Abstract:
Brachytherapy is the use of encapsulated radioactive sources to deliver
a radiation dose at a short distance over a short time for treatment of malignant
tumors. In Sudan, mainly in Radiation and Isotopes Centre – Khartoum (RICK)
brachytherapy was introduced in 1989 using manual afterloading low dose rate
137Cs for treatment of carcinoma of the cervix, but for safety reasons now it
replace by high dose rate 192Ir afterloading system (HDR) with remotely
controlled device to deliver controlled radiation dose for treatment of
carcinoma of cervix, esophagus and nasopharynx.
This study was carried out in high dose rate 192Ir afterloading brachytherapy
equipment (Gamma Med 12i unit) located at RICK to evaluate the performance
and to perform comprehensive quality control of the treatment unit with respect
to three poles: safety systems, physical parameters and calibration of Ir-192
source through some quality control checks, so as to ensure that the equipment
meets the safety standard.
The study shows that all the safety systems which include the mechanical
checks are work properly; the average of the dose rate measured at different
positions from the treatment unit which represent the leakage radiation by using
RDS- 120 universal survey meter is less than10μSv/h.
The physical parameters which include the check of a source position accuracy
by using X-OMAT ready pack film and catheter guide tube is 1mm. The source
strength that was obtained from the calibration procedures following the
IAEA-TEC DOC 1274 protocol by using HDR 1000 plus well type ionization
chamber is different from the value of International Standard Laboratory by
1.5%.It was found that the brachytherapy equipment and the source used in
iv
brachytherapy meets the user's requirements except some necessary
requirements, so some recommendations was putted include these requirements
