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

Shao Hui Huang; John R de Almeida; Erin Watson; Michael Glogauer; Wei Xu; Sareh Keshavarzi; Brian O'Sullivan; Jolie Ringash; Andrew Hope; Andrew Bayley; Scott V Bratman; John Cho; Meredith Giuliani; John Kim; John Waldron; Anna Spreafico; David P Goldstein; Douglas B Chepeha; Tong Li; Ali Hosni

doi:10.1002/hed.26496

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.

Authors

Shao Hui Huang^{1

2}, John R de Almeida², Erin Watson³, Michael Glogauer³, Wei Xu⁴, Sareh Keshavarzi⁴, Brian O'Sullivan^{1

2}, Jolie Ringash^{1

2}, Andrew Hope¹, Andrew Bayley¹, Scott V Bratman¹, John Cho¹, Meredith Giuliani¹, John Kim¹, John Waldron^{1

2}, Anna Spreafico⁵, David P Goldstein², Douglas B Chepeha², Tong Li¹, Ali Hosni¹

Affiliations

¹ Department of Radiation Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
² Department of Otolaryngology-Head & Neck Surgery/Surgical Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
³ Department of Dental Oncology and Maxillofacial Prosthetics, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.
⁴ Department of Biostatistics, Princess Margaret Cancer Centre / University of Toronto, Toronto, Ontario, Canada.
⁵ Department of Medical Oncology, Princess Margaret Cancer Centre/University of Toronto, Toronto, Ontario, Canada.

PMID: 33058305
DOI: 10.1002/hed.26496

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