Corrections to traditional methods of verifying tangential‐breast 3D monitor‐unit calculations: Use of an equivalent triangle to estimate effective fields
نویسندگان
چکیده
This paper describes an innovative method for correctly estimating the effective field size of tangential-breast fields. The method uses an "equivalent triangle" to verify intact breast tangential field monitor-unit settings calculated by a 3D planning system to within 2%. The effects on verification calculations of loss of full scatter due to beam oblique incidence, proximity to field boundaries, and reduced scattering volumes are handled properly. The methodology is validated by comparing calculations performed by the 3D planning system with the respective verification estimates. The accuracy of this technique is established for dose calculations both with and without heterogeneity corrections.
منابع مشابه
Verifying monitor unit calculations for tangential breast fields
An essential component of quality assurance in radiation therapy is verifying the accuracy of monitor unit calculations. Differences between between sophisticated algorithms using 2.5D or 3D calculations and simpler Monitor unit check algorithms assuming a flat water phantom must be expected. For many anatomical sites such differences are small and of little or no consequence in the context of ...
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