Learning Curve for Automated Ultrasound Cystovolumetry in Patients With Localized Prostate Cancer

Abstract

PurposeThe purpose of this study was to investigate the learning curve of automated ultrasound cystovolumetry in novice radiation nurses and to determine how much experience is required before reliable measurements can be obtained. MethodFive consecutive patients with localized prostate cancer who underwent intensity modulated radiation therapy were included in this study. Immediately before each irradiation, three novice radiation nurses with no experience in ultrasonography measured urinary bladder volume using an automated ultrasound cystovolumetry system (CUBEScan). Changes in the relative error of bladder volume were examined. ResultsThe mean value of the relative error decreased and became constant after the third irradiation, that is, the fifteenth measurement. The mean value of the relative error from the first to the third irradiation was 0.12 ± 0.03 (mean ± standard deviation [SD]), whereas that from the fourth to the tenth irradiation was 0.05 ± 0.03 (mean ± SD) (p = .03). ConclusionIt takes at least 15 measurements for a novice radiation nurse to be able to accurately measure bladder volume using the automated ultrasound cystovolumetry system.