title: Clinical-dosimetric analysis of measures of dysphagia including gastrostomy-tube dependence among head and neck cancer patients treated definitively by intensity-modulated radiotherapy with concurrent chemotherapy.
abstract: OBJECTIVE
  To investigate the association between dose to various anatomical structures and dysphagia among patients with head and neck cancer treated by definitive intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy.
  
  
  METHODS
  Thirty-nine patients with squamous cancer of the head and neck were treated by definitive concurrent chemotherapy and IMRT to a median dose of 70 Gy (range, 68 to 72). In each patient, a gastrostomy tube (GT) was prophylacticly placed prior to starting treatment. Prolonged GT dependence was defined as exceeding the median GT duration of 192 days. Dysphagia was scored using standardized quality-of-life instruments. Dose-volume histogram (DVH) data incorporating the superior/middle pharyngeal constrictors (SMPC), inferior pharyngeal constrictor (IPC), cricoid pharyngeal inlet (CPI), and cervical esophagus (CE) were analyzed in relation to prolonged GT dependence, dysphagia, and weight loss.
  
  
  RESULTS
  At 3 months and 6 months after treatment, 87% and 44% of patients, respectively, were GT dependent. Spearman's rho analysis identified statistical correlations (p < 0.05) between prolonged GT dependence or high grade dysphagia with IPC V65, IPC V60, IPC Dmean, and CPI Dmax. Logistic regression model showed that IPC V65 > 30%, IPC V60 > 60%, IPC Dmean > 60 Gy, and CPI Dmax > 62 Gy predicted for greater than 50% probability of prolonged GT dependence.
  
  
  CONCLUSIONS
  Our analysis suggests that adhering to the following parameters may decrease the risk of prolonged GT dependence and dysphagia: IPC V65 < 15%, IPC V60 < 40%, IPC Dmean < 55 Gy, and CPI Dmax < 60 Gy.
authors.affiliation: Departments of Radiation Oncology, University of California Davis Cancer Center, Sacramento, CA 95817, USA. bao-qing.li@ucdmc.ucdavis.edu
authors.forename: Baoqing
authors.initials: B
authors.lastname: Li
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Derick H
authors.initials: DH
authors.lastname: Lau
authors.forename: D Gregory
authors.initials: DG
authors.lastname: Farwell
authors.forename: Quang
authors.initials: Q
authors.lastname: Luu
authors.forename: David M
authors.initials: DM
authors.lastname: Rocke
authors.forename: Kathleen
authors.initials: K
authors.lastname: Newman
authors.forename: Jean
authors.initials: J
authors.lastname: Courquin
authors.forename: James A
authors.initials: JA
authors.lastname: Purdy
authors.forename: Allen M
authors.initials: AM
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001037:Aphasia / Q000209:etiology*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D005260:Female; D005774:Gastrostomy; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012189:Retrospective Studies
chemical_list: D000970:Antineoplastic Agents