Scintillating crystals: the best things come in small packages

The European project ENDO TOFPET-US, which involves a team from the PH Department, was officially launched last month. Its main objective is to design a high-performance medical imaging device for use in pancreatic cancer research. 13 partners (including three hospitals and three companies) are involved in the initiative, which has obtained funding of 5.5 million euros from the European Union's FP7 programme and will last for four years.


CERN researchers participating in the ENDO TOFPET-US project.

The scintillating crystals developed at CERN have a wide variety of applications, ranging from the LHC to use in hospitals. Now experts in the field, members of the PH Department are currently working on the development of a new type of crystal in the framework of the European project ENDO TOFPET-US. These new-generation crystals, which will be used in endoscopic probes for studying the biological processes associated with pancreatic cancer, are among the finest grown for medical imaging in the world.

Why pancreatic cancer? The particularly difficult feature of pancreatic cancer is that it remains asymptomatic for a long time. Not only are there no symptoms but, more significantly, there are no biomarkers that allow its presence to be detected so that when signs of the disease do eventually appear it is often too far advanced for its progress to be halted. It is therefore important to be able to identify the biological markers associated with the disease (such as the presence of given proteins in the blood) in the very early stages. However, this requires anatomical and functional images of the pancreas of a sufficient quality to reveal a very small tumour.

The Endo TOFPET-US endoscopic probe.

The device. The project, which is coordinated by the Université de la Méditerranée, is an ambitious one to say the least. "To obtain the very high-resolution images the cancer specialists need you have to get right up close to the tumour," explains Paul Lecoq of the PH Department, the project's technical coordinator. To be able to do this, the researchers are currently working on the creation of an innovative endoscopic probe designed to be inserted through the oesophagus into the stomach and down to the first section of the small intestine, which surrounds the pancreas. "The ENDO TOFPET-US endoscope will have a dual-mode imaging system. We'll use an ultrasound probe with a biopsy attachment plus a PET (Positron Emission Tomography) detector head," continues Lecoq. The ultrasound signals will provide an anatomical image of the tumour, while the PET head will supply highly detailed information about its activity and, indirectly, the associated proteins. The results of the imaging will be correlated with the biological analysis of the tumour.

An innovative micro-detector. The scintillating crystals, which have been industrially produced in close collaboration with CERN, represent a real technological challenge. They are essential components of the internal micro-detector and will have to be miniaturised to a length of just ten millimetres and a diameter of 750 microns to be able to be fitted on a PET endoscope head. As Positron Emission Tomography requires at least two detection points, the PET head will also be coupled with an external PET plate placed on the patient's stomach.

With its 324 miniature crystals, the endoscopic PET detector will be a jewel of technology, allowing tumours only a millimetre in size to be "seen". "Doctors hope to find the biomarkers of pancreatic cancer using the PET probe. Although technological development plays a vital role in the project, the goal is ultimately a medical one," underlines Lecoq. Following four years of collaboration, the ENDO TOFPET-US probe should be operational by December 2014.

by Anaïs Schaeffer