Radiation Therapy for Para-Aortic Lymph Node Metastasis from Uterine Cervical Cancer

Aim: To evaluate the efficacy of radiation therapy for para-aortic lymph node metastases from uterine cervical cancer and to identify an optimal radiation regimen. Patients and Methods: A total of 80 metastatic para-aortic lymph nodes, ranging from 11-50 mm (median=20 mm) on computed tomography, in 22 patients with squamous cell carcinoma of the uterine cervix were initially treated with radiation therapy. Total radiation doses for para-aortic lymph node metastases were 40-61.2 Gy (median=50.4 Gy) in 1.8-2 Gy fractions. Results: Eight out of the 22 patients remained alive at a median follow-up of 32 months. Seven irradiated lymph nodes, 20-50 mm in diameter, in four patients progressed after irradiation at total doses of 44-50.4 Gy. No metastatic lymph nodes administered >50.4 Gy (median=55.8 Gy) exhibited progression after irradiation. All metastatic lymph nodes <= 25 mm in diameter irradiated with 50 or 50.4 Gy were controlled. The 3-year lymph node progression-free rates were 78% in the cohort of 22 patients and 89% considering all 80 metastatic lymph nodes. Apart from transient hematological reactions, two patients developed grade 3 or more therapy-related toxicities, including radiation proctitis in one and hemorrhagic cystitis and colitis in another. Conclusion: Radiation therapy can effectively control para-aortic lymph node metastases in patients with uterine cervical cancer. A total dose of 50.4 Gy in 1.8 Gy fractions is sufficient to control metastatic lymph nodes <= 25 mm in diameter, whereas a higher dose (approximately 55.8 Gy) may be required for larger nodes.