Assessment of Measured and Calculated Dose Rate of Co-60 Teletherapy Machine: 06 Years’ Experience at NORIN Nawabshah, Pakistan

It is essential to determine the absolute output dose of Co-60 source in the radiation treatment periodically. It is because overdosage may cause radiation hazards whereas under dosage may lead to the unsatisfactory treatment of cancer. The current study is focused on the consistency of monthly dose output verification of the cobalt-60 Teletherapy unit which should be within ±2% as per international standards. In the present study, the measured and calculated dose rate of the Co-60 teletherapy unit at Nuclear Medicine Oncology and Radiotherapy Institute Nawabshah (NORIN) for the last 6 years is analyzed. The dose measurement was done in water phantom 30×30×30 cm3 at 80 cm Source to Surface Distance with 5cm depth by using calibrated electrometer and PTW ionization chamber. The measured output dose rate obtained by actual dosimetry is within ±2% of the dose rate calculated by the decay method and the deviation lies within the permissible limit as prescribed by International Atomic Energy Agency (IAEA), International Commission on Radiological Units and Measurement (ICRUM)and American Association of Physicists in Medicine (AAPM). The variation in measurements obtained is within the tolerable limits according to standard protocols and codes. Thus, our study shows a homogenous trend in the dose rate of the Co-60 teletherapy machine

Absorbed Dose Calculation In Irregular Blocked Radiation Fields: Evaluation of Clarkson’s Sector Integration Method for Radiation Fields Commonly Used in Conventional Radiotherapy

Introduction: Irregular/blocked fields are routinely used in radiotherapy. The doses of these fields are usually calculated by means of equivalent square method that is inherently prone to uncertainty. On the other hand, Clarkson’s sector integration method is a dose calculation method which offers far better accuracy in dose calculation of irregular fields. The Scatter Air Ratio (SAR) of an individual sector, in which whole field has been divided, is calculated and averaged over all sectors to find total SAR for the whole field. Percentage depth dose (PDD) and tissue-maximum ratio (TMR) for irregularly shaped beams can be calculated by the SAR values using the standard relationships of these measurement quantities. Material and Methods: The present study was conducted on 40 actual patient treatment fields. The PDD values for depths up to 15 cm were calculated using both Clarkson’s sector integration method and conventional methods, and their results were compared with the measured PDDs for all patients. Results: Maximum deviation for Clarkson’s calculation was under 2.7% for any field size, shape, and depth. However for conventional methods, this value exceeded ±5.5% for some field shapes, specifically at larger depths. Conclusion: Better results of sector integration are more prominent for field shapes with a large field size and a shielded area of regular shape. For the treatment fields with a very large degree of approximation for assessing reduced field size, Clarkson’s method is the most accurate technique for the calculation of absorbed dose

Incidence of Colorectal Carcinoma in the Remote Area of Sindh, Pakistan

Background: Colorectal carcinoma (CRC) is the third most common cancer in the world that show malignant growth in the colon, rectum, and or appendix. CRC is the second most common malignancy in females and third in males. This study aimed to ascertain the incidence of colorectal carcinoma (CRC) in a population in a remote area of Sindh, Pakistan, and also compared and correlated the sociodemographic characteristics and different parameters such as diagnosis, grade, and histopathology of the CRC cases.Methods: The study was conducted from February 2012 to 2019 at Pakistan Atomic Energy Cancer Hospital (NORIN) Nawabshah Sindh, Pakistan. All cases were evaluated through a detailed history, clinical examination, radiological examination, and histopathology-proven cases. The sociodemographic parameters, diagnosis grades, and histopathology of the CRC were statistically compared and correlated by SPSS version 21.Results: Out of a total of 10,848 reported patients, 424 (3.9%) were of CRC. The CRC was further comprised of 63.9% males and 36.1% females. We classified our patients into two age groups, ≤ 40 years (Group-A), and > 40 years (Group B). Group-A comprised 41% of patients, and their mean age was 28±6.98 years, while Group B comprised 59% of patients with a mean age of 43±8.3 years. Histological specimens divulged that most of the common specimens were of adenocarcinoma. Early diagnosis was very strenuous due to no signs and symptoms. Thus, the majority of the patients, approximately 39%, were found to be of grade 2 carcinoma.Conclusion: Our study unveils an increased number of patients with CDC at an age of <40 belonging to rural areas. Further studies are needed to elucidate the cause of this high incidence with a particular focus on genetic and molecular risk factors.Keywords: Active lifestyle, Colorectal Carcinoma; Age group; Colorectal Adenocarcinoma

Evaluation of Radiation Workers Occupational Doses for Newly Established Medical Center NORIN Nawabshah in Pakistan

AbstractThe purpose of this study is the evaluation of radiation doses received by radiation personnel in newly established medical Centre, Nuclear Medicine Oncology and Radiotherapy Institute Nawabshah (NORIN) Pakistan. In this study the annual dose data of workers for the year 2013 and 2014 in different sections will be analyzed using different statistical methods and results. It will be discussed that how we careful in occupational radiation dose and comparison with national and international organization will be done to know that the facility in NORIN for radiation protection is reasonable and satisfactory