Safety of particle therapy versus photon stereotactic body radiotherapy (SBRT) for lung cancer with interstitial lung disease (ILD): a systematic review and meta-analysis

Patients with early-stage lung cancer complicated by ILD are at substantially increased risk of radiation-related lung toxicity, including severe radiation pneumonitis (RP) and acute exacerbation of ILD. Although photon SBRT is widely used, its safety in patients with ILD remains uncertain and is largely based on small, single-center retrospective studies. While particle therapy (proton or carbon-ion) offers theoretical dosimetric advantages that could reduce the low-dose lung volume, there is limited and inconsistent clinical evidence. There are currently no studies that directly compare particle therapy and SBRT based on the same eligibility criteria. This systematic review collects and quantitatively integrates toxicity and survival outcomes from studies published since 2010. The aim is to clarify the relative safety of particle therapy and to identify candidate parameters to guide clinical selection and future trials.