["New Modalities in Cancer Imaging and Therapy" XVth edition of the workshop organized by the network "Tumor Targeting, Imaging, Radiotherapies" of the Cancéropôle Grand-Ouest, 5-8 October 2022, France]. / « New Modalities in Cancer Imaging and Therapy ¼ XVe édition de l'atelier organisé par le réseau « Vectorisation, Imagerie, Radiothérapies ¼ du Cancéropôle Grand-Ouest, 5­8 octobre 2022, Erquy, France.

The fifteenth edition of the international workshop organized by the "Tumour Targeting and Radiotherapies network" of the Cancéropôle Grand-Ouest focused on the latest advances in internal and external radiotherapy from different disciplinary angles: chemistry, biology, physics, and medicine. The workshop covered several deliberately diverse topics: the role of artificial intelligence, new tools for imaging and external radiotherapy, theranostic aspects, molecules and contrast agents, vectors for innovative combined therapies, and the use of alpha particles in therapy.

["Imaging of diagnostic and therapeutic biomarkers in oncology" XIIIth edition of the workshop organised by the « Vectorisation, Imagerie, Radiothérapies ¼ network of the Cancéropôle Grand-Ouest, September 25-28, 2019, Le Bono, France]. / "Imaging of diagnostic and therapeutic biomarkers in oncology" XIIIe édition du workshop organisé par le réseau « Vectorisation, Imagerie, Radiothérapies ¼ du Cancéropôle Grand-Ouest, 25­28 septembre 2019, Le Bono, France.

The thirteenth edition of the workshop focused on the last developments on oncologic imaging techniques. Our goal was purposely large, consisting in bringing together chemists, biologists, physicists, pharmacists and physicians to discuss these imaging developments. The meeting focused in four main topics: i) the evolution of imaging modalities such as photoacoustic or the latest PET (positrons emission tomography) imaging progress; ii) the improvements in imaging process; iii) the numerous contributions of chemistry towards medical imaging and iv) novel approaches of nuclear medicine in therapeutic monitoring strategies and theranostic aspects.

["Adaptation of the tumour and its ecosystem to radiotherapies: Mechanisms, imaging and therapeutic approaches" XIVth edition of the workshop organised by the "Vectorisation, Imagerie, Radiothérapies" network of the Cancéropôle Grand-Ouest, 22-25 September 2021, Le Bono, France]. / « Adaptation of the tumour and its ecosystem to radiotherapies: Mechanisms, imaging and therapeutic approaches ¼ XIVe édition du workshop organisé par le réseau « Vectorisation, Imagerie, Radiothérapies ¼ du Cancéropôle Grand-Ouest, 22­25 septembre 2021, Le Bono, France.

The fourteenth edition of the workshop covered the latest advances in internal and external radiotherapy obtained through a better understanding of the adaptive capacity of the tumor and its microenvironment, from different disciplinary angles, chemistry, biology, physics, and medicine, paving the way for numerous technological innovations. The biological aspects and the contribution of imaging in monitoring and understanding the adaptation of tumors to radiotherapy were presented, before focusing on innovative radiotherapy strategies and machine learning and data-driven techniques. Finally, the challenges were explored in the radiobiology of targeted radionuclide therapy as well as data science and machine learning in radiomics.

Purification of [18F]-fluoro-L-thymidine ([18F]-FLT) for positron emission tomography imaging.

3'-Deoxy-3'-[18F]fluorothymidine ([18F]-FLT) has recently been described as a positron emission tomography (PET) radiopharmaceutical for visualizing cellular proliferation in vivo. All published radiosyntheses of [18F]-FLT provide crude products that must be purified before injection to human. This study describes a reliable purification procedure for [18F]-FLT. It is based on HPLC. In 17.9+/-0.5 min, pure [18F]-FLT is obtained that could be injected to human after a passage through a sterile 0.22 microm filter.

[Is 3'-deoxy-3'- [18F] fluorothymidine ([18F]-FLT) the next tracer for routine clinical PET after R [18F]-FDG?]. / La 3'-déoxy-3'-[18F] fluorothymidine ([18F]-FLT) est-elle le prochain traceur utilisé en routine pour la TEP après le [18F]-FDG?

Positron emission tomography (PET) with [18F]-FDG is now firmly established as a clinical tool in oncology. Its applications are however limited in some indications, due to the lack of specificity of its uptake mechanism for tumors, or the low avidity of some cancer types such as prostate. Alternative tracers are thus being developed, in order to fill up this void. Proliferation as a biological target is particularly attractive in cancer imaging. From that perspective, fluorothymidine ([18F]-FLT or FLT) has generated a strong interest among the scientific community, especially since the radiosynthesis process has been improved and simplified, thus making possible to envision a routine use for the tracer. This article aims at summarizing the status of the current scientific data regarding FLT. The uptake mechanism of FLT is well known, relying on the thymidine kinase 1 (TK1) enzymatic activity, and thus on DNA synthesis. Preclinical studies have shown a clear relationship between tracer accumulation and level of tumor proliferation, even though DNA salvage pathwayss intervene in the process and may complicate the interpretation of the results. Several clinical studies suggest a good specificity for tumor, albeit with a lower sensitivity than with FDG. In all likelihood however, the future of FLT lies in the evaluation of antitumor response and possibly the pretherapeutic prognostic characterization, rather than in the diagnosis and staging of malignancies. Although the scientific data regarding this issue remain limited, initial results are encouraging. Further significant work remains to be done in order to fully assess the clinical performances of the tracer, on the one hand, and to determine its place relative to FDG and other emerging tracers, on the other hand. Until these studies are completed, FLT should be considered as a promising tracer, but remaining at an experimental stage of its development.