Comparison of the Effectiveness of Radiotherapy with Photons and Particles for Chordoma After Surgery: A Meta-Analysis.

OBJECTIVE: Particle therapy has been reported as an emerging radiotherapy for several tumors, but its effectiveness for chordoma remains to be studied. This meta-analysis was performed to compare the effectiveness of photon therapy, proton therapy, and carbon-ion therapy for chordoma.

METHODS: Studies reporting the use of conventional radiotherapy (CRT), stereotactic radiotherapy (SRT), proton therapy, and carbon-ion therapy were identified in several databases. A fixed-effects model was used to perform a meta-analysis of 3-, 5-, and 10-year overall survival. The χ2 test was used to compare pooled estimates for each treatment type.

RESULTS: Twenty-five studies were included in this meta-analysis. The results showed that the 3-, 5-, and 10-year overall survival rates were higher for SRT, proton therapy, and carbon-ion therapy than for CRT. The 10-year overall survival was higher for proton therapy than for SRT.

CONCLUSIONS: We revealed that particle therapy was more effective following surgery for chordoma than CRT. After 10 years, proton therapy was more beneficial than SRT. However, future studies should include more studies to enable accurate meta-analysis and a better exploration of prognosis.