• 18F-fluorodeoxyglucose
• Disease Activity
• Langerhans cell histiocytosis
• PET/CT

• Humans
• Positron Emission Tomography Computed Tomography/methods
• Fluorodeoxyglucose F18
• Retrospective Studies
• Histiocytosis, Langerhans-Cell/diagnostic imaging
• Histiocytosis, Langerhans-Cell/therapy
• Metabolic Diseases

• 99mTc-MDP
• Langerhans cell histiocytosis
• bone scan
• pediatric
• skeletal LCH

• National Natural Science Foundation of China

• Children
• Imaging
• Neurology
• Oncology
• PET/MRI
• Pediatric
• [18F]FDG

• Humans
• Child
• Magnetic Resonance Imaging/methods
• Positron-Emission Tomography
• Diffusion Magnetic Resonance Imaging

• Langerhans cell histiocytosis
• PET/CT
• SPECT
• rib
• surgery

• BRAF
• Langerhans cell histiocytosis
• chemotherapy
• disease reactivation

• FDG PET-CT
• Langerhans cell histiocytosis
• Radiographic skeletal survey
• Whole-body MRI
• Whole-body bone scan

The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and professional organization founded in 1954 to promote the science, technology, and practical application of nuclear medicine. The European Association of Nuclear Medicine (EANM) is a professional nonprofit medical association founded in 1985 to facilitate communication worldwide among individuals pursuing clinical and academic excellence in nuclear medicine. SNMMI and EANM members are physicians, technologists, and scientists specializing in the research and practice of nuclear medicine.

The SNMMI and EANM will periodically put forth new standards/guidelines for nuclear medicine practice to help advance the science of nuclear medicine and improve service to patients. Existing standards/guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner, if indicated. Each standard/guideline, representing a policy statement by the SNMMI/EANM, has undergone a thorough consensus process, entailing extensive review. The SNMMI and EANM recognize that the safe and effective use of diagnostic nuclear medicine imaging requires particular training and skills, as described in each document. These standards/guidelines are educational tools designed to assist practitioners in providing appropriate and effective nuclear medicine care for patients. These guidelines are consensus documents, and are not inflexible rules or requirements of practice. They are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the SNMMI and the EANM cautions against the use of these standards/guidelines in litigation in which the clinical decisions of a practitioner are called into question.

The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by medical professionals taking into account the unique circumstances of each case. Thus, there is no implication that action differing from what is laid out in the standards/guidelines, standing alone, is below standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the standards/guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources, or advances in knowledge or technology subsequent to publication of the standards/guidelines.

The practice of medicine involves not only the science, but also the art of dealing with the prevention, diagnosis, alleviation, and treatment of disease. The variety and complexity of human conditions make it impossible for general guidelines to consistently allow for an accurate diagnosis to be reached or a particular treatment response to be predicted. Therefore, it should be recognized that adherence to these standards/guidelines will not ensure a successful outcome. All that should be expected is that the practitioner follows a reasonable course of action, based on their level of training, the current knowledge, the available resources, and the needs/context of the particular patient being treated.

PET and computerized tomography (CT) have been widely used in oncology. ¹⁸F-FDG is the most common radiotracer used for PET imaging. The purpose of this document is to provide imaging specialists and clinicians guidelines for recommending, performing, and interpreting ¹⁸F-FDG PET/CT in pediatric patients in oncology. There is not a high level of evidence for all recommendations suggested in this paper. These recommendations represent the expert opinions of experienced leaders in this field. Further studies are needed to have evidence-based recommendations for the application of ¹⁸F-FDG PET/CT in pediatric oncology. These recommendations should be viewed in the context of good practice of nuclear medicine and are not intended to be a substitute for national and international legal or regulatory provisions.

Background and Objectives: Langerhans cell histiocytosis (LCH) is a rare disease characterized by the infiltration of one or more organs by Langerhans cell-like dendritic cells. LCH often involves the bone, and its clinical evidence is limited. The purpose of this study is to report on the treatment of LCH at our institution and to add to the evidence for LCH. Materials and Methods: We reviewed six cases of LCH treated in our hospital between November 2005 and February 2016. Patient age at the first visit, sex, site of origin, symptoms, image tools used for diagnosis, biopsy site, complications, treatment, and final clinical outcome were evaluated. The median follow-up period was 41 months. Results: The median patient age at the first visit was 13.5 years. Three male and three female individuals were enrolled. Multiple lesions were observed in five cases, and a solitary lesion was observed in one case. Pain was the chief complaint in five cases. Radiography was the most commonly used imaging tool. Bone scintigraphy or magnetic resonance imaging and positron emission tomography-computed tomography were also used to diagnose systematic LCH. Biopsy of the femur was performed in two cases, and biopsy of the tibia, lumbar vertebrae, rib, and radius was performed in one case each. Regarding comorbidities, one case of hepatitis B and one case of autism were observed. Chemotherapy was initiated in two patients. The other four patients were observed naturally. Continuous disease-free survival was observed in five patients. One patient remained alive but not without disease during the final follow-up examination. Conclusion: LCH should be diagnosed as early as possible to treat it appropriately.

• Langerhans cells
• histiocytosis
• outcomes

• Female
• Histiocytosis, Langerhans-Cell/diagnostic imaging
• Histiocytosis, Langerhans-Cell/drug therapy
• Humans
• Male
• Positron Emission Tomography Computed Tomography
• Retrospective Studies
• Tomography, X-Ray Computed
• Treatment Outcome

• LCH
• Langerhans cell histiocytosis
• PET
• PET/CT

Histiocytic sarcoma (HS) of the spleen is reported to be a rare and lethal disease. The clinicopathological features of splenic HS have not been well described. The objective of this paper is to describe the diagnosis and treatment of a case of this rare disease and provide a review of the literature.

In this article, we discuss the case of a 40-year-old Hispanic female who presented with progressive thrombocytopenia and multiple hypoechoic lesions in the spleen without splenomegaly. Positron emission tomography-computed tomography showed increased activity in cervical lymph nodes, as well as multiple bone and splenic lesions with positive uptake. Two bone marrow biopsies and fine-needle aspiration of the cervical lymph node were inconclusive. Laparoscopic splenectomy was performed, and gross examination showed a 110.1 g spleen with multiple rubbery, nodular lesions within the subcapsular sinus and splenic parenchyma. The microscopic findings showed multinodular histiocyte proliferation with atypia and multilobulated nuclei, which were positive for CD163, CD4, and CD68 by immunohistochemical analysis. The final pathologic diagnosis was difficult and was found to be low-grade HS of the spleen, after consultations with two renowned hematopathology institutions. At the patient’s five-month follow-up visit, her bone marrow metastasis had progressed. She is waiting to be enrolled in a clinical trial.

Pathologic diagnosis of splenic HS can be challenging. Low-grade differentiation may be associated with a slow progressive disease.

• Histiocytic sarcoma
• Spleen
• Proliferation
• Thrombocytopenia
• Bone marrow metastasis
• Case report

• LCH
• Langerhans cell histiocytosis
• PET
• PET-CT
• histiocytosis

• orthopaedic and trauma surgery
• orthopaedics

Langerhans cell histiocytosis (LCH) is a disorder caused by clonal proliferation of CD1a⁺/CD207⁺ cells and characterized by varying degrees of organ involvement. Treatment of LCH is risk adapted; patients with multisystem disease and risk-organ involvement require more intensive therapy. Optimal therapies for multisystem, high-risk LCH remain uncertain. Recently, targeted therapy using inhibitors of mutated BRAF (the gene encoding serine/threonine-protein kinase B-Raf) has proven very effective in patients with multisystem refractory LCH. Herein, we report a case of LCH with involvement of the bones, liver, and lymph nodes. Using next-generation sequencing of the patient’s pathological sample, we identified a mutation in MAP2K1 in exon 3 (c.362G>C, p.Cys121Ser) and no mutation in BRAF; thus, high-risk, multisystem LCH with MAP2K1 mutation and wild-type BRAF was diagnosed. After four chemotherapy treatments (COEP regimen), the patient received autologous hematopoietic stem cell transplantation (auto-HSCT). Complete remission was confirmed by follow-up positron emission tomography–computed tomography, which showed no lesions in liver, lymph nodes, or bones compared with the pretreatment period. To date, the patient has sustained good health for 24 months. In conclusion, auto-HSCT may be an effective treatment option for high-risk, multisystem BRAF V600E-negative LCH.

• BRAF V600E mutation negative
• Langerhans cell histiocytosis
• MAP2K1 mutation
• autologous hematopoietic stem cell transplantation
• high-risk
• multisystem

• Adolescent
• Child
• Fluorodeoxyglucose F18
• Humans
• Medical Oncology
• Neoplasm Staging/methods
• Neoplasms/diagnostic imaging
• Pediatrics
• Positron Emission Tomography Computed Tomography/methods
• Radiopharmaceuticals

Accurate risk stratification according to the extent of Langerhans cell histiocytosis (LCH) determined on whole-body evaluation is important for determining the treatment plans and prognosis in patients with LCH. This study aimed to compare the lesion detectability and the accuracy of risk stratification of skeletal survey, bone scan, and whole-body magnetic resonance imaging (WB-MRI) in patients with LCH. Patients with newly-diagnosed LCH who underwent all three imaging modalities were retrospectively included (n = 46). The sensitivity and mean number of false-positives per patient for LCH lesions, and the accuracy of risk stratification of each modality were assessed. WB-MRI had significantly higher sensitivity (99.0%; 95% confidence interval, 93.2–99.9%) than skeletal survey (56.6%; p < 0.0001) and bone scan (38.4%; p < 0.0001) for LCH lesions, and there were no significant differences in the number of false-positives per patient (p > 0.017). WB-MRI tended to have higher accuracy for the risk stratification than skeletal survey and bone scan (concordance rate of 0.98, 0.91, and 0.83, respectively), although the differences were not significant (overall p-value 0.066). In conclusion, WB-MRI had higher detectability for LCH lesions than skeletal survey and bone scan, while the three whole-body imaging modalities had comparable accuracy in the initial risk stratification of LCH.

Langerhans cell histiocytosis is a rare clonal disease characterized by the proliferation of CD1a-positive immature dendritic cells. The purpose of this article was to present an updated review of recent advances in the pathogenesis, clinical features, imaging and treatment of this disease. The discovery of oncogenic BRAF mutations and the presence of proinflammatory cytokines and chemokines confirmed the unusual characteristics of this disease. Currently, children with organ involvement who do not have a good response to chemotherapy and have neurodegeneration or diabetes insipidus are the most problematic patients. Further research is needed to improve the results of treatment.

• Langerhans cell histiocytosis
• children
• pathogenesis
• symptoms
• treatment

Langerhans cell histiocytosis (LCH) is a rare disease in which Langerhans cells, which are bone marrow-derived antigen-presenting cells, proliferate in single or multiple organs. We successfully treated a patient with unifocal LCH of the mandible with malocclusion due to a severe pathological fracture, using reconstruction with a vascularised free bone.

• Langerhans cell histiocytosis
• pathological fracture
• vascularised free bone

• Dermatology
• Imaging
• Pediatric

• 18F-FDG PET/CT
• Histiocytosis
• Langerhans cell histiocytosis
• PET/CT

• Adolescent
• Adult
• Aged
• Child
• Child, Preschool
• Female
• Fluorodeoxyglucose F18
• Histiocytosis, Langerhans-Cell/diagnostic imaging
• Humans
• Image Processing, Computer-Assisted/methods
• Male
• Middle Aged
• Positron Emission Tomography Computed Tomography/methods
• Radiopharmaceuticals
• Reproducibility of Results
• Severity of Illness Index
• Whole Body Imaging/methods
• Young Adult

Langerhans cell histiocytosis (LCH) is a benign disorder related to the histiocytes which can infiltrate bone tissue. The most effective method for demonstrating severity of this disease is PET/CT and bone scintigraphy might show bone lesions. We present a seventeen year old male patient with disseminated LCH presented with exophtalmos and having multiple vertebral lesions which were identified by F-18 FDG PET/CT scan and diagnostic CT but not in the bone scintigraphy.

• Langerhans’ cell histiocytosis
• Positron emission tomography
• Radiotherapy

• Adult
• Female
• Fluorodeoxyglucose F18
• Histiocytosis, Langerhans-Cell/diagnosis
• Histiocytosis, Langerhans-Cell/drug therapy
• Histiocytosis, Langerhans-Cell/radiotherapy
• Humans
• Lymph Nodes/diagnostic imaging
• Multimodal Imaging
• Positron-Emission Tomography
• Radiopharmaceuticals
• Radiotherapy, Conformal
• Tomography, X-Ray Computed

Positron emission tomography (PET) is a minimally invasive technique which has been well validated for the diagnosis, staging, monitoring of response to therapy, and disease surveillance of adult oncology patients. Traditionally the value of PET and PET/computed tomography (CT) hybrid imaging has been less clearly defined for paediatric oncology. However recent evidence has emerged regarding the diagnostic utility of these modalities, and they are becoming increasingly important tools in the evaluation and monitoring of children with known or suspected malignant disease. Important indications for 2-deoxy-2-(¹⁸F)fluoro-D-glucose (FDG) PET in paediatric oncology include lymphoma, brain tumours, sarcoma, neuroblastoma, Langerhans cell histiocytosis, urogenital tumours and neurofibromatosis type I. This article aims to review current evidence for the use of FDG PET and PET/CT in these indications. Attention will also be given to technical and logistical issues, the description of common imaging pitfalls, and dosimetric concerns as they relate to paediatric oncology.

• Positron emission tomography
• Computed tomography
• Fluorodeoxyglucose F18
• Paediatrics
• Oncology
• Technical issues
• Dosimetry

• Adults
• Children and adolescents
• Diagnosis
• Langerhans cell histiocytosis
• Spine

• Adolescent
• Adult
• Aged
• Child
• Female
• Histiocytosis, Langerhans-Cell/complications
• Histiocytosis, Langerhans-Cell/pathology
• Humans
• Male
• Middle Aged
• Retrospective Studies
• Spinal Diseases/complications
• Spinal Diseases/pathology
• Young Adult

Langerhans cell histiocytosis (LCH) represents a disorder characterised by an abnormal accumulation of histiocytes in miscellaneous tissues. The bone is commonly affected, especially the flat bones, the spine and the long bones. Some lesions in children such as a “vertebra plana” or a solitary lytic lesion of the skull may be suggestive for LCH, whereas others can be confused with a malignant tumour or osteomyelitis. This pictorial essay presents the main usual and unusual skeletal manifestations observed in LCH.

• Osseous involvement in children with LCH is very similar to that seen in multiple myeloma.

• A solitary lytic lesion of the cranial vault is a typical radiographic finding of LCH.

• A vertebra plana appearance in the spine is another typical radiographic finding.

• Extensive signal intensity changes within bone marrow on MRI are a helpful sign for the diagnosis.

• In long bones, endosteal scalloping may be responsible for a “budding appearance”.

• Adolescent
• Bone Diseases/diagnosis
• Bone Diseases/mortality
• Bone Diseases/therapy
• Child
• Child, Preschool
• Combined Modality Therapy
• Female
• Histiocytosis, Langerhans-Cell/diagnosis
• Histiocytosis, Langerhans-Cell/mortality
• Histiocytosis, Langerhans-Cell/therapy
• Humans
• Infant
• Infant, Newborn
• Italy/epidemiology
• Male
• Pain
• Prognosis
• Retrospective Studies
• Survival Rate
• Treatment Outcome

Pulmonary Langerhans Cell Histiocytosis (PLCH) is a relatively uncommon lung disease that generally, but not invariably, occurs in cigarette smokers. The pathologic hallmark of PLCH is the accumulation of Langerhans and other inflammatory cells in small airways, resulting in the formation of nodular inflammatory lesions. While the overwhelming majority of patients are smokers, mechanisms by which smoking induces this disease are not known, but likely involve a combination of events resulting in enhanced recruitment and activation of Langerhans cells in small airways. Bronchiolar inflammation may be accompanied by variable lung interstitial and vascular involvement. While cellular inflammation is prominent in early disease, more advanced stages are characterized by cystic lung destruction, cicatricial scarring of airways, and pulmonary vascular remodeling. Pulmonary function is frequently abnormal at presentation. Imaging of the chest with high resolution chest CT scanning may show characteristic nodular and cystic abnormalities. Lung biopsy is necessary for a definitive diagnosis, although may not be required in instances were imaging findings are highly characteristic. There is no general consensus regarding the role of immunosuppressive therapy in smokers with PLCH. All smokers must be counseled on the importance of smoking cessation, which may result in regression of disease and obviate the need for systemic immunosuppressive therapy. The prognosis for most patients is relatively good, particularly if longitudinal lung function testing shows stability. Complications like pneumothoraces and secondary pulmonary hypertension may shorten life expectancy. Patients with progressive disease may require lung transplantation.

• pet-ct
• pediatric cancer
• infection
• ¹⁸f-fdg pet

Langerhans cell histiocytosis (LCH) is a rare histiocytic disorder in which pathological langerhans cells accumulate in a variety of organs. Manifestations may include lung infiltrates, lymph node involvements, bone lesions, hepatic, hematopoietic and endocrine dysfunctions. In this case report we present fluorine-18 positron emission tomography (F-18 PET/CT) and bone scintigraphy findings of a 18-year-old male patient with disseminated LCH, mimicking multiple hypermetabolic metastatic lesions. Clinicians should be aware that LCH infiltrations can be seen as intense uptake and to differentiate infiltrations from other metastatic intense uptake with fluorodeoxyglucose PET/CT and bone scintigraphy, clinical and laboratory findings should be kept in mind.

• Bone scan
• FDG PET/CT
• Tc-99m MDP
• langerhans cell histiocytosis