Background and purpose: 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. Materials and methods: Medical records and CTs of patients treated with programmed death 1 (PD-1) or programmed death ligand 1 (PD-L1) inhibitors for advanced lung cancer between 2014 and 2019 at our tertiary center, and who had a previous history of lung irradiation were retrospectively analyzed. We identified RRP as lung CT modifications occurring in the irradiation field >6 months after conventionally fractionated radiotherapy completion and >1 year after stereotactic body radiation therapy. Clinical and dosimetric data were analyzed to identify potential risk factors for RRP. Results: Among 348 patients treated with ICIs, data from 80 eligible patients were analyzed (median age, 69 years [interquartile range, 11]; 45 men). Fifteen patients (18.8%) presented with RRP. Median time between end of radiotherapy and RRP was 450 days (range, 231-1859). No risk factor was significantly associated with RRP. ICI-related pneumonitis was associated with RRP in 33.3% of cases (p = 0.0021), developing either concomitantly or after RRP. Incidence of grade ! 3 pneumonitis in the RRP population was 13.3 %. Conclusion:We demonstrated a high incidence of RRP (18.8%) in our population of previously irradiated patients treated with ICIs for lung cancer. We identified no risk factors for RRP, but an association was noted between RRP and ICI-related pneumonitis.

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A 59 year-old man fallen from a roof covering 3 meters high, was carried to the emergency department. A short loss of consciousness was noted with scalp wound. Patient major complaint at arrival was sternal pain. Body-CT was realised for this blunt trauma. There was no cerebral trauma except left parietal cutaneous abrasion. An uncommon association of left cartilage fractures from piece 1 to 6 (Fig. A, B) and right adrenal haemorrhage with small retroperitoneal hematoma was diagnosed (not shown). The patient was observed in the intensive care unit for 5 days and 2 days more in gastroenterology department. He came back to hospital 1,5 month later for dyspnea and left thoracic pain. Chest radiography and CT revealed a huge right pleural effusion (Fig. C) and some healing right anterior arch costal fractures revealed by callus formation. Second look to basal body-CT did not find those not displaced rib lesions. A possible post-traumatic late chylothorax was suggested. He was definitively discharged 5 days after surgical pleural treatment via thoracotomy. Comment Body-CT is a daily practice in emergency radiologic department. Ever increasing number of images and pressure related to urgent management make body-CT interpretation not so easy and may become in some circumstances an uncomfortable task for the radiologist. Uncommon injuries may be present or associated as in this case report. This presentation also illustrates the fact that some lesions may be missed and that delayed injuries may appear. Costal cartilages are easily recognized at CT (1), their shapes are well-known and their density is higher compared to direct environment. Fracture classically corresponds to focal interruption of the cartilage with or without displacement. No gas was isolated in the six cartilage fractures. Late post-traumatic chylothorax is rare. Chylothorax develops in penetrating and less often blunt trauma by damage to the thoracic duct and collection of chyle within the chest. Management combines intercostal drainage and total parenteral nutrition to reduce chyle flow. When this conservative treatment fails, surgery consists in thoracic duct revision (repair of focal wound or ligation) and pleurodesis. Adrenal gland trauma is present on 1-2% of CT imaging for blunt trauma although the occurrence is thought to be much higher. The right adrenal gland is more commonly affected with a ratio of 3-4/1. The only way to exclude a preexisting adrenal mass is to compare with prior or further imaging test. Isolated adrenal gland trauma is uncommon (< 5%). Body-CT seems very sensitive and specific concerning the two acute diagnoses exemplified in this traumatic history. CT is also the key diagnostic tool to handle delayed traumatic events.