ABSTRACT
OBJECTIVE: The goal of the Radiation standards and Dosimetry is to ensure that the output of the Teletherapy Unit is within ±2% of the stated one and the output of the treatment dose calculation methods are within ±5%. In the present paper, we studied the dosimetry of Cobalt-60 (Co-60) Teletherapy unit at Sher-I-Kashmir Institute of Medical Sciences (SKIMS) for last 10 years. Radioactivity is the phenomenon of disintegration of unstable nuclides called radionuclides. Among these radionuclides, Cobalt-60, incorporated in Telecobalt Unit, is commonly used in therapeutic treatment of cancer. Cobalt-60 being unstable decays continuously into Ni-60 with half life of 5.27 years thereby resulting in the decrease in its activity, hence dose rate (output). It is, therefore, mandatory to measure the dose rate of the Cobalt-60 source regularly so that the patient receives the same dose every time as prescribed by the radiation oncologist. The under dosage may lead to unsatisfactory treatment of cancer and over dosage may cause radiation hazards. Our study emphasizes the consistency between actual output and output obtained using decay method. METHODOLOGY: The methodology involved in the present study is the calculations of actual dose rate of Co-60 Teletherapy Unit by two techniques i.e. Source to Surface Distance (SSD) and Source to Axis Distance (SAD), used for the External Beam Radiotherapy, of various cancers, using the standard methods. Thereby, a year wise comparison has been made between average actual dosimetric output (dose rate) and the average expected output values (obtained by using decay method for Co-60.). RESULTS: The present study shows that there is a consistency in the average output (dose rate) obtained by the actual dosimetry values and the expected output values obtained using decay method. The values obtained by actual dosimetry are within ±2% of the expected values. CONCLUSION: The results thus obtained in a year wise comparison of average output by actual dosimetry done regularly as a part of Quality Assurance of the Telecobalt Radiotherapy Unit and its deviation from the expected output data is within the permissible limits. Thus our study shows a trend towards uniformity and a better dose delivery.
ABSTRACT
BACKGROUND/OBJECTIVE: Esophageal cancer has a peculiar geographical distribution and shows marked differences in incidence within a particular geographical region. Presently, as there seems little prospect of early detection of this cancer, an understanding of the etiological factors may suggest opportunities for its primary prevention. In this paper, we have tried to determine the role of diet and other life-style related factors in the etiology of cancer of esophagus. MATERIAL AND METHODS: A total of 100 confirmed squamous cell carcinoma of esophagus patients were enrolled for the study (Group A). 100 healthy subjects were included as controls (Group B). A predesigned questionnaire dealing with the basic patient data, dietary and smoking habits etc. was distributed among the cases in both groups. The data was thoroughly analyzed to define an association with the development of cancer of esophagus. RESULTS: Group A patients included 71 males and 29 females in the age range of 40-70 years. Majority 37% were farmers, 29% house wives. Of the 72% smokers, 66% smoked hookah. 29% had positive family history. More than 90% took salt-tea at breakfast. Meat consumption was low, 44% took it weekly and 42% on monthly basis. 69% took fish yearly. Group B included 75 males and 25 females of which 35.7% were hookah smokers. CONCLUSION: Poor socio-economic status resulting in fewer intakes of fresh fruits, vegetables and fish in addition to heavy hookah smoking are suspected to be the major risk factors for the development of esophageal cancer.
