Use of radiotherapy for seminoma patients with low-volume infradiaphragmatic nodal disease.

Abstract

335 Background: Radiation therapy (RT) is established as standard management in testicular seminoma patients with low volume (< 5cm in maximum diameter) retroperitoneal lymphadenopathy. Increasingly multi-agent chemotherapy (CT) is being recommended as first line therapy with its attendant toxicity. To further examine this issue, we reviewed the outcomes for such patients managed at our institution. Methods: After ethics board approval, data on 106 patients identified from a prospectively maintained institutional database with low volume retroperitoneal disease (<5cm) were retrospectively reviewed. All patients were treated between 1995-2010 and had either relapsed Stage I disease on surveillance (59 pts) or Stage IIA/B at diagnosis (47 pts). Fifty eight patients had nodal disease of <2cm (57 treated with RT, 1 with CT), and 48 had disease 2-5cm (30 treated with RT, 18 with CT). Median age was 37 years (range 24-83). The preferred treatment policy was to use RT when possible (25 Gy in 20 fractions to para-aortic and pelvis with 10 Gy boost to gross disease). Reasons for using chemotherapy included multiple enlarged nodes with largest node at least 3cm (n=11), disease proximity to renal hilum (n=4), inflammatory bowel disease (n=3) and patient choice (n=1). Seventeen-patients received EP (4 cycles) chemotherapy and 2 received BEP (3 cycles). Results: With a median follow-up of 73 months, there were no disease or treatment related deaths. The 5-year overall and relapse-free survival was 100% and 91%. Of 58 patients with LN size ≤ 2 cm, 5 relapsed, all initially treated with RT. Of 48 patients with LN size 2-5cm, 4 relapsed (3/30 treated with RT, 1/18 treated with CT). Acute toxicity (CTCAE v4 >grade 1) was not observed in any patient treated with RT. In patients treated with CT, 7 developed G3/4 neutropenia, 2–grade 3 anemia, 2–grade 3 diarrhea, and 1 patient grade 3 weight loss. All relapsed patients were successfully salvaged by CT. Conclusions: A policy of routine use of RT in patients with low-volume nodal disease gives excellent results with >75% of patients avoiding CT and only 6% of patients receiving both RT and CT. Retroperitoneal RT should be strongly considered as the treatment of choice in these patients.