Delineation of target volume in intensity-modulated radiotherapy for para-aortic lymph node metastases in patients with gynecological malignancies / 中华放射肿瘤学杂志

ABSTRACT

Objective To preliminarily explore the delineation of clinical target volume in intensity-modulated radiotherapy for para-aortic lymph node metastases in patients with gynecological malignancies.Methods A retrospective analysis was performed on 56 gynecological tumor patients with para-aortic lymph node metastases who were admitted to our department from January 2010 to September 2016.The number and distribution of metastatic para-aortic lymph nodes were determined by imaging method.Results A total of 108 positive para-aortic lymph nodes were found in the 56 patients,with 1-4(mean,2) positive para-aortic lymph nodes per patient.The mean diameter of positive para-aortic lymph nodes was 2.3 cm (1.2-4.0 cm).A total of 20 metastatic lymph nodes (19%) were located at the L4 level,38(35%) at the L3 level,44(41%) at the L2 level,and 6(5%) at the L1 level.There were 71 metastatic lymph nodes (66%) at the left side of the para-aortic region,20 metastatic lymph nodes (19%) between the abdominal aorta and the vena cava,and 17 metastatic lymph nodes (15%) at the right side of the inferior vena cava.Conclusions For patients with gynecological malignancies,nodal contouring for the para-aortic region should not be defined by a fixed circumferential margin around the vessels.The left side of the para-aortic region should be covered adequately;the upper target should be extended up to the renal artery,and needs to be further extended for patients who have nodal involvement near the renal arteries and veins.