title: Reduction of the dose of radiotherapy to the elective neck in head and neck squamous cell carcinoma; a randomized clinical trial. Effect on late toxicity and tumor control.
abstract: A multi-center prospective randomized clinical trial has been performed investigating whether a reduction of the dose to the elective nodal sites in head and neck cancer delivered by intensity modulated radiotherapy (IMRT) would result in a reduction of late side effects without compromising tumor control.
  
  
  
  Two hundred patients were included. The prescription dose to the elective nodal volumes was a normalized iso-effective dose in 2Gy fractions (NID2Gy) of 50Gy in the standard arm and of 40Gy in the experimental arm. Late toxicity was scored at 6, 12, 18 and 24months using the RTOG scoring system.
  
  
  
  We observed a trend toward less dysphagia at 6months in the experimental arm, however this was not confirmed after longitudinal analysis. Regarding moderate salivary gland toxicity we observed lower incidence of salivary gland toxicity ⩾grade 1, at 6 (p=0.01) and 18months (p=0.03). After two years of follow up, we did not observe significant differences in estimated local failure rate (14.1% in the 40Gy arm vs 14.4% in the 50Gy arm), estimated regional failure rate (13.0% vs 5.5% in the 40 and the 50Gy arm respectively), estimated metastatic recurrence (13.4% vs 18.5% in the 40 and the 50Gy arm respectively), estimated disease-free survival (57.9% vs 65.3% in the 40 and the 50Gy arm respectively) nor estimated overall survival (72.0% vs 73.2% in the 40 and the 50Gy arm respectively).
  
  
  
  In our study population there was no statistically significant difference regarding survival and estimated recurrence rates between both arms of this study. We found a trend toward less dysphagia at 6months (however not significant after longitudinal analysis) and found a significant reduction of any salivary gland toxicity at 6 and 18months in the 40Gy arm.
authors.affiliation: Department of Radiation Oncology, KU Leuven - University of Leuven, University Hospitals Leuven, Belgium. Electronic address: daan.nevens@uzleuven.be.
authors.forename: Daan
authors.initials: D
authors.lastname: Nevens
authors.affiliation: Department of Radiotherapy, Ghent University Hospital, Belgium.
authors.forename: Fréderic
authors.initials: F
authors.lastname: Duprez
authors.affiliation: Department of Radiation Oncology, Clinique et Maternité Sainte-Elisabeth, Namur, Belgium.
authors.forename: Jean Francois
authors.initials: JF
authors.lastname: Daisne
authors.affiliation: Laboratory of Experimental Radiotherapy, Department of Oncology, Katholieke Universiteit Leuven (KU Leuven), Belgium.
authors.forename: Ruveyda
authors.initials: R
authors.lastname: Dok
authors.affiliation: Leuven Biostatistics and Statistical Bioinformatics Centre, University of Leuven, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: Belmans
authors.affiliation: Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel, Belgium.
authors.forename: Mia
authors.initials: M
authors.lastname: Voordeckers
authors.affiliation: Department of Radiation Oncology, ZNA Middelheim, Antwerp, Belgium.
authors.forename: Danielle
authors.initials: D
authors.lastname: Van den Weyngaert
authors.affiliation: Department of Radiotherapy, Ghent University Hospital, Belgium.
authors.forename: Wilfried
authors.initials: W
authors.lastname: De Neve
authors.affiliation: Department of Radiation Oncology, KU Leuven - University of Leuven, University Hospitals Leuven, Belgium.
authors.forename: Sandra
authors.initials: S
authors.lastname: Nuyts
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000532:radiotherapy*; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects; D012469:Salivary Glands / Q000528:radiation effects; D000077195:Squamous Cell Carcinoma of Head and Neck
keywords: Dose reduction; Elective nodes; Head and neck cancer; Radiotherapy