Combination of photon and proton radiation therapy for chordomas and chondrosarcomas of the skull base: the Centre de Protonthérapie D'Orsay experience.
OBJECTIVE
Prospective analysis of local tumor control, survival, and treatment complications in 44 consecutive patients treated with fractionated photon and proton radiation for a chordoma or chondrosarcoma of the skull base.


METHODS
Between December 1995 and December 1998, 45 patients with a median age of 55 years (14-85) were treated using a 201-MeV proton beam at the Centre de Protonthérapie d'Orsay, 34 for a chordoma and 11 for a chondrosarcoma. Irradiation combined high-energy photons and protons. Photons represented two-thirds of the total dose and protons one-third. The median total dose delivered within the gross tumor volume was 67 cobalt Gray equivalent (CGE) (range: 60-70).


RESULTS
With a mean follow-up of 30.5 months (range: 2-56), the 3-year local control rates for chordomas and chondrosarcomas were 83.1% and 90%, respectively, and 3-year overall survival rates were 91% and 90%, respectively. Eight patients (18%) failed locally (7 within the clinical tumor volume and 1 unknown). Four patients died of tumor and 2 others of intercurrent disease. In univariate analysis, young age at time of radiotherapy influenced local control positively (p < 0.03), but not in multivariate analysis. Only 2 patients presented Grade 3 or 4 complications.


CONCLUSIONS
In skull-base chordomas and chondrosarcomas, the combination of photons with a proton boost of one-third the total dose offers an excellent chance of cure at the price of an acceptable toxicity. These results should be confirmed with a longer follow-up.
Noël
G
G
Centre de Protonthérapie d'Orsay, Orsay, France. noel@ipno.in2p3.fr
Habrand
J L
JL
Mammar
H
H
Pontvert
D
D
Haie-Méder
C
C
Hasboun
D
D
Moisson
P
P
Ferrand
R
R
Beaudré
A
A
Boisserie
G
G
Gaboriaud
G
G
Mazal
A
A
Kérody
K
K
Schlienger
M
M
Mazeron
J J
JJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D002813:Chondrosarcoma / Q000401:mortality / Q000532:radiotherapy*; D002817:Chordoma / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017785:Photons / Q000627:therapeutic use*; D011446:Prospective Studies; D061766:Proton Therapy; D011832:Radiation Injuries / Q000150:complications; D019292:Skull Base Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D016019:Survival Analysis; D017211:Treatment Failure; D011522:Protons
D011522:Protons