Ga68DOTATOC

Ga-68 DOTATOC is a radiopharmaceutical used in positron emission tomography (PET) imaging to visualize somatostatin receptor expression in tumors, most notably neuroendocrine tumors (NETs). It consists of a Tyr3-octreotide (TOC) derivative linked to the chelator DOTA and labeled with the radioisotope gallium-68. The tracer targets somatostatin receptor subtype 2 (SSTR2), which is commonly overexpressed in NET cells.

Production and labeling of Ga-68 DOTATOC rely on gallium-68 supplied from a generator. The DOTATOC molecule is radiolabeled with Ga-68 under controlled conditions to form Ga-68 DOTATOC with high radiochemical purity. The radionuclide has a physical half-life of about 68 minutes, allowing same-day imaging after administration.

Clinically, Ga-68 DOTATOC is used to map disease distribution, assist in staging and restaging, and inform therapeutic decisions for patients with somatostatin receptor–positive tumors. Imaging is typically conducted about 45 to 90 minutes after injection, with uptake patterns reflecting receptor density and enabling assessment of disease extent and suitability for peptide receptor radionuclide therapy (PRRT).

Availability and comparison: Ga-68 DOTATOC is one of several Ga-68 somatostatin receptor imaging tracers. Other commonly used tracers include Ga-68 DOTATATE, which has FDA-approved products in some regions. Differences in receptor affinity and biodistribution among tracers can influence image quality and interpretation, and availability depends on local regulatory status and production capabilities.

Safety considerations: As with other radiopharmaceuticals, Ga-68 DOTATOC carries risks related to radiation exposure and rare adverse reactions. Standard precautions apply, and use is avoided in pregnancy and lactation unless clearly justified.