Toxicity with proton therapy for oral and/or oropharyngeal cancers: A scoping review

Oral and/or oropharyngeal cancers account for approximately 2% of all malignancies, with variation across age groups, genders, and geographic locations. Treatments for oral and/or oropharyngeal cancers usually consist of a combination of surgical excision most commonly followed by radiotherapy ± chemotherapy and/or immunotherapy/biotherapy depending on the nature of the malignancy. The significant morbidity caused by high-dose radiotherapy to the head and neck region is widely observed. Proton therapy is a promising treatment option that localises a proton beam to direct radiation at a specific target, with reduced irradiation to adjacent structures.

The objective was to explore the toxicity associated with proton therapy for adults with oral and/or oropharyngeal cancer. Eligibility criteria included full-text articles, English articles, published between up till 7 January 2023. Databases included PubMed, Scopus, Web of Science, Embase, and Scopus.

The systematic search identified 345 studies and a total of 18 studies were included after two independent reviewers completed title, abstract, and full-text screening. Included studies were from four countries, and median participant age range was 53.3 to 66 years. The most commonly reported acute toxic effects included dysphagia, radiation dermatitis, oral mucositis, dysgeusia, and alopecia.

Proton therapy is an evolving cancer treatment technique that has diverse advantages over conventional radiotherapy and chemotherapy. This review provides evidence that supports that proton therapy has an improved acute toxicity profile compared to radiotherapy to treat oral and/or oropharyngeal cancer individuals.