For more than 50 years patients with seminoma stage I have received adjuvant radiotherapy to the retroperitoneal lymph nodes. Radiotherapy was also used as definitive treatment in patients with metastases, eventually combined with chemotherapy. Traditionally, up to the 1990s the target dose for stage I seminoma had been 30–40 Gy, applied to a so called dog-leg field covering the para-aortic and ipsilateral lymph nodes. Two randomized studies with long-term follow-up data have demonstrated that radiotherapy to the paraaortic lymph nodes is sufficient, and that the target dose can be lowered to 20 Gy [3].

The acute adverse effects of radiotherapy are mild to moderate nausea and diarrhea, often combined with fatigue during the treatment period and for a few weeks thereafter, however with a complete recovery after 3 months [4]. Follow up of these irradiated patients is relatively easy with no need of regular CTs after dog-leg irradiation. After radiotherapy restricted to the paraaortic region, regular pelvic CT examinations during the first 5 years are mandatory to diagnose an eventual pelvic relapse. The recurrence rate after such radiotherapy is 1–2 %, the majority of the relapsing patients being cured by salvage treatment.

Due to the aforementioned risk of overtreatment in patients with stage I seminoma most clinicians agree that radiotherapy no longer has a place in treatment of stage I seminoma and that these patients should be followed with a surveillance strategy, with salvage treatment in relapsing patients [5, 6]. This view finds its strongest support by the increased development of radiation-related second cancers in testicular cancer survivors. Several studies have shown that abdominal radiotherapy in testicular cancer survivors is followed by a significantly elevated risk of second cancer incidence, the relative risk varying between 1.6 and 2.0 [7, 8]. The second cancers are typically diagnosed within or adjacent to the target field (pancreas, ventricle, bladder and colon). There is also evidence for increased risk of cardiac morbidity, even after infra-diaphragmatic radiotherapy alone [9] and reports on occasional renal dysfunction probably related to radiation induced stenosis of the renal arteries.

In the US adjuvant radiotherapy is still considered an option in 50–60 % of patients with stage I seminoma, as compliance to follow-up routines during surveillance has proven difficult [10]. However, the life-long risk of a radiotherapy-related second malignancy is increasingly acknowledged [11]. This awareness should gradually reduce the application of adjuvant radiotherapy of stage 1 seminoma patients. In selected patients radiotherapy may exceptionally be considered, for example if regular follow-up is extremely difficult due to geography, very high age or severe co-morbidity, and if adjuvant chemotherapy with Carboplatin is no option [12]. In this case, radiotherapy should be restricted to the para-aortic region, the total dose not exceeding 20 Gy.

Radiotherapy is still a valid option in the primary treatment of patients with early stage II disease [5]. The target field covers the retroperitoneal and ipsilateral iliac lymph nodes, the target dose being 25–30 Gy, with 10 Gy given to the involved lymph node area.

The relapse rate approximates 10 % in the largest series with most recurrences located above the diaphragm. Initial cisplatin-based chemotherapy seems, however, to be more efficient than radiotherapy as indicated by the following relapse rates: The Swedish Norwegian Testicular Cancer Group (SWENOTECA) reported three relapses (11.3 %) after radiotherapy with 27 Gy among 29 patients with clinical stage IIA [13]. In contrast none of the 73 patients with CS IIA or B (6 and 67, respectively) did experience a relapse after median 5 years of observation. These figures are in concordance with those from the Spanish Germ Cell Cancer Group which show no relapses among 26 with CS2A patients treated with chemotherapy, whereas three of 19 CS2A/B patients (16 %) relapsed following initial radiotherapy [14]. Also Kollmannsberger et al from British Columbia observed similar figures in their study; 3 of 19 (16 %) irradiated patients with small volume stage II seminoma relapses compared to 1 of 65 (2 %) of patients with stage II/A/B treated with chemotherapy [15]. The combination of one to two cycles of Carboplatin prior to radiotherapy has been shown to lower the risk of relapse in seminoma stage II with limited extent [16].