Whole-body and Single-Photon Emission Computed Tomography/Computed Tomography Postpeptide Receptor Alpha Radionuclide Therapy Images of Actinium 225-Tetraazacyclododecanetetraacetic Acid-Octreotide as a Primary Modality of Treatment in a Patient with Advanced Rectal Neuroendocrine Tumor with Metastases.

Somatostatin receptor-targeted alpha radionuclide therapies have been introduced including actinium-225 labeled tetraazacyclododecanetetraacetic acid-octreotide (Ac-225 DOTATATE) for advanced metastatic neuroendocrine tumors (NET). Very limited data are available on the posttherapy imaging using Ac-225 DOTATATE therapy in metastatic NET. We present Ac-225 single-photon emission computed tomography/computed tomography images of a 72-year-old patient diagnosed as a case of advanced rectal NET treated primarily with Ac-225 DOTATATE.