Research Papers/Topics in Medical Physics

Quality Control Programme On Mammography Systems In The Republic Of Benin: Assessment Of Patients Dose Optimisation In Three Selected Facilities.

ABSTRACT The Mean Glandular Dose (MGD) was estimated first using Polymethylmethacrylate (PMMA) slabs and secondly MGD was estimated per right craniocaudal (RCC) projection view and left craniocaudal (LCC) projection view. A number of 21 patients out of a total of 28 patients, undergoing breast examination in three (3) selected mammography facilities in the Republic of Benin were involved. Image quality was evaluated based on subjective analysis of images with Leeds Tests Objects...

Peak Skin Dose Estimation in Adult Examinations For Selected Multi Detector Computed Tomography: An Approach For Patient Dose Optimization

ABSTRACT Computed Tomography (CT) is a valuable tool among diagnostic imaging modalities. However, the increase in its utilization has resulted to a considerable increase in its contribution to the collective dose from medical exposure. The main aim of this study was to propose a patient dose optimization method from exposure parameters that would estimate the peak skin doses (PSDs) to patients undergoing chest CT and abdomen CT examinations. PSDs were estimated on the surface of a Pers...

Assessment of The Effect of Beam Modifiers on Skin Dose For External Beam Radiotherapy Using Gafchromic EBT2 Films

ABSTRACT In radiotherapy, a patient may present irregular surface contour at the point of beam entry and this coupled with tissue heterogeneities within the irradiated region would pose problems for dose optimization if beam modifiers are not used. Skin dose is of great concern in external beam radiotherapy with megavoltage beam as the skin is very radiosensitive, and there is the need to minimize the radiation dose received by the skin. The use of beam modifiers affects the skin do...

Quality Control Programme On Mammography Systems In The Republic Of Benin: Assessment Of Patients Dose Optimisation In Three Selected Facilities

ABSTRACT The Mean Glandular Dose (MGD) was estimated first using Polymethylmethacrylate (PMMA) slabs and secondly MGD was estimated per right craniocaudal (RCC) projection view and left craniocaudal (LCC) projection view. A number of 21 patients out of a total of 28 patients, undergoing breast examination in three (3) selected mammography facilities in the Republic of Benin were involved. Image quality was evaluated based on subjective analysis of images with Leeds Tests Objects...

Ultrasound And Pet-Ct Image Fusion For Prostate Brachytherapy Image Guidance

ABSTRACTFusion of medical images between different cross-sectional modalities is widely used, mostly where functional images are fused with anatomical data. Ultrasound has for some time now been the standard imaging technique used for treatment planning of prostate cancer cases. While this approach is laudable and has yielded some positive results, latest developments have been the integration of images from ultrasound and other modalities such as PET-CT to compliment missing properties of ul...

Validation of Calculated Tissue Maximum Ratio (TMR) Obtained from Measured Percentage Depth Dose (PPD) Data for High Energy Photon Beam (6 MV and 15 MV)

ABSTRACT During 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 treatment. This leads to the consideration of treatment parameters such as percentage depth dose (PDD), tissue air ratio (TAR) and tissue phantom ratio (TPR), which show the dose distribution in the patient. Nevertheless, tissue air ratio (TAR) for treatment time calculation, calls for the need...

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 1...

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...

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 var...

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 dosi...

Modeled Risk Of Radiation Induced Cancers After Prostate Cancer Radiation Treatment

ABSTRACTThis 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 localis...

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

ABSTRACTThe 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 patie...

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

ABSTRACTFor 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 int...

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

ABSTRACTIbuprofen, 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- distill...

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 o...


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