that indicate the development of new-onset CKD following PN, adding kidney volume data to various clinical parameters.

Results: Of the 319 patients who underwent PN for T1 localized RCC, a total of 13 patients (4.0%) had new-onset CKD at last follow up and developed it at a median follow up of 46 months. Univariate analyses of the Cox proportional hazards model showed that age, hypertension, preoperative/postoperative eGFR, and total kidney volume/kilogram body weight were potential risk factors associated with new-onset CKD development. In multivariable cox proportional models, the likelihood-ratio test confirmed that overall performance of models was improved by including total kidney volume (p = 0.008).

Conclusions: Renal parenchymal volume of first postoperative CT was a significant risk factor of CKD development on long-term follow up in patients with T1 RCC after PN. Therefore, first postoperative imaging studies will be able to help predict CKD development, as well as to assess the success of the surgery and to monitor recurrence or complications.