Proton beam therapy for chordoma: A systematic review and meta-analysis

To systematically evaluate the efficacy and safety of proton beam therapy (PBT) for the treatment of chordoma.

A comprehensive search of PubMed, Embase, Web of Science, and the Cochrane Library databases from their inception to February 25, 2025, was conducted to identify studies reporting survival outcomes and toxicity in patients with chordoma treated with PBT. Two researchers independently screened the literature and extracted data based on the inclusion and exclusion criteria. Statistical analyses were performed using STATA version 14.0.

We searched for 1750 candidate articles, of which 11 studies were included in our study. These studies reported the survival and toxicity for 561 chordoma patients who received PBT, with a median sample size of 36 patients (range, 13-151), a median age ranged of 13.2-61 years, a female proportion of 43.2 %, and a median follow-up time ranged of 10.7-69.3 months. The local control (LC) rate at 1, 2, 3, 5, and 7 years in these studies were 97 %, 92 %, 88 %, 77 %, and 71 %, respectively. The overall survival (OS) rate at 1, 2, 3, 5 and 7 years in these studies were 100 %, 90 %, 89 %, 86 %, and 80 %, respectively. The most common median total dose was 74 Gy (RBE). Acute and late toxicities were predominantly grade 1 and 2.

Proton therapy has good clinical applications for a local treatment strategy for the safe treatment of chordomas. Encouraging results were observed for LC and OS. Both acute and late toxicity responses were acceptable.