[Radiation therapy for chordomas and chondrosarcomas of the base of the skull and cervical spine].
OBJECTIVE
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.


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.


CONCLUSIONS
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.
Centre de protonthérapie, BP 65, 91402 Orsay Cedex, France. noel@ipno.in2p3.fr
Georges
G
Noël
Eric
E
Jauffret
Renaud De
RD
Crevoisier
Jean-Louis
JL
Habrand
Hamid
H
Mammar
Christine
C
Haie-Meder
Dominique
D
Hasboun
Régis
R
Ferrand
Gilbert
G
Boisserie
Dominique
D
Pontvert
Anne
A
Beaudré
Geneviève
G
Gaboriaud
Alexandre
A
Mazal
Ferran
F
Guedea
Lourdes
L
Petriz
Jean-Jacques
JJ
Mazeron
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae; D002813:Chondrosarcoma / Q000532:radiotherapy*; D002817:Chordoma / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D006801:Humans; D008875:Middle Aged; D017785:Photons / Q000009:adverse effects / Q000627:therapeutic use; D011446:Prospective Studies; D061766:Proton Therapy; D011522:Protons / Q000009:adverse effects; D011882:Radiotherapy, High-Energy / Q000009:adverse effects / Q000379:methods*; D019292:Skull Base Neoplasms / Q000532:radiotherapy*
D011522:Protons