Reducing the cost of PET tracers to bring molecular imaging diagnostics to more people
Getting access to the best diagnostic techniques available is the first step towards a solution to your problem. If it’s a broken arm, you need to get an X-ray to understand the type of break and therefore the type of treatment. If it’s cancer you need to undergo a series of examinations to understand the type of cancer you have and its stage of development. Many people nowadays have heard of CT scans or MR, but how many have heard about PET?
PET is an acronym for Positron Emission Tomography. It is a type of radioactive imaging that typically involves injecting a small quantity of a substance, called a tracer, into a patient and then following the distribution of the tracer as it moves through the body. It’s an incredibly sensitive technique that can produce results with quantities of a tracer as small as the amount of DNA found in a droplet of blood. The secret in PET lies in the tracer. If you choose the right tracer, you can look inside the body and see how it is working, down at the molecular level! In practical terms that might mean that you can see the effects of chemotherapy on a tumor long before the mass of the tumor has started to shrink. You can do that by watching the rate of consumption of a ‘fuel’ that is required for cell division. It’s simply a matter of using the right tracer.
The reason you may not have heard about PET is that today it is not offered at every hospital. It really comes down to economics. Tracers need to be prepared fresh because their radioactivity decaysover times ranging from minutes to hours. This preparation requires a substantial investment in a lab called a Radiopharmacy. Only the larger hospitals can afford the space, manpower, and equipment, needed for a Radiopharmacy. It can amount to $4MM, 200m2, 100 tonnes of radioactivity shielding, and 2-4 skilled personnel. Another cost challenge is that even the large hospitals can only use their equipment economically if they manufacture batches of tracers for many patients at the same time. Batches of the same tracer for many patients also means that preparing the right tracer for the condition under investigation may not be possible unless there are many patients waiting for the same test, at the same time.
Microfluidics is a technology that can be used to create miniature fluid analysis or processing systems by connecting together tiny reactors and other components, with tubing that can be smaller than a hair.
Microfluidics can help by making smaller machines that lead to cheaper and simpler production of tracers on a small scale. This is important because it addresses one of the infrastructure barriers that prevent small clinics from including PET in their portfolio of tools. At the same time it also allows everyone, big or small, to produce single patient doses of PET tracers in a cost-effective process. A microfluidic PET tracer synthesizer is envisioned as a machine that can sit on top of a table, has all the radiation protection built into the box, and is as easy to use as a coffee machine. Users would load a cartridge into the machine, press a button, and wait until the tracer synthesis is complete.
At GE we have been working on the PET tracer ‘espresso machine’ for some time now. Piece by piece we have been exploring and testing components that could one day be combined in a microfluidic PET tracer synthesizer. So far the results have been very promising.
Await with interest this micrifluidic expresso machine !