End-to-end tests using alanine dosimetry in scanned proton beams
| Autor: | Hugo Palmans, E. Traneus, C. Gouldstone, A. Carlino, Maurizio Marrale, S. Vatnitsky, Markus Stock, G. Kragl |
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| Přispěvatelé: | Carlino, A., Gouldstone, C., Kragl, G., Traneus, E., Marrale, M., Vatnitsky, S., Stock, M., Palmans, H. |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Radiology
Nuclear Medicine and Imaging Materials science Pelvi Monte Carlo method anthropomorphic phantom audit Radiation Dosage Imaging phantom 030218 nuclear medicine & medical imaging law.invention Pelvis Synchrotron 03 medical and health sciences 0302 clinical medicine law Ionization end to end test Dosimetry Humans Pencil-beam scanning Radiometry Alanine dosimetry Radiological and Ultrasound Technology Phantoms Imaging Radiotherapy Planning Computer-Assisted equipment and supplies 030220 oncology & carcinogenesis Ionization chamber Proton Protons Head Monte Carlo Method Beam (structure) Synchrotrons Biomedical engineering Human |
| Popis: | This paper describes end-to-end test procedures as the last fundamental step of medical commissioning before starting clinical operation of the MedAustron synchrotron-based pencil beam scanning (PBS) therapy facility with protons. One in-house homogeneous phantom and two anthropomorphic heterogeneous (head and pelvis) phantoms were used for end-to-end tests at MedAustron. The phantoms were equipped with alanine detectors, radiochromic films and ionization chambers. The correction for the 'quenching' effect of alanine pellets was implemented in the Monte Carlo platform of the evaluation version of RayStation TPS. During the end-to-end tests, the phantoms were transferred through the workflow like real patients to simulate the entire clinical workflow: immobilization, imaging, treatment planning and dose delivery. Different clinical scenarios of increasing complexity were simulated: delivery of a single beam, two oblique beams without and with range shifter. In addition to the dose comparison in the plastic phantoms the dose obtained from alanine pellet readings was compared with the dose determined with the Farmer ionization chamber in water. A consistent systematic deviation of about 2% was found between alanine dosimetry and the ionization chamber dosimetry in water and plastic materials. Acceptable agreement of planned and delivered doses was observed together with consistent and reproducible results of the end-to-end testing performed with different dosimetric techniques (alanine detectors, ionization chambers and EBT3 radiochromic films). The results confirmed the adequate implementation and integration of the new PBS technology at MedAustron. This work demonstrates that alanine pellets are suitable detectors for end-to-end tests in proton beam therapy and the developed procedures with customized anthropomorphic phantoms can be used to support implementation of PBS technology in clinical practice. |
| Databáze: | OpenAIRE |
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