The impact of self-shielded cyclotron operation on small-animal PET/CT equipment installed nearby, on the floor just above.
OBJECTIVE
The purpose of this study was to evaluate the impact of a cyclotron on small-animal PET equipment installed directly above the cyclotron.


METHODS
The cyclotron equipment was HM-12, which has two targets, and the PET/CT equipment was Inveon. The equipment was installed in conformity to Japanese law and regulations. Before installation of the PET/CT equipment, the radiation dose, radio waves, and static and fluctuating magnetic fields were measured at the position where it would be placed, both when the cyclotron was in use and when it was not in use. After installation of the PET/CT, natural background and emission counts were measured at the same place under the same conditions.


RESULTS
An increase of radiation dose was observed when the target nearest the PET equipment was used. There were no distinct effects of radio waves or static and fluctuating magnetic fields. A significant increase of emission counts, approximately 300 cpm, was observed when the nearest target was used.


CONCLUSIONS
Though radio waves and static and fluctuating magnetic fields generated by running cyclotron had no influence, a significant increase in emission count was observed. Careful attention should be paid to this influence when very low-radioactivity PET measurements are done.
Departments of Medical Imaging, Institute of Health Biosciences, the University of Tokushima Graduate School.
Hitoshi
H
Kubo
Tamaki
T
Otani
Hideki
H
Otsuka
Masafumi
M
Harada
D000818:Animals; D017357:Cyclotrons; D004868:Equipment Failure; D007564:Japan; D060526:Magnetic Fields; D049268:Positron-Emission Tomography; D011829:Radiation Dosage; D011846:Radio Waves; D055672:Static Electricity; D014057:Tomography, X-Ray Computed