Giles, UK) for position verification. The transporter, the CT scanner and the treatment gantries coupling systems have been designed to guarantee a positioning accuracy within 1 mm and the coupling/decoupling of the PLX-4720 mw table of both systems requires about 2 min. Gantry and CT scanner this website isocenters are coincident to allow the same positioning accuracy. Once the table is coupled to the CT scanner, orthogonal scout images are taken and compared with the corresponding ones generated
at the time of acquisition of the CT scan used for planning (acquired on the same CT scanner). On the basis of the daily images, translational corrections to the table at the treatment gantry are calculated to minimize patient misalignment. After completing imaging and analysis procedures, the patient and table are find more uncoupled from the CT scanner and moved into the treatment room. The distance from CT to treatment gantry is approximately 20 m, requiring approximately 2 min for transportation. Since there is a risk that the patient moves during transportation, scout images
are periodically acquired after irradiation (usually every 10th fraction), allowing an assessment of the extent of target movement and its consequences on the treatment dose delivery. The new delivery system at PSI, named GANTRY 2, not yet in use, has a robotic couch with three degrees of freedom that can transport the patient between the beam gantry and a CT scanner placed in the treatment room. In this way patient fixation and verification are performed directly in the treatment
room without an additional transportation system. The Centre de proton-therapie d’Orsay In hadrontherapy centres that have only fixed horizontal beams (i.e. most carbon ions centres and first generation protons centres), the beam incidence angles remain technically limited, especially for treatment of children under general anaesthesia needing posterior-oblique (40 degrees or so) beams in the supine position. Therefore at Orsay a system allowing the child positioning on a 30° inclined (left or right) treatment table while keeping the child under general anaesthesia has been recently developed . The supine position improves patient comfort and treatment quality and gives an easier approach to the anaesthetic team. The table is made of polystyrene Clostridium perfringens alpha toxin (with a maximum beam attenuation of 3%), is 79 cm long and allows 10° recovery and 40° incidence angles. Regarding the contention system, an easy transportable device, low production costs and reproducible patient positioning, is necessary. The chosen solution at Orsay is a 3 cm thick, 60 cm wide and 137 cm long polystyrene plate placed on the treatment table. The plate can be moved for any kind of lateral beam (from the left or right), and has a fixation system for the thermoformed mask and straps for patient contention. A carbon insert has been placed into the polystyrene plate to mask positioning.