title: Sparing bilateral neck level IB in oropharyngeal carcinoma and xerostomia outcomes.
abstract: OBJECTIVE
  To assess whether sparing neck-level IB in target delineation of node-positive (N+) oropharyngeal carcinoma (OPC) can improve xerostomia outcomes without compromising locoregional control (LRC).
  
  
  METHODS
  A total of 125 N+ OPC patients with a median age of 57 years underwent chemoradiation between May 2010 and December 2011. A total of 74% of patients had T1-T2 disease, 26% T3-T4, 16% N1, 8% N2A, 48% N2B, 28% N2C; 53% base of tongue, 41% tonsil, and 6% other. Patients were divided into those who had target delineation sparing of bilateral level IB (the spared cohort) versus no sparing (the treated cohort). Sparing of contralateral high-level II nodes was also performed more consistently in the spared cohort. A prospective xerostomia questionnaire (patient reported) was given at each patient follow-up visit to this cohort of patients to assess late xerostomia. Clinical assessment (observer rated) at each patient follow-up visit was also recorded.
  
  
  RESULTS
  The 2-year LRC for the spared and treated cohorts was 97.5% and 93.8%, respectively (median follow-up, 23.2 mo). No locoregional failures occurred outside of treatment fields. The spared cohort experienced significant benefits in patient-reported xerostomia summary scores (P=0.021) and observer-rated xerostomia scores (P=0.006). In addition, there were significant reductions in mean doses to the ipsilateral submandibular gland (63.9 vs. 70.5 Gy; P<0.001), contralateral submandibular gland (45.0 vs. 56.2 Gy; P<0.001), oral cavity (35.9 vs. 45.2 Gy; P<0.001), and contralateral parotid gland (20.0 vs. 24.4 Gy; P<0.001).
  
  
  CONCLUSIONS
  Target delineation sparing of bilateral level IB nodes in N+ OPC reduced mean doses to salivary organs without compromising LRC. Patients with reduced target volumes had better patient-reported xerostomia outcomes.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Moses
authors.initials: M
authors.lastname: Tam
authors.forename: Nadeem
authors.initials: N
authors.lastname: Riaz
authors.forename: Danita
authors.initials: D
authors.lastname: Kannarunimit
authors.forename: Angela P
authors.initials: AP
authors.lastname: Peña
authors.forename: Karen D
authors.initials: KD
authors.lastname: Schupak
authors.forename: Daphna Y
authors.initials: DY
authors.lastname: Gelblum
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Wolden
authors.forename: Shyam
authors.initials: S
authors.lastname: Rao
authors.forename: Nancy Y
authors.initials: NY
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000628:therapy*; D016022:Case-Control Studies; D059248:Chemoradiotherapy / Q000379:methods; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000628:therapy*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D059351:Organ Sparing Treatments / Q000379:methods; D058958:Organs at Risk; D009959:Oropharyngeal Neoplasms / Q000473:pathology / Q000628:therapy*; D010306:Parotid Gland; D011829:Radiation Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012469:Salivary Glands; D000077195:Squamous Cell Carcinoma of Head and Neck; D013363:Submandibular Gland; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014987:Xerostomia / Q000517:prevention & control*
chemical_list: D000970:Antineoplastic Agents