https://repository.auw.edu.bd/handle/123456789/739 2026-06-10T01:01:56Z 2026-06-10T01:01:56Z Meaze, AKM Moinul Haque https://repository.auw.edu.bd/handle/123456789/922 2026-02-18T06:15:02Z 2019-01-01T00:00:00Z

Measurements of Entrance Surface Dose and Effective Dose of Patients in Diagnostic Radiography Meaze, AKM Moinul Haque In radiography, a dose to patients primarily depends on the Entrance Surface Dose (ESD) and the sensitivity of organs which are irradiated during treatment plan. The main goal of this study is to look into the patient’s dose to assess ESD and ED for patients in digital diagnostic radiography examinations for the optimization of radiation protection of the patients who are exposed to radiation dose thereby facing the increasing probability of fatal cancer risk and other biological effects. Patients dosimetry carried out on 15 adult patients (Male-4 and Female-11) of age 20 to 69 years. The IAEA TRS No. 457 dosimetry protocol was followed in accordance with non-invasive kV-meter, DIAVOLT UNIVERSAL T43014-001400, locating at 100 cm from focus to surface distance for measurement of radiological parameters such as kVp and mAs. The ESD has a wide range from 0.05mGy to 0.35 mGy for chest even for the same examination carried out on the patients of different age and gender and the corresponding effective dose lies from 0.01 to 0.04 mSv, additionally, in other parts like L-spine AP, Lat and in foot ESDs are 1.24 mGy, 2.06 mGy and 0.07 mGy respectively with their corresponding EDs are 0.13 mSv, 0.05 mSv and 0.0003 mSv. The ESDs and EDs reported in this study are generally lower than the doses published in literatures.

2019-01-01T00:00:00Z Meaze, Akm Moinul Haque https://repository.auw.edu.bd/handle/123456789/921 2026-02-18T06:14:55Z 2019-01-01T00:00:00Z

Effective Point of Measurement (EPOM) of Some Ionization Chambers for High Energy Photon Beam Dosimetry used in Radiotherapy for the Treatment of Cancer Patient Meaze, Akm Moinul Haque The volumetric effect occupied by the air cavity for the dosimetry of high energy photon beam is impossible to ignore using standard ionization chambers. Hence, the dose measurement should be corrected with a displacement perturbation correction factor (Pdis) or using an Effective Point of Measurement (EPOM). The aim of this study was to calculate the EPOM of some ionization chambers and evaluation of the shift of EPOM that recommended by various international protocols under both reference and non-reference condition. The work was performed with Percentage Depth Dose (PDD) curves by placing chambers (PTW 30013, FC 65G and Semiflex 31010) at the geometrical centers for field size(s) of 5cm × 5cm to 30cm × 30cm at 100cm Source to Surface Distance (SSD) for photon energy 6, 10 and 15MV respectively. The shift of the cylindrical chambers also estimated from PDD values in comparison with reference PDD values by Parallel Plate Chamber (PPC 40 and Murkus 23343) of 100%, 80% and 50% depth in the water. The present study shows that the effective shift is not only varies with chamber materials but also with photon energy. On the other hand the periodical calibration factor of some ionization chambers at standard procedures were compared with manufacturer values also varies with time which is an important issues for the precisional dosimetry in radiotherapy. The details of the EPOM and chamber calibration factor is discussed.

2019-01-01T00:00:00Z