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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
Evolutionary DVH evaluation for beam orientations
in intensity modulated radiation therapy
Ahmad Saher Azizi Sultan
Taibah University, Saudi Arabia
Ahmad Saher Azizi Sultan, J. med phys & appl sci 2018, Volume: 3
DOI: 10.21767/2574-285X-C1-003
Biography
Ahmad Saher Azizi Sultan received his Diploma and PhD in
Mathematics from Kaiserslautern University, Fraunhofer Insti-
tute, where he gained his training in Industrial Mathematics for
several years. He has received his Diploma and PhD; he started
his Post-doctoral training in Mathematical Logic at the Inter-
national Centre for Computational Logic in Dresden. He then
moved to Saudi Arabia and started his own research at Tai-
bah University. His interdisciplinary research focuses on Dose
Evaluation and Beam Orientations in Multi-criteria Intensity
Modulated Radiation Therapy. Especially his knowledge about
industrial multi-criteria optimization made him one of the refer-
ees for some journals such as
European journal of Operational
Research
and
Science Journal of Mathematics and Statistics
.
On the other hand, he is currently developing techniques in com-
putational logic to speedup SAT solvers.
sultansaher@hotmail.comT
he problem of beam orientations in intensity-modulated radiation therapy
(IMRT) is an important, but large-scale non-deterministic polynomial-time
(NP) hard optimization problem. A considerable part of this difficulty is due to
the essential prerequisite of defining, appropriately, counter-intuitive criteria for
a mathematical plan evaluation that coincides with the clinical judgement of the
considered plan. Moreover, the quality of beam directions depends heavily on its
corresponding beam intensity profiles. Usually a stochastic selector is utilized
for optimizing beam orientations, and an inverse treatment planning algorithm
is employed to optimize beam intensity profiles for every selection of beam
orientations. Thus, intensity profiles are calculated many thousands of times,
each time for a different selection of beam directions, resulting in excessive time
complexity. Therefore selecting an appropriate set of beam directions in IMRT
is still a time consuming manual trial and error search procedure that depends
on intuition and empirical knowledge. To overcome these difficulties, this work
utilizes the concept of dose volume histogram (DVH), which is one of the main
recognized quantitative measurement tools used for plan judgement, to present
a DVH evaluation scheme that parallelizes plan evaluation with clinical plan
judgement. The DVH evaluation scheme is then combined with an evolutionary
algorithm manufactured particularly to solve the problem of beam orientation
in IMRT. The results of applying the presented methods to real clinical cases
demonstrated that while the evolutionary algorithm converges to appropriate
solutions in practical clinical time slot, significant improvement were reported in
all clinical cases in comparison to the standard equally spaced beam plans, even
when sometimes using a fewer number of beams. A fewer number of beams is
always desirable without compromising the quality of the treatment plan. This
results in a shorter treatment delivery time which reduces potential errors in terms
of patient movements and decreases discomfort, as well as the risk of reoccurring
cancers in the future.