[en] Highlights: • Radiation recall pneumonitis (RRP) is a delayed radiation-induced lung toxicity. • RRP was detected in 15 out of 80 (18.8%) lung cancer patients under immunotherapy. • RRP was associated in one third of the cases with immune checkpoint inhibitor-related pneumonitis. • RRP was mistaken for cancer progression on imaging in 53% of the cases. Radiation recall pneumonitis (RRP) is a delayed radiation-induced lung toxicity triggered by systemic agents, typically anticancer drugs. Immune checkpoint inhibitors (ICIs) have recently been identified as potential causal agents of RRP but its real incidence and potential risk factors remain unknown.