title: Radiotherapy of tonsillar and base of the tongue carcinoma. Prediction of local control.
abstract: 119 patients with squamous cell carcinoma of the tonsillar region (68) and the base of the tongue (51), who received external radiotherapy with curative intent between 1966 and 1984, are analysed with respect to overall treatment results, local tumour control and prognostic factors. Radiation doses were equivalent to 60-70 Gy in 6-7 weeks, with a mean fraction dose of 2.4 Gy on the cobalt 60 equipment and 2 Gy on the linear accelerator. Significant differences were found between both oropharyngeal subsites. Three-year overall survival was 57% in tonsillar carcinoma and 38% in base of the tongue (P = 0.006); disease-specific survival was 70% and 47%, respectively (P = 0.005); and local control rates were 82% and 61% (P = 0.02). Late damage to normal tissues, like persistent dysphagia and osteomyelitis, were seen in 11% of patients. Patients with large tumours in the tongue based developed significantly more complications (P = 0.04). T-stage and tumour subsite predicted local control independently before start of the treatment (P = 0.02 in both cases). A significant nonlinear correlation between Normalised Total Dose (using an alpha/beta ratio of 15 Gy) and local control rate was found (P = 0.006), the middle range having the worst prognosis. The size of radiation field and overall treatment time did not correlate with local control in either site. Response at the end of radiotherapy and 6 weeks later have additional prognostic value for local control, irrespective of the initial stage or subsite (P = 0.004 and < 0.001, respectively).
authors.affiliation: Department of ENT/Head and Neck Surgery, University of Amsterdam, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Mak-Kregar
authors.forename: G
authors.initials: G
authors.lastname: Baris
authors.forename: J V
authors.initials: JV
authors.lastname: Lebesque
authors.forename: A J
authors.initials: AJ
authors.lastname: Balm
authors.forename: A A
authors.initials: AA
authors.lastname: Hart
authors.forename: F J
authors.initials: FJ
authors.lastname: Hilgers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000532:radiotherapy*; D016009:Chi-Square Distribution; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D016016:Proportional Hazards Models; D011879:Radiotherapy Dosage; D012044:Regression Analysis; D016019:Survival Analysis; D015996:Survival Rate; D013997:Time Factors; D014062:Tongue Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D014067:Tonsillar Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D016896:Treatment Outcome