[en] The use of heavy particles in the treatment of cancer is increasing remarkably, whether with external radiation or using a vector such as an antibody in radioimmunotherapy. Recent pre-clinical and clinical developments of alpha-radioimmunotherapy have provided more interesting information in parallel of the use of high Linear Energy Transfer (Let) external irradiation. This review aims at presenting recent advances of this therapeutic approach, and at detailing the biological specificities of this kind of radiation. (authors)

[en] The helical tomo-therapy allows a better dose homogeneity than the tri dimensional conformal radiotherapy while reducing the doses received by the majority of extra-cranial organs at risk, but this induces a significant increase of the percentage of sane tissue irradiated at low dose. (N.C.)

[en] The full text of the publication follows. The dysfunctions of the endothelium are clearly involved in early and late pathologies induced by radiotherapy [1]. Senescence, one of the alternative becoming of cells after radiation, is defined by cell cycle blockage and also by an increase of metabolic activity. Senescence presents therapeutic benefits by lowering the tumor progression and drawbacks by inducing vascular dysfunctions. Molecular pathways inducing radiation-induced senescence remain unclear, but may involve the generation of reactive oxygen species and the induction of DNA damage. Previously, our team describes a differential endothelial death response in function of the dividing cell status. Proliferating cells died after exposure to ionizing radiation through either a Ceramide generation-induced pre-mitotic apoptosis or a DNA damage-induced mitotic death. Non-dividing cells keep the ability to die by the ceramide-induced apoptosis, but not mitotic death. In fact, sphingosin-1-Phosphate, inhibitor of ceramide-dependent signaling pathway, blocks death of quiescent, but not proliferating endothelial cells [2]. However, consequences of DNA damage and their potential roles remain to be clarified. In consequence, our hypothesis is that remaining DNA-damage provokes radio-induced senescence on quiescent endothelial cells, which comprise the vascular functions in healthy tissues. This hypothesis will be verified by underlining X-rays-induced senescence in vitro (HUVEC and HMVEC-L) and in vivo (mouse and patient) on quiescent endothelial cells using Senescence-associated β-Galactosidase staining. Next, the involvement of ceramide and DNA-repair pathways in senescence progression will be explored. References: [1] Milliat F, et al. Role of endothelium in radiation-induced normal tissue damages. Ann Cardiol Angeiol. 2008; 57: 139-148. [2] Bonnaud S, et al. Sphingosine-1-Phosphate Protects Proliferating Endothelial Cells from Ceramide-Induced Apoptosis but not from DNA Damage-Induced Mitotic Death. Cancer Res. 2007; 67: (4): 1803-1811. (authors)

[en] The principle of radioimmunotherapy is to vectorize radioisotopes to the vicinity of tumor cells where radiation can destroy these targets. The most currently established protocols use beta-emitters. Recently, new RIT approaches using alpha radiation have been developed. These types of radiation, unlike beta emissions, have a high LET, i.e. the energy deposit related to the emission of an alpha particle is high and is performed over a short pathway of several tens of lm. Thus, this type of emission allows very localized irradiation to be performed, while preserving surrounding tissues, and cellular toxicity is achieved with only a few disintegrations at the cell surface. Unlike beta-emitters, alpha-emitters, because of their short range of action, seem more suitable for the treatment of diffuse cancers or micro metastasis subsequent to ablation of a primary tumour. However, the few radionuclides required for cell destruction in this case require very specific targeting of tumor cells. To date, alpha RIT is still at a pre-clinical stage of development: the radiolabeling methods need to be optimized to ensure in vivo stability of the radio-pharmaceuticals. The modalities of administration of radiolabeled antibodies in animal models require also to be improved for delivering higher doses to tumor targets. A comprehensive analysis of the specific events occurring at cell or tissue level in response to alpha irradiation would be of great interest in order to define the best therapeutic association, chemotherapy or the possibilities of initiating immune response to tumors in patients treated by alpha-RIT. (authors)

[en] Patients who survive a cancer occurring during childhood or young adulthood, treated with radiation, are at a very high risk of chronic sequelae and secondary tumours. To reduce this radioinduced morbidity and mortality, efforts are put on reducing the burden of the treatments and a long-term monitoring of these patients is progressively organized. We present a general review of the literature about the risk factors for developing a secondary breast cancer, which is the most frequent secondary tumour in this population. We suggest that contouring the prepubescent breast as an organ at risk may help predict the risk and reduce the dose to the breasts using modern radiotherapy techniques. (authors)

No abstract available

[en] Introduction: The aim of this work was to report the experience of image-guided radiotherapy at the C.L.C.C. Nantes-Atlantique using three repositioning imaging devices, the ExacTrac (BrainLABTM), the on-board imager cone beam computed tomography (O.B.I.-C.B.C.T.) (Varian^TM) and the M.V.C.T. (Tomotherapy Inc^TM), in the case of prostate external radiotherapy.Material and methods: For each linac and its imaging device, a treatment plan was described. Moreover, studies concerning calculated shifts after imaging sessions were achieved. Using ExacTrac, for eight patients, a study compared daily shifts based on bony anatomy or on implanted markers. Considering mean values of displacements over a course of radiotherapy, dosimetric impact was evaluated. With the O.B.I.-C.B.C.T., two imaging modalities were used, kV-kV (0. and 270.) and C.B.C.T.. Up to now, whatever the images, displacements were calculated using the bony anatomy. For both modalities and for 26 patients, shifts were compared. Since the beginning of the Tomotherapy HiArt use, mega voltage cone tomography (M.V.C.T.) was performed for each session of each patient. For 12 patients, mean displacements were calculated after five fractions. Then the deviations to those values were calculated. This was done to show the relevance of daily M.V.C.T.. Results and conclusion: This work allows us to report the use of three repositioning imaging devices in the radiotherapy department. At least: they provide an efficient positioning tool. And they let us see the future radiotherapy which would probably be the dose-guided radiotherapy. (N.C.)

[en] The authors discuss the results obtained on 58 patients suffering from a biochemical recurrence after a first radical and initial treatment of a prostatic cancer, and who have been treated by a Positron Emission Tomography (PET) with F-18 fluorine choline. The remedial high-dose image-guided intensity-modulated conformational radiation therapy technique appeared to be efficient with a low toxicity. It therefore may lead to a new remission. Short communication

[en] Follow-up after prostate cancer radiotherapy aims at detecting local or metastatic relapse, as well as long-term toxicity, requiring adapted treatments. Several scientific societies have published guidelines including clinical, biological and imaging recommendations. More data suggest a role for aggressive salvage therapy in case of local failure following radiotherapy. An adequate follow-up is required for the sake of patients' safety, i.e. to a posteriori validate dose constraints and radiation technique in each radiotherapy department. (authors)

[en] The objective of this study is to take stock on the validated and potential indications of the conformal radiotherapy with intensity modulation ( intensity modulated radiotherapy I.M.R.T.) in pediatrics and to propose recommendations for its use as well as the adapted dose constraints. About 40 to 50% of children treated for a cancer are irradiated. The I.M.R.T., by linear accelerator or helical tomo-therapy has for aim to give a homogenous dose to the target volume and to save organs at risk. Its use in pediatrics seems particularly interesting because of the complexity of target volumes and the closeness of organs at risk. In compensation for these positive elements, the importance of low doses irradiation given in big volumes makes fear event consequences on growth and an increased incidence of secondary cancers in children suffering from tumors with high cure rates and long life expectancy. (N.C.)