Facility considerations

The scope of the planned facility will determine the type of cyclotron and the associated resource requirements, which can range from a comprehensive facility manufacturing multiple radionuclides and radiopharmaceuticals to a much smaller facility dedicated only to the production of fluorodeoxyglucose (FDG).

2.3.1. Definition of facility type

In a discussion concerning facility configuration, it is desirable to have a common set of references to ensure that everyone understands what is being discussed. Five categories were formally defined by a task group on PET site and facility planning set up by the American Association of Physicists in

Medicine. It is obvious that there is really a continuum of facilities and the lines of definition are purely arbitrary [2.1]. Here, slightly different categories have been defined based on the assumption that a cyclotron will be in place in the facility and the differences will be in the mission and scope of the facility. The five categories are as follows.

Type I — Facility with only FDG production. This type of facility has a small cyclotron in the proton energy range of 9–19 MeV. The goal of the facility is to produce enough FDG to be used locally and to distribute it to nearby hospitals. There is no involvement with basic radiotracer development research and there is complete reliance on the equipment vendor for repairs, maintenance, and upgrades. Such a facility is much less demanding on resources, technical as well as personnel. Even at a small facility with a small cyclotron, it is quite feasible to manufacture a large quantity of FDG for distribution to other PET centres to which deliveries can be made within a few hours. Furthermore, such a facility can be financially viable.

Type II — Cyclotron facility with radionuclide production for PET. Like the previous example, this type of facility also has a cyclotron in the proton energy range of 9–19 MeV, having the production of FDG as the principal objective. However, this facility is designed to also produce the other short-lived positron emitters (¹¹C, ¹³N and ¹⁵O), convert them into radiopharmaceuticals and distribute them locally. The facility may also distribute FDG to nearby hospitals. There is little involvement with basic radiotracer development research and nearly complete dependence on the vendor for maintenance, equipment upgrades, and new capabilities in the form of new radiotracers.

Type III — Cyclotron facility with a research support staff. Along with a cyclotron in the 13–19 MeV range and automated synthesis modules, this facility has a scientific support staff of chemist(s), physicist(s), or other scientists capable of developing procedures and radiopharmaceuticals that have been described in the literature. The major emphasis is to provide radiopharmaceuticals for routine patient studies, but some independent research can be carried out including biodistribution and biokinetic studies based on a micro-PET. There may be production of more than just the four traditional PET radionuclides mentioned earlier. This can include radionuclides such as ⁶⁴Cu, ⁸⁶Y, ¹²³I and ¹²⁴I.

Type IV — Radionuclide production and distribution facility. This type of facility is devoted to the large scale production of radionuclides, and radiopharmaceuticals, for distribution to users. If FDG is the major product, then the cyclotron is probably a small one. If other radioisotopes (²⁰¹Tl, ¹²³I, ¹²⁴I,

67Ga, ⁶⁴Cu, ⁸⁶Y, etc.) are being produced, then the cyclotron is typically larger (~30 MeV) than those used only for PET. Separate areas may be required for

target preparation, target recovery, target processing, sterile setup, quality control (QC) and shipping.

There are also possibilities of setting up cyclotron centres dedicated to the production of a single radionuclide such as ¹⁰³Pd for therapy.

Type V — Cyclotron facility with an extensive research programme.

Along with a larger (30 MeV) cyclotron used for the production of PET and SPECT radionuclides and radiopharmaceuticals, the facility will have a team of research scientists performing basic research on developing new radiotracers and procedures. Considerable space is allocated for laboratories and animal facilities. There is little or no pure clinical work done, but there may be an extensive clinical research programme. This programme may involve production of non-traditional PET radioisotopes such as ⁶⁴Cu, ⁸⁶Y, ¹²³I, and ¹²⁴I and many other radionuclides that can be produced by (p, xn), (d, xn) or (a, xn) reactions. Moreover, other research activities including but not limited to radiation physics, chemistry, biology and material science can be performed at this type of facility.

In a national facility, a cyclotron with higher energies (30 MeV and above) and a more flexible configuration in terms of beam lines and targets, makes an attractive tool for applications in the field of physics (determination of nuclear cross sections for (particle, X) reactions), fabrication of micro-optics, chemistry, analytical applications such as particle induced X ray emission (PIXE), biochemistry, geology, etc. Such applications actually require appreciable amounts of beam time, meaning that a careful scheduling for radionuclide production and ‘other applications’ must be established. Besides, some interesting applications require not only protons, but also deuterons, helium-3 or a particles.

As a conclusion it can be stated that, if the cyclotron is used for both radionuclide production and scientific or industrial applications, a multi-particle, variable energy, and variable beam current (a few nA up to a few hundred mA) accelerator with several beam lines is the preferred cyclotron to be installed. Higher energy accelerators for industrial and specific applications are beyond the scope of this book.

The transition from a smaller, somewhat focused, facility to the more general research facility is often a gradual one, occurring over several years.

Some specific examples for these facilities and a few minimum requirements for type I–V facilities are given in Section 6.