Samenvatting

PRRT is a method of treatment that is used for a variety of diseases. In this method of treatment patient are infused with a radiopharmaceutical. This radiopharmaceutical will deliver a radiation dose to the specific targeted organ. However, due to infusion in the bloodstream other organs will also sustain a radiation dose like for example the bone marrow. There is a method to determine the radiation dose sustained by the bone marrow. This method requires that the amount of activity in blood is determined for several moments in time. Currently this is done by taking blood samples from patients and measuring these samples in dose calibrators.

Theoretically, it should be possible to measure the amount of activity in blood by means of external measurements. These measurements could be performed by using two oppositely positioned CeBr3 scintillation detectors that are linked to photomultiplier tubes. However, before these measurements could be conducted preliminary investigations were necessary. These preliminary investigations were described in this thesis.

Preliminary investigations were conducted on several criteria. These criteria ranged from position of the detector system to detector properties. In specific, the optimal detector system position with
respect to the body, and with respect to the arm was determined. The detector properties that have been investigated were detector linearity, detector response and detector linearity. In addition,
investigations on SNR and shielding have been conducted.

Experiments and simulation showed that the optimal position for the detector system is at wrist position with the arm extended sideways as far as possible. It has also been shown that the optimal
position for the detectors with respect to the arm is at a distance of 10 cm between detectors and arm. With this detector position the signal-to-noise ratio can be improved by use of shielding. With 1.60 cm thickness of lead shielding the SNR will not become lower than 100. In addition, it has been shown that the detector properties for both detector is nearly similar.

These investigations led to promising results. The results show a specific set-up for the detector
system with which the amount of activity in blood could be determined by means of external measurements.