**8.9 Radiopharmaceuticals for diagnosis and tumor therapy**

For effective imaging in diagnosis and tumor therapy [52], three enzymes -which are not commonly expressed by normal/non-infected cells- encoded by viral gene are required [53]:


**Figure 2.** *Selective prodrug gene therapy.*

*Radiopharmaceuticals: On-Going Research for Better Diagnosis, Therapy, Environmental… DOI: http://dx.doi.org/10.5772/intechopen.99204*
