title: Improved local control with stereotactic radiosurgical boost in patients with nasopharyngeal carcinoma.
abstract: OBJECTIVE
  Treatment of nasopharyngeal carcinoma using conventional external beam radiotherapy (EBRT) alone is associated with a significant risk of local recurrence. Stereotactic radiosurgery (STR) was used to boost the tumor site after EBRT to improve local control.
  
  
  METHODS
  Forty-five nasopharyngeal carcinoma patients received a STR boost after EBRT at Stanford University. Seven had T1, 16 had T2, 4 had T3, and 18 had T4 tumors (1997 American Joint Commission on Cancer staging). Ten had Stage II, 8 had Stage III, and 27 had Stage IV neoplasms. Most patients received 66 Gy of EBRT delivered at 2 Gy/fraction. Thirty-six received concurrent cisplatin-based chemotherapy. STR was delivered to the primary site 4-6 weeks after EBRT in one fraction of 7-15 Gy.
  
  
  RESULTS
  At a medium follow-up of 31 months, no local failures had occurred. The 3-year local control rate was 100%, the freedom from distant metastasis rate was 69%, the progression-free survival rate was 71%, and the overall survival rate was 75%. Univariate and multivariate analyses revealed N stage (favoring N0-N1, p = 0.02, hazard ratio HR 4.2) and World Health Organization histologic type (favoring type III, p = 0.002, HR 13) as significant factors for freedom from distant metastasis. World Health Organization histologic type (p = 0.004, HR 10.5) and age (p = 0.01, HR 1.07/y) were significant factors for survival. Late toxicity included transient cranial nerve weakness in 4, radiation-related retinopathy in 1, and asymptomatic temporal lobe necrosis in 3 patients who originally had intracranial tumor extension.
  
  
  CONCLUSIONS
  STR boost after EBRT provided excellent local control in nasopharyngeal carcinoma patients. The incidence of late toxicity was acceptable. More effective systemic treatment is needed to achieve improved survival.
authors.affiliation: Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305-5302, USA.
authors.forename: Quynh-Thu
authors.initials: QT
authors.lastname: Le
authors.forename: David
authors.initials: D
authors.lastname: Tate
authors.forename: Albert
authors.initials: A
authors.lastname: Koong
authors.forename: Iris C
authors.initials: IC
authors.lastname: Gibbs
authors.forename: Steven D
authors.initials: SD
authors.lastname: Chang
authors.forename: John R
authors.initials: JR
authors.lastname: Adler
authors.forename: Harlan A
authors.initials: HA
authors.lastname: Pinto
authors.forename: David J
authors.initials: DJ
authors.lastname: Terris
authors.forename: Willard E
authors.initials: WE
authors.lastname: Fee
authors.forename: Don R
authors.initials: DR
authors.lastname: Goffinet
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D003131:Combined Modality Therapy; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery*; D011379:Prognosis; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011878:Radiotherapy / Q000009:adverse effects