Stella Ling | PubMed Health

PubMed2004

Prostate movement during simulation resulting from retrograde urethrogram compared with "natural" prostate movement.

PURPOSE: Retrograde urethrography (UG) is commonly used at the time of simulation to assist in defining the prostate apex. Some investigators have reported that performing the UG introduces error by causing prostate displacement. We investigate the movement of the prostate caused by the retrograde UG. METHODS AND MATERIALS: Twenty-four patients treated with three-dimensional conformal radiotherapy for prostate cancer who had gold marker seeds placed into their prostates were studied. Marker seed locations at the time of simulation and on the portal images acquired just before the treatment were compared with the locations on digitally reconstructed radiographs (DRR). Movement in the superior-inferior and anteroposterior directions as seen on lateral images was measured from 402 portal images by offline customized imaging software and evaluated using analysis of variance methods for continuous variables and chi-square statistics for categoric variables. RESULTS: "Natural" nonrandom movement of the prostate around an "origin" as defined by markers on DRR was observed. This movement tends to be in a superior and anterior direction, with the average shift being 1 mm and 0.82 mm, respectively. The magnitude of movement in the superior direction averaged 2.88 mm compared with 1.64 mm in the inferior direction (p = 0.04). There was slightly greater movement after the UG compared with mean "natural" movement but the difference was less than 3 mm in either direction on average (difference: superior-inferior = 2.64 mm, p = 0.004; anteroposterior = 2.24, p = 0.035). CONCLUSIONS: Use of the UG induces a small but clinically insignificant displacement of the prostate when "natural" movement is taken into account.

Humans↗

PubMed2002

Effectiveness of heptavalent pneumococcal conjugate vaccine in children younger than five years of age for prevention of pneumonia.

OBJECTIVE: To determine the effectiveness of the Wyeth heptavalent pneumococcal conjugate vaccine against clinical and radiograph-confirmed pneumonia in children. METHODS: The heptavalent CRM(197) pneumococcal conjugate vaccine (PCV) was given to infants at 2, 4, 6 and 12 to 15 months of age in a randomized, double blind trial. Children were randomized to receive either the CRM(197) PCV (vaccine group) or the meningococcal type C CRM(197) conjugate vaccine (control group). The primary outcome of this trial was invasive pneumococcal disease. In addition children with the clinical diagnosis of pneumonia in the study population were identified through review of automated inpatient, emergency and outpatient databases. The subset of the cohort of these children who had chest radiographs obtained at the time of diagnosis was identified, and the original reading of their radiographs by the radiologist was obtained from automated databases. Rates of clinically diagnosed pneumonia, of pneumonia with a radiograph obtained regardless of result, of pneumonia with positive radiograph (consolidation, empyema or parenchymal infiltrate) and of pneumonia with only perihilar infiltrates were compared between vaccinated and nonvaccinated groups. In addition risk of disease pneumonia was evaluated by race and ethnicity. RESULTS: The incidence of a first pneumonia episode in the control group was 55.9 per 1000 person-years. A radiograph was obtained in 61% of episodes, a positive radiograph in 21% and perihilar findings in an additional 5%. In per protocol follow-up of children given PCV, first episodes of all clinically diagnosed pneumonia were reduced by 4.3% [95% confidence interval (CI), -3.5, 11.5%, = 0.27], episodes with a radiograph were reduced by 9.8% (CI 0.1, 18.5%, < 0.05) and episodes with a positive radiograph were reduced by 20.5% (CI 4.4, 34.0, = 0.02). In the intent to treat analysis including all episodes after randomization, episodes with a positive radiograph were reduced by 17.7%, =.01). The greatest impact was in the first year of life with a 32.2% reduction and a 23.4% reduction in the first 2 years, but only a 9.1% reduction in children >2 years of age. Asians, blacks and Hispanics were at higher risk of pneumonia than were whites, but there was no evidence of ethnic variation in PCV effectiveness. Ten of the 11 cases of pneumococcal pneumonia with a positive blood culture were in the control group. CONCLUSION: The pneumococcal conjugate vaccine tested was effective in reducing the risk of pneumonia in young children.

Age Factors↗