Langerhans cell histiocytosis

Follow-up frequency depends on the extent of disease at diagnosis, but monitoring should include the following elements.[2]Haupt R, Minkov M, Astigarraga I, et al; Euro Histio Network. Langerhans cell histiocytosis (LCH): guidelines for diagnosis, clinical work-up, and treatment for patients till the age of 18 years. Pediatr Blood Cancer. 2013 Feb;60(2):175-84. https://onlinelibrary.wiley.com/doi/10.1002/pbc.24367 http://www.ncbi.nlm.nih.gov/pubmed/23109216?tool=bestpractice.com [129]ClinicalTrials.gov. H-9926-LCH-III: treatment protocol of the third international study for Langerhans cell histiocytosis. NCT00488605. May 2016 [internet publication]. https://clinicaltrials.gov/ct2/show/NCT00488605

• Clinical evaluation, including history of polydipsia or polyuria, neurologic assessment, height, weight, pubertal status, and blood tests (complete blood count [CBC], inflammatory markers, liver function tests, albumin) in all patients at clinically appropriate intervals. Patients with multisystem disease (with or without risk organ involvement) should be assessed clinically every 6 weeks during the first year of therapy, while those with multifocal bone disease require clinical assessment every 3 months during the first year.

• Fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) should be performed every 2 to 3 months after initiation of therapy in adults to assess for response. Other imaging studies (CT or magnetic resonance imaging [MRI]) may be needed depending on the organ manifestations. Once steady remission has been documented, the imaging interval can be prolonged to every 6 to 12 months.

• Radiographs of bone lesions (involved locations only) at 6 weeks, 3 months, and 6 months after therapy until healing or a stable residual defect is observed (e.g., after surgery or vertebra plana). Skeletal survey is indicated only if reactivation of disease is suspected.

• Low-dose multidetector CT scan of the chest and pulmonary function tests every 6 months during the first year in all patients with lung involvement, then repeat every 6 months in subsequent years, or as clinically indicated.

• Abdominal ultrasound at the end of therapy and every 6 months during the first year after therapy in all patients with liver involvement, then repeat as clinically indicated.

• Brain MRI at the end of therapy and then annually, or more frequently if indicated, in patients with endocrine involvement, central nervous system (CNS) involvement, or skull base or orbital bone lesions, to detect early CNS radiographic degeneration. Brain stem auditory-evoked potentials should also be monitored to define the onset of clinical CNS disease.

• Neuropsychometric assessment annually or at least every 2 years in patients with CNS involvement.

• Orthopedic assessment at the end of therapy and annually until the completion of pubertal growth in all patients with axial skeleton or limb involvement.

• Audiometry (or audiometry-evoked responses in younger children) should be done in patients with ear, mastoid, and skull base lesions at the end of therapy and before entering school, or if symptoms develop. If hearing loss is detected, a CT scan of the petrous temporal bone should be done.

• Dental assessment annually in patients with oral mucosa or jaw bone involvement.