Chemotherapy of advanced seminoma: clinical significance of radiological findings before and after treatment.

The predictive significance of the mass detected following chemotherapy was assessed in 46 patients with advanced seminoma. Patients with residual viable seminoma in the post-chemotherapy operation specimen or who developed recurrent disease were regarded as chemotherapy failures. This group included 1 of 20 patients in whom the retroperitoneal masses were less than or equal to 10 cm2 3 to 4 weeks after chemotherapy and 4 of 15 patients whose residual masses were greater than 10 cm2. Four of 11 patients with mediastinal tumours achieved a complete remission (mediastinal masses less than or equal to 1 cm2). However, 2 of these 4 patients relapsed, as did 2 of the 4 who achieved a partial remission. In no case was the original size of the tumour significantly related to treatment failure. Three patients had residual lung masses; 1 of these contained histological evidence of viable tumour. In one-third of the irradiated relapse-free patients, slightly enlarged masses were visible on follow-up computed tomography scans taken several years after treatment, even in patients without tumour activity. There is a 25% risk of relapse in patients with advanced seminoma who have retroperitoneal masses greater than 10 cm2 following cisplatin-based chemotherapy. They should be followed up regularly for many years.