Carbon ion radiotherapy of skull base chondrosarcomas.
OBJECTIVE
To evaluate the effectiveness and toxicity of carbon ion radiotherapy in chondrosarcomas of the skull base.


METHODS
Between November 1998 and September 2005, 54 patients with low-grade and intermediate-grade chondrosarcomas of the skull base have been treated with carbon ion radiation therapy (RT) using the raster scan technique at the Gesellschaft für Schwerionenforschung in Darmstadt, Germany. All patients had gross residual tumors after surgery. Median total dose was 60 CGE (weekly fractionation 7 x 3.0 CGE). All patients were followed prospectively in regular intervals after treatment. 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
Median follow-up was 33 months (range, 3-84 months). Only 2 patients developed local recurrences. The actuarial local control rates were 96.2% and 89.8% at 3 and 4 years; overall survival was 98.2%at 5 years. Only 1 patient developed a mucositis CTCAE Grade 3; the remaining patients did not develop any acute toxicities >CTCAE Grade 2. Five patients developed minor late toxicities (RTOG/EORTC Grades 1-2), including bilateral cataract (n = 1), sensory hearing loss (n = 1), a reduction of growth hormone (n = 1), and asymptomatic radiation-induced white matter changes of the adjacent temporal lobe (n = 2). Grade 3 late toxicity occurred in 1 patient (1.9%) only.


CONCLUSIONS
Carbon ion RT is an effective treatment for low- and intermediate-grade chondrosarcomas of the skull base offering high local control rates with low toxicity.
Schulz-Ertner
Daniela
D
Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany. Daniela.Ertner@med.uni-heidelberg.de
Nikoghosyan
Anna
A
Hof
Holger
H
Didinger
Bernd
B
Combs
Stephanie E
SE
Jäkel
Oliver
O
Karger
Christian P
CP
Edler
Lutz
L
Debus
Jürgen
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D002247:Carbon Isotopes / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002813:Chondrosarcoma / Q000401:mortality / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D018365:Neoplasm, Residual; D061766:Proton Therapy; D011879:Radiotherapy Dosage; D016879:Salvage Therapy; D019292:Skull Base Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D015996:Survival Rate
D002247:Carbon Isotopes