DOTA TATE

Chemistry and mechanism of action

DOTA-TATE is an amide of the acid DOTA (top left in the image), which acts as a chelator for a radionuclide, and (Tyr³)-octreotate, a derivative of octreotide. The latter binds to somatostatin receptors, which are found on the cell surfaces of a number of neuroendocrine tumours, and thus directs the radioactivity into the tumour.

Usage examples

Gallium (⁶⁸Ga) DOTA-TATE (GaTate) is used for tumour diagnosis in positron emission tomography (PET). DOTA-TATE PET/CT has a much higher sensitivity compared to In-111 octreotide imaging.

Lutetium (¹⁷⁷Lu) DOTA-TATE has been tested for the treatment of tumors such as carcinoid and endocrine pancreatic tumor. It is also known as Lutathera.

Patients are typically treated with an intravenous infusion of 7.5 GBq of lutetium-177 octreotate. After about four to six hours, the exposure rate of the patient has fallen to less than 25 microsieverts per hour at one metre and the patients can be discharged from hospital.

A course of therapy consists of four infusions at three monthly intervals.

Availability

Lu177 octreotate therapy is currently available under research protocols in five different medical centers in North America: Los Angeles (CA), Quebec City, (Qc), Edmonton, (Ab), London, (On) as Houston (Tx) on clinical trial. Medical centers in Europe also offer this treatment. For instance: Uppsala Centre of Excellence in Neuroendocrine Tumors in Sweden and Erasmus University in the Netherlands. In Israel, treatment is available at Hadassah Ein Kerem Medical Center. In Australia, treatment is available at Liverpool Hospital and St Vincent's Hospital, Sydney; the Peter MacCallum Cancer Centre and at the Department of Nuclear Medicine at Fremantle Hospital in Western Australia. In Aarhus universitet hospital in Denmark. In the coming years such therapy will also become commercially available in Latvia, Riga - "Clinic of nuclear medicine".