PubMed · 13419809
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W D HOLDEN, A OCHSNER, H L FRIEDELL, A B CHINN. 1957. Gastrointestinal bleeding.. https://doi.org/10.1080/00325481.1957.11691795
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PURPOSE: The aim of this study was to investigate prospectively the rectal wall (Rwall) spatial dose distribution, toxicity, and mucosal changes after prostate cancer radiotherapy with or without an endorectal balloon (ERB). METHODS AND MATERIALS: A total of 24 patients with ERB and 24 without ERB (No-ERB) were treated with three-dimensional conformal radiotherapy (3D-CRT) to a dose of 67.5 Gy. The Rwall was divided into 16 mucosal areas and Rwall dose surface maps were constructed. After 3 months, 6 months, 1 year, and 2 years a rectosigmoidoscopy was performed, and each mucosal area was scored on telangiectasia, congestion, ulceration, stricture, and necrosis. Late rectal toxicity was correlated with the endoscopic findings. RESULTS: The ERB significantly reduced the Rwall volume exposed to doses >40 Gy. Late rectal toxicity (grade >or=1, including excess of bowel movements and slight rectal discharge) was reduced significantly in the ERB group. A total of 146 endoscopies and 2,336 mucosal areas were analyzed. Telangiectases were most frequently seen and appeared after 6 months. At 1 and 2 years, significantly less high-grade telangiectasia (T 2-3) was observed in the ERB group at the lateral and posterior part of the Rwall. In mucosal areas exposed to doses >40 Gy, less high-grade telangiectases (T 2-3) were seen in the ERB group compared with the No-ERB group. CONCLUSIONS: An ERB reduced the Rwall volume exposed to doses >40 Gy, resulting in reduction of late rectal mucosal changes and reduced late rectal toxicity. Although further analysis is needed, these data suggest an ERB-induced increased tolerance for late Rwall damage.
OBJECTIVE: HemoCue is routinely used to manage bleeding patients, but few studies have evaluated its accuracy in this population. We compared HemoCue with laboratory determination of blood hemoglobin in patients with gastrointestinal bleeding. DESIGN AND SETTING: A prospective observational study in a 14-bed medicosurgical ICU and an emergency department in an urban general hospital. PATIENTS: 94 patients admitted to the emergency department or to the ICU for gastrointestinal bleeding. INTERVENTIONS: Blood was drawn at admission to measure laboratory hemoglobin and capillary hemoglobin was measured simultaneously by HemoCue. The unit of hospitalization and the presence or absence of impaired vital signs (tachycardia and/or hypotension and/or shock) were recorded. MEASUREMENTS AND RESULTS: The mean difference between HemoCue and hemoglobin (bias) was -0.06 g/dl and standard deviation (precision) 0.87 g/dl. (95% CI -1.8 to 1.68). Discrepancies between HemoCue and hemoglobin were greater than 1 g/dl in 21% of cases. Bias was comparable between patients admitted to the ICU and those in the emergency department. The accuracy of HemoCue was not affected by the presence of impaired vital signs or by a hemoglobin level below 9 g/dl or 7 g/dl. CONCLUSIONS: Although we demonstrated a low bias between HemoCue and blood hemoglobin determination, large HemoCue vs. hemoglobin differences may still occur, and therefore therapeutic decisions based upon capillary HemoCue alone should be very cautious.
We investigate the utility of principal component analysis as a tool for obtaining dose-volume combinations related to rectal bleeding after radiotherapy for prostate cancer. A direct implementation of principal component analysis reduces the number of degrees of freedom from the patient's dose-volume histograms that are associated with bleeding. However, when low-variance principal components are strongly correlated to outcome, their interpretation is problematic. A Varimax rotation is employed to aid in interpretability of the low-variance principal components. This procedure brings us closer to finding unique dose-volume combinations related to outcome but reintroduces correlation, requiring analysis of the overlap of information contained in such modes. Finally, we present examples of cost-benefit analyses for candidate dose-volume constraints for use in treatment planning.