Verification of accuracy of multileaf collimator leaf position using a two-dimensional ion chamber array

Objective: To design a new method to verify the position of multileaf collimator(MLC) leaf using a two-dimensional ion chamber array(2D-array). Methods: 2D-array of PTW T10018 Seven29TM was used to calibrate the accuracy of MLC leaf position of Elekta Precise accelerator. The edge function of the leaf position of MLC was measured and used as the reference value. The precision of MLC leaf was then evaluated through comparing the measured and reference values. Results: The accuracy of MLC leaf position was found within ± 0.1 mm. Conclusion: This method of verifying the accuracy of multileaf collimator leaf position is easy, simple and reliable. (authors)