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Page 38
Journal of Medical Physics and Applied Sciences
ISSN: 2574-285X
I n t e r n a t i o n a l C o n f e r e n c e o n
Nuclear Medicine &
Radiation Therapy
Nuclear Medicine & Radiation Therapy 2018
O c t o b e r 0 1 - 0 2 , 2 0 1 8
S t o c k h o l m , S w e d e n
Dosimetry of small photon radiation fields: comparison of the
German DIN-6809 (2016) and the IAEA TRS- 483 (2017) protocols
Golam Abu Zakaria
Klinikum Oberberg-Kreiskrankenhaus Gummersbach Hospital, Academic Teaching Hospital of the
University of Cologne, Germany
Biography
Prof. Dr. G. A. Zakaria studied physics at the University of Hal-
le-Wittenberg in 1978, and post-graduated at the University of
Goettingen and received his Ph. D in medical physics at Heidel-
berg University, Germany.
Prof. Zakaria is currently the chairman of the Department of
Medical Radiation Physics at Gummersbach Teaching Hos-
pital of the University of Cologne and professor of Biomedical
Engineering at the University of Applied Sciences in Koethen.
Furthermore he has been invited as Guest/honorary/adjunct
professor in many institutes or universities in Germany, Italy,
China and Bangladesh. Since January 2018, Dr. Zakaria is nom-
inated as the Accreditation Committee-2 Chair (Radio-Oncolo-
gy Physics) of the International Medical Physics Certification
Board (IMPCB).
Modern radiation techniques such as stereotactic radiosurgery and intensity
modulated radiation therapy (IMRT) use small radiation fields (field sizes
<2x2 cm2), which deviate significantly from the dosimetric reference field size
10x10 cm2. Small photon field dosimetry requires further development of today’s
codes of practice, because of the changing physical conditions. The resulting
changes in physical and dosimetric conditions go beyond the measuring methods
defined in the popular standard protocols like IAEA TRS-398, German DIN 6800-2,
and AAMPTG-51. For this reason, the German standard DIN6809-8 (2016) and the
international IAEA TRS-483 (2017) protocols have recently been developed. They
define the measuring methods and physical parameters of dosimetry of small
photon fields. The IAEA TRS-483 protocol is an extension of the Codes of Practice
TRS-378 based on the basicwork of Alfonso et al. Similarly the standard DIN6809-
8 is an extension of the DIN 6800-2 for small field. The content of the DIN 6809-8
standard is, among others, the introduction of a new reference field size to ensure
an adaptation to the conditions of the small photon fields. It is defined as the small
calibration field. Furthermore, correction values are recommended which correct
the influence of the detectors on the measured value when measured field sizes
are smaller than the small calibration field. In this norm, the detector-dependent
correction factors are based on the formalism of Alfonso et al. The DIN 6809-8 is
a suitable recommendation for small field dosimetry and ensures the alignment
of the Codes of practice. The principles of determination of the absorbed dose in
water according to both protocols and a comparison of results for different high
energy photon beams are explained in this paper.
Golam Abu Zakaria, J. med phys & appl sci 2018, Volume: 3
DOI: 10.21767/2574-285X-C1-002