Can we omit ipsilateral pelvic irradiation in patients with stage I seminoma of the testis?

Purpose: Results of treatment of patients with stage I seminoma with orchiectomy and radiotherapy are excellent. Even without adjuvant radiotherapy, the relapse rate is only 15-20%; most of the patients fail in the abdominal cavity with rare failures observed in the pelvis (0.5-2%). In 1991 we began a prospective study evaluating para-aortic lymph node radiation as the only adjuvant treatment for such patients. This paper reports our preliminary results. Materials and Methods: Between March 1991 and June 1995, 25 patients with histologically proven stage I seminoma were entered on study. Median age was 38.5 years (range: 27 - 64 years). A radical inguinal orchiectomy was performed in all patients. Staging work-up consisted of a chest x-ray, β HCG, α fetoprotein, and CT scan of the abdomen and pelvis in all patients. Lymphogram was done in (18(25)) (72%) patients for further evaluation of the retroperitoneal lymph nodes. Only patients with medical or other contraindication to this procedure were exempt. Radiotherapy consisted of treatment to the para-aortic region only. Parallel opposed fields extending from the top of T11 to the bottom of L5 were used. The average field size was 22.4 x 8.8 cm (range: 18 - 26 x 7 - 11 cm). (22(25)) patients received a total dose, prescribed at mid-point, of 25 Gy given in 15 daily fractions of 16.6 Gy. Three other patients received 24 Gy, 30 Gy and 30 Gy, respectively. Follow-up was performed every 3 months for the first year, every 4-5 months for the second and third year and every 6 months thereafter. Chest x-ray tumor markers, and CT scan of the abdomen and pelvis were performed routinely as part of the follow-up investigation. Results: At a median follow-up time of 32 months (range: 8 - 60 months), (24(25)) patients (96%) are alive with no evidence of disease. One patient died of an unrelated cause (second malignancy outside the radiotherapy field) at one year for an overall survival rate of 96% at 5 years and a cause-specific survival rate of 100%. Treatment morbidity was limited to grade 1-2 acute side effects consisting of nausea and cramps necessitating medication in(14(25)) patients (56%). No late side effects were seen. Conclusion: From our preliminary results, it appears that adjuvant radiation treatment limited to the para-aortic lymph node region without ipsilateral pelvic irradiation for stage I seminoma is adequate treatment. Such an approach in our patients resulted in minimal toxicity and excellent disease-free survival