RESUMO
OBJECTIVES: The introduction of low-dose CT (LDCT) altered the landscape of lung cancer (LC) screening and contributed to the reduction of mortality rates worldwide. Here we report the final results of HUNCHEST-II, the largest population-based LDCT screening program in Hungary, including the screening and diagnostic outcomes, and the characteristics of the LC cases. METHODS: A total of 4215 high-risk individuals aged between 50 and 75 years with a smoking history of at least 25 pack-years were assigned to undergo LDCT screening. Screening outcomes were determined based on the volume, growth, and volume doubling time of pulmonary nodules or masses. The clinical stage distribution of screen-detected cancers was compared with two independent practice-based databases consisting of unscreened LC patients. RESULTS: The percentage of negative and indeterminate tests at baseline were 74.2% and 21.7%, respectively, whereas the prevalence of positive LDCT results was 4.1%. Overall, 76 LC patients were diagnosed throughout the screening rounds (1.8% of total participants), out of which 62 (1.5%) patients were already identified in the first screening round. The overall positive predictive value of a positive test was 58%. Most screen-detected malignancies were stage I LCs (60.7%), and only 16.4% of all cases could be classified as stage IV disease. The percentage of early-stage malignancies was significantly higher among HUNCHEST-II screen-detected individuals than among the LC patients in the National Koranyi Institute of Pulmonology's archive or the Hungarian Cancer Registry (p < 0.001). CONCLUSIONS: HUNCHEST-II demonstrates that LDCT screening for LC facilitates early diagnosis, thus arguing in favor of introducing systematic LC screening in Hungary. CLINICAL RELEVANCE STATEMENT: HUNCHEST-II is the so-far largest population-based low-dose CT screening program in Hungary. A positive test's overall positive predictive value was 58%, and most screen-detected malignancies were early-stage lesions. These results pave the way for expansive systematic screening in the region. KEY POINTS: ⢠Conducted in 18 medical facilities, HUNCHEST-II is the so far largest population-based low-dose CT screening program in Hungary. ⢠The vast majority of screen-detected malignancies were early-stage lung cancers, and the overall positive predictive value of a positive test was 58%. ⢠HUNCHEST-II facilitates early diagnosis, thus arguing in favor of introducing systematic lung cancer screening in Hungary.
RESUMO
A novel method was introduced for the quantitative determination of substances in aqueous solutions by using the evaporative light scattering (ELS) detector of a high performance liquid chromatograph (HPLC). The principle of the measurement is the different equilibrium vapor pressure of the solvent and the analyte resulting in decreasing evaporation rate, larger droplets and stronger signal with increasing concentration. The new technique based on vapor pressure analysis was validated with traditional UV-Vis detection carried out with a diode array detector (DAD). The new technique was used for monitoring the concentration of solutions obtained during the enzymatic degradation of poly(3-hydroxybutyrate) yielding the 3-hydroxybutyrate monomer as the product. The accuracy of the measurement allowed the determination of degradation kinetics as well. The results obtained with the two techniques showed excellent agreement at small concentrations. Deviations at larger concentrations were explained with the non-linear correlation between analyte concentration and detector signal and the linear regression used for calibration. Mathematical analysis of the method made possible the determination of the evaporation enthalpy of the analyte as well. The new approach is especially suitable for the quantitative analysis of compounds, which do not absorb in the detection range of the DAD detector or if their characteristic absorbance is close to the lower end of its wavelength range.
