Abstract:

Particle beam radiation therapy （PBRT）， using proton and heavy ion （mainly carbon ion in clinical practice） beams， provides precise cancer treatment by targeting tumor sites while sparing healthy tissues， by leveraging the Bragg peak for superior dose distribution. Proton beams have a relative-biological-effectiveness （RBE） of 1.1， which is slightly higher than that of photon beams. And carbon ions have an RBE of 2-3 due to their high linear energy transfer， thus being more advantageous for radioresistant and hypoxic tumors. Treatment strategies include single-beam and mixed-beam approaches， the latter of which combines the advantages of different particles and is an important direction of cancer treatment research. PBRT faces challenges such as managing moving targets and dose uncertainties， requiring advanced techniques like respiratory gating and adaptive planning. Additionally， the scarcity of randomized clinical trials （RCTs） limits PBRT's clinical validation. Existing RCTs， such as those from MD Anderson， indicate the benefits， as well as the need for further studies to confirm PBRT's long-term efficacy and safety. Future research should compare PBRT to photon therapy and explore the therapeutic benefit of combining PBRT with systemic therapies like immunotherapy. Reviewing the clinical practice and research of PBRT， and further discussing its cost-effectiveness in tumor treatment， can provide readers with a comprehensive understanding and promote the development and application of PBRT in cancer treatment.

Key words: Proton therapy, Heavy ion radiotherapy, Clinical study, Cost-benefit analysis, Particle beam radiation therapy, Clinical application