AIDA Lab

Targeted Alpha Therapy (TAT) is a new therapeutic modality in nuclear medicine based on the injection of alpha emitters coupled or not with biological vectors to treat patients with haematological or metastatic cancers. It is a very promising therapy whose rationale is based on the high cytotoxicity of alpha-particles and the limited irradiation of neighbouring tissues. This treatment modality is a major evolution in nuclear medicine. TAT indeed presents numerous new challenges to face in terms of production, radiochemistry, therapeutic indications, imaging, dosimetry and radiation protection. Three of the most promising alpha emitters, actinium-225, radium-223 and thorium-227, generate a decay chain producing alpha- and beta-emitters with short half-lives. This decay chain increases the tumouricidal potential of the treatment but it is also at the origin of the uncontrolled redistribution of radioactivity in the patient organs. With these "decay chain" alpha emitters, a mix of radionuclides will be present in the radiolabelling solution and inside the patient body. Toxicity has been observed in animal models due to this redistribution. It is essential, in the current of TAT development, to be able to follow, localise and quantify the micro-distribution of daughter radionuclides in tissues. This can only be done in preclinical experiments. The poor spatial resolution of imaging devices in clinics and the difficulty to acquire images from alpha emitters do not allow for sufficient high-resolution imaging on patients. The only imaging modality able to reach the required resolution is the autoradiography. However, current autoradiography devices do not allow for radionuclides discrimination on the images, in the presence of a mix of radionuclides. The autoradiography technology BeaQuant is developed by the AI4R company. It is based on a parallel ionisation multiplier gaseous detector. This new detector technology allows for the localisation of radioactive signals in real time. The BeaQuant characteristics make possible the development of Spectroscopic Alpha Autoradiography : i.e. a high-resolution (< 30 µm) imaging system able to display the radioactivity distribution in a solution or a tissue section and to discriminate 225Ac from its daughter radionuclides (221Fr, 217At and 213Bi). The "Laboratoire commun" AIDALab aims at proposing a new technological device and imaging, analysis and quantification process to help research labs and pharmaceuticals companies to address key challenges in the development of TAT. To that purpose, AIDALab will focus on three major research projects: i) technological innovation to develop Spectroscopic Autoradiographic Modalities (SAM) that are, in the end, able to produce imaging of each individual radionuclide present in a solution or a tissue ii) the development of a faster radiolabelling QC procedure using SAM iii) the development of new small-scale dosimetry methods to transform activity distribution images acquired with the BeaQuant into absorbed dose maps, essential to study treatment toxicity in normal tissues. AIDALab is composed by the AI4R company, based in Nantes, the develops new autoradiography devices and the "Nuclear Oncology" research lab (CRCI2NA) that has been focused on target radionuclide therapy and TAT for more than 20 years.