title: Highly effective treatment of skull base chordoma with carbon ion irradiation using a raster scan technique in 155 patients: first long-term results.
abstract: BACKGROUND
  The current study was conducted to evaluate the long-term results of irradiation with carbon ions in a raster scanning technique in patients with skull base chordomas.
  
  
  METHODS
  Between 1998 and 2008, a total of 155 patients (76 men and 79 women) with a median age of 48 years (range, 15 years-85 years) were irradiated with carbon ions using a raster scan technique. The irradiation was performed at the Society for Heavy Ion Research in Darmstadt, Germany. The median total dose was 60 gray (relative biological effectiveness) at 3 gray (relative biological effectiveness) per fraction. The median boost planning target volume was 70 mL (range, 2 mL-294 mL). Local control (LC) and overall survival (OS) were evaluated using the Kaplan-Meier method, whereas long-term toxicity was evaluated via questionnaires.
  
  
  RESULTS
  The median follow-up was 72 months (range, 12 months-165 months). All patients had residual macroscopic tumors at the initiation of radiotherapy. The authors observed 55 local recurrences during follow-up, as well as systemic disease progression in 4 patients. The resulting 3-year, 5-year, and 10-year LC rates were 82%, 72%, and 54%, respectively, whereas the 3-year, 5-year, and 10-year OS rates were 95%, 85%, and 75%, respectively. Age <48 years and a boost volume >75 mL were associated with a significantly improved LC and OS. Primary treatment resulted in a significantly better OS probability. No higher late toxicity could be detected after carbon ion treatment.
  
  
  CONCLUSIONS
  Carbon ion therapy appears to be a safe and effective treatment for patients with skull base chordoma, resulting in high LC and OS rates.
authors.affiliation: Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany; Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Uhl
authors.forename: Matthias
authors.initials: M
authors.lastname: Mattke
authors.forename: Thomas
authors.initials: T
authors.lastname: Welzel
authors.forename: Falk
authors.initials: F
authors.lastname: Roeder
authors.forename: Jan
authors.initials: J
authors.lastname: Oelmann
authors.forename: Gregor
authors.initials: G
authors.lastname: Habl
authors.forename: Alexandra
authors.initials: A
authors.lastname: Jensen
authors.forename: Malte
authors.initials: M
authors.lastname: Ellerbrock
authors.forename: Oliver
authors.initials: O
authors.lastname: Jäkel
authors.forename: Thomas
authors.initials: T
authors.lastname: Haberer
authors.forename: Klaus
authors.initials: K
authors.lastname: Herfarth
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002250:Carbon Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D002817:Chordoma / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D019292:Skull Base Neoplasms / Q000473:pathology / Q000532:radiotherapy*
chemical_list: D002250:Carbon Radioisotopes
keywords: carbon ion; chordoma; heavy ion; proton; radiotherapy; skull base