Evaluation of dose received by critical organs in radical external cervical cancer irradiation

Abstract

The main objective of this study was to evaluate the dose received by the bladder and rectum in patient with cervical cancer treaded by radical external irradiation via four fields (box technique); in order to estimate the doses at these critical organs using body characteristics and the radiation parameters in the future. The study was conducted at Radiation and Isotopes Centre in Khartoum in the period from December 2011 to October 2012. The data were collected from 50 patients with Ca cervix treated by Co-60 machine. The location and depths of the cervix, bladder and rectum were measured using from the patient CT images. The doses (rectum and bladder) were calculated using central dose calculation method “according to RICK” for anterior and posterior field, and Day’s method for the lateral fields. The result of this study showed that the average dose received by the bladder and rectum was 5603.5±471.4 and 6774±566.5 respectively. As well the dose received by the bladder directly related to the AP and lateral separation with a coefficients of 33.4cGy/cm and 50.7cGy/cm. Similarly the rectum also showed a direct linear relationship with coefficients of 29.9cGy/cm and 72.4cGy/cm.