Effectiveness of carbon ion radiotherapy in the treatment of skull-base chordomas.
OBJECTIVE
The aim of this study was to evaluate the effectiveness and toxicity of carbon ion radiotherapy in chordomas of the skull base.


METHODS
Between November 1998 and July 2005, a total of 96 patients with chordomas of the skull base have been treated with carbon ion radiation therapy (RT) using the raster scan technique at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany. All patients had gross residual tumors. Median total dose was 60 CGE (range, 60-70 CGE) delivered in 20 fractions within 3 weeks. Local control and overall survival rates were calculated using the Kaplan-Meier method. Toxicity was assessed according to the Common Terminology Criteria (CTCAE v.3.0) and the Radiation Therapy Oncology Group (RTOG) / European Organization for Research and Treatment of Cancer (EORTC) score.


RESULTS
Mean follow-up was 31 months (range, 3-91 months). Fifteen patients developed local recurrences after carbon ion RT. The actuarial local control rates were 80.6% and 70.0% at 3 and 5 years, respectively. Target doses in excess of 60 CGE and primary tumor status were associated with higher local control rates. Overall survival was 91.8% and 88.5% at 3 and 5 years, respectively. Late toxicity consisted of optic nerve neuropathy RTOG/EORTC Grade 3 in 4.1% of the patients and necrosis of a fat plomb in 1 patient. Minor temporal lobe injury (RTOG/EORTC Grade 1-2) occurred in 7 patients (7.2%).


CONCLUSIONS
Carbon ion RT offers an effective treatment option for skull-base chordomas with acceptable toxicity. Doses in excess of 75 CGE with 2 CGE per fraction are likely to increase local control probability.
Schulz-Ertner
Daniela
D
Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany.Daniela.Ertner@med.uni-heidelberg.de
Karger
Christian P
CP
Feuerhake
Alexandra
A
Nikoghosyan
Anna
A
Combs
Stephanie E
SE
Jäkel
Oliver
O
Edler
Lutz
L
Scholz
Michael
M
Debus
Jürgen
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D002250:Carbon Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D002817:Chordoma / Q000401:mortality / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D018365:Neoplasm, Residual; D011832:Radiation Injuries / Q000209:etiology; D011879:Radiotherapy Dosage; D019292:Skull Base Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D016019:Survival Analysis
D002250:Carbon Radioisotopes