title: Radiosurgery for cranial base chordomas and chondrosarcomas.
abstract: OBJECTIVE
  To evaluate the efficacy and toxicity of radiosurgery in the treatment of cranial base chordoma and chondrosarcoma.
  
  
  METHODS
  We reviewed 29 patients with cranial base chordoma (n = 25) or chondrosarcoma (n = 4) who underwent stereotactic radiosurgery between September 1990 and December 2002. The median patient age was 45 years (range, 10-81 yr). Nineteen patients also had radiation therapy before or in conjunction with radiosurgery (median dose, 50.4 Gy). The median tumor volume was 14.4 cm3 (range, 0.6-65.1 cm3). The median tumor margin dose was 15 Gy (range, 10-20 Gy); the median maximum radiation dose was 30 Gy (range, 20-40 Gy). Median clinical and imaging follow-up periods were 4.8 and 4.5 years, respectively.
  
  
  RESULTS
  Seven chordoma patients (28%) had tumor progression (in-field, n = 3; out-of-field, n = 4), whereas 18 had stable disease or tumor shrinkage. No patient with a chondroid chordoma had tumor enlargement. The actuarial tumor control rates were 89 and 32% at 2 and 5 years, respectively. All 4 patients with chondrosarcoma had tumor control. Clinically, 7 patients (24%) had improvement of pretreatment symptoms, 16 (55%) remained stable, and 6 (21%) worsened. Three patients with tumor progression died. Ten patients (34%) had radiation-related complications. Complications included cranial nerve deficits (n = 6), radiation necrosis (n = 5), and pituitary dysfunction (n = 3). Patients having radiosurgery alone had no toxicity.
  
  
  CONCLUSIONS
  Cranial base chordomas and chondrosarcomas remain a formidable management challenge. Radiosurgery as an adjunct to surgical resection provides in-field tumor control for some patients, but radiation-related complications are relatively high, especially when radiosurgery is combined with fractionated radiation therapy.
authors.affiliation: Division of Radiation Oncology, Department of Oncology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Sunil
authors.initials: S
authors.lastname: Krishnan
authors.forename: Robert L
authors.initials: RL
authors.lastname: Foote
authors.forename: Paul D
authors.initials: PD
authors.lastname: Brown
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Pollock
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
authors.forename: Yolanda I
authors.initials: YI
authors.lastname: Garces
mesh_terms: D002813:Chondrosarcoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D002817:Chordoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery; D012189:Retrospective Studies; D019292:Skull Base Neoplasms / Q000601:surgery*; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome