Background: Radiation recall pneumonitis (RRP) is an unpredictable but 
relatively severe subclinical radiation damage which occurs in the previously 
irradiated fields of pulmonary tissue after administration of a systemic agent. 
Previous reports of RRP were mainly attributed to chemotherapy and 
molecular-target agents. RRP induced by immunotherapy has been rarely reported. 
Here we describe a case of a novel pattern of RRP induced by anti-PD-1 blockade 
Camrelizumab 2 years after radiotherapy, with some focus on further 
understanding of this phenomenon. Case Report: A 64-year-old man with non-small 
cell lung cancer (NSCLC) received two cycles of chemotherapy with cisplatin and 
pemetrexed first. Subsequently, he underwent concomitant chemoradiotherapy with 
cisplatin and pemetrexed to simultaneous integrated boost (SIB) radiotherapy. 
After 15 months, due to tumor progression and brain metastasis, he started with 
administration of anti-PD-1 blockade Camrelizumab (200 mg q2w) and stereotactic 
radiosurgery (SRS). The patient developed fever, dyspnea and cough after the 
eighth administration of Camrelizumab. Meanwhile, his chest CT revealed patchy 
consolidation and ground-glass opacities localized within the previously 
irradiated area. Subsequent treatment regimen was adjusted to 80 mg q12h 
prednisolone with discontinuation of Camrelizumab. Then the symptoms gradually 
eased and reexamination of CT showed significant improvement in RRP after 2 
weeks. Conclusion: Our case report presents a novel pattern of RRP induced by 
anti-PD-1 blockade Camrelizumab 2 years after radiotherapy. This indicates that 
previous radiotherapy combined with subsequent anti-PD-1 blockade has a 
potential to cause overlapping damage to lung, suggesting that intensive 
attention might be needed for patients who are treated with anti-PD-1 blockade 
in conjunction with a prior history of thoracic radiation.