If a patient with a seminoma fails after chemotherapy in the paraaortic nodes, what is the best salvage therapy - different chemotherapy or radiation?  

It depends on what the prior intent of chemotherapy was, what type it was, how confident you are that the patient has indeed relapsed as well as the size of the nodes. Three scenarios might be considered.  If the patient received adjuvant carboplatin, somewhere between 5 and 10% will relapse a...

If a patient has failed after adjuvant chemo (single agent carbo) and the volume of disease is small (3 cm or less), I would treat with RT. If there is a large volume of disease, then would favor chemotherapy with BEP or EP.

I agree that confirmation of relapse is key, which typicaly means that either there is unambiguous growth of disease or else histopathological confirmation of relapse.  Stage I patients treated with two cycles of adjuvant carboplatin have a relapse rate of only about 2% and the randomized tria...