Y. Ota

Impact of Nodal Metastatic Volume on Distant Metastasis in Patients with Cervical Cancer and Para-aortic Nodal Metastases Treated With Definitive Radiation Therapy

To report institutional outcomes following definitive radiation therapy (RT) for cervical cancer with para-aortic lymph node (PAN) metastasis and explore the risk factors for subsequent distant metastasis (DM) and the optimal elective radiation field. Ninety-seven patients treated between 2011 and 2023 were evaluated. The median patient age was 60 (range, 29-86) years. The numbers of patients with International Federation of Gynecology and Obstetrics (FIGO) 2008 stages I, II, III, and IVA were 6 (6%), 32 (33%), 43 (44%), and 16 (16%), respectively. Eighty-two patients had squamous cell carcinoma. The median gross tumor volumes of primary (GTVp) and nodal metastasis (GTVn) were 110.4 (range, 20.6-340.7) cm With a median follow-up of 34 (range, 4-143) months, the 3-year in-field recurrence-free survival, DM-free survival, and overall survival rates were 74%, 51%, and 66%, respectively. Patients with a higher GTVn/GTVp ratio had a significantly higher risk of developing DM than their counterparts. Only two (2%) patients developed isolated PAN recurrence outside the irradiated field. DM is the most common mode of recurrence, the risk of which is significantly higher in patients with higher GTVn/GTVp ratios. An ample margin above the involved PAN may not necessarily be required to achieve disease control in the pelvis and PAN.