Comparison of two methods for anterior-posterior isocenter localization in pelvic radiotherapy using electronic portal imaging.

PURPOSE: The two setup methods commonly used to determine the anterior-posterior isocenter location in pelvic radiotherapy are to align lateral localization lasers with lateral skin tattoos on the patient, or to set the couch height so that the isocenter is at a fixed height (determined during simulation or treatment planning) above the couch top. This study was implemented to determine which technique gives more accurate patient treatment by comparison of the anterior-posterior setup variation measured with electronic portal imaging. METHODS AND MATERIALS: Eleven supine prostate patients were treated with tattoo localization and 159 left-lateral portal images were taken during the treatments. The field displacements were then determined by template matching. These patients were compared to nine patients (205 images) set up to a fixed isocenter height. Similarly, eight prone rectal patients (136 right-lateral images) set up to tattoos were compared to six patients (108 images) set up to a fixed height. The patients were not immobilized and were all treated with three field techniques on a hard couch top. The overall mean treatment position deviation and the standard deviation of the displacements (total setup variation) were calculated for each patient group along with the systematic (simulator-to-treatment) and the random (treatment-to-treatment) setup variation. RESULTS: The mean treatment position deviations were 3.3 mm anterior and 5.2 mm posterior with the tattoo method for the prostate and rectal patients, respectively. These mean position deviations were 0.4/0.1 mm anterior with the fixed height technique. The total setup variations were 4.6/5.2 mm (1 SD) with tattoo localization and 1.7/1.5 mm (1 SD) with the fixed height method. Similarly, random variation was 2.3/3.3 mm (1 SD) with the tattoo method compared to 1.3/1.2 mm (1 SD) with the fixed height method. Systematic variation was 3.7/4.5 mm (1 SD) compared to 1.2/1.1 mm (1 SD). CONCLUSION: The fixed height technique gives much more accurate localization of the anterior-posterior isocenter in pelvic radiotherapy than lateral skin tattoos.

[Brown syndrome in an adult patient with morbus Still]. / Browns syndrom hos en voksen patient med morbus Still.

A 25 year-old woman, known to be suffering from destructive rheumatoid arthritis, was admitted to the hospital due to influenza-like symptoms lasting three weeks. Adult Still's disease was diagnosed. During her disease she developed painful ophthalmoplegia due to tenosynovitis of the superior oblique muscle and tendon sheath (Brown's syndrome). Total resolution was obtained within three weeks of corticosteroid therapy.

Anterior-posterior treatment localization in pelvic radiotherapy: tattoos or fixed couch-to-isocentre distance.

The methods of determining the anterior-posterior isocentre location in pelvic radiotherapy are either by aligning lateral localization lasers to tattoo marks on skin, or by setting a constant daily couch-to-isocentre distance. While using the former method the day-to-day vertical couch movement was recorded and combined with measurements of day-to-day anterior-posterior patient movement made with an electronic portal imaging device to determine whether couch vertical movement contributes to anterior-posterior setup variation. Seven unimmobilized patients were studied, four supine prostate and three prone rectum patients. The two motions were found to be highly correlated (correlation coefficient = 0.82) which supports the constant couch-to-isocentre distance approach. When the day-to-day couch vertical movement was subtracted from the anterior-posterior movement results the setup variation was reduced in six of the seven patients.

Benzidine positive multicentric eosinophilic colonies in human blood mimicking erythroid bursts.

When normal human mononuclear blood cells are cultured in plasma clot or methylcellulose in the presence of erythropoietin, two types of benzidine positive multicentric colonies can be recognized in the light microscope at high magnification: one containing diffusely stained cells with the morphology of erythroblasts (erythroid bursts), and another containing diffusely and/or granular stained benzidine positive cells with a morphology of neutrophils/macrophages. Based on their cytochemical properties, lack of inhibition of the benzidine reaction by potassium cyanide, and strong granular staining with luxol fast blue and alkaline eosin, the cells from the latter are identified as eosinophils.