FDOPA PET/CT

Neuroendocrine tumor cells show increased activity of the enzyme DOPA decarboxylase, which catalyzes the transformation of the amine precursor DOPA into biogenic dopamine. Nuclear medicine takes advantage of this fact and uses radiolabeled amine 18F-DOPA to quantitatively estimate the activity of DOPA decarboxylase in a specific region of the body (tumor).

Unlike the receptor-mediated PET/CT imaging for the presentation of NETs (e.g. 68Ga-DOTANOC), a conclusion can be made regarding the cell metabolism within the tumor cells and thus therapeutically groundbreaking information about tumor biology can be obtained. In principle, F-DOPA-PET/CT is indicated for every tumor of neurectodermal origin, particularly for medullary thyroid carcinomas, paeochromocytomas/ paragangliomas and congenital hyperinsulinemia.

Indications / Fields of application

• Neuroendocrine tumors (NET), in particular pancreas NET and known as “carcinoids“ (serotonin-producing tumors. also called as NET of the small intestine, lungs or rectum)
• Medullary thyroid carcinomas
• Pheochromocytomas and paragangliomas
• Neuroblastomas
• Congenital hyperinsulinemia

Investigation preparation

To ensure that the examination is successful, you should be in a fasting state for a minimum of 4 hours. Please ask for the requirements of fasting when registering with regard to your question. Since the radiopharmaceutical has a short half-life of approx. 2 hours and is delivered especially for this purpose, we kindly ask you to present it at the scheduled time.

Documents

Please bring all relevant documents with you to the examination (especially images and findings from preliminary examinations, preferably also in digital form on CD and doctor's letters). For the possible intravenous administration of contrast material as part of CT (computed tomography), please have a recent creatinine level in the blood determined by your family doctor - ideally in the week before the examination.

Examination procedure

Patient's medical history will be reviewed and patient will be provided detailed information about the examination by the responsible physician; thereafter the (radiopharmaceutical) 18F-DOPA will be injected into an arm vein. After a waiting period of 30-90 minutes (depending upon the clinical question, additional early intake), during which the medication is distributed in the body, thereafter the actual examination on the PET scanner is started. During the image acquisition (for 20-30 min) you have to lie still.

Side effects

No side effects are to be expected from the injection of the radioactive tracer itself.

Side effects can occur as a result of the administration of iodine-containing contrast medium within the framework of an accompanying CT study (intolerance reaction, hyperthyroidism, worsening of a pre-existing renal insufficiency). During the consultation with our physicians, please make sure to point out if you have experienced a contrast agent reaction in the past (reddening of the skin, itching, swelling, shortness of breath, etc.).