title: Changes in tumor volume of sacral chordoma after carbon ion radiotherapy.
abstract: OBJECTIVE
  We evaluated changes in tumor volume in cases of sacral chordoma after carbon ion radiotherapy.
  
  
  METHODS
  Thirty-four patients with sacral chordoma underwent carbon ion radiotherapy between June 1996 and June 2003. We assessed 23 patients without previous surgery using T2-weighted magnetic resonance imaging. The tumor volume was calculated semiautomatically.
  
  
  RESULTS
  Two cases showed local recurrence. The median interval of this examination was 46 months. At the end of the treatment, the tumor showed an enlargement larger than 10% of its volume in 13 of the 23 cases, no change in 4 cases, and regression in 6 cases. At the last examination, 20 cases showed a reduction in tumor volume, and the median ratio, determined as the tumor volume at the last examination divided by that before the treatment, was 0.36.
  
  
  CONCLUSIONS
  An increase in tumor volume at the end of the treatment does not indicate the ineffectiveness of carbon ion radiotherapy.
authors.affiliation: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Serizawa
authors.forename: Reiko
authors.initials: R
authors.lastname: Imai
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuji
authors.forename: Riwa
authors.initials: R
authors.lastname: Kishimoto
authors.forename: Susumu
authors.initials: S
authors.lastname: Kandatsu
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Tsujii
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Tatezaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000000981:diagnostic imaging; D002250:Carbon Radioisotopes / Q000627:therapeutic use*; D002817:Chordoma / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D018714:Radiotherapy, Adjuvant; D012447:Sacrum / Q000473:pathology* / Q000601:surgery; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D002250:Carbon Radioisotopes