Online measurement of fluence and position for protontherapy beams

Tumour therapy with proton beams has been used for several decades in many centres with very good results in terms of local control and overall survival. Typical pathologies treated with this technique are located in head and neck, eye, prostate and in general at big depths or close to critical organs. The Experimental Physics Department of the University of Turin and the local Section of INFN, in collaboration with INFN Laboratori Nazionali del Sud Catania and Centre de Protontherapie de Orsay Paris, have developed detector systems that allow the measurement of beam position and fluence, obtained in real time during beam delivery. The centre in Catania (CATANA: Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) has been treating patients with eye pathologies since spring 2002 using a superconducting cyclotron accelerating protons up to 62 MeV. This kind of treatments need high-resolution monitor systems and for this reason we have developed a 256-strip segmented ionisation chamber, each strip being 400 μm wide, with a total sensitive area 13 × 13 cm2. The Centre de Protontherapie de Orsay (CPO) has been operational since 1991 and features a synchrocyclotron used for eye and head and neck tumours with proton beams up to 200 MeV. The monitor system has to work on a large surface and for this purpose we have designed a pixel-segmented ionisation chamber, each pixel being 5×5 mm2, for a total active area of 16 × 16 cm2. The results obtained with two prototypes of the pixel and strip chambers demonstrate that the detectors allow the measurement of fluence and centre of gravity as requested by clinical specifications

Proton Therapy at the Institut Curie – CPO: operation of an IBA C235 cyclotron looking forward scanning techniques

Since 1991, more than 6100 patients (mainly eye and head&neck tumours) were treated at the Institut Curie – Centre de Protonthèrapie d’Orsay (IC – CPO) using Single Scattering and Double Scattering (DS) proton beam delivery technique. After 19 years of activity, a 200 MeV synchrocyclotron has been shut down and replaced by a 230 MeV C235 IBA proton cyclotron. This delivers beam to two passive fixed treatment rooms and to one universal nozzle equipped gantry (DS, Uniform Scanning – US, Pencil Beam Scanning – PBS). In the past two years of operation more than 95.5% of the scheduled patients (near 500/year) were treated without being postponed. According to IBA recommendations, we have realized preventive maintenance and we have improved some diagnostic tools allowing us to reduce the number of downtime events from 499 in 2011 to 351 in 2012 [1]. In order to enhance cancer treatment capabilities we are now involved in the transition towards scanning particle therapy, requiring even more accurate quality assurance protocols. We describe here the main cyclotron issues looking forward the scanning technique, the main goal being the progress of our reliability performances

Towards scanning particle therapy at the Institut Curie – Centre de Protontherapie d’Orsay: detectors characterisation and development for relative dose metrology

Since 2010, at the Institut Curie – CPO, a 230 MeV IBA proton cyclotron delivers beam to two passive fixed treatment rooms and to one universal nozzle equipped gantry. In order to improve cancer treatment capabilities we are now involved in the transition towards scanning particle therapy. We describe here possible solutions for its relative dose metrology

Practicability of protontherapy using compact laser systems

International audienceProtontherapy is a well-established approach to treat cancer due to the favorable ballistic properties of proton beams. Nevertheless, this treatment is today only possible with large scale accelerator facilities which are very difficult to install at existing hospitals. In this article we report on a new approach for proton acceleration up to energies within the therapeutic window between 60 and 200 MeV by using modern, high intensity and compact laser systems. By focusing such laser beams onto thin foils we obtained on target intensities of 6×10^19 W/cm^2, which is sufficient to produce a well-collimated proton beam with an energy of up to 10 MeV. These results are in agreement with numerical simulations and indicate that proton energies within the therapeutic window should be obtained in the very near future using such economical and very compact laser systems. Hence, this approach could revolutionize cancer treatment by bringing the “lab to the hospital—rather than the hospital to the lab.