How would you manage stable/slightly enlarged pulmonary metastasis from non-seminoma testicular cancer after receiving 3 cycles of BEP, which resulted in a mixed responses on chest CT but normalized AFP?

This is a patient with nonseminomatous germ cell tumor, with presumably pulmonary metastases at start of BEP X 3. I am also assuming that his abdominal CT scan was either normal baseline or it reverted to normal post BEP. The issue now is a mixed response in the lungs, implying some lesions are smal...