Incidence of hypopituitarism in adults undergoing radiotherapy for neck and head cancer: protocol for a systematic review and meta-analysis

Introduction When children with head and neck cancer receive radiation therapy as part of their treatment, a considerable frequency of hypopituitarism has been recognised. However, in adults, it has been little studied and it is possible that patients may be inadvertently affected. The objective is to estimate the incidence of anterior pituitary dysfunction in adults undergoing radiotherapy for head and neck cancer. Methods and analysis A total of five databases will be used to perform the document search: PubMed, Scopus, Web of Science (Core Collection), Ovid-MEDLINE and Embase. Cohort studies will be included without restriction by language or date. The main outcome will be the incidence of adenohypophyseal dysfunction for each axis: prolactin, growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, luteinising hormone and follicle-stimulating hormone. Incidence meta-analysis will be performed using the Freeman-Tukey double arcsine method. In addition, a random-effects model will be used along with a 95% CI. Subgroup analyses will be performed according to tumour location, radiation dose and endocrine assessment time. Meta-regression will be applied according to patient's age and time elapsed until diagnosis. Ethics and disclosure Since this will be a systematic review of published data, no ethics committee approval is required. The results will be presented at conferences and finally published in a peer-reviewed journal. PROSPERO registration number CRD42021235163.