title: Dorsal vagal complex of the brainstem: conformal avoidance to reduce nausea.
abstract: OBJECTIVE
  To investigate the role of dose to the dorsal vagal complex (DVC) as an emetic stimulus in head-and-neck cancer patients treated with intensity modulated radiation therapy but without chemotherapy.
  
  
  METHODS
  Seventy consecutively treated patients were analyzed for factors associated with nausea. The DVC was contoured on treatment planning scans using a previously published template and mean dose to the structure was analyzed for dose response.
  
  
  RESULTS
  Nausea occurred in 26 of 70 patients (37%). Two patients (3%) experienced grade 2 nausea, with the remainder having grade 1 nausea. On univariate analysis, dose to the DVC, age, and T-stage were the only significant predictors of nausea. The highest quartile of dose to the DVC (>3000 cGy) was associated with an incidence of nausea of 67% compared with less than 30% in each of the other 3 quartiles (P = .0255).
  
  
  CONCLUSIONS
  Dose to the DVC of the brainstem appears to correlate with radiation-induced nausea and vomiting. Attentive treatment planning efforts can reduce dose to this critical structure and hopefully minimize the risk of nausea.
authors.affiliation: Department of Radiation Oncology, Penrose Cancer Center, Colorado Springs, Colorado. Electronic address: dralmonroe@yahoo.com.
authors.forename: Alan T
authors.initials: AT
authors.lastname: Monroe
authors.affiliation: Department of Diagnostic Radiology, United States Air Force Academy, Colorado Springs, Colorado.
authors.forename: Sathya C
authors.initials: SC
authors.lastname: Reddy
authors.affiliation: Department of Radiation Oncology, Penrose Cancer Center, Colorado Springs, Colorado.
authors.forename: Anuj V
authors.initials: AV
authors.lastname: Peddada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001933:Brain Stem / Q000502:physiology* / Q000528:radiation effects*; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000209:etiology / Q000517:prevention & control*; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D014839:Vomiting / Q000209:etiology / Q000517:prevention & control