Patient dose reduction during voiding cystourethrography

Voiding cystourethrography (VCUG) is a commonly performed examination in a pediatric uroradiology practice. This article contains suggestions on how the radiation dose to a child from VCUG can be made ‘as low as reasonably achievable–(ALARA). The pediatric radiologist should consider the appropriateness of the clinical indication before performing VCUG and utilize radiation exposure techniques and parameters during VCUG to reduce radiation exposure to a child. The medical physicist and fluoroscope manufacturer can also work together to optimize a pulsed-fluoroscopy unit and further reduce the radiation exposure. Laboratory and clinical research is necessary to investigate methods that reduce radiation exposures during VCUG, and current research is presented here

Applying the ALARA concept to the evaluation of vesicoureteric reflux

The voiding cystourethrogram (VCUG) is a widely used study to define lower urinary tract anatomy and to diagnose vesicoureteric reflux (VUR) in children. We examine the technical advances in the VCUG and other examinations for reflux that have reduced radiation exposure of children, and we give recommendations for the use of imaging studies in four groups of children: (1) children with urinary tract infection, (2) siblings of patients with VUR, (3) infants with antenatal hydronephrosis (ANH), and (4) children with a solitary functioning kidney. By performing examinations with little to no radiation, carefully selecting only the children who need imaging studies and judiciously timing follow-up examinations, we can reduce the radiation exposure of children being studied for reflux

The change of radiation doses to the patient when switching from conventional technique to digital technique without films in barium enema and IVU examinations. Final report SSI research project P933

X-ray examinations of the colon (barium enema) and the kidneys (IVU) are combined with rather high radiation doses to the patients when using analogue technique with film-screen systems. It is therefore of great interest to see if the change from analogue to digital technique involves a reduction of doses. Barium enema and IVU examinations were monitored with DAP-meters before and after the X-ray department changed to digital techniques. For IVU also the change from storage phosphor plates to a Direct Digital detector is included. The study comprises between 53 and 87 patients for each modality of the two examinations. A considerable dose reduction was observed. In barium enema the overview images with large field sizes were omitted when using digital technique. On the other hand the number of spot images was increased from 6 to 22. The fluoroscopy time was increased from 4 minutes to 6 minutes. The DAP value was reduced from 54,3 Gy cm sup 2 to 21,9 Gy cm sup 2. For IVU a dose reduction from 44,5 Gy cm sup 2 to 32,5 Gy cm sup 2 was achieved in the first step when storage phosphor plates replaced the film-screen system. In the next step one exposure was omitted and the storage phosphor plates were replaced with a flat panel detector. This step resulted in a dose reduction from 32,5 Gy cm sup 2 to 12,5 Gy cm sup 2. The main dose reduction in barium enema was a result of omitting the overview images and the use of pulsed fluoroscopy. In IVU the introduction of the flat panel detector was the main reason for the dose reductio

Phantom study of radiation doses outside the target volume brachytherapy versus external radiotherapy of early breast cancer

Background and purpose: Brachytherapy is sometimes suggested as an adjuvant treatment after surgery of some tumours. When introducing this, it would be useful to have an estimate of the dose distribution to different body sites, both near and distant to target, comparing conventional external irradiation to brachytherapy. The aim of the present study was to determine radiation doses with both methods at different body sites, near and distant to target, in an experimental situation on an operated left sided breast cancer on a female Alderson phantom. Methods: Five external beam treatments with isocentric tangential fields were given by a linear accelerator. A specified dose of 1.0 Gy was given to the whole left sided breast volume. Five interstitial brachytherapy treatments were given to the upper, lateral quadrant of the left breast by a two plane, 10 needles implant. A dose of 1.0 Gy specified according to the Paris system was administered by a pulsed dose rate afterloading machine. Absorbed dose in different fixed dose points were measured by thermoluminescence dosimeters. Results: Both methods yielded an absorbed dose of the same size to the bone marrow and internal organs distant to target, 1.0-1.4% of the prescribed dose. There was a trend of lower doses to the lower half of the trunk and higher doses to the upper half of the trunk, respectively, by brachytherapy. A 90% reduction of absorbed dose with brachytherapy compared to external irradiation was found in the near-target region within 5 cm from target boundary where parts of the left lung and the heart are situated. If an adjuvant dose of 50 Gy is given with the external radiotherapy and brachytherapy, the absorbed dose in a part of the myocardium could be reduced from 31.8 to 2.1 Gy. Conclusions: Near target, brachytherapy yielded a considerably lower absorbed dose which is of special importance when considering radiation effects on the myocard and lungs. We could not demonstrate any difference of importance, in absorbed dose to dose points distant to target. (C) 2003 Elsevier Ireland Ltd. All rights reserved