How do you approach patients with neonatal intrapericardial germ cell tumor, as compared to other patients with mediastinal germ cell tumors?

I need help too!!

I have a patient in their teens with recurrent mediastinal GCT. Failed standard therapy radiation HD therapy/stem cell... but never tried immunotherapy, anti-angiogenesis, or TKI. Does anyone have experience with CPI in combination with Lenvatinib??