Do you routinely use tumor lysis prophylaxis when starting chemotherapy for germ cell tumors?

THere is not reason to use tumor lysis prophylaxis. Hydration of course is required for the cisplatin. I am not aware of anyone using allopurinol or other TLS approaches

It depends on the size and the bulk of the tumor. Tumor lysis syndrome has been reported. If there are no contraindications to allopurinol, it should be considered.