Radiation Recall Pneumonitis in the Setting of Immunotherapy and Radiation: a Focused Review

Abstract

Radiation recall pneumonitis (RRP) is an entity described as pneumonitis localized to a previously irradiated field after exposure to a systemic agent. It has previously been described in the literature in the context of chemotherapeutic agents as well as certain biologics. With immunotherapy taking a more prominent role in the treatment of several different malignancies and its own baseline risk of pneumonitis, it is important to explore the likelihood of RRP, specifically in those patients who have been previously treated with radiation therapy. The current literature regarding RRP with checkpoint inhibitors is reviewed in this article. Alongside this review, we report a case of RRP after pembrolizumab initiation in a patient in our practice.

The mechanism and risk factors for immune checkpoint inhibitor pneumonitis in non-small cell lung cancer patients

“…Two patients treated with nivolumab were reported to suffer from RRP within two years of radiotherapy completion, which is different from the windows for chemotherapy and targeted therapy 109 . RRP triggered by pembrolizumab has also been detailed in one case report 110 . Oncologists should be alert for RRP when radiological findings occur in irradiated areas following the application of drugs.…”

Radiation-induced lung toxicity – cellular and molecular mechanisms of pathogenesis, management, and literature review

“…Programmed cell death 1 (PD-1)/ Programmed cell death 1 ligand 1 (PD-L1) inhibition alone can cause immune-mediated pneumonitis in less than 5% [145]. Furthermore, radiation recalls several months after thoracic radiotherapy while ICI is still being administered have been described in some cases [144,146]. The first systematic retro-and prospective studies have shown acceptable toxicity of sequential and concurrent radio-immunotherapy [147][148][149][150].…”

Radiation Recall Pneumonitis After Treatment With Checkpoint Blockade Immunotherapy: A Case Series and Review of Literature

“…everolimus, sunitinib, erlotinib) (9-11). However, the literature is much sparser on RRP arising in the context of immunotherapy (12)(13)(14), with the largest case series containing only two patients (13). Here, we describe three cases of suspected immunotherapy-induced RRP treated at our institution.…”