Short-term and long-term unstimulated saliva flow following unilateral vs bilateral radiotherapy for oropharyngeal carcinoma

Head Neck. 2021 Feb;43(2):456-466. doi: 10.1002/hed.26496. Epub 2020 Oct 15.

Abstract

Background: We aimed to compare unstimulated saliva flow using 3-minute modified Schirmer test (MST) following bilateral vs unilateral radiotherapy (RT) in oropharyngeal carcinoma (OPC).

Methods: We reviewed OPC patients treated with definitive intensity-modulated radiation therapy (IMRT) between 2011 and 2017. MST was measured at baseline, 1-/6-/12-/24-month post-RT. MST values were compared between bilateral-RT vs unilateral-RT groups. Multivariable logistic regression analysis (MVA) identified predictors of hyposalivation (MST < 25 mm).

Results: Total 498 bilateral-RT and 36 unilateral-RT patients were eligible. The MST values at 1-/6-/12-/24-month post-RT were all significantly reduced from baseline for the entire cohort. Baseline unilateral-RT and bilateral-RT MST values (in mm) were similar (P = .2), but much higher for unilateral-RT 1-month (mean: 19.1 vs 13.0, P = .03), 6-month (20.5 vs 9.3, P < .001), 12-month (20.1 vs 11.9, P < .01), and 24-month post-RT (22.2 vs 13.9, P = .04). MVA confirmed that unilateral RT reduced the likelihood of hyposalivation vs bilateral RT (OR 2.36, P = .006).

Conclusion: Unilateral RT reduces unstimulated salivary flow in OPC patients.

Keywords: IMRT; oropharyngeal cancer; radiotherapy; salivary function; unilateral; unstimulated saliva flow; xerostomia.

Publication types

  • Review

MeSH terms

  • Carcinoma*
  • Head and Neck Neoplasms*
  • Humans
  • Oropharyngeal Neoplasms* / radiotherapy
  • Radiotherapy, Intensity-Modulated*
  • Saliva
  • Xerostomia* / etiology