SAVE Testis-sparing score: a multicenter retrospective study of a novel predictive tool for quantifying testicular tumors

Abstract

Background: Testis-sparing surgery (TSS) is a safe treatment for patients with benign testicular tumors. Presently, assessments for evaluating the suitability of TSS are poorly standardized, partially because testicular anatomical elements cannot be quantitatively described. Materials and methods: The authors developed a scoring method known as the SAVE testis-sparing score based on four critical and accessible anatomical features of a testicular tumor. The SAVE score ranges from 0 to 8 and is divided into four risk classes (low, medium, high, and extremely high) to evaluate the feasibility of TSS, wherein low-risk indicates high feasibility and vice versa. This study included 444 testicular tumor patients from eight centers. Among them, 216 patients (model group: 151 patients, validation group: 65 patients) were included in the modeling analysis, and the other 228 patients from children’s centers were included in the proportion analysis. Using retrospective data, patient characteristics associated with surgical methods were identified. Furthermore, a multivariate logistic regression model was built quantify the associations between these characteristics and the surgery method. The receiver operator characteristic curve was used to evaluate the classification efficiency of SAVE. Results: The SAVE testis-sparing score includes size (tumor size as maximal diameter), available testicular tissue volume, volume ratio of the tumor to the testis, and the exophytic/endophytic properties of the tumor. The SAVE scoring system accurately classified the suitability of TSS based on the complexity of benign testicular tumors. Conclusion: The SAVE score is a reproducible and robust tool for quantitatively describing the anatomical characteristics of benign testicular tumors and guide the preoperative evaluation of TSS.