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Buzdar S.A.,University College London | Buzdar S.A.,Islamia University of Bahawalpur | Afzal M.,Islamia University of Bahawalpur | Nazir A.,Islamia University of Bahawalpur | Gadhi M.A.,Bahawalpur Institute of Nuclear Medicine and Oncology BINO
Journal of the College of Physicians and Surgeons Pakistan | Year: 2013

Radiation therapy attempts to deliver ionizing radiation to the tumour and can improve the survival chances and/or quality of life of patients. There are chances of errors and uncertainties in the entire process of radiotherapy that may affect the accuracy and precision of treatment management and decrease degree of conformation. All expected inaccuracies, like radiation dose determination, volume calculation, complete evaluation of the full extent of the tumour, biological behaviour of specific tumour types, organ motion during radiotherapy, imaging, biological/molecular uncertainties, sub-clinical diseases, microscopic spread of the disease, uncertainty in normal tissue responses and radiation morbidity need sound appreciation. Conformity can be increased by reduction of such inaccuracies. With the yearly increase in computing speed and advancement in other technologies the future will provide the opportunity to optimize a greater number of variables and reduce the errors in the treatment planning process. In multi-disciplined task of radiotherapy, efforts are needed to overcome the errors and uncertainty, not only by the physicists but also by radiologists, pathologists and oncologists to reduce molecular and biological uncertainties. The radiation therapy physics is advancing towards an optimal goal that is definitely to improve accuracy where necessary and to reduce uncertainty where possible.

Ismail M.,Islamia University of Bahawalpur | Afzal M.,Islamia University of Bahawalpur | Nadeem M.,Bahawalpur Institute of Nuclear Medicine and Oncology BINO | Rana A.M.,Bahauddin Zakariya University | And 2 more authors.
Iranian Journal of Radiation Research | Year: 2011

Background: Radiotherapy Treatment Planning requires different dosimetric quantities as input in order to calculate a desired dose distribution. This study has been focused to evaluate the depth dose characteristics of superficial X-rays being used for radiotherapy treatment. Materials and Methods: Computerized 3-D water phantom of multi-data system was used. The measurements were made through PTW (Physikalirsch-Technische Werkstalten) farmer type NT-30006 waterproof ionization chamber of 0.6cc, and PTW electrometer for digital dose rate reading in Gy/min using five different diameter applicators and filters at five different values of accelerating potentials (kVps). Results: The dose rate at various kVp X-ray beams was observed to decrease significantly with increasing depth in water phantom for all applicator diameters from 98% (at 0.1cm depth) down to 43% (at 2cm i.e. reference condition). The dose rate increases by increasing the value of kVp with a maximum at 150 kVp (1.6 and 0.93 Gy/ min for respective applicator diameters 2.5cm and 10cm). Applicator with 2.5cm diameter demonstrates better dose rate at 85kVp at different depths. PDD decreases lower than 50% for all combination of applicators and kVps at/or above 2cm depth so these measurements should not be considered for treatment planning. Conclusion: Higher energy X-rays are suggested to be used for applicators of higher diameters and smaller energy X-rays for applicators having smaller diameters.

Gadhi M.A.,Bahawalpur Institute of Nuclear Medicine and Oncology BINO | Gadhi M.A.,Islamia University of Bahawalpur | Fatmi S.,Bahawalpur Institute of Nuclear Medicine and Oncology BINO | Chughtai G.M.,Philadelphia | And 5 more authors.
Australasian Physical and Engineering Sciences in Medicine | Year: 2016

The objective of this work was to enhance the quality and safety of dose delivery in the practice of radiation oncology. To achieve this goal, the absorbed dose verification program was initiated by using the diode in vivo dosimetry (IVD) system (for entrance and exit). This practice was implemented at BINO, Bahawalpur, Pakistan. Diodes were calibrated for making absorbed dose measurements. Various correction factors (SSD, dose non-linearity, field size, angle of incidence, and wedge) were determined for diode IVD system. The measurements were performed in phantom in order to validate the IVD procedure. One hundred and nineteen patients were monitored and 995 measurements were performed. For phantom, the percentage difference between measured and calculated dose for entrance setting remained within ±2 % and for exit setting ±3 %. For patient measurements, the percentage difference between measured and calculated dose remained within ±5 % for entrance/open fields and ±7 % for exit/wedge/oblique fields. One hundred and nineteen patients and 995 fields have been monitored during the period of 6 months. The analysis of all available measurements gave a mean percent deviation of ±1.19 % and standard deviation of ±2.87 %. Larger variations have been noticed in oblique, wedge and exit measurements. This investigation revealed that clinical dosimetry using diodes is simple, provides immediate results and is a useful quality assurance tool for dose delivery. It has enhanced the quality of radiation dose delivery and increased/improved the reliability of the radiation therapy practice in BINO. © 2016 Australasian College of Physical Scientists and Engineers in Medicine

Akhtar M.S.,Bahawalpur Institute of Nuclear Medicine and Oncology BINO | Kousar F.,Center for Nuclear Medicine | Masood M.,Institute of Nuclear Medicine and Oncology INMOL | Fatimi S.,Bahawalpur Institute of Nuclear Medicine and Oncology BINO | Kokab,Bahawalpur Institute of Nuclear Medicine and Oncology BINO
Journal of the College of Physicians and Surgeons Pakistan | Year: 2010

Objective: To compare the results of patients with locally advanced breast cancer receiving two different regimens Fluorouracil, Doxorubicin and Cyclophosphamide (FAC) and Paclitaxel and Carboplatin. Study Design: Comparative study. Place and Duration of Study: The Oncology Department, Institute of Nuclear Medicine and Oncology (INMOL), Lahore, from March 2007 to September 2008. Methodology: Patients with inoperable locally advanced breast cancer of stage were included. Sixteen patients were given FAC regimen and 9 patients were given Paclitaxel and Carboplatin, each combination was cycled after 21 days for four times. Before enrollment, detailed medical histories, physical examinations and performance status assessments were done as well as postchemotherapy evaluation with regular follow-up visits was done. Complete Response (CR, ↓100%) is defined as the disappearance of all known disease parameter i.e. disappearance in detectable tumour size, node free disease and surgery is possible. Paratial Response (PR, ↓ > 50%) was defined by 50% or greater decrease in the sum of the areas of bidimensionally measured lesions i.e. change of N2 to N1 or no status and some surgical procedure is possible to downstage the disease. Minor Response (MR) was defined as a decrease in the tumour insuffieceint to quality for partial responce. Static disease or no evaluable reflected no significant change in disease and no evidence of new disease. Progression of disease (> 25%) was defined as a 25% or greater increase in the area of any lesion > 2 cm or in the sum of the products of the individual lesions or the apprearance of new malignant lesions, surgery not possible. Results: Twenty five patients completed neoadjuvant chemotherapy. Sixteen (66%) patients received FAC and 9 (37%) patients received PC chemotherapy. Overall CR (breast and axilla) was 54%, PR was 16% and minor response (MR) was 8%. FAC treatment induced more emesis, mucositis, alopecia and cardiotoxicity. No death occurred. Conclusion: The Paclitaxel and Carboplatin regimen was better tolerated; both regimens were effective in improving disease and overall survival. © 2010. College of Physicians & Surgeons Pakistan.

Gadhi M.A.,Bahawalpur Institute of Nuclear Medicine and Oncology BINO | Buzdar S.A.,Islamia University of Bahawalpur | Afzal M.,Islamia University of Bahawalpur | Fatmi S.,Bahawalpur Institute of Nuclear Medicine and Oncology BINO | And 2 more authors.
International Journal of Radiation Research | Year: 2013

Background: The effectiveness and safety of brachytherapy treatment is mainly concerned with the calibration of sources and their traceability to internationally accepted Standards. Secondary Standard Dosimetry Laboratory (SSDL) does not offer calibration of ionization chambers with gamma-ray spectrum of high dose rate source 192Ir. This work has been carried out to calibrate the high dose rate (HDR) 192Ir sources. Materials and Methods: An interpolation procedure, using calibrations above 1.25 MeV (60Co), and below 135 kV X-rays (61.1 keV), the exposure-weighted average energy 397 keV of 192Ir is employed. Using Farmer ionization chamber HDR 192Ir source has been calibrated by free in-air measurement technique and then the calibrated source has been used to calibrate well-type ionization chamber. Results: Difference between in-air measurement and that of manufacturer's remained within ± 3%, and the difference between in-air measurement and well-type chamber remained within ± 1%. Comparison between well-type measurements and manufacturer values shows differences less than ± 2%. All these differences are within the acceptable tolerance limits. Conclusion: The method presented shows good degree of accuracy so that the traceability of calibration is assured. Installation of a new brachytherapy source needs to be calibrated by in-air measurement technique and then this calibrated source should be used for well chamber calibration. Brachytherapy community is suggested to calibrate their sources with this method.

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