Medical Physics Research Papers/Topics

Evaluation Of Doses Delivered During Ct Examinations By Different Scanners For Purposes Of Intercomparison And Dose Optimization.

ABSTRACT This research study was aimed at performing dosimetry intercomparison on different CT scanners in the diagnostic radiology departments of Korle-Bu Teaching Hospital (KBTH), Sweden Ghana Medical Center (SGMC) and Global Medical and Imaging Center (GMIC).Using the standard body phantom and integrated ion chamber technique volume computed tomography dose index (CTDIvol) and Dose-Length Product (DLPs) within the phantom were evaluated. The ion chamber technique was applied to two 16 slic...

Modelling Radiation Doses to Critical Organs of Patients Undergoing Intracavitary Brachytherapy Treatment at Komfo ANOKYE Teaching Hospital

ABSTRACT  The main aim of radiotherapy is to destroy cancerous tissues with ionizing radiation while the other normal parts of the body are saved or spared. Intracavitary brachytherapy is a procedure in which radioactive sources are placed in the body cavities close to or inside the target volume to deliver radiation at short distances. In this mode of treatment, high radiation dose can be delivered to the tumour volume with rapid dose fall-off into the surrounding normal tissues. In brachyt...

Dependence Of Teletherapy Timer Error On Treatment Parameters In External Beam Radiotheraphy (EBRT) Using The Theratron Equinox 100 Cobalt 60 Machine

ABSTRACT The purpose of this research work is to evaluate the variation (or dependence) of the timer error as a function of the teletherapy treatment parameters such as treatment field size (FS) and treatment depth (d) for a SSD setup and compare the method used for others. Teletherapy timer error measurements were performed in a full scatter, large water phantom using a 0.6cc ionization chamber and an average photon energy of 1.25MeV from a cobalt-60 unit at an SSD of 100cm at various field...

Inter-Institutional Dosimetric Comparison For Radiotherapy Centres In Ghana Using Cirs Thorax Phantom..

ABSTRACT Quality assurance (QA) in all aspects of radiotherapy reduces the number of instances of accidental dose misadministration. Reduction of such errors and uncertainties plays an important role in the outcome of radiotherapy. As part of the audit supported by the IAEA in Ghana this study was designed to review the whole chain of activities in 3D conformal radiotherapy (3D-CRT) workflow, from patient data acquisition to treatment planning and dose delivery.The study focused on dosimetry ...

Modeled Risk Of Radiation Induced Cancers After Prostate Cancer Radiation Treatment

ABSTRACT This study investigates into the second cancer risks to the bladder and rectum during Three-Dimensional Conformal Radiotherapy Treatment (3D-CRT) of prostate cancer compared to the baseline cancer risks in literature. The risk of induced-radiation cancer related with radiation treatment for patients with prostate cancer is of great importance in clinical radiation oncology. Therefore, the dose response relationship to predict radiation-induced secondary cancers was modeled for locali...

Patient Radiation Dose Assessment During Fluoroscopic Procedures: A Survey To Propose Local Diagnostic Reference Levels For Selected Facilities

ABSTRACT The primary aim of this work was to propose local diagnostic reference levels for fluoroscopic examinations in some selected radiological imaging facilities in Ghana. The work also aimed at investigating the distribution levels of patient radiation dose received during fluoroscopic examinations for subsequent improvement of optimization. Prior to the starting of this research a series of quality control tests were performed using the Piranha kit to assess the machine output. The pati...

A Study To Compare The Motorised Wedge Output Factor Of An Elekta Synergy Linear Accelerator With Reference Data (Tps Data).

ABSTRACT For external beam radiotherapy treatments, high doses are delivered to the cancerous cell. Accuracy and precision of dose delivery are primary requirements for effective and efficient cancer treatment. The dose delivered to the patient might not be uniform and therefore need to be compensated for. In treatment these inhomogeneities are taken care of by using wedge filters and incorporating wedge factors in the Treatment Planning System. Computer controlled wedges were alternatives in...

Anti-Ulcerative Effect Of Aqueous Extract Of Cucumis Melo On Non-Steroidal Anti-Inflammatory Drugs (Nsaids) Induced Gastric Ulceration In Male Wistar Rats

ABSTRACT Ibuprofen, a strong analgesic and an anti-inflammatory drug used over a long period caused side effects such as peptic ulcer and constipation. Honeydew melon has been shown to possess anti-secretory, antiulcer and angiogenic. Hence, this study investigated the anti-ulcer effect of aqueous extract of honeydew melon on ibuprofen induced gastric ulcer in male Wistar rats. Wistar rats (n=35,150-200g) were randomly divided into seven groups. They were treated as follows; I (control- disti...

Evaluation of Surface Doses And Effect of Air Gaps Under Bolus During External Photon Beam Radiotherapy

ABSTRACT This study was performed to evaluate surface doses and the effect of air gaps under bolus on surface dose during external beam radiotherapy for photon beam energies of 6 MV and 15 MV. Surface doses were measured by using calibrated GafChromic EBT3 films and the Roos chamber for various bolus-to-surface distances (including no bolus and bolus placed directly on the RW3 phantom surface) and various field sizes. Dose verification was also done for beam energies of 6 MV and 15 MV on the...

Assessment And Evaluation OF Photon Beam Dosimetric Accuracy Requirement of Tuning Medical Linear Accelerator

ABSTRACT In radiotherapy, accuracy and precision are key, and thus, a small deviation in dose delivered by a treatment machine can be detrimental to patients. For this reason, in any radiotherapy department, linacs that have been tuned to match each other dosimetrically require critical assessment and evaluation since patients may be moved between linacs without any adjustments to treatment plans. The main aim of this study was to assess and evaluate the photon beam dosimetric accuracy betwe...

Develpoment Of Calculation Approach For The Determination Of Central Axis Depth Doses In Water For Cobalt 60 Beam.

ABSTRACT Radiotherapy is a complicated procedure with several steps, and these procedures have a great influence on the treatment outcome. Exact determination of dosimetric functions that are used to calculate dose within a patient undergoing external beam radiotherapy to realize the intent of treatment is very crucial for any radiotherapy treatment technique. One of the dosimetric functions, which is of great importance, is central axis percentage depth dose, which are usually measured with ...

Design and Construction of Heterogeneity Phantom for Comparison of Dose Calculation Algorithms of Treatment Planning Systems

ABSTRACT  Verification of the output of a treatment planning system (TPS) is considered to be part of quality assurance (QA) requirement for the TPS and need to be performed during commissioning and annually, but this is not given the needed priority due to non availability of appropriate phantoms to facilitate the process. Phantoms with heterogeneities that can simulate clinical situations are needed to assess the performance of TPSs. This research work sought to design and construct such a...

EVALUATION AND VALIDATION OF COMPUTED TOMOGRAPHY DOSE ACCURACY (CTDIw AND CTDIvol)

ABSTRACT Weighted and average dose within a scan volume of a phantom have been evaluated and validated using two different devices and techniques. The Barracuda electrometer and Ion Chamber techniques were applied on a 16 slice Siemens CT scanner and the results compared to the console displayed CTDIw and CTDIvol valuesfor accuracy and compared to each other for validation purposes. With fixed exposure parameter of 130kVp and varying tube current-time products from 140mAs to 300mAs for the ...

Assessment Of Diagnostic Radiography Practice In South Of Benin: Application Of Quality Control Procedures And Estimation Of Patient Entrance Surface Dose

ABSTRACT The use of X-ray equipment in diagnostic radiography increases with demographic growth of population and Benin is not an exception. Achieving good quality image while keeping workers, public and patient exposure to ionizing radiation at an acceptable level has become a prerequisite for radiology department in their effort to comply with radiation protection principle of optimization. The present research work undertook quality control measurement of seven diagnostic radiography equip...

Heat Transfer Analysis of A Proposed Fuel Assembly For Supercritical Water Reactors Under Star CCM + CFD Code

ABSTRACT Accurate knowledge and understanding of heat transfer characteristics near and above critical conditions is crucial to the successful design of the SCWR. Many studies, both numerical and experimental assessments have been conducted on bare tubes and simple geometries like annuli. However, heat transfer performance studies of the fuel assemblies for SCWR are scarce. Thus, there is still a lack of understanding of heat transfer performance in the fuel assembly designs for SCWR. Moreov...


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