There are a number of tests and scans that a patient can be asked to undergo as part of their evaluation for receiving PRRT. The exact order in which the patient takes these tests or scans may depend upon their specific medical condition or the need for the doctors to evaluate results in some order.
While the patient is at the Zentralklinik, it is customary for them to be given directions to find the department where tests or scans are performed. For Non-German speaking patients this can be a challenge in that signage is in German and the Zentralklinik is a very large medical center. There are no maps. It is suggested that you write down the directions, if you can. Also it is suggested that you take a book, iPod or something with you to occupy your time while waiting. It is not unusual to be waiting for an hour or longer before being called for a test or scan.
Blood Lab Work
Typically the first test for those patients who check into the klinik for a PRRT, is a blood test. When the patient checks into the klinik on Sunday, blood is usually drawn as a baseline for the doctors and a point of reference going forward.
The Scans
The next test is for renal function and this usually takes place first thing on Monday morning. If an ultra sound for the pancreas or a heart echocardiogram is needed, these may come next during the day on Monday or on Tuesday morning.
Dynamic Renal Scintigraphy with Tc-99-MAG3
Typically this is among the first tests/scans to be done on a patient because the function of the kidneys is essential to the PRRT process. The kidneys are key to ridding the body of the radiation that is administered with the PRRT. For this particular test the patient has an IV tube put in place and is injected with a radioactive tracer. The patient is scanned with a gamma camera and these images are used to assess the function of the kidney. A blood sample is also drawn from the patient for analysis related to kidney function. Two measurements are taken:
• Tubular Extraction Rate (TER)
• Glomerular Filtration Rate with Tc-99m-DTPA
The 68-Gallium PET/CT scan
This scan is among the most important scans the patient will receive at Bad Berka. Typically a patient will do dynamic renal testing prior to the 68-Ga scan, consequently, the IV tube inserted for the renal test will be used for the infusion of the 68-Gallium isotope for this scan. The usual procedure is for the patient to report to the PET center after their renal testing. The patient will be injected with the isotope and then instructed to wait about 45min to an hour in the waiting area. During that time the patient must drink about 1 liter of a slightly licorice flavored contrast agent and to also drink about a liter of water, all prior to the scan.
It is recommended that during the waiting period, the patient should urinate as much as possible, especially immediately before being called into the scanning room. The dual scans take about 40-50 minutes in total and take place back to back. There is no break in between scans.
This scan is both a PET scan and a CT scan. Usually the PET scan is done first and this is followed by the CT scan with no stopping. The CT scan uses an injected contrast agent (through the IV tube).
Whole Body FDG PET/CT scan
It is common for the patient to undergo an FDG PET/CT scan as the last step before discharge. For this scan the patient must not take any meals after the evening meal of the night before -- until after the scan. The patient is first injected with a radioactive tracer attached to a glucose solution. About an hour later the patient undergoes a whole body, spiral CT.
The purpose of the scan is to seek out increased glucose metabolic activity that is characteristic of cancer tumor cell activity.