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E Aird

Publications and source records attributed to E Aird.

8 recordsLinked to original sources
PubMed2001

A survey of radiotherapy quality control practice in the United Kingdom for the START trial.

BACKGROUND AND PURPOSE: This paper compares the quality control checks performed in departments in the United Kingdom with those recommended by the Institute of Physics and Engineering in Medicine (IPEM) in Report 81. METHOD: The data were gathered by the quality assurance team for the START trial, during visits to individual departments. Data are compared with the frequencies suggested in IPEM report 81. Where applicable, data are also analyzed with respect to machine manufacturer. RESULTS: All departments with linear accelerators check the output at least weekly for both photons and electrons, however 11% of departments do not perform a constancy check of the output on a daily basis. The majority of departments check flatness at gantry zero on a monthly basis. However 27% of departments never check at non-zero gantry angles. In 51% of departments no fluoroscopy checks are performed on simulators on a daily basis. CONCLUSION: The majority of departments are following the frequencies suggested in IPEM report 81 although there are a number of discrepancies particularly for simulators. Accelerator type needs to be considered when designing quality assurance checks. In many departments more time than is currently allocated is needed on equipment, particularly simulators, to complete all of the checks suggested in Report 81.

Breast Neoplasms↗
PubMed2001

The START trial-measurements in semi-anatomical breast and chest wall phantoms.

This paper describes dosimetry measurements performed prior to departments entering patients into the START Trial, a breast fractionation trial. Absolute and relative doses were measured in semi-anatomical breast and chest wall phantoms, as part of a quality assurance programme visit. Doses were measured using an ionization chamber and the resulting distributions were compared with those calculated by the department. The mean ratio of measured to calculated dose at the START reference point was found to be 0.981 for the breast phantom and 0.978 for the chest wall phantom. This average measured dose was significantly less than the prescribed dose (p < 0.001). Differences were found between 2D and 3D planning systems and for departments using cobalt 60 beams. A number of departments had deviations of greater than 4%, which was the tolerance applied for this trial. It is essential for dose measurements of this type to be performed for randomized clinical trials involving radiotherapy, particularly where dose fractionation regimes are being compared.

Algorithms↗
PubMed2000

Breast radiotherapy phantom design for the START trial. START trial management group.

The design of phantoms for use in radiotherapy involves a number of complex issues. This paper describes breast and chest wall phantoms that have been designed and constructed for the START trial. Four phantoms have been manufactured, including two two-dimensional phantoms used on the first round of audit visits to assess the ability of departments to plan with the required accuracy. Two further phantoms have been constructed and will be used in the second round of audit visits; one is a water-filled three-dimensional phantom for investigating off-axis dosimetry, the other is to be used to assess dose in the junction region between the tangential fields and the supraclavicular fossa field. The manufacturing and design process for each of the phantoms is discussed.

Breast Neoplasms↗
PubMed1993

Precision in reporting the dose given in a course of radiotherapy.

A knowledge of the precise dose given in a course of radiotherapy is vital to the interpretation of the result. Despite this, an acceptable level of reporting was found in only 72 (36%) of 200 papers published in the two leading journals of radiation oncology. Analysis of the treatment data of the cases with head and neck tumours in the pilot study of CHART showed that the mean of the minimum tumour doses given was 5.1% lower than the mean of those at the intersection points. Had the same total dose been prescribed to the intersection point instead of the minimum there would have been a similar lowering of dose. There is evidence from published clinical data and a suggestion from an analysis of the CHART pilot study data that a dose difference as small as 5% may lead to real impairment or enhancement of tumour response, as well as altering the risk of morbidity. Inadequate reporting may lead to a false interpretation of a study and to its wrongful application. It is strongly recommended that it should be editorial policy to publish only those papers where the radiation dose is fully described.

Absorption↗
PubMed1977

Thermography.

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Humans↗