Analysis of the Toxicity and Efficacy of Daily 1 vs 2 Beam Proton Therapy

Inclusion Criteria

• •Chordoma, chondrosarcoma of the skull base and spine, Ewing's sarcoma, and osteosarcoma meeting the criteria for treatment by proton therapy
• •Tumour requiring 2 beams
• •MRI less than one month old
• •PS 0-2.
• •Patient who has read the patient information note and signed the consent form.
• •Patient with healthcare insurance cover.
• •Age over 18 years.
• •For women of childbearing age, negative urine pregnancy test and effective contraception in place for the duration of treatment and for six months following the end of treatment.