Quality of life and fatigue in association with maximum extent of disease and treatment duration. HRQOL was assessed with PedsQL 4.0 Generic Core Scale, and fatigue was assessed with PedsQL multidimensional fatigue scale. Individual responses (scores) of total HRQOL (N = 32) are illustrated by maximum extent of disease (A), with HRQOL subscales (B), and by active treatment time (C). Individual responses (scores) of total fatigue (N = 30; 2 missing) are illustrated by maximum extent of disease (D), with fatigue subscales (E), and by active treatment time (F). CNS, LCH with CNS involvement; MFB, multifocal bone; MS, multisystem; RO+, with risk organ (liver, spleen, and/or hematopoietic system) involvement; RO-, without risk organ involvement; SS, single system.