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

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 intensitymodulated 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.

World Workshop on Oral Medicine VIII: Development of a core outcome set for dry mouth: a systematic review of outcome domains for salivary hypofunction

“…Nine studies also measured unstimulated parotid saliva alongside stimulated parotid saliva. 305,306,311,315,319,322,324,325,327 The next most common outcome measure was unstimulated saliva from the floor of mouth (n=9) 270,[329][330][331][332][333][334][335][336] measured most frequently by the modified Schirmer's test. The submandibular and sublingual glands were assessed together, investigating both unstimulated, 236,312,322,[337][338][339] and stimulated salivary flow rate.…”