Typical Causes of Discrepancies between Measured and Calculated Data in the Verification of Intensity Modulated Exposure Plans and Possibilities for Their Elimination

This paper describes the experience of the process of dosimetric verification of irradiation plans with photon fluence modulation based on the AAPM TG119 report on the basis of the inhouse set of dosimetric equipment. Identified operational deficiencies that can reduce the effectiveness of quality control of IMRT verification plans were described, namely human factors, lack of clear instructions, technical problems, environmental conditions, and dosimetry problems. Practical solutions including spatial resolution, normalization and data interpretation are discussed.