MODERN RADIOTHERAPY RESULTS WITH BULKY STAGE-II AND STAGE-III SEMINOMA

We treated 20 patients with stage II seminoma by primary radiotherapy from 1971 to 1982. Median patient age was 38 years (range 26 to 52 years) and median disease width in the transverse plane was 11 cm. (range 5 to 25 cm.). Four tumors were 5 to 9 cm., 9 were 10 to 14 cm. and 7 were 15 cm. or more wide. Tumor was palpable in 13 patients. Generous radiation ports (such as wide hockey stick or whole abdomen) often followed by a boost to the area of bulky disease were used as primary therapy in all patients. Median tumor dose was 37.5 Gy. (range 13.3 to 56.7 Gy.). Supradiaphragmatic prophylactic radiation was given to 16 patients (median dose 26 Gy., range 12 to 37.3 Gy.). Median followup was 56 months, and all patients currently are free of disease except for 1 who died without disease more than 10 years after completion of all therapy. Mediastinal failure occurred in 2 of 4 patients without and 1 of 16 with mediastinal prophylaxis. All 4 patients with relapse are currently free of disease after salvage therapy. Five patients 16 to 42 years old (median age 30 years) received primary radiation therapy for stage III disease. The median size of abdominal disease was 10 cm. (range 5 to 17 cm.). Of the 5 stage III cancer patients 3 had supradiaphragmatic disease demonstrated only in supraclavicular lymph nodes and all 3 were continuously free of disease 115 to 136 months after therapy. The remaining 2 stage III cancer patients had supradiaphragmatic disease by virtue of bulky mediastinal disease with or without supraclavicular involvement. Both patients had relapse in-field and distantly, and they died of disease despite salvage chemotherapy. A total of 30 fields with bulky disease (greater than 5 cm.) was treated either primarily or at relapse among the 25 stage II and III cancer patients. In-field relapse occurred in 3 of 21 patients receiving less than or equal to 36 Gy. and 0 of 9 who received greater than 36 Gy. These results justify radiation therapy as an acceptable initial primary treatment modality for typical bulky stage II seminoma. Disease greater than 5 cm. should receive than 36 Gy. Prophylactic radiation to the mediastinum is effective. However, patients who have mediastinal failure often can be salvaged with chemotherapy and/or radiation, and prophylactic mediastinal radiotherapy may be associated with poor tolerance to salvage chemotherapy and other significant late effects. Our series also confirms that subsets of stage III seminoma may do well with primary radiotherapy but mortality and distant metastasis occur frequently enough to warrant chemotherapy as initial therapy in stage III disease.