The proton therapy system for MGH's NPTC: equipment description and progress report.

At the beginning of 1994, the Massachusetts General Hospital (MGH) of the Harvard Medical School in Boston (MA, USA) a pioneer in proton therapy since 1959, selected a team led by Ion Beam Applications SA (IBA) to supply the proton therapy equipment of its new Northeast Proton Therapy Centre (NPTC). The IBA integrated system includes a compact 235 MeV isochronous cyclotron, a short energy selection system transforming the fixed energy beam extracted from the cyclotron into a variable energy beam, one or more isocentric gantries fitted with a nozzle, a system consisting of one or more horizontal beam lines, a global control system including an accelerator control unit and several independent but networked therapy control stations, a global safety management system, and a robotic patient positioning system. The present paper presents the equipment being built for the NPTC.