title: High dose rate versus low dose rate interstitial radiotherapy for carcinoma of the floor of mouth.
abstract: OBJECTIVE
  Patients with cancer of the floor of mouth are treated with radiation because of functional and cosmetic reasons. We evaluate the treatment results of high dose rate (HDR) and low dose rate (LDR) interstitial radiation for cancer of the floor of mouth.
  
  
  METHODS
  From January 1980 through March 1996, 41 patients with cancer of the floor of mouth were treated with LDR interstitial radiation using 198Au grains, and from April 1992 through March 1996 16 patients with HDR interstitial radiation. There were 26 T1 tumors, 30 T2 tumors, and 1 T3 tumor. For 21 patients treated with interstitial radiation alone, a total radiation dose of interstitial therapy was 60 Gy/10 fractions/6-7 days in HDR and 85 Gy within 1 week in LDR. For 36 patients treated with a combination therapy, a total dose of 30 to 40 Gy of external radiation and a total dose of 48 Gy/8 fractions/5-6 days in HDR or 65 Gy within 1 week in LDR were delivered.
  
  
  RESULTS
  Two- and 5-year local control rates of patients treated with HDR interstitial radiation were 94% and 94%, and those with LDR were 75% and 69%, respectively. Local control rate of patients treated with HDR brachytherapy was slightly higher than that with 198Au grains (p = 0.113). For late complication, bone exposure or ulcer occurred in 6 of 16 (38%) patients treated with HDR and 13 of 41 (32%) patients treated with LDR.
  
  
  CONCLUSIONS
  HDR fractionated interstitial brachytherapy can be an alternative to LDR brachytherapy for cancer of the floor of mouth and eliminate radiation exposure for the medical staff.
authors.affiliation: Department of Radiation Oncology, Biomedical Research Center, Osaka University Medical School, Suita, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: H
authors.initials: H
authors.lastname: Yamazaki
authors.forename: M
authors.initials: M
authors.lastname: Koizumi
authors.forename: K
authors.initials: K
authors.lastname: Kagawa
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: H
authors.initials: H
authors.lastname: Shiomi
authors.forename: A
authors.initials: A
authors.lastname: Imai
authors.forename: K
authors.initials: K
authors.lastname: Shimizutani
authors.forename: E
authors.initials: E
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Nose
authors.forename: T
authors.initials: T
authors.lastname: Teshima
authors.forename: S
authors.initials: S
authors.lastname: Furukawa
authors.forename: H
authors.initials: H
authors.lastname: Fuchihata
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D005260:Female; D006050:Gold Radioisotopes / Q000627:therapeutic use; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009060:Mouth Floor; D009062:Mouth Neoplasms / Q000532:radiotherapy*; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D011879:Radiotherapy Dosage
chemical_list: D006050:Gold Radioisotopes; D007496:Iridium Radioisotopes; D019275:Radiopharmaceuticals