Pelvic node control in patients with locally advanced uterine cervical cancer treated with concurrent chemoradiotherapy

16018 Background: To evaluate pelvic node control in cervical cancer patients treated with concurrent chemoradiotherapy (CCRT) without surgical resection. Methods: Ninety-six patients (stage IB2, 3; IIA, 2; IIB, 49; IIIA, 1; IIIB, 40; IVA, 1) with uterine cervical squamous cell carcinoma treated with CCRT were analyzed. Cervical tumor diameter and pelvic node status were assessed by MRI. The median maximum tumor diameter was 58 mm (range, 36–86 mm). Thirty-four patients had positive pelvic nodes (= 10 mm in shortest diameter). The largest diameter of the positive nodes ranged from 10–50 mm (median, 18 mm). All patients received CDDP (20 mg/m2 for 5 days every 21 days), pelvic external beam RT (PERT), and high-dose-rate intracavitary brachytherapy (HDR-ICBT). The planned RT schedule consisted of PERT with 40 Gy/20 fractions (frs) followed by HDR-ICBT with 18–24 Gy/3–4 frs and PERT with 10 Gy/5 frs using a midline block. Thirty of thirty-four node-positive patients received boost RT (6–10 Gy/3–5 frs) to involved nodes. The dose from HDR-ICBT to the pelvic nodes was estimated at a point 6 cm lateral to the midline at the level of the vaginal fornix. Doses of ERT and HDR-ICBT were simply summed and used for pelvic node dose-response analysis. The median total dose was 60 Gy (range, 52–64 Gy) for positive nodes and 54 Gy (range, 51–55 Gy) for negative nodes. Median follow-up of the surviving 79 patients was 41 months (range, 8–98 months). Results: Four-year overall survival (OAS), pelvic control (PC), and distant metastasis-free (DMF) rates for all 96 patients were 79%, 90%, and 79%, respectively. Four-year OAS, PC, and DMF rates for node-positive/node-negative patients were 60%/89% (P=0.002), 82%/95% (P=0.08), and 66%/86% (P=0.008), respectively. Pelvic nodal recurrence was observed in 4 patients. One patient developed isolated pelvic node recurrence while the other 3 had concurrent recurrences at other sites, including 1 with a cervical tumor and 2 with cervical tumor and distant metastases. Nodal recurrence rates by largest diameter were 1/62 for node-negative patients, 1/14 for nodes 10–14 mm, 0/13 for nodes 15–29 mm, and 2/7 for nodes = 30 mm. Conclusions: Pelvic nodal metastases < 30 mm were well controlled by CCRT without surgical resections using RT dose delivered. No significant financial relationships to disclose.