Clinical use of asymmetric collimators

Kwa, William; Tsang, Victor; Fairey, R.N.; Jackson, Stewart M.; El‐Khatib, Ellen; Harrison, Robert W.; Kristensen, Sarah

doi:10.1016/s0360-3016(96)00543-3

Cited by 6 publications

(1 citation statement)

References 22 publications

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“…In a similar manner, asymmetric collimation is commonly used in oncologic radiation therapy to reduce harmful radiation for the patient and/or provide more flexibility in the ability to shield sensitive organs. 11,12 In this study, we examined the potential impact of introducing an asymmetric collimation technique in the electrophysiology lab for use in fluoroscopy-guided treatment of AF. We compared the effective dose for both optimal symmetric and asymmetric collimation approaches to assess the potential impact of a simple collimation measure on total patient radiation exposure.…”

Section: Introductionmentioning

confidence: 99%

Asymmetric collimation can significantly reduce patient radiation dose during pulmonary vein isolation†

et al. 2011

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Implementation and effective application of an optimal asymmetric collimation approach would yield an average three- to nine-fold reduction of fluoroscopy dose during AF ablation procedures. This reduction exceeds what has been previously reported by implementing an electromagnetic catheter tracking approach. Furthermore, it can be easily integrated in the clinical workflow with limited additional one-time cost. Manufacturers of imaging systems should consider its implementation a priority, and physicians should adopt it in their workflow.

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Section: Introductionmentioning

confidence: 99%

Asymmetric collimation can significantly reduce patient radiation dose during pulmonary vein isolation†

et al. 2011

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A study on beam homogeneity for a Siemens Primus linac

Henríquez

Vargas-Castrillón

2007

Australas. Phys. Eng. Sci. Med.

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Asymmetric offset fields are an important tool for radiotherapy and their suitability for treatment should be assessed. Dose homogeneity for highly asymmetric fields has been studied for a Siemens PRIMUS clinical linear accelerator. Profiles and absolute dose have been measured in fields with two jaws at maximal position (20 cm) and the other two at maximal overtravel (10 cm), corresponding to 10 cm x 10 cm fields with extreme offset. Measured profiles have a marked decreasing gradient towards the beam edge, making these fields unsuitable for treatments. The flattening filter radius is smaller than the primary collimator aperture, and this creates beam inhomogeneities that affect large fields in areas far from the collimator axis, and asymmetric fields with large offset. The results presented assess the effect that the design of the primary collimator and flattening filter assembly has on beam homogeneity. This can have clinical consequences for treatments involving fields that include these inhomogeneous areas. Comparison with calculations from a treatment planning system, Philips Pinnacle v6.3, which computes under the hypotheses of a uniformly flattened beam, results in severe discrepancies.

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