title: Mucositis reduction by selective elimination of oral flora in irradiated cancers of the head and neck: a placebo-controlled double-blind randomized study.
abstract: OBJECTIVE
  The aim of the study was to test the hypothesis that aerobic Gram-negative bacteria (AGNB) play a crucial role in the pathogenesis of radiation-induced mucositis; consequently, selective elimination of these bacteria from the oral flora should result in a reduction of the mucositis.
  
  
  METHODS
  Head-and-neck cancer patients, when scheduled for treatment by external beam radiation therapy (EBRT), were randomized for prophylactic treatment with an oral paste containing either a placebo or a combination of the antibiotics polymyxin E, tobramycin, and amphotericin B (PTA group). Weekly, the objective and subjective mucositis scores and microbiologic counts of the oral flora were noted. The primary study endpoint was the mucositis grade after 3 weeks of EBRT.
  
  
  RESULTS
  Seventy-seven patients were evaluable. No statistically significant difference for the objective and subjective mucositis scores was observed between the two study arms (p = 0.33). The percentage of patients with positive cultures of AGNB was significantly reduced in the PTA group (p = 0.01). However, complete eradication of AGNB was not achieved.
  
  
  CONCLUSIONS
  Selective elimination of AGNB of the oral flora did not result in a reduction of radiation-induced mucositis and therefore does not support the hypothesis that these bacteria play a crucial role in the pathogenesis of mucositis.
authors.affiliation: Department of Radiation Oncology, University Hospital Rotterdam-Daniel, The Netherlands.
authors.forename: O B
authors.initials: OB
authors.lastname: Wijers
authors.forename: P C
authors.initials: PC
authors.lastname: Levendag
authors.forename: E R
authors.initials: ER
authors.lastname: Harms
authors.forename: A M
authors.initials: AM
authors.lastname: Gan-Teng
authors.forename: P I
authors.initials: PI
authors.lastname: Schmitz
authors.forename: W D
authors.initials: WD
authors.lastname: Hendriks
authors.forename: E B
authors.initials: EB
authors.lastname: Wilims
authors.forename: H
authors.initials: H
authors.lastname: van der Est
authors.forename: L L
authors.initials: LL
authors.lastname: Visch
mesh_terms: D000328:Adult; D000368:Aged; D000666:Amphotericin B / Q000627:therapeutic use; D003091:Colistin / Q000627:therapeutic use; D004311:Double-Blind Method; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000187:drug effects / Q000382:microbiology* / Q000528:radiation effects; D010919:Placebos; D011832:Radiation Injuries / Q000209:etiology / Q000382:microbiology / Q000517:prevention & control*; D012469:Salivary Glands / Q000528:radiation effects; D013280:Stomatitis / Q000209:etiology / Q000382:microbiology* / Q000517:prevention & control*; D014031:Tobramycin / Q000627:therapeutic use
chemical_list: D010919:Placebos; D000666:Amphotericin B; D014031:Tobramycin; D003091:Colistin