Carbon ion radiotherapy for chordomas and low-grade chondrosarcomas of the skull base. Results in 67 patients.
OBJECTIVE
To prospectively evaluate outcome and toxicity after carbon ion radiotherapy (RT) in chordomas and low-grade chondrosarcomas.


METHODS
Between September 1998 and December 2001, 74 patients were treated for chordomas and chondrosarcomas with carbon ion RT at the "Gesellschaft für Schwerionenforschung" (GSI). Seven patients reirradiated with reduced carbon ion doses after conventional RT were excluded from the analysis, leaving 67 evaluable patients (44 chordomas and 23 chondrosarcomas) who received a full course of carbon ion therapy. Tumor-conform application of carbon ion beams was realized by intensity-controlled raster scanning with active energy variation. Three-dimensional treatment planning included intensity modulation and biological plan optimization. A median dose of 60 GyE was applied to the target volume within 20 consecutive days at a dose of 3.0 GyE per fraction.


RESULTS
Median follow-up was 15 months (range 3-46 months). At 3 years, actuarial local control was 100% for chondrosarcomas and 87% for chordomas, respectively. Partial tumor remission was observed in 14/44 (31%) chordoma patients and in 4/23 (17%) chondrosarcoma patients. At 3 years, actuarial overall survival was 100% for chondrosarcomas and 89% for chordomas, respectively. No severe side effects > CTC degrees III have been observed.


CONCLUSIONS
These data demonstrate the clinical efficiency and safety of scanning beam delivery of carbon ion beams in patients with skull base chordomas and chondrosarcomas. The observation of tumor regressions at a dose level of 60 GyE may indicate that the biological effectiveness of carbon ions in chordomas and chondrosarcomas is higher than initially estimated.
Schulz-Ertner
Daniela
D
Department of Clinical Radiology, University of Heidelberg, Germany. d.ertner@dkfz.de
Nikoghosyan
Anna
A
Thilmann
Christoph
C
Haberer
Thomas
T
Jäkel
Oliver
O
Karger
Christian
C
Scholz
Michael
M
Kraft
Gerhard
G
Wannenmacher
Michael
M
Debus
Jürgen
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon / Q000627:therapeutic use; D002813:Chondrosarcoma / Q000175:diagnosis / Q000532:radiotherapy*; D002817:Chordoma / Q000175:diagnosis / Q000532:radiotherapy*; D017321:Clinical Trials, Phase I as Topic; D017322:Clinical Trials, Phase II as Topic; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D063193:Heavy Ion Radiotherapy; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D019292:Skull Base Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D016019:Survival Analysis; D013997:Time Factors
D002244:Carbon