Quantitative SPECT imaging for diagnosis and dosimetry in radionuclide therapy.

Effective therapeutic treatment with in vivo administered radioactivity depends on the localization of appropriate concentrations in tissues to be treated. Accurate assessment of both diagnostic and therapeutic concentrations of radiopharmaceuticals is the goal of quantitative SPECT imaging. The technology of SPECT imaging has significantly improved over the past 5 years, and routine quantitation for SPECT users may not be far away. The four operational steps by quantitative SPECT imaging are described, along with technical factors that require further development before it can be used routinely.