20.500.12556/DiRROS-19079 Evaluation of two-dimensional dose distributions for pre-treatment patient-specific IMRT dosimetry The accuracy of dose calculation is crucial for success of the radiotherapy treatment. One of the methods that represent the current standard for patient-specific dosimetry is the evaluation of dose distributions measured with an ionization chamber array inside a homogeneous phantom using gamma method. Nevertheless, this method does not replicate the realistic conditions present when a patient is undergoing therapy. Therefore, to more accurately evaluate the treatment planning system (TPS) capabilities, gamma passing rates were examined for beams of different complexity passing through inhomogeneous phantoms. Materials and methods The research was performed using Siemens Oncor Expression linear accelerator, Siemens Somatom Open CT simulator and Elekta Monaco TPS. A 2D detector array was used to evaluate dose distribution accuracy in homogeneous, semi-anthropomorphic and anthropomorphic phantoms. Validation was based on gamma analysis with 3%/3mm and 2%/2mm criteria, respectively. Results Passing rates of the complex dose distributions degrade depending on the thickness of non-water equivalent material. They also depend on dose reporting mode used. It is observed that the passing rate decreases with plan complexity. Comparison of the data for all set-ups of semi-anthropomorphic and anthropomorphic phantoms shows that passing rates are higher in the anthropomorphic phantom. Conclusions Presented results raise a question of possible limits of dose distribution verification in assessment of plan delivery quality. Consequently, good results obtained using standard patient specific dosimetry methodology do not guarantee the accuracy of delivered dose distribution in real clinical cases IMRT 2D dose verification gamma method antropomorphic phantom intenzitetna modulirana terapija dvodimenzionalna dozna verifikacija metoda gama antropomorfni fantom true false true Association of Radiology and Oncology Ljubljana Angleški jezik Slovenski jezik by Authors Neznano 2024-06-10 15:06:28 2024-06-10 15:06:29 2024-06-11 03:36:35 0000-00-00 00:00:00 2018 0 0 str. 346-352, VIII no. 3 Vol. 52 2018 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2018-01-01 615.82/.84 1318-2099 10.2478/raon-2018-0019 2986875 https://content.sciendo.com/view/journals/raon/ahead-of-print/article-10.2478-raon-2018-0019.xml 1 4229e271-272a-11ef-9c9e-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=26230 RAZ_Smilovic_Radojcic_Deni_2018.pdf RAZ_Smilovic_Radojcic_Deni_2018.pdf 1 4D2BD9D966525D9211CE6F82D53D9714 a3220212de2ddc3269d9a0fd1bc1fd5f70b048cf1d4039c908d7ba6a6fd17a30 6a3f495b-272a-11ef-9c9e-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=26231 Onkološki inštitut Ljubljana 0 0 0