Table 4.

The crucial questions for radiopharmaceuticals.

Questions (Radiopharmaceutical Applications)	Therapeutic Antibody or Specialized Radiopharmaceuticals
Where the antibody goes? (Biodistribution)	Therapeutic antibody
Where is the target protein expressed? (Assess expression and heterogeneity of target in tumor and normal tissues)	Radiopharmaceuticals
Does the therapeutic antibody reach the target? (Target engagement and dose range)	Therapeutic antibody
Does therapeutic-antibody target interaction result in the expected biological effects? (Response prediction/theranostic applications)	Therapeutic antibody
Is there a specific pharmacodynamic marker linked to response? (Imaging-surrogate efficacy endpoint)	Radiopharmaceuticals