- Diffusion lung capacity for carbon monoxide (DLCO) adjusted for hemoglobin ≥60% predicted, except if related to high volume metastatic GCT to the lungs in which case there is no minimum DLCO requirement. In some cases, patients may not be able to undergo PFT testing due to the severity of their presentation. such as those with high volume lung metastases or tumor-related pain (from large mediastinal masses, pleural disease, etc.) limiting their ability to complete PFTs. Even when PFTs can be completed in these cases, patients will still be eligible if the low DLCO can be attributed directly to the patient's disease (e.g., large mediastinal mass) rather than intrinsic lung disease. Since there is no minimum DLCO for these patients, under these extraordinary circumstances, this will be allowed. Most patients in this situation will be expected to receive disease-stabilizing chemotherapy. An unadjusted DLCO may be used in place of the DLCO adjusted for hemoglobin in certain situations as per institutional policy. For example, MSKCC policy is to not adjust the DLCO for hemoglobin when the hemoglobin is ≥ 14.6 g/dL for males and ≥ 13.4 g/dL for females. In these cases, the unadjusted DLCO must be >60% predicted.