Comparison of FDG‐PET scans to conventional radiography and bone scans in management of Langerhans cell histiocytosis

Abstract

BackgroundWe evaluated the effectiveness of FDG‐PET scans in identifying sites of active disease and assessing response to therapy in patients with Langerhans cell histiocytosis (LCH). Changes in standardized uptake value (SUV) indicated increased or decreased disease activity before changes are evident by plain films or bone scans.MethodsOne hundred and two PET scans for 44 patients (41 children, 3 adults) with biopsy‐proven LCH were compared with 83 corollary imaging modalities and were rated for overall clinical utility: false positive or negative (“inferior”), confirming lesions identified by another imaging modality (“confirmatory”), or showing additional lesions, response to therapy or recurrence of disease activity (“superior”), in comparison to bone scans, MRI, CT or plain films.ResultsFDG‐PET was rated superior in that 90/256 (35%) new, recurrent, or lesions responding to therapy were identified via change in standard uptake value (SUV) before other radiographic changes. PET scans confirmed active LCH in 146/256 (57%). FDG‐PET was superior to bone scans in that 8/23 (34%) lesions, 11/53 (21%) comparisons to lesions found by MRI, 13/64 (20%) CT, and 58/116 (50%) plain films. PET scans confirmed lesions found by: 14/23 (61%) bone scans, 33/53 (62%) MRI, 45/64 (65%) CT, and 54/116 (46%) of plain films.ConclusionsWhole body FDG‐PET scans can detect LCH activity and early response to therapy with greater accuracy than other imaging modalities in patients with LCH lesions in the bones and soft tissues. Whole‐body FDG‐PET scanning is an important and informative study at diagnosis and for following disease course in patients with LCH. Pediatr Blood Cancer 2009;52:97–101. © 2008 Wiley‐Liss, Inc.

18F‐fluorodeoxyglucose–positron emission tomography scanning is more useful in followup than in the initial assessment of patients with Erdheim‐Chester disease

“…There is preliminary evidence that PET scanning could be useful in evaluating patients with Langerhans' cell histiocytosis (23) and other inflammatory diseases, such as sarcoidosis (24) or primary large-vessel arteritides (15). In these diseases, FDG uptake is believed to be related to the high density of activated macrophages present in inflammatory lesions.…”

How I treat Langerhans cell histiocytosis

“…PET scans are effective to screen for lesions. 28 Ultrasound or MRI may identify lesions in patients with suspected liver involvement. CT scanning is useful to assess lesions in the orbit, mastoid, sphenoid, and temporal bones.…”

“…MRI is effective in evaluating lesions in brain, pituitary, vertebrae, spinal cord, and pelvis. 28 We perform bone marrow biopsy and aspirate on patients younger than 2 years old or any patients with cytopenias, and endoscopy with biopsy on patients with evidence of malabsorption ( Table 1).…”

“…28 Vertebral CT scans may add information on bone response to therapy and CT scans are also optimal for following bony lesions of the skull, whereas MRI is most effective for parenchymal brain and pituitary lesions. Bone healing may lag resolution of other lesions (Figures 5-6).…”

“…(Blood. 2015;126(1): [26][27][28][29][30][31][32][33][34][35] Clinical scenarios Case 1 A newborn has a scaly rash diagnosed as "cradle cap." Due to persistence despite topical therapy for 2 months, a skin biopsy is diagnostic of Langerhans cell (LC) histiocytosis (LCH).…”