Long-term tumor control and fertility after limited paraaortic radiotherapy in stage I seminoma

Purpose: To review patterns of relapse in a long-term analysis of patients with Stage I seminoma treated by orchidectomy and radiotherapy to the paraa ortic lymph nodes only and to follow follicle stimulating hormone (FSH) lev els dependent on testicular scatter dose. Patients and Methods: From 1980 to 1995, 58 patients with Stage I seminoma received elective radiotherapy to the pa paraaortic lymph nodes only (Th12 to L4), with a mean total dose of 28.07 Gy (+/- 2.2 SD), using fractional d oses between 1.5 and 2 Gy (mean 1.62 Gy +/- 0.083 SD). Since 1989, testicul ar scatter doses were measured routinely by in-vivo thermoluminescent dosim etry (TLD) in 45 patients. In 26 patients with normal pre-treatment values of FSH, FSH-levels were repeatedly controlled after radiotherapy in order t o evaluate any radiation induced sequelae. Results: 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 ipsilate ral pelvic lymph nodes 14 months and 5 years after radiotherapy, respective ly. 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 came to 100%. The mean tes ticular scatter dose in 45 patients was 0.22 Gy (+/- 0.087 SD). Seven out o f 26 patients (26.9%) developed a transient increase of FSH-levels, reachin g 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. Testicula r scatter doses showed no clear correlation to FSH risings (Figure 1). Conclusion: After exclusive paraaortic radiation of Stage I seminoma, even at follow-up periods in excess of 5 years the incidence of pelvic lymph nod e relapses remains below 4%. However, there seems to be a small potential f or the development of late recurrences. With limited radiotherapy, permanen t radiation-induced effects on the remaining testicle are very unlikely.