dotatate

DOTATATE, or DOTA-Tyr3-Octreotate, is a radiopharmaceutical used in positron emission tomography (PET) imaging. It consists of the somatostatin analogue Tyr3-octreotate linked to the chelator DOTA and labeled with the radionuclide Gallium-68. The compound binds with high affinity to somatostatin receptor subtype 2 (SSTR2), which is overexpressed on many neuroendocrine tumors (NETs) and some other lesions, enabling PET/CT visualization of somatostatin receptor–positive tissue.

Clinical use centers on detecting, staging, and restaging somatostatin receptor–positive NETs, including pancreatic and gastrointestinal tumors. Ga-68 DOTATATE PET/CT is also used to assess eligibility and planning for peptide receptor radionuclide therapy (PRRT) with Lu-177 DOTATATE and can help differentiate NETs from non–SSTR-expressing lesions.

Administration and imaging involve radiolabeling Tyr3-octreotate with Ga-68 at a radiopharmacy. The typical administered activity ranges from 185 to 370 MBq (5–10 mCi); imaging is usually performed about 60 minutes after injection. Uptake is interpreted qualitatively and, when available, quantitatively via standardized uptake values (SUVs).

Safety and regulatory considerations reflect standard radiopharmaceutical practice. Ionizing radiation exposure is a factor, but adverse events are generally mild. Contraindications include pregnancy and lactation; appropriate precautions are taken for allergies or prior reactions to radiopharmaceuticals. Ga-68 DOTATATE is one of several somatostatin receptor imaging agents used in NET evaluation, alongside comparable tracers and subsequent therapeutic options.