Jeong SJ, et al. Korean J Urol. 2012 May;53(5):342-348. http://dx.doi.org/10.4111/kju.2012.53.5.342

Currently, no standardized method is available to predict success rate after percutaneous nephrolithotomy. We devised and validated the Seoul National University Renal Stone Complexity (S-ReSC) scoring system for predicting the stone-free rate after single-tract percutaneous nephrolithotomy (sPCNL). The data of 155 consecutive patients who underwent sPCNL were retrospectively analyzed. Preoperative computed tomography images were reviewed. The S-ReSC score was assigned from 1 to 9 based on the number of sites involved in the renal pelvis (#1), superior and inferior major calyceal groups (#2–3), and anterior and posterior minor calyceal groups of the superior (#4–5), middle (#6–7), and inferior calyx (#8–9). The inter- and intra-observer agreements were accessed using the weighted kappa (κ). The stone-free rate and complication rate were evaluated according to the S-ReSC score. The predictive accuracy of the S-ReSC score was assessed using the area under the receiver operating characteristic curve (AUC). The overall SFR was 72.3%. The mean S-ReSC score was 3.15±2.1. The weighted kappas for the inter- and intra-observer agreements were 0.832 and 0.982, respectively. The SFRs in low (1 and 2), medium (3 and 4), and high (5 or higher) S-ReSC scores were 96.0%, 69.0%, and 28.9%, respectively (p<0.001). The predictive accuracy was very high (AUC 0.860). After adjusting for other variables, the S-ReSC score was still a significant predictor of the SFR by multiple logistic regression. The complication rates were increased to low (18.7%), medium (28.6%), and high (34.2%) (p = 0.166). The S-ReSC scoring system is easy to use and reproducible. This score accurately predicts the stone-free rate after sPCNL. Furthermore, this score represents the complexity of surgery.

Aim: To compare the prostate volume, as measured by transrectal ultrasonography (TRUS) and by MRI, with that of the actual prostate volume measured after a radical prostatectomy (RRP). Materials and Methods: This prospective study included 21 patients who had undergone RRP. TRUS prostate volumes were calculated using the prolate ellipsoid volume formula, with the anteroposterior diameter measured from axial (TRUS-V1) and mid-sagittal images (TRUS-V2). Two prolate ellipsoid volumes (MRI-EV1 and MRI-EV2) were calculated from the MRI using the same method, and planimetric volume (MRI-PV). The actual prostate volume (Actual-V) was measured in a measuring jug within 1 h after RRP. Results: Mean of Actual-V was 40.3ml (21.0–82.0). In paired sample tests, the correlation coefficients (R) for all methods were over 0.8. In a Student’s t test (paired), MRI-PV (p = 0.620), MRI-EV2 (p = 0.703) and TRUS-V1 (p = 0.099) showed no significant differences compared to the Actual-V. The linear regression models of these three methods were y = 1.025x – 0.268, y = 0.946x + 2.979 and y = 1.046x + 0.381, respectively. Conclusions: Between two TRUS volumes, TRUS-V1 was shown to be superior to TRUS-V2. In MRI, MRI-EV2 was more accurate than MRI-EV1. However, MRI-PV was the most accurate method. TRUS-V1 and MRI-EV2 could be used instead of MRI-PV in general clinical settings.