Evaluation of Entrance and Exit Doses in Tangential Fields in Breast Cancer Treatment .SAD and SSD Techniques

Abstract

The carcinoma of the Breast is a common disease in Sudan , about 51.5% of 10 common cases ,195 out of 379 cases during 2008 in National Cancer Institute-Madani-Sudan .Appendix-A(1), For radical treatment the external beam therapy is common , given via two tangential fields cover the area of the breast , chest wall and parasternal lymph nodes by a dose around 5000 cGy in 25 fractions , 5 fractions per week . This study conducted at the National Cancer Institute in the period from July 2009 to December 2009. The main objective of this study is to evaluate the sum of entrance and exit doses of tangential fields in Breast cancer for SAD and SSD techniques to find out the differences whether it is within the acceptable limits or not . The radiation dose was measured and evaluated during the planning course using the THERAPLANPLUS .The data analysis by using Statistical Package for Social Studies and from Appendix (4.1) the correlation is 0.972 , is significant .And by using t-test the value : (P-value = 0.000 < 0.05) Indicate that there is difference between two variables so from Appendix(4.1) and other Appendices, there is difference between the two variables .The last results reveal that the dose increase by increasing separation in case of SAD , and the skin dose is higher in case of SAD than in SSD .