Long-term tumor control and fertility after para-aortic limited radiotherapy of stage I seminoma

Abstract

To review patterns of relapse in a long-term analysis of patients with Stage I seminoma treated by orchidectomy and radiotherapy to the paraaortic lymph nodes only and to follow follicle stimulating hormone (FSH) levels dependent on testicular scatter dose. From 1980 to 1995, 58 patients with Stage I seminoma received elective radiotherapy to the paraaortic lymph nodes only (Th12 to L4), with a mean total dose of 28.07 Gy (+/- 2.2 SD), using fractional doses between 1.5 and 2 Gy (mean 1.62 Gy +/- 0.083 SD). Since 1989, testicular scatter doses were measured routinely by in-vivo thermoluminescent dosimetry (TLD) in 45 patients. In 26 patients with normal pre-treatment values of FSH, FSH-levels were repeatedly controlled after radiotherapy in order to evaluate any radiation-induced sequelae. During a mean observation period of 69.4 months (range 30 to 210), 2 out of 57 patients (3.5%) developed regional recurrences in the ipsilateral pelvic lymph nodes 14 months and 5 years after radiotherapy, respectively. One patient was lost to follow-up. The relapse-free survival rate at 5 years was 96.5% after radiotherapy alone. After salvage chemotherapy, both relapse-free survival and overall survival rates come to 100%. The mean testicular scatter dose in 45 patients was 0.22 Gy (+/- 0.087 SD). Seven out of 26 patients (26.9%) developed a transient increase of FSH-levels, reaching peak values at 4.2 months and returning to normal ranges within 18 months after radiotherapy. Below 0.2 Gy, no effect on FSH was observed. Testicular scatter doses showed no clear correlation to FSH risings (Figure 1). After exclusive paraaortic radiation of Stage I seminoma, even at follow-up periods in excess of 5 years the incidence of pelvic lymph node relapses remains below 4%. However, there seems to be a small potential for the development of late recurrences. With limited radiotherapy, permanent radiation-induced effects on the remaining testicle are very unlikely.