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[en] The total-body irradiation (TBI) technique at St Bartholomew's Hospital has been developed to improve dose homogeneity within the patient. Using a standard 6 MV linear accelerator in an orthodox-sized treatment room, the midpoint doses in head, neck, shoulders, mid-mediastinum, pelvis, knees and ankles are + - 5% of that of the umbilicus in our current technique. This homogeneity has been achieved by a four-field technique, a reproducible patient set-up, careful use of a new bolus material and an additional beam-flattening filter mounted near the machine head. In addition, thermoluminescent dosimetric data collected at a test irradiation before TBI are used to influence field weightings and further improve dosimetry. This individualised and empirical TBI technique has dosimetric advantages over theoretical TBI dosimetric considerations in reducing dose gradients within the patient. These advantages are discussed. (author)

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[en] In this contribution the possibilities of the thremoluminiscence dosimetry method under the difficult conditions of total body irradiation at low dose rate are illustrated. (H.W.). 2 res.; 1 fig

[en] Purpose: Approximately 4000 volunteers will undergo whole-body magnetic resonance imaging (WB-MRI) within the next 3 years in the population-based Study of Health in Pomerania (SHIP). Here we present a pilot study conducted (a) to determine the feasibility of adding a WB-MRI protocol to a large-scale population-based study, (b) to evaluate the reliability of standardized MRI interpretation, and (c) to establish an approach for handling pathological findings. Materials and Methods: The institutional review board approved the study, and oral and written informed consent was obtained from each participant. Two hundred healthy volunteers (99 women, 101 men; mean age 48.3 years) underwent a standardized WB-MRI protocol. The protocol was supplemented by contrast-enhanced cardiac MR1 and magnetic resonance (MR) angiography in 61 men (60.4%) and cardiac MRI and MR mammography in 44 women (44.4%). MR scans were evaluated independently by two readers. Abnormalities were discussed by an advisory board and classified according to the need for further clinical work-up. Results: One hundred ninety-four (97.0%) WB-MRI examinations were successfully completed in a mean scan time per subject of 90 minutes. There were 431 pathological findings in 176 (88%) of the participants. Of those 45 (10.4%) required further clinical work-up and 386 (89.6%) characterized as benign lesions did not. The interobserver agreement for the detection of pathological findings was excellent (K = 0.799) (orig.)

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No abstract available

[en] Published in summary form only

[en] Tissue-air ratio (TAR), as the basic dosimetric function, is not ideally applicable to all important locations in total body irradiation (TBI) dosimetry because it generally refers to central ray measurements. Therefore, the local TAR is introduced, which depends on the specific distribution of the scattering centres around the location of interest. Local TAR measurements were performed in an anatomical water phantom, produced by a sculptor, representing a patient during TBI in the real treatment position. A comparison has been made between TAR values, defined on the beam's ray at different locations in the anatomic phantom and cubic phantoms of different size. The local TAR values in the anatomic phantom, having more realistic outer surface curvatures, are lower by a few percent in most locations. These values are considered more accurate and better applicable to TBI conditions than those obtained in cubic water phantoms, even if the volume of the phantom is adapted to the particular side of the body. (author). 13 refs.; 5 figs.; 1 tab