Development of radiodetection systems towards miniaturised quality control of PET and SPECT radiopharmaceuticals

Abstract

The ability to detect radiation in microfluidic devices is important for the on-chip analysis of radiopharmaceuticals, but previously reported systems have largely suffered from various limitations including cost, complexity of fabrication, and insufficient sensitivity and/or speed. Here, we present the use of sensitive, low cost, small-sized, commercially available silicon photomultipliers (SiPMs) for the detection of radioactivity inside microfluidic channels fabricated from a range of conventional microfluidic chip substrates. We demonstrate the effects of chip material and thickness on the detection of the positron-emitting isotope, [(18)F]fluoride, and find that, while the SiPMs are light sensors, they are able to detect radiation even through opaque chip materials via direct positron and gamma (γ) ray interaction. Finally, we employed the SiPM platform for analysis of the PET (positron emission tomography) radiotracers 2-[(18)F]fluoro-2-deoxy-d-glucose ([(18)F]FDG) and [(68)Ga]gallium-citrate, and highlight the ability to detect the γ ray emitting SPECT (single photon emission computed tomography) radiotracer, [(99m)Tc]pertechnetate.

Monolith-based 68Ga processing: a new strategy for purification to facilitate direct radiolabelling methods

“…[17][18][19][20] Due to these characteristics monolith columns have shown their applications in a variety of chromatographic modes. [21][22][23][24] Importantly, the integration of monolith columns with microfluidic systems has already been demonstrated in an enzymatic reaction module. 25 If a cationexchange monolith can purify 68 Ga generator eluate, it would therefore be possible to build an integrated system comprising a monolith for ion-exchange and a microfluidic system for performing flow-based 68 Ga preparation and radiolabelling in an automated dose-on-demand system.…”

Suitability of a SiPM photodetector for implementation in an automated thermoluminescent dosimeter reader

“…This was determined for the SensL device studied using a lator that has found uses in a variety of applications from medical physics [44][45][46][47][48] to more fundamental research [49][50][51]. It was selected due to its high stopping power, which increases with both density and effective atomic number (ρ = 4.51 g/cm 3 , Z e f f = 54), very good light yield (54,000 photons/MeV), and it being the only scintillator in the laboratory that would physically fit on the space allowed by the SiPM evaluation board. As can be seen in Figure 4, CsI(Tl) has a peak wavelength at around 550 nm, somewhat offset from the peak responsivity of the SiPM at 420 nm, however the high light yield compensates for this mismatch.…”

“…The silicon photomultiplier (SiPM) is becoming increasingly popular in a variety of fields, from nuclear security [1,2], to radiopharmeceutical quality control [3], to health physics [4], to medical imaging [5,6], to name but a few. Effectively, any field that was formerly the domain of the photomultiplier tube is now rapidly being invaded with solid state technology.…”

18F-labelling innovations and their potential for clinical application

“…In spite of all those difficulties, several syntheses of clinically relevant 18 Last not least, another serious demand with regard to the production by microfluidics is the fulfilment of pharmaceutical regulations [241]. This includes the qualification of starting materials, the in-process control and particularly the quality control of single batch (dose-on-demand) productions [210,242,243].…”