Before re-challenging a patient with ICI after grade 1-2 pneumonitis, do you re-image to confirm resolution of pneumonitis?

Grade 1 pneumonitis is defined as confined to one lobe of the lung or <25% of the total lung parenchyma, while grade 2 pneumonitis is defined as involving more than one lobe of the lung or 25-50% of the lung parenchyma. Grade 1 pneumonitis is typically an incidental finding on CT in an asymptomatic patient, while grade 2 pneumonitis is associated with symptoms by definition.

As immunotherapy-induced pneumonitis can be fatal, extra precaution is taken in the setting of grade 1 toxicity. It is reasonable to hold immunotherapy, though this is not required. As per the management guidelines we published in JCO in 2018, in the setting of grade 1 pneumonitis, patients should be monitored closely for the development of symptoms. Repeat imaging afte...