Effectiveness of reduced- versus standard-dose radiotherapy on survival and radiation-associated toxicity in patients with human papillomavirus-associated oropharyngeal squamous cell carcinoma: a systematic review protocol.

Objective: The objective of this review is to investigate overall survival in patients with human papillomavirus positive oropharyngeal squamous cell carcinoma (HPV+ OPSCC) comparing standard- versus reduced-dose radiotherapy.

Introduction: The improved survival of patients with HPV+ compared to HPV-negative OPSCC has raised the question of reducing the total radiation treatment dose delivered to patients with HPV+ OPSCC. A de-escalated radiotherapy protocol may provide equal oncological benefit, with reduced adverse events/toxicity.

Inclusion Criteria: We will include any adult patients aged 18years or older who have undergone curative intent treatment for HPV+ OPSCC. These patients can be at any stage at the time treatment is initiated. Exclusion criteria are as follows: pre-clinical or animal studies, patients with non-squamous cell carcinoma lesions of the oropharynx, patients with primary lesions in other head and neck sites, or patients receiving palliative treatment.

Methods: A three-step search strategy will be used to identify relevant articles for inclusion through MEDLINE, CINAHL, Embase, Web of Science, Scopus, and gray literature sources. These articles will be assessed against our inclusion and exclusion criteria at the title and abstract level as well as at full-text level. Remaining studies will be critically appraised based on their trial design. Data extraction will occur for all studies and, where possible, will be pooled with statistical meta-analysis.

Systematic Review Registration Number: PROSPERO CRD42021252161.