DELAYED MANIFESTATION OF RADIATION PNEUMONITIS: RECALL RADIATION PNEUMONITIS SECONDARY TO CHEMOTHERAPY

TOPIC: Imaging TYPE: Fellow Case Reports INTRODUCTION: Radiation pneumonitis (RP) usually occurs 3-6 months after radiation and fibrosis within 6-12 months. We report a patient who developed the classic imaging features of RP 2 years 6 initiation chemotherapeutic agent – Paclitaxel, consistent with phenomenon recall (RRP). RRP can occur when agents such as doxorubicin, erlotinib, etoposide, gemcitabine, paclitaxel, pemetrexed immune checkpoint inhibitors are administered to has received prior therapy lung.1 Though rare, its recognition will allow for discontinuation offending use immunosuppressive drugs like steroids in an attempt reverse process. CASE PRESENTATION: A 73 year old woman was diagnosed stage 4 lung cancer treated full course chest radiotherapy chemotherapy. Following failure respond multiple agents, started on paclitaxel initial diagnosis. admitted fever respiratory distress. CT Chest (See Fig.) revealed consolidation which strictly confined portal that given two ago indicative RP. done 1 completion showed no changes. Hence, diagnosis made, stopped improved steroids. DISCUSSION: is form injury previously irradiated parenchyma chemotherapy or immunotherapy beyond time frame typical pneumonitis. Exact mechanism unclear. One hypothesis indicates administration systemic anti-tumor triggers “remembered” reaction remaining surviving cells areas resulting enhanced sensitivity drugs. leading heritable mutation produces subgroup defective stem anti tumor alternate possibility.2 Another explanation offered leads local vascular permeability proliferative changes decrease threshold subsequent from antitumor immunotherapeutic CONCLUSIONS: While there clear consensus diagnosis, should be suspected seen outside conventional patients receiving these agents. Recognition this entity important order discontinue provide potentially beneficial steroid. Reference #1: Hochstrasser et al. Interstitial treatment pemetrexed: rare event? Chemotherapy. 2012;58(1):84. Epub 2012 Feb 23. #2: Azria D, Magne N, Zouhair A, Castadot P, Culine S, Ychou M, recall: well recognized but neglected phenomenon. Cancer Treat Rev. (2005) 31:555-70.doi: 10.1016/j.ctrv.2005.07.008other inciting #3: Bogtrom Sjolin-Forsberg G, Wilking Bergh J. recall- another call tamoxifen. Acta Oncol. (1999) 38:955-9. Doi: 10.1080/028418699432653. DISCLOSURES: No relevant relationships by Padmanabhan Krishnan, source=Web Response Gurjit Inder Sidhu, Sumedha Sonde,