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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-25 0:03 |
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Conference: Bucharest University Faculty of Physics 2004 Meeting
Section: Electricity and Biophysics
Title:
Procedure of quality assurance and quality control for good alignment of systems for stereotactic radiosurgery technique
Authors:
Pop Madalina,Vasile Gabriel
Affiliation:
Institute of Oncology ¡°Prof.Dr.AL.Trestioreanu¡±- Bucharest
252 Fundeni Street, 2 Sectors, 72435 cod, Bucharest , Romania.
Dr. Carol Davila Central Clinical Emergency Military Hospital
55 Plevnei Str., Bucharest,Romania.
E-mail
Keywords:
stereotactical radiosurgery techniques,laser systems
Abstract:
Aim: In the Institute of Oncology Prof.Dr.AL.Trestioreanu- Bucharest was performed for first time in Romania stereotactical radiosurgery techniques in July 2003. The aim of this procedure is to assure the best alignment of the systems and accessories to perform a correct administration of prescribed dose in stereotactical radiosurgery technique.
Material and Methods: The procedure provides instructions for checking of the couch alignment with the LINAC isocenter. This alignment is made in 2 steeps. In first steep, the lasers system is aligned with LINAC isocenter. For this are used: MEVATRON PRIMUS LINAC, Radionics accessory for stereotactic, collimator accessory holding, stereotactic collimators accessory, mechanical isocenter standard, film holder assembly, film test, laser target pointer, radiopaque ball optical comparator, and concentric circle overlay template. After the alignment, it is performed one film test, for different gantry angles (0¡ã, 90¡ã, and 270¡ã). The level of tolerance criteria is ¡À0.5 mm. In the second steep, the couch is positioned in concordance with intersection lasers point system. To perform this steep are used in additional: LINAC couch mount adapter, linac couch stabilizers and rectilinear phantom pointer. To verify all alignment, are made 2 final film tests , one for different gantry angles (0¡ã,90¡ã,270¡ã) and the other for different couch angles (0¡ã,90¡ã,270¡ã). The tolerance level is ¡Ü 1.5mm. General conditions to make the film tests are: dose=9UM, energy=6 MV or 15 MV and LINAC jaws 6X6 cm, with 12.5mm diameter collimator.
Results: The results prove as a very good alignation of system and accessory. The deviations are in tolerance criteria of this protocol.
Conclusion: Implementation of this protocol for QA\QC for stereotactic radiosurgery, demonstrate a very good alignment of systems that¡¯s means a correct administration of prescription in stereotactic radio surgery technique.
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