الفهرس 
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Abstract
There are more than 200 types of human cancer, each with different causes,
symptoms and treatments. In general, cancer is predominantly an environmental disease
with 90-95% of cases being attributed to lifestyle factors, and 5-10% due to genetics.
While cancer can affect people of all ages the overall risk of developing cancer
generally increases with age, at least up to age 80-85 yr. In 2007, cancer caused about 13%
of all human deaths worldwide (7.9 million). These rates are rising as more people live to
an old age and as lifestyle changes occur in the developing world.
Cancer incidence rates projected increase 2012-2030, worldwide. The agestandardized
rate was at least 300 per 100,000 for nine countries (Denmark, France,
Australia, Belgium, Norway, United States of America, Ireland, Republic of Korea and
The Netherlands).
A malignant brain tumor is a fast-growing cancer that spreads to other areas of the
brain and spine. Cancer of the brain can be a primary brain tumor that originates in the
brain or a metastatic (secondary) brain tumor that originates from cancer cells that have
migrated from other parts of the body. Most malignant tumors are secondary cancers,
which mean they started in another part of the body and spread to the brain. Primary brain
tumors are those that started in the brain.
A primary malignant brain tumor needs to be treated as soon as possible, because it
can spread and damage other parts of the brain and spinal cord.
Surgery usually need to be carried out to remove as much of the tumor as possible.
This may be followed by radiotherapy and/or chemotherapy to kill any cancerous cells
left behind and reduce the chances of the tumor regrowth.
Radiotherapy, on the other hand, uses controlled doses of high energy radiation
beams to destroy brain tumor cells whilst causing as little damage as possible to
surrounding cells. When it is not possible to destroy all of the cancer, radiation therapy
may be used to shrink tumors and relieve symptoms. This may reduce pressure, pain, and
other symptoms, where the goal is to improve a person’s quality of life.
Chapter (7) Summary
107
The aim of the present study was to study the comparison between the effect of
using similar wedges and opposed wedges in brain tumor cases in the form of a thesis
presented for the M.Sc. degree in Medical biophysics.
The thesis is divided into ten chapters:
• Chapter one: concerns with an introduction about cancer tumors incidence
worldwide, and brief note on the incidence and brief review as reported in
literature.
• Chapter two: includes notes and types of ionizing radiation, radiotherapy
and external beam radiation therapy and techniques used for curing tumors
in clinical medicine, with special reference to the use of linear accelerators
and beam modification.
• Chapter three: defines the aim of the study which is coinciding with the
title of the thesis.
• Chapter four: includes the subjects and methods used in this work. For
this purpose, twenty patients of brain cancer (glioblastoma multiform) of
both sexes were enrolled in the study. Three treatment planning were
performed to compare between using similar wedges and opposed wedges
in addition to the non-wedges used for radiotherapy treatment of the
patients. The planning target volume (PTV) and the volumes of the organs
at risk were delineated using CT scan (Somatom scope Siemens Computed
Tomography Scanner) for each patient. The CT data is imported to the
contouring workstation via local area network system. A software
application medical systems (Prowess panther V 5.1 treatment system) was
used for the treatment planning procedures. Bearing in mind, for
comparison, the estimation of some parameters, namely; the D2(Dose
delivered to 2% of the PTV), D5(Dose delivered to 5% of the PTV),
D50(Dose delivered to 50% of the PTV), D95(Dose delivered to 95% of the
PTV), D98(Dose delivered to 98% of the PTV), And D100(Dose delivered
to 100% of the PTV), the maximum, minimum, and the mean doses
received by the PTV, V95(Volume covered by 95% of the received dose),
V107(Volume covered by 107% of the received dose), in addition to the
homogeneity index, the conformity index and the global maximum of the
Chapter (7) Summary
108
PTV. The organs at risk considered in this work were: Right and Left
lenses, Right and left eyes, Right and Left optic nerves, the Optic chiasm,
and the brain stem. Lateral beams, with the isocenter placed in the patients’
midline, were used for irradiation using Siemens primus linear accelerator.
• Chapter five: deals with the results were obtained throughout the study.
The results can be summarized as follows: In general, the D2, D5, D50,
D95, D98, and D100 received by the planning target volume (PTV) were
better in case of using the opposed wedges planning. The maximum,
minimum, and the mean absorbed radiation doses received by the PTV were
the closest to the pre-described dose in the opposed wedges plan.
- The V95 were the closest to the pre-described dose, moreover, no sites received
more than V107.
- The homogeneity index was better in case of both the non-wedges and the opposed
wedges plans.
- The non-wedge planning was the closest to unity, which indicated the best results
of the target coverage index, however, the next in order of acceptance is the
opposed wedges planning.
- The global maximum of the PTV excludes the non-wedges planning, and the
acceptable results appeared for both the similar and opposed planning.
- In comparing the screens obtained for more comparison to determine the areas
receiving higher doses, it is of importance to say that the areas receiving higher
doses are less in case of opposed wedges plan.
• Chapter six: discussed the data, and the overall conclusion was the better
use of opposed wedges planning in treatment of brain tumors than the other
two planning, i.e., the non-wedges and the similar wedges planning.
• Chapter seven: The summary of the study is given in it.
• Chapter eight: The conclusion of the work is mentioned in it.
• Chapter nine: The recommendation is reported in it , and
• Chapter ten: The references used in literature review all over the work are
listed in it.