Use CT Images To Assess The Adequacy Of Common Iliac Lymph Node Coverage Of Conventional Pelvic Fields Based On Bony Landmarks In The Radiotherapy Of Cervical Carcinoma

Purpose:To assess the adequacy of common iliac lymph node coverage of conventional pelvic radiation fields for the treatment of cervical carcinoma,using computed tomography(CT)images.Methods and Material:Pretreatment CT images of 58 patients with cervical carcinoma and 816 normal populations of women were evaluated to locate the aortic bifurcation and the subsequent common iliac lymph drainage.Anatomy of the lymph drain was correlated with conventional pelvic portals.Results:In 40/58 patients(69.0%)the aortic bifurcation lay superior to the upper portal border(L4/L5 vertebral disc).In additional ten patients(17.2%)the aortic bifurcation was located on the level of the upper border.Conventional pelvic fields could not compass the common iliac lymph node sufficiently in 86.2% patients.If the superior border extended to L3/L4 vertebral disc,the aortic bifurcation could be included in the fields in 91.5%(747/816)normal populations.Conelusions:Conventional pelvic fields based on bony landmarks do not provided satisfactory common iliac lymph node coverage in a substantial proportion of patients with cervical carcinoma.The superior border of pelvic fields should extend to L3/L4 vertebral disc in conventional radiotherapy.