title: [Respiratory gated radiotherapy: the 4D radiotherapy].
abstract: Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart...) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath hold techniques or respiration synchronized gating techniques. Breath hold techniques can be achieved with active, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily breath-hold. Synchronized gating techniques use external devices (CCD camera for the GEMS/Varian system tested at Curie Institute) to predict the phase of the respiration cycle while the patient breaths freely. A new strategy is currently developed: the 4D Respiration correlated CT. It consists of retrospectively reconstruct CT slices at different phases of the breathing cycle allowing to measure residual movements and to choose the optimal patient's breathing phase where tumor movements are lower. These techniques presently investigated in several medical centers worldwide. The first results are very promising.
authors.affiliation: Département d'oncologie-radiothérapie, Institut Curie, 26, rue d'Ulm, 75005 Paris. philippe.giraud@curie.net
authors.forename: Philippe
authors.initials: P
authors.lastname: Giraud
authors.forename: Luc
authors.initials: L
authors.lastname: Simon
authors.forename: Marie
authors.initials: M
authors.lastname: Saliou
authors.forename: François
authors.initials: F
authors.lastname: Reboul
authors.forename: Robin
authors.initials: R
authors.lastname: Garcia
authors.forename: Christian
authors.initials: C
authors.lastname: Carrie
authors.forename: Ulrike
authors.initials: U
authors.lastname: Lerolle
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Rosenwald
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Cosset
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy; D006801:Humans; D008113:Liver Neoplasms / Q000532:radiotherapy; D008175:Lung Neoplasms / Q000532:radiotherapy*; D009068:Movement; D020266:Radiotherapy, Conformal / Q000379:methods*; D012119:Respiration