title: 3-D-conformal radiation therapy for pediatric giant cell tumors of the skull base.
abstract: BACKGROUND
  Giant cell tumors (GCT) of the base of skull are rare neoplasms. This report reviews the treatment of four pediatric patients presenting with aggressive giant cell tumor, using fractionated and combined, conformal proton and photon radiation therapy at Massachusetts General Hospital and Harvard Cyclotron Laboratory.
  
  
  METHODS
  Three female patients and one adolescent male, ages 10-15 years, had undergone prior, extensive surgical resection(s) and were treated for either primary (two patients) or recurrent (two patients) disease. Gross residual tumor was evident in three patients and microscopic disease suspected in one patient. Combined proton and photon radiation therapy was based on three-dimensional (3-D) planning, consisting of fractionated treatment, one fraction per day at 1.8 CGE (cobalt-gray equivalent) to total target doses of 57.6, 57.6, 59.4, and 61.2 Gy/CGE.
  
  
  RESULTS
  With observation times of 3.1 years, 3.3, 5.3, and 5.8 years, all four patients were alive and well and remained locally controlled without evidence of recurrent disease. Except for one patient with partial pituitary insufficiency following radiotherapy for sellar recurrent disease, thus far no late effects attributable to radiation therapy have been observed.
  
  
  CONCLUSIONS
  3-D-conformal radiation therapy offers a realistic chance of tumor control for aggressive giant cell tumor in the skull base, either postoperatively or at time of recurrence. Conformal treatment techniques allow the safe delivery of relatively high radiation doses in the pediatric patient without apparent increase of side effects.
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA, USA. eugen.hug@hitchcock.org
authors.forename: Eugen B
authors.initials: EB
authors.lastname: Hug
authors.forename: Marc W
authors.initials: MW
authors.lastname: Muenter
authors.forename: Judy A
authors.initials: JA
authors.lastname: Adams
authors.forename: Alexander
authors.initials: A
authors.lastname: de Vries
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Rosenberg
authors.forename: John E
authors.initials: JE
authors.lastname: Munzenrider
mesh_terms: D000293:Adolescent; D002648:Child; D003131:Combined Modality Therapy; D003399:Craniotomy; D019583:Dose Fractionation, Radiation; D005260:Female; D018212:Giant Cell Tumor of Bone / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery; D011880:Radiotherapy Planning, Computer-Assisted; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal; D019292:Skull Base Neoplasms / Q000175:diagnosis / Q000532:radiotherapy* / Q000601:surgery; D014057:Tomography, X-Ray Computed