The number of intensity modulated radiation therapy !IMRT" procedures is continuously growingworldwide and it is necessary to develop tools for patient specific quality assurance !QA" that avoidusing machine time that could be employed in treating additional patients. One way of achievingthis goal is to perform a multileaf collimator quality assurance periodically in the linear acceleratorand check the treatment planning system !TPS" calculation by employing an independent calculationsystem. Within the work frame of the pencil beam kernel approach, a new system was developedfor obtaining an experimental kernel. This new technique is based on a deconvolution procedureusing the Hankel transform. The resulting kernel is obtained in a way completely independentof those employed in commercial treatment planning systems, usually calculated by Monte Carlosimulations. Also provided are comparisons between calculated and measured doses with radiographicfilm, linear array of diodes, and ionization chamber. Measurements taken in polystyrene andwater for clinical IMRT plans demonstrate that this method can calculate IMRT dose distributions,as well as treatment times, with great accuracy. Apart from other applications, it can be used as adouble-check algorithm for IMRT QA.
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