Immune-Related Pneumonitis in Patients Undergoing Adjuvant Durvalumab for NSCLC

The standard of care for patients with inoperable stage III NSCLC is chemoradiotherapy (CRT) and adjuvant durvalumab (IO) for 12 months. Pneumonitis is the most common toxicity that leads to IO discontinuation, but failure to distinguish between radiation-induced changes, IO pneumonitis, and infection can lead to unnecessary IO discontinuation. Results of a study that investigated the use of a structured multidisciplinary review of CT scans, radiation dose distributions, and clinical symptoms for the diagnosis of IO pneumonitis were presented at the ESMO Congress 2023.

The researchers conducted a retrospective study at an academic medical center for patients with stage III NSCLC treated with CRT and adjuvant IO between 2018 and 2021, and expert clinicians and radiologists reviewed baseline and follow-up CT scans, radiological features consistent with pneumonitis, and radiation dose distributions. A final consensus diagnosis incorporating views of the expert clinicians and the radiologist was made, and a diagnosis of IO pneumonitis was made only when both the radiologist and pulmonologists were in agreement.

Results showed that among 45 patients, 14 (31.1%) had a pneumonitis scored in patient records, and IO was discontinued in 11 of 45 (24.4%). Review by the radiologist led to a diagnosis of IO pneumonitis in just six patients (13.3%) and by the expert clinicians in only four (8.9%). In addition, suspicion of IO pneumonitis was rejected in three separate patients (6.7%) after the clinicians reviewed the patient’s radiation fields.

The researchers concluded that in patients treated using the PACIFIC regimen of IO, a multidisciplinary assessment of CT scans, radiation doses, and patient symptoms resulted in fewer diagnoses of IO pneumonitis (8.9%). “In contrast, routine clinical assessment by treating pulmonary oncologists led to discontinuation of IO in 24.4% of patients. This [finding] highlights the need for multidisciplinary review in order to avoid inappropriate cessation of adjuvant IO.”

Source: Smesseim I, Mets O, Daniels HMA, et al. A structured multidisciplinary approach for diagnosing immune-related pneumonitis in patients undergoing adjuvant durvalumab for stage III non-small cell lung cancer. Abstract of a poster presented at the ESMO Congress 2023; October 20-24, 2023; Madrid, Spain.