Best cut-off values for [14C]-urea breath tests for Helicobacter pylori detection

Background: The 'test and treat' strategy for Helicobacter pylori is recommended in dyspeptic patients under 55 years of age with no alarm symptoms. Reliable non-invasive tests are therefore needed. The aim of this study was to assess the pre- and post-treatment accuracy of a low dose (1 muCi [37kBq]), short collecting time [C-14]-UBT (urea breath test) in diagnosing H pylori infection, examining different methods to analyse the best cut-off points. Methods: The study included 119 patients. Endoscopy and [C-14]-UBT were performed in the pre- and post-treatment setting. [(14) C]-UBT results were expressed in three different ways: 1) the measured disintegrations per minute (dpm) at sample time, 2) the difference (D) in dpm between sample time and the dpm at T-0 , 3) the ratio of dpm at sample time to dpm at T-0 . Results : Seventy-six out of the 119 patients (63.9%; 95% CI: 54.9 to 71.9) were infected. Seventy-three (96%) patients completed the follow-up. The most accurate results in both pre- (sensitivity 95.9%; specificity 97.7%) and post-treatment (sensitivity 90.9%; specificity 100%) were obtained using the difference (D) in dpm between sample time at T-0 and at T-12.5 . Conclusion : A low dose [C-14]-UBT, with a short collecting time, is a reliable method to evaluate H. pylori infection in both the pre- and post-treatment setting.