Quantification of the volumetric benefit of image-guided radiotherapy (IGRT) in prostate cancer: margins and presence probability map

International audiencePURPOSE: To quantify the prostate and seminal vesicles (SV) anatomic variations in order to choose appropriate margins including intrapelvic anatomic variations. To quantify volumetric benefit of image-guided radiotherapy (IGRT). PATIENTS AND METHODS: Twenty patients, receiving a total dose of 70 Gy in the prostate, had a planning CT scan and eight weekly CT scans during treatment. Prostate and SV were manually contoured. Each weekly CT scan was registered to the planning CT scan according to three modalities: radiopaque skin marks, pelvis bone or prostate. For each patient, prostate and SV displacements were quantified. 3D maps of prostate and SV presence probability were established. Volumes including minimal presence probabilities were compared between the three modalities of registration. RESULTS: For the prostate intrapelvic displacements, systematic and random variations and maximal displacements for the entire population were: 5mm, 2.7 mm and 16.5mm in anteroposterior axis; 2.7 mm, 2.4mm and 11.4mm in superoinferior axis and 0.5mm, 0.8mm and 3.3mm laterally. Margins according to van Herk recipe (to cover the prostate for 90% of the patients with the 95% isodose) were: 8mm, 8.3mm and 1.9 mm, respectively. The 100% prostate presence probability volumes correspond to 37%, 50% and 61% according to the registration modality. For the SV, these volumes correspond to 8%, 14% and 18% of the SV volume. CONCLUSIONS: Without IGRT, 5mm prostate posterior margins are insufficient and should be at least 8mm, to account for intrapelvic anatomic variations. Prostate registration almost doubles the 100% presence probability volume compared to skin registration. Deformation of SV will require either to increase dramatically margins (simple) or new planning (not realistic)

Salivary gland-sparing other than parotid-sparing in definitive head-and-neck intensity-modulated radiotherapy does not seem to jeopardize local control.

International audienceBACKGROUND: The objective was to analyze locoregional (LR) failure patterns in patients with head-and-neck cancer (HNC) treated using intensity-modulated radiotherapy (IMRT) with whole salivary gland-sparing: parotid (PG), submandibular (SMG), and accessory salivary glands represented by the oral cavity (OC). METHODS: Seventy consecutive patients with Stage I-II (23%) or III/IV (77%) HNC treated by definitive IMRT were included. For all LR failure patients, the FDG-PET and CT scans documenting recurrence were rigidly registered to the initial treatment planning CT. Failure volumes (Vf) were delineated based on clinical, radiological, and histological data. The percentage of Vf covered by 95% of the prescription isodose (Vf-V95) was analyzed. Failures were classified as "in-field" if Vf--V95 >= 95%, "marginal" if 20% < Vf-V95 < 95%, and "out-of-field" if Vf-V95 <=20%. Correlation between Vf-V95 and mean doses (Dmean) in the PG, SMG, and OC was assessed using Spearman's rank-order correlation test. The salivary gland dose impact on the LR recurrence risk was assessed by Cox analysis. RESULTS: The median follow-up was 20 months (6--35). Contralateral and ipsilateral PGs were spared in 98% and 54% of patients, respectively, and contralateral and ipsilateral SMG in 26% and 7%, respectively. The OC was spared to a dose <=40 Gy in 26 patients (37%). The 2-year LR control rate was 76.5%. One recurrence was "marginal", and 12 were "in-field". No recurrence was observed in vicinity of spared structures. Vf-V95 was not significantly correlated with Dmean in PG, SMG, and OC. The LR recurrence risk was not increased by lower Dmean in the salivary glands, but by T (p = 0.04) and N stages (p = 0.03). CONCLUSION: Over 92% of LR failures occurred "in-field" within the high dose region when using IMRT with a whole salivary gland-sparing strategy. Sparing SMG and OC in addition to PG thus appears a safe strategy

Intérêt des nouvelles techniques d'imagerie dans le diagnostic da la maladie de Takayasu à la phase pré-occlusive

ROUEN-BU Médecine-Pharmacie (765402102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Evolution à 6 mois des images d'angio-scanner hélicoïdal au cours de l'embolie pulmonaire

ROUEN-BU Médecine-Pharmacie (765402102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Recalage Rigide Pour La Quantification Du Bénéfice Du Repositionnement Du Patient En Cas De Radiothérapie Pour Cancer De La Prostate.

International audienc

Mise à l’écart et embarras dans l’enquête en sciences sociales

Retour réflexif sur l’enquête et les conditions concrètes du travail de production scientifique lorsque l’inconfort ou la déstabilisation éthique et émotionnelle heurte le sens de la justice et de la justesse. La rupture épistémologique ne passe plus alors uniquement par la mise à distance mais par l’objectivation des réactions sensorielles devenant un levier pour la production de connaissances. Reflexive return on the investigation and the conditions of scientific production work when ethical and emotional discomfort or destabilization offends the sense of justice and accuracy. The epistemological rupture no longer only involves distance but also the objectification of sensory reactions, which become a lever for the production of knowledge. Retroalimentación reflexiva sobre la investigación y las condiciones del trabajo de producción científica cuando la incomodidad ética y emocional o la desestabilización ofenden el sentido de justicia y exactitud. La ruptura epistemológica ya no sólo implica la distancia, sino también la objetivación de las reacciones sensoriales, que se convierten en una palanca para la producción de conocimiento

Texte/image — Nouveaux problèmes

Ce volume collectif voudrait témoigner de la variété des questionnements et des approches que suscitent aujourd’hui les études engagées sur le terrain de la confrontation raisonnée des pratiques littéraires (tous genres confondus) et des artefacts artistiques visuels (des réalisations plastiques, figuratives ou non, aux images écrites). Il se propose de rendre compte de la vivacité d’une réflexion qui déplace les frontières notionnelles, redéfinit ses objets et décloisonne ses champs d’investigation et d’application. Le titre « Texte/Image : nouveaux problèmes » avoue cette intention, en même temps qu’il atteste, explicitement, le refus de tout parti pris théorique exclusif. Au dialogue du texte et de l’image correspond ainsi le dialogue ouvert ou le débat contradictoire des chercheurs qui ont participé au colloque de Cerisy-la-Salle et dont les communications recueillies dans le présent volume résument ou développent les propositions