Histological diagnosis of all rebiopsy cases and 290 cases with r-PET analysis. The flow chart demonstrates the initial histology, the most recent histology before rebiopsy, and the histology at rebiopsy of all cases and separately demonstrates the most recent histology before rebiopsy and the histology at rebiopsy in 290 cases with r-PET analysis. ∗iNHL includes grade 1 to 3A FL (N = 54, 21%), marginal zone lymphoma (N = 14, 5%), chronic lymphocytic leukemia or small lymphocytic lymphoma (N = 14, 5%), and other low grade NHL (N = 4, 15%). aNHL includes large B-cell lymphoma (N = 92, 35%), grade 3B FL (N = 9, 3%), mantle cell lymphoma (N = 19, 7%), T-cell lymphomas (N = 11, 4%), and other high grade NHL (N = 5, 4%). HL includes 2 cases with nodular lymphocyte predominant HL. †Two patients received salvage therapy for presumed R/R disease, based on clinical and radiological findings without subsequent rebiopsy. After a period of observation, an additional 3 patients had subsequent rebiopsy within 3 months at different sites; 2 demonstrated R/R marginal zone lymphoma, and 1 demonstrated nonspecific inflammatory changes. ‡Subsequent rebiopsy occurred in 5 cases with nondiagnostic histology, and none were within 3 months.