Effects of photobiomodulation and bethanechol chloride treatment on salivary composition and flow rate in head and neck cancer patients undergoing radiotherapy: longitudinal interventional experimental clinical study

Abstract

Objective
To evaluate the efficacy of photobiomodulation therapy (PBMT) and bethanechol chloride (BC) on the quantity and quality of saliva in patients undergoing radiotherapy (RT) for head and neck cancer.

Methods
Saliva samples were collected from patients before and after RT, who were treated with PBMT or BC. Clinical parameters, including salivary flow rate (SFR), pH, xerostomia, and concentrations of macro and microelements in saliva, were assessed. Data were compared and analyzed using a self-organizing map.

Results
No significant changes were observed in SFR, pH, and xerostomia pre- and post-RT in both the PBMT and BC-treated groups. However, there was an increase in Cr levels in the BC group and a reduction in P levels in the PBMT group.

Conclusion
The results suggest that both PBMT and BC treatments can effectively mitigate the impacts of RT, since quality and quantity of saliva were maintained.

Full text

Vol.:(0123456789)
Supportive Care in Cancer (2025) 33:113
https://doi.org/10.1007/s00520-024-09120-y
RESEARCH
Effects ofphotobiomodulation andbethanechol chloride treatment
onsalivary composition andflow rate inhead andneck cancer
patients undergoing radiotherapy: longitudinal interventional
experimental clinical study
NatáliaSchepanski1· BrunaMelodaSilvaLiebl1· ReilaTainaMendes1· FloriatanSantosCosta2·
ClariceD.B.Amaral2· RaquelC.Machado3· AnaRitaA.Nogueira4· LaurindoMoacirSassi5·
MelissaRodriguesdeAraujo1
Received: 27 June 2024 / Accepted: 18 December 2024 / Published online: 18 January 2025
© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025
Abstract
Objective To evaluate the efficacy of photobiomodulation therapy (PBMT) and bethanechol chloride (BC) on the quantity
and quality of saliva in patients undergoing radiotherapy (RT) for head and neck cancer.
Methods Saliva samples were collected from patients before and after RT, who were treated with PBMT or BC. Clinical
parameters, including salivary flow rate (SFR), pH, xerostomia, and concentrations of macro and microelements in saliva,
were assessed. Data were compared and analyzed using a self-organizing map.
Results No significant changes were observed in SFR, pH, and xerostomia pre- and post-RT in both the PBMT and BC-
treated groups. However, there was an increase in Cr levels in the BC group and a reduction in P levels in the PBMT group.
Conclusion The results suggest that both PBMT and BC treatments can effectively mitigate the impacts of RT, since quality
and quantity of saliva were maintained.
Keywords Xerostomia· Radiotherapy· Saliva· Photobiomodulation· Trace elements
Introduction
Head and neck cancer (HNC) ranks as the seventh most
common type of cancer worldwide. Radiotherapy (RT)
stands as a primary clinical therapy for its treatment, often
used in conjunction with chemotherapy or surgery [1, 2].
During treatment, several side effects emerge, including
changes in the oral mucosa (oral mucositis), in salivary
glands (resulting in hyposalivation, dry mouth and altera-
tion in salivary composition), and in taste buds (resulting in
loss or changes in taste) [3–5].
Xerostomia, commonly known as dry mouth, is one of the
most prevalent symptoms experienced by patients undergo-
ing and following RT for HNC [6–9]. Hyposalivation, or
reduced saliva production, significantly increases the risk
of oral infections and can lead to speech, taste, chewing,
and swallowing alterations, thereby profoundly impact-
ing patients’ quality of life during RT treatment [4, 5, 10].
Salivary glands are particularly sensitive to radiation, often
resulting in damage during treatment. This damage can man-
ifest as either temporary or permanent, leading to a loss of
glandular function [11].
Saliva is a complex biological fluid primarily composed
of water, but it also contains organic components, proteins,
peptides, polynucleotides, gingival fluid, and residual tissues
[12, 13]. Also, saliva contains an inorganic fraction, primar-
ily composed of electrolytes such as sodium (Na), potas-
sium (K), calcium (Ca), magnesium (Mg), bicarbonates, and
* Natália Schepanski
nat_schepanski@hotmail.com
1 Department ofStomatology, Federal University ofParaná,
Av. Prefeito Lothário Meissner, 632, 80210-170Curitiba,
PR, Brazil
2 Department ofChemistry, Federal University ofParaná,
81531-980Curitiba, PR, Brazil
3 Embrapa Instrumentação, 13565-905SãoCarlos, SP, Brazil
4 Embrapa Pecuária Sudeste, 13560-970SãoCarlos, SP, Brazil
5 Erasto Gaertner Hospital, Curitiba, PR, Brazil
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