Figure 1. . Response to imatinib, sunitinib and regorafenib therapy in case 1.

¹⁸F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) done post imatinib, sunitinib and regorafenib therapy in patient A. (A) maximum intensity projection, (B, C & D) axial contrast enhanced CT and (E, F & G) fused PET/CT images showing multiple solid cystic masses with increased FDG uptake in the enhancing solid component (arrows) suggestive of metabolically active liver metastases. Follow-up ¹⁸F-FDG PET/CT done 3 months after initiation of avapritinib therapy, which revealed resolution of metabolic activity in the corresponding lesions (H–N) with hypodense/cystic changes in the previously enhancing lesions, suggestive of complete metabolic response.