Development of quality control standards for radiation therapy equipment in Canada

Dunscombe, Peter; Johnson, H. L.; Aresnault, Clement; Mawko, George; Bissonnette, Jean‐Pierre; Seuntjens, J

doi:10.1120/jacmp.v8i1.2380

Cited by 18 publications

(8 citation statements)

References 2 publications

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“…However, the former is the main option due to the high chances of cures or at least benefit in life quality of patients 1 . It requires the use of immobilization devices in order to assure the application of routine doses in the same area, reducing damage of healthy tissue and enhancing the dose volume in the target 2, 3 . Their preparation is the first step of the application planning when using a linear accelerator (X-rays) to provide a quality treatment 4, 5…”

Section: Introductionmentioning

confidence: 99%

Radiation and thermal effects on polymeric immobilization devices used in patients submitted to radiotherapy

Pereira-Loch¹,

Benavides

Lima

et al. 2011

J Radiother Pract

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Immobilization devices in radiotherapy are made of a soft plastic easy to mould when immersed in hot water. Same item is usually used for 6 patients (according to protocol), but at Hospital Sao Jose (HSJ) they have been showing some deformation during the re-utilization process. The latter is the reason for this research where devices were treated with 6 thermal conditions, 6 irradiation procedures and the joint effect of both treatments. DSC, TGA and WAXD indicated devices are made of polycaprolactone (PCL), but no signs of degradation, except a slight variation in crystalinity; however, mechanical properties by means of Young's modulus steadily increase its values through number of treatments up to a 20%. Activation energy (Ea) obtained by multi-ramps of TGA-Arrhenius evaluated for the most treated samples (6th treatment) indicates that temperature facilitates degradation while irradiation and joint treatments enhance the stability of PCL, apparently by crosslinking.

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Section: Introductionmentioning

confidence: 99%

Radiation and thermal effects on polymeric immobilization devices used in patients submitted to radiotherapy

Pereira-Loch¹,

Benavides

Lima

et al. 2011

J Radiother Pract

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“…Thus, the accelerator output is critically important when performing patient specific IMRT QC with absolute dose tolerances since the ppp may be significantly affected by output variations even within the accepted tolerance range. 11 This effect clearly decreases the level of detectability of any mismatch between the predicted and the measured dose maps irrespective of the evaluation criteria used.…”

Section: Discussionmentioning

confidence: 99%

The sensitivity of patient specific IMRT QC to systematic MLC leaf bank offset errors

Rangel

Palte²,

Dunscombe

2010

Medical Physics

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“…Until now, periodic quality checks for the geometric set-up of the imaging devices inside the facility do not include phantom based verification of the X-ray imaging equipment [4].…”

Section: State Of the Art And Advances By The Presented Contributionmentioning

confidence: 99%

Geometry calibration for x-ray equipment in radiation treatment devices and estimation of remaining patient alignment errors

et al. 2008

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Positioning a patient accurately in treatment devices is crucial for radiological treatment, especially if accuracy vantages of particle beam treatment are exploited. To avoid sub-millimeter misalignments, X-ray images acquired from within the device are compared to a CT to compute respective alignment corrections. Unfortunately, deviations of the underlying geometry model for the imaging system degrade the achievable accuracy. We propose an automatic calibration routine, which bases on the geometry of a phantom and its automatic detection in digital radiographs acquired for various geometric device settings during the calibration. The results from the registration of the phantom's X-ray projections and its known geometry are used to update the model of the respective beamlines, which is used to compute the patient alignment correction. The geometric calibration of a beamline takes all nine relevant degrees of freedom into account, including detector translations in three directions, detector tilt by three axes and three possible translations for the X-ray tube. Introducing a stochastic model for the calibration we are able to predict the patient alignment deviations resulting from inaccuracies inherent to the phantom design and the calibration. Comparisons of the alignment results for a treatment device without calibrated imaging systems and a calibrated device show that an accurate calibration can enhance alignment accuracy.

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Development of quality control standards for radiation therapy equipment in Canada

Cited by 18 publications

References 2 publications

Radiation and thermal effects on polymeric immobilization devices used in patients submitted to radiotherapy

Radiation and thermal effects on polymeric immobilization devices used in patients submitted to radiotherapy

The sensitivity of patient specific IMRT QC to systematic MLC leaf bank offset errors

Geometry calibration for x-ray equipment in radiation treatment devices and estimation of remaining patient alignment errors

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