The results show that the array-type measurement system can measure prompt gamma distributions from a therapeutic proton beam within a short measurement time, and that the distal dose edge can be determined within a few millimeters of error without using any sophisticated analysis.

In a recent Letter, 1 our group introduced the new idea of "gamma electron vertex imaging (GEVI)" for beam range verification in proton therapy. In the Letter, we mentioned that the proton beam range can be determined within 2-3 mm error by using GEVI. Recently, however, we found that multiple Coulomb scattering (MCS) process for electron was mistakenly omitted in our Geant4 simulation. It was a serious mistake. Therefore, we have repeated the simulation study again including the MCS process, and this letter provides the revised result.FIG. 1. GEVI image and projections. The upper plots show the results for d = 5 cm. The lower plots provide the GEVI image projections (gray square markers) and prompt gamma distributions (red step lines), along with the distributions of absorbed dose (blue dash lines).

BACKGROUND: The effect of serial change in alcohol consumption on stroke risk has been limitedly evaluated. We investigated the association of change in alcohol consumption with risk of stroke. METHODS: This study is a population-based retrospective cohort study from National Health Insurance Service database of all Koreans. Four lakh five hundred thirteen thousand seven hundred forty-six participants aged ≥40 years who underwent 2 subsequent national health examinations in both 2009 and 2011. Alcohol consumption was assessed by average alcohol intake (g/day) based on self-questionnaires and categorized into non-, mild, moderate, and heavy drinking. Change in alcohol consumption was defined by shift of category from baseline. Cox proportional hazards model was used with adjustment for age, sex, smoking status, regular exercise, socioeconomic information, and comorbidities, Charlson Comorbidity Index, systolic blood pressure, and laboratory results. Subgroup analysis among those with the third examination was conducted to reflect further change in alcohol consumption. RESULTS: During 28 424 497 person-years of follow-up, 74 923 ischemic stroke events were identified. Sustained mild drinking was associated with a decreased risk of ischemic stroke (adjusted hazard ratio, 0.88 [95% CI, 0.86–0.90]) compared with sustained nondrinking, whereas sustained heavy drinking was associated with an increased risk of ischemic stroke (adjusted hazard ratio, 1.06 [95% CI, 1.02–1.10]). Increasing alcohol consumption was associated with an increased risk of ischemic stroke (adjusted hazard ratio, 1.11 [95% CI, 1.06–1.17] from mild to moderate; adjusted hazard ratio, 1.28 [95% CI, 1.19–1.38] from mild to heavy) compared with sustained mild drinkers. Reduction of alcohol consumption from heavy to mild level was associated with 17% decreased risk of ischemic stroke through 3× of examinations. CONCLUSIONS: Light-to-moderate alcohol consumption is associated with a decreased risk of ischemic stroke, although it might be not causal and could be impacted by sick people abstaining from drinking. Reduction of alcohol consumption from heavy drinking is associated with a decreased risk of ischemic stroke.

Background Little is known about the risk of ischemic heart disease (IHD) in tuberculosis (TB) survivors. Methods We performed a population-based retrospective cohort study using the Korean National Health Insurance Service database. TB survivors (n = 60,602) and their 1:1 age- and sex-matched controls (n = 60,602) were enrolled. Eligible participants were followed up from 1 year after their TB diagnosis to the date of an IHD event, date of death, or the end of the study period (December 31, 2018), whichever came first. The risk of IHD was estimated using a Cox proportional hazards regression, and stratified analyses were performed for related factors. Among IHD events, we additionally analyzed for myocardial infarction (MI). Results During a median of 3.9 years of follow-up, 2.7% of TB survivors (1,633/60,602) and 2.0% of the matched controls (1,228/60,602) developed IHD, and 0.6% of TB patients (341/60,602) and 0.4% of the matched controls (223/60,602) developed MI. The overall risk of developing IHD and MI was higher in TB patients (adjusted hazard [aHR] 1.21, 95% CI 1.12–1.32 for IHD and aHR 1.48, 95% CI 1.23–1.78 for MI) than in the matched controls. Stratified analyses showed that TB survivors have an increased risk of IHD and MI regardless of income, place of residence, smoking status, alcohol consumption, physical activity, body mass index, and Charlson comorbidity index. Conclusions TB survivors have a higher risk of IHD than matched controls. Strategies are needed to reduce the burden of IHD in TB survivors.