Fig. 1.

a Disease and treatment course for patient 1. b Irradiation field. SBRT in September 2015 was delivered in 3 fractions of 15 Gy on consecutive days to three liver lesions located close together. c, d FDG-PET/CT before (c) and 5 months after the ICB initiation/4 months after SBRT (d). Irradiated lesions are highlighted by red circles, non-irradiated lesions by blue circles, and responding lesions by green circles. e FDG-PET/CT sections showing the three closely spaced liver lesions (numbered 1–3) that were irradiated. ICB Immune checkpoint blockade, SBRT stereotactic body radiation therapy