RT3_OA_Himanshu 1

Background: Concurrent Chemotherapy and Radiotherapy (RT) is considered as standard of care in advanced carcinoma cervix. The superior border of radiation portal is kept at L4-L5 junction to cover common iliac group of lymph nodes which lie along common iliac vessels. Methods: Level of aortic bifurcation in to two common iliacs was retrospectively evaluated in 90 patients of carcinoma cervix to reconsider the level of superior border of radiation portal while RT planning. Evaluation was done on contrast enhanced computed tomography (CT) simulation images of the patients who were previously treated with radical intent. Results: We found that aortic bifurcation occured mostly at mid vertebral level of L4 and it was above L4-L5 junction in 74.4% of the cases. Conclusion: With conventional simulator based RT planning the superior border of radiation Portal should be kept above mid-vertebral level of L4 while with CTsimulator based planning, it should be placed considering individual patient anatomy.