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Sarcomas are a common type of tumor within the pediatric population. The utilization of proton therapy as a primary attribute the ability to spare adjacent healthy tissue, therefore, proton therapy has become a preferential indication in pediatrics compared to other photon irradiation modalities. Proton therapy is also a proven and historically validated irradiation technique in the treatment of chondrosarcomas and chordomas of the skull base and spine. Additionally, proton therapy can potentially limit irradiated healthy tissue volumes in adults and limit the risk of acute and late toxicities. The evaluation of the effectiveness of proton therapy in sarcomas is underway in many clinical situations in prospective trials, some of which are randomized., (Copyright © 2018 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.)

Purpose: Prospective analysis of local tumour control, survival and treatment complications in 67 consecutive patients treated with fractionated photon and proton radiation for a chordoma or a chondrosarcoma of the base of the skull and of the cervical spine., Patients and Methods: Between December 1995 and January 2000, 67 patients with a median age of 52.3 years (14-85), were treated using 201 MeV proton beam of the centre de protonthérapie d'Orsay (CPO), 49 for a chordoma and 18 for a chondrosarcoma. Irradiation combined high-energy photons and protons. Photons represented 2/3 of the total dose and protons 1/3. The median total dose delivered within gross tumour volume was 67 Cobalt Gray Equivalent (CGE) (60-70)., Results: With a mean follow-up of 32 months (4-71), the 3-year local control rates were for chordomas and chondrosarcomas of 70.8% and 85.2%, respectively and 4-year overall survival rates of 87.7% and 75%, respectively. Fourteen tumours (21.5%) failed locally (eight within the gross tumor volume, four into the CTV and 2 in an unknown site). Seven patients died of tumour and one of intercurrent disease. In univariate analysis, age inférieur ou égal à 52.3 years (p = 0.002), maximum tumoral diameter < 44.7 mm (p = 0.02) and GTV < 28.4 mL (0.02), at time of radiotherapy, influenced positively the local control. According to multivariate analysis, only age was an independent prognostic factor of local control. Only five (7.7%) patients presented grade 3 or 4 complications., Conclusion: In base of skull chordomas and chondrosarcomas, the combined photon and proton therapy offers excellent chances of cure at the price of an acceptable toxicity. These results should be confirmed with a longer follow-up.