Proton therapy for craniopharyngioma in adults: a protocol for systematic review and meta-analysis

Introduction Craniopharyngioma is the most challenging to treat brain tumour with high recurrence rates, which can be effectively reduced by adjuvant radiotherapy. In recent years, proton therapy (PT), with its physical properties of heavy ion beam, that is, Prague peak phenomenon, has been more frequently used in patients with craniopharyngioma. Compared with conventional X-ray beam radiotherapy, PT can reduce the damage to normal tissues and enlarge the damage to tumours. Some studies have shown that PT has advantages in the treatment of craniopharyngioma in adults. However, the optimal management of craniopharyngioma remains controversial. The purpose of this study was to evaluate the efficacy and safety of PT for craniopharyngioma in adults. Methods and analysis We will search six databases (MEDLINE, EMBASE, Web of Science, the Cochrane Library, Amed, Scopus), clinical research registration websites and grey literature, aiming to identify randomised controlled trials (RCTs) on PT for craniopharyngioma in adults between 1 January 1954 and 28 September 2021. In the RCTs, PT will be used as the intervention group, and conventional X-ray beam radiotherapy will be used as the comparator group. Tumour recurrence and survival will be the primary outcome, and treatment-related toxicity will be the secondary outcome. The study selection, data extraction, bias risk and quality evaluation will be operated by two to four researchers independently. We will use Review Manager V.5.2 (RevMan V.5.2) for data analysis. If there is significant heterogeneity, we will identify the source of heterogeneity by subgroup analysis. Ethics and dissemination Our study is based on existing RCTs and does not require ethical approval. The results of the study will be published in a peer-reviewed journal or at a related conference. PROSPERO registration number CRD42020200909.