(P075) Management of Nodal Recurrences of Endometrial Cancer With IMRT

Jennifer Ho, Anuja Jhingran, MD, Shannon Westin, MD, Karen Lu, MD, Patricia Eifel, Ann Klopp, MD, PhD; UT MD Anderson Cancer Center

PURPOSE: Pelvic and para-aortic lymph node regions are frequent sites of relapse in women with endometrial cancer who have not undergone adjuvant pelvic radiation. We investigated outcomes following radiation therapy with intensity-modulated radiation therapy (IMRT) for definitive treatment of nodal relapses of endometrial cancer at our institution.

MATERIALS AND METHODS: Between 2002 and 2012, a total of 42 patients with endometrial cancer who had no prior pelvic external beam radiation were treated definitively using IMRT for pelvic and/or para-aortic nodal recurrences. A total of 12 patients (29%) had pelvic nodal recurrences only, 8 (19%) had para-aortic recurrences only, 10 (24%) had simultaneous pelvic and para-aortic recurrences, and 12 (28%) had simultaneous pelvic and other regionally confined recurrences. Also, 15 patients (35%) had chemotherapy before radiation, and 21 (50%) had concurrent chemotherapy with radiation. The median size of the largest nodal recurrence site was 2.9 cm (range: 1.3–9.1 cm). The nodal basins at risk were typically treated to 45–50 Gy, with a boost to the gross tumor, for a mean total dose of 64.8 Gy (range: 59–73 Gy). Survival rates were calculated using the Kaplan-Meier method.

RESULTS: The median overall survival (OS) from date of recurrence was 45.1 months (95% confidence interval [CI], 28.3–61.8 mo), and the 2-year survival was 71%. A total of 16 (38%) patients developed local failures within the salvage radiation fields at a median time of 7.2 months (range: 2.4–28.6 mo), of which 11 were failures located within the high-dose regions. Further, 20 (48%) patients developed distant recurrences at a median time of 6.8 months (range: 1.2–31.9 mo). Patients who received concurrent chemotherapy had longer median survival than patients treated without concurrent chemotherapy (61.9 mo vs 28.9 mo; P = .029). Patients who received chemotherapy prior to radiation had shorter median survival compared with those who did not (28.3 mo vs 61.9 mo; P = .001) and a lower rate of survival free of local recurrence (28% vs 73% at 2 yr; P = .012). No significant survival difference was detected in survival or local recurrence based on histology, tumor size, or site of recurrence. A total of 11 patients (26%) experienced grade ≥ 3 gastrointestinal toxicity.

CONCLUSION: Long-term survival can be achieved following salvage radiation for nodal recurrence of endometrial cancer. However, central and distant recurrences remain a challenge. Chemotherapy prior to radiation was associated with an increased rate of central recurrences and reduced survival, while the use of concurrent chemotherapy was associated with higher rates of survival.

Proceedings of the 97th Annual Meeting of the American Radium Society- americanradiumsociety.org