Widespread osteonecrosis in children with leukemia revealed by whole-body MRI

Management of osteonecrosis of the humeral head in the pediatric population: A systematic review

Purpose

Humeral head osteonecrosis in the pediatric patients most often occurs in patients with underlying hemoglobinopathies, exposure to chronic corticosteroids, or after trauma. The purpose of this study was to perform a systematic review evaluating the prevalence, clinical characteristics, and management of humeral head osteonecrosis in the pediatric population.

Methods

PubMed, Ovid MEDLINE, and Scopus were screened with the terms "osteonecrosis," "avascular necrosis," "pediatric," and "proximal humerus" on January 10, 2024. A total of 218 studies were screened, and 74 studies were evaluated for eligibility. Studies that reported on the prevalence and/or management of pediatric humeral head osteonecrosis were included. The systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines.

Results

Twelve studies met inclusion criteria: four retrospective case series, three prospective case series, one retrospective cohort study, one retrospective case-control study, and three case reports. A majority of the studies (67%) discussed chemotherapy-induced osteonecrosis of the humeral head. A total of 77 patients (106 shoulders) with humeral head osteonecrosis were identified. The overall prevalence of osteonecrosis of the humeral head across eight studies examining at-risk populations (underlying hemoglobinopathies or undergoing chemotherapy) was 2%. Intra-articular steroid injections, physical therapy, and activity modification are effective conservative management strategies. Additionally, core decompression and hemiarthroplasty are surgical treatment options.

Conclusions

The prevalence of osteonecrosis of the humeral head is low even among at-risk populations with associated medical conditions. A variety of conservative and surgical treatment options have been described, but no comparative evaluations of these modalities has been conducted.

Level of evidence

IV.

Reductions in Bone Mineral Density Are Apparent Early in Children With Prevalent Osteonecrosis Lesions Following Leukemia Therapy

Osteonecrosis (ON) is a serious complication of childhood acute lymphoblastic leukemia. We determined the prevalence of osteonecrotic lesions in our patient population by a one-time multisite magnetic resonance imaging (MRI) more than 1 year following leukemia therapy. MRI findings were evaluated in relationship to clinical factors (including longitudinal changes in bone mineral density [BMD]). Eighty-six children enrolled in the Steroid Associated Osteoporosis in the Pediatric Population (STOPP) study were evaluated for ON at 3.1 ± 1.3 years following therapy. Thirty children had a total of 150 confirmed ON lesions (35%). Lumbar spine (LS) BMD Z-scores (mean ± SD) were low at diagnosis and similar between patients with and without ON (-1.09 ± 1.53 versus -1.27 ± 1.25, p = 0.549). LS BMD Z-scores declined from baseline to 12 months in children with ON (-0.31 ± 1.02) but not in those without (0.13 ± 0.82, p = 0.035); the hip BMD Z-scores from baseline to 24 months declined in both groups, but to a greater extent in those with ON (-1.77 ± 1.22) compared to those without (-1.03 ± 1.07, p = 0.045). At the time of the MRI, mean total hip and total body (TB) BMD Z-scores were lower in children with ON (hip -0.98 ± 0.95 versus -0.28 ± 1.06, p = 0.010; TB -1.36 ± 1.10 versus -0.48 ± 1.50, p = 0.018). Pain occurred in 11/30 (37%) with ON versus 20/56 (36%) without, p = 0.841. In multivariable models, older age at diagnosis (odds ratio [OR] 1.57; 95% confidence interval [CI], 1.15-2.13; p = 0.004), and hip BMD Z-score at MRI (OR 2.23; 95% CI, 1.02-4.87; p = 0.046) were independently associated with ON. Overall, one-third of children demonstrated ON after leukemia therapy. Those with ON had greater reductions in spine and hip BMD Z-scores in the first 1 and 2 years of therapy, respectively. Older age and lower hip BMD Z-scores at MRI were significantly associated with prevalent, off-therapy ON. These data assist in identifying children at risk of ON. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Whole body imaging in musculoskeletal oncology: when, why, and how

The use of whole-body imaging has become increasingly popular in oncology due to the possibility of evaluating total tumor burden with a single imaging study. This is particularly helpful in cases of widespread disease where dedicated regional imaging would make the evaluation more expensive, time consuming, and prone to more risks. Different techniques can be used, including whole-body MRI, whole-body CT, and PET-CT. Common indications include surveillance of cancer predisposing syndromes, evaluation of osseous metastases and clonal plasma cell disorders such as multiple myeloma, and evaluation of soft tissue lesions, including peripheral nerve sheath tumors. This review focuses on advanced whole-body imaging techniques and their main uses in musculoskeletal oncology.

Nonbacterial and bacterial osteomyelitis in children: a case-control retrospective study

Purpose

Osteomyelitis is a group of bone infectious (bacterial osteomyeilitis-BO) and noninfectious inflammatory diseases (nonbacterial osteomyelitis-NBO) with similar clinical, radiology, and laboratory features. Many patients with NBO are misdiagnosed as BO and receive unnecessary antibiotics and surgery. Our study aimed to compare clinical and laboratory features of NBO and BO in children, to define key discriminative criteria, and to create an NBO diagnostic score (NBODS).

Methods

The retrospective multicenter cohort study included clinical, laboratory, and instrumental information about histologically confirmed NBO (n = 91) and BO (n = 31). The variables allowed us to differentiate both conditions used to construct and validate the NBO DS.

Results

The main differences between NBO and BO are as follows: onset age-7.3 (2.5; 10.6) vs. 10.5 (6.5; 12.7) years (p = 0.03), frequency of fever (34.1% vs. 90.6%, p = 0.0000001), symptomatic arthritis (67% vs. 28.1%, p = 0.0001), monofocal involvement (28.6% vs. 100%, p = 0.0000001), spine (32% vs. 6%, p = 0.004), femur (41% vs. 13%, p = 0.004), foot bones (40% vs. 13%, p = 0.005), clavicula (11% vs. 0%, p = 0.05), and sternum (11% vs. 0%, p = 0.039) involvement. The following four criteria are included in the NBO DS: CRP ≤ 55 mg/l (56 points), multifocal involvement (27 points), femur involvement (17 points), and neutrophil bands ≤ 220 cell/μl (15 points). The sum > 17 points allowed to differentiate NBO from BO with a sensitivity of 89.0% and a specificity of 96.9%.

Conclusion

The diagnostic criteria may help discriminate NBO and BO and avoid excessive antibacterial treatment and surgery.

Whole-body MRI in children: state of the art

Whole-body magnetic resonance imaging (WBMRI) is an increasingly popular technique in paediatric imaging. It provides high-resolution anatomical information, with the potential for further exciting developments in acquisition of functional data with advanced MR sequences and hybrid imaging with radionuclide tracers. WBMRI demonstrates the extent of disease in a range of multisystem conditions and, in some cases, disease burden prior to the onset of clinical features. The current applications of WBMRI in children are hereby reviewed, along with suggested anatomical stations and sequence protocols for acquisition.

Whole-body magnetic resonance imaging in children - how and why? A systematic review

Whole-body magnetic resonance imaging (MRI) is increasingly being used for a number of indications. Our aim was to review and describe indications and scan protocols for diagnostic value of whole-body MRI for multifocal disease in children and adolescents, we conducted a systematic search in Medline, Embase and Cochrane for all published papers until November 2018. Relevant subject headings and free text words were used for the following concepts: 1) whole-body, 2) magnetic resonance imaging and 3) child and/or adolescent. Included were papers in English with a relevant study design that reported on the use and/or findings from whole-body MRI examinations in children and adolescents. This review includes 54 of 1,609 papers identified from literature searches. Chronic nonbacterial osteomyelitis, lymphoma and metastasis were the most frequent indications for performing a whole-body MRI. The typical protocol included a coronal STIR (short tau inversion recovery) sequence with or without a coronal T1-weighted sequence. Numerous studies lacked sufficient data for calculating images resolution and only a few studies reported the acquired voxel volume, making it impossible for others to reproduce the protocol/images. Only a minority of the included papers assessed reliability tests and none of the studies documented whether the use of whole-body MRI affected mortality and/or morbidity. Our systematic review confirms significant variability of technique and the lack of proven validity of MRI findings. The information could potentially be used to boost attempts towards standardization of technique, reporting and guidelines development.

Pain Management in Childhood Leukemia: Diagnosis and Available Analgesic Treatments

Pain is one of the most common symptoms in children suffering from leukemia, who are often misdiagnosed with other childhood painful diseases such as juvenile idiopathic arthritis. Corticosteroid-induced osteonecrosis (ON) and vincristine-induced peripheral neuropathy (VIPN) are the most common painful manifestations. Additionally, ongoing pain may continue to impact quality of life in survivorship. This narrative review focuses on the pathophysiological mechanisms of pain in childhood leukemia and current available indications for analgesic treatments. Pain management in children is often inadequate because of difficulties in pain assessment, different indications across countries, and the lack of specific pediatric trials. Analgesic drugs are often prescribed off-label to children by extrapolating information from adult guidelines, with possible increased risk of adverse events. Optimal pain management should involve a multidisciplinary team to ensure assessment and interventions tailored to the individual patient.

Initial Presentation and Progression of Secondary Osteonecrosis of the Knee

BACKGROUND

Early detection and intervention are critical to maintaining the native articular cartilage before collapse in secondary osteonecrosis of the knee (SOK). We conducted a retrospective study documenting the initial stage of presentation and the progression of SOK.

METHODS

Our database was reviewed for patients younger than 65 years of age diagnosed with atraumatic SOK between 2002 and 2018. Demographic data, plain radiographs as well as MRI at initial evaluation, and initial treatment were classified and analyzed.

RESULTS

One hundred four patients with 164 knees were identified. Mean age was 39 ± 16 years. Females (64%) with bilateral disease (58%) predominated. Seventy-five percent of patients had a history of corticosteroid use, of which 41% were diagnosed with hematologic malignancy and lupus. Fifteen percent of patients had a history of ethanol abuse. At initial presentation, 55% of patients were diagnosed with Ficat-Arlet stage I/II, while 45% were diagnosed with Ficat-Arlet stage III/IV. We found a significant difference in the mean age of patients at early stage of SOK with corticosteroid use (31 ± 12 years of age) when compared to ethanol use (43 ± 13 years of age, P = .02). Treatments included observation (57%), joint preservation surgery (20%), and total knee arthroplasty (23%).

CONCLUSION

Nearly half of patients presented at late stage compromising the potential for joint preservation. The difference in age of referral by over a decade, based on etiology of SOK, suggests a strong provider-based referral or screening bias may be present. Hence, a multidisciplinary approach to earlier detection and referral may be a more effective strategy for preventing the progression of SOK.

Severe bilateral Legg-Calvé-Perthes resolved with pamidronate in combination with casts, physiotherapy and adductor tenotomy: a pictorial essay over 11 years

We describe an 11-year prospective clinical and radiologic course of a 6-year-old boy with bilateral Legg-Calvé-Perthes disease, who was treated with intravenous pamidronate (IV-PAM). His baseline radiographs showed grade IV avascular necrosis/Catterall stage IV, and at worst he progressed to lateral pillar/Herring stage C bilaterally. His disease initially was extremely functionally limiting with expected poor outcome with eventual joint replacement. Because IV-PAM stops bone breakdown and allows for ongoing bone formation while revascularisation of bone occurs, we hypothesised that IV-PAM could act as an adjunct to traditional treatment to help heal the femoral heads. Our patient received nine once monthly doses of IV-PAM (1 mg/kg/dose) over 13 months, along with Petrie/broomstick casts and physiotherapy. Remarkably, over time, his femoral heads healed. Now, at 11-year follow-up, he has excellent functional and radiologic outcome with congruence between femoral head and acetabulum, no residual osteonecrosis and minimal loss of femoral head sphericity.

The radiological and clinical follow-up of osteonecrosis in cancer patients

BACKGROUND

In patients with cancer, osteonecrosis (ON) lesions can affect multiple sites throughout the skeleton, including the long and short bones and the joints. The aims of this study were to explore the natural course of ON in patients treated for cancer by using radiological classification suitable for multisite ON lesions and to assess correlations between the ON grade and surgical procedures.

MATERIAL AND METHODS

Data were retrieved from hospital databases on 233 ON lesions in 54 patients (aged 2-73 years at cancer diagnosis; mean age: 25 years). ONs were graded according to the Niinimäki classification, based on magnetic resonance images. Medical records were reviewed to identify surgical procedures.

RESULTS

A total of 14 different ON sites were detected; the hip was the most common site (n = 51), followed by the femur (n = 45), tibia (n = 41) and knee (n = 37). Among the 233 ON lesions, 78.1% did not require surgical procedures. The remaining lesions required total joint arthroplasty (TJA; 40/233, 17.2%), core decompression (3.4%) and arthroscopy (1.3%). Most TJAs (33/40, 82.5%) were performed on the hip. ONs of the knee required TJAs only once; grade 3 knee ONs frequently healed (58%, 11/19). None of the diaphyseal or metaphyseal (grade 1-2) ONs of the long bones required surgery, and no fractures of those bones were identified.

CONCLUSIONS

In conclusion, the natural history of ONs varied by the grade and site. Based on our findings, we would not recommend routine radiological follow-ups for grades 1-2 ON lesions that do not affect the joints, because the clinical consequences of those lesions appear to be minimal, although pain relief would be warranted. In contrast, joint deformations (grade 5) require surgery; therefore, intervention studies should focus on grades 3-4 ON lesions.

Osteonecrosis of the Shoulders in Pediatric Patients Treated for Leukemia or Lymphoma: Single-Institutional Experience

BACKGROUND

Osteonecrosis of the hips and knees is an often debilitating adverse event in children treated with glucocorticoids for leukemia and lymphoma but the impact of shoulder involvement has been understudied. Thus, we investigated the severity and functional impairment of shoulder osteonecrosis in a well-characterized population of pediatric patients treated for acute lymphoblastic leukemia or lymphoma.

METHODS

We retrospectively reviewed orthopaedic clinic and physical therapy evaluations to determine range of motion (ROM), pain, and impact of magnetic resonance-defined osteonecrosis (ON) on activities of daily living. Adverse events were classified according to the National Cancer Institute's Common Terminology Criteria for Adverse Events version 4.03.

RESULTS

We identified 35 patients (22 female), median age at cancer diagnosis 14.2 (range, 4.3 to 19) years; median age at ON diagnosis 16.7 (range, 5.5 to 28) years. Median time to last follow-up from diagnosis of primary malignancy was 6.4 (range, 0 to 12.7) years and from diagnosis of ON was 4.0 (range, 0 to 8.9) years. Twenty-two patients had magnetic resonance evidence of ON; 43 shoulders involved at least 30% of the articular surface of the capital humeral epiphyses.Common Terminology Criteria for Adverse Events mean scores for initial assessments of 55 shoulders (29 patients) showed moderate negative impact of ON on activity of daily living (1.94), decreased ROM limiting athletic activity (0.98), and mild to moderate levels of pain (1.38). Analysis of this group's most recent assessment showed improvement in pain and ON over time, with an average pain grade of 0.58 indicating no pain to mild pain, and 1.37 for ON grade, indicating asymptomatic to mildly symptomatic impact on activities of daily living. We also found minimal worsening average ROM grades (1.11).

CONCLUSIONS

Shoulder ON is an underappreciated adverse late effect of therapy in children treated for leukemia/lymphoma which can limit quality of life and functionality. In most cases, pain and disability can be improved with treatment.

LEVEL OF EVIDENCE

Level IV-case series.

Skeletal Morbidity in Children and Adolescents during and following Cancer Therapy

Skeletal abnormalities are common in children and adolescents diagnosed and treated for a malignancy. The spectrum ranges from mild pain to debilitating osteonecrosis and fractures. In this review, we summarize the impact of cancer therapy on the developing skeleton, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life in childhood cancer survivors.

Tracking Cell Transplants in Femoral Osteonecrosis with Magnetic Resonance Imaging: A Proof-of-Concept Study in Patients

PURPOSE

Osteonecrosis is a devastating complication of high-dose corticosteroid therapy in patients with cancer. Core decompression for prevention of bone collapse has been recently combined with the delivery of autologous concentrated bone marrow aspirates. The purpose of our study was to develop an imaging test for the detection of transplanted bone marrow cells in osteonecrosis lesions.

EXPERIMENTAL DESIGN

In a prospective proof-of-concept clinical trial (NCT02893293), we performed serial MRI studies of nine hip joints of 7 patients with osteonecrosis before and after core decompression. Twenty-four to 48 hours prior to the surgery, we injected ferumoxytol nanoparticles intravenously to label cells in normal bone marrow with iron oxides. During the surgery, iron-labeled bone marrow cells were aspirated from the iliac crest, concentrated, and then injected into the decompression track. Following surgery, patients received follow-up MRI up to 6 months after bone marrow cell transplantation.

RESULTS

Iron-labeled cells could be detected in the access canal by a dark (negative) signal on T2-weighted MR images. T2* relaxation times of iron-labeled cell transplants were significantly lower compared with unlabeled cell transplants of control patients who were not injected with ferumoxytol (P = 0.02). Clinical outcomes of patients who received ferumoxytol-labeled or unlabeled cell transplants were not significantly different (P = 1), suggesting that the added ferumoxytol administration did not negatively affect bone repair.

CONCLUSIONS

This immediately clinically applicable imaging test could become a powerful new tool to monitor the effect of therapeutic cells on bone repair outcomes after corticosteroid-induced osteonecrosis.

Avascular necrosis of the femoral head in patients treated for leukaemia. Assessment of the need for a diagnostic protocol

OBJECTIVE

To evaluate the incidence of avascular necrosis of the hip in leukaemia patients treated in our hospital with high doses of corticosteroids in order to evaluate the necessity for an early detection protocol.

MATERIAL AND METHODS

Observational-descriptive and retrospective study from 2005 to 2016 of 253 patients diagnosed with paediatric leukaemia. Patients with musculoskeletal pathology were identified and patients with avascular necrosis were analysed.

RESULTS

A total of 26 patients (10%) had musculoskeletal symptoms. Three patients with avascular necrosis (1.2%) were analysed. One girl, 7 years old, was treated conservatively with traction - suspension and discharge. Two boys, an 11 and a 15.4 year-old,who developed graft-versus-host disease secondary to bone marrow transplantation, and whose treatment included high doses of corticosteroids, developed avascular necrosis of the hip. One was treated with bisphosphonates and forage and the other ended up with a total hip arthroplasty.

DISCUSSION

The occurrence of musculoskeletal symptoms during the treatment of leukaemia is different according to the bibliographic series (0.43 -12.6%). Some authors observe an increased risk in female patients between the ages of 10 and 17. A retrospective study reveals that there is a delay of 3.9 months in the diagnosis of CAP since the onset of pain. Other authors relate NAV to loading joints, age and high doses of corticosteroids.

CONCLUSION

Based on the low incidence of avascular necrosis of the hip in our 14-year-old population treated for leukaemia, the creation of diagnostic protocols seems not to be necessary. However, close monitoring of patients with potential risk factors recognized in the literature, is advisable.

Bone marrow oedema predicts bone collapse in paediatric and adolescent leukaemia patients with corticosteroid-induced osteonecrosis

OBJECTIVES

Corticosteroid treatment of paediatric leukaemia patients can lead to osteonecrosis (ON). We determined whether bone marrow oedema (BME) is an early sign of progressive ON and eventual bone collapse.

METHODS

In a retrospective study, two radiologists reviewed MR imaging characteristics of 47 early stage epiphyseal ON in 15 paediatric and adolescent leukaemia patients. Associations between BME on initial imaging studies and subchondral fracture, disease progression and bone collapse were assessed by Cochran-Mantel-Haenszel tests. Differences in time to progression and bone collapse between lesions with and without oedema were assessed by log rank tests.

RESULTS

Forty-seven occurrences of ON were located in weight bearing joints, with 77% occurring in the femur. Seventeen lesions progressed to collapse, two lesions worsened without collapse, and 28 remained stable or improved. BME was significantly associated with subchondral fracture (p = 0.0014), disease progression (p = 0.0015), and bone collapse (p < 0.001), with a sensitivity and specificity of 94% and 77%, respectively, for bone collapse. Time to progression for ON with oedema was 2.7 years (95% CI: 1.7-3.4); while the majority of no-oedema ON were stable (p = 0.0011).

CONCLUSIONS

BME is an early sign of progressive ON and eventual bone collapse in paediatric and adolescent leukaemia patients.

KEY POINTS

• Bone marrow oedema in corticosteroid-induced osteonecrosis predicts progression to bone collapse. • Bone marrow oedema is associated with subchondral fractures in corticosteroid-induced osteonecrosis. • Bone marrow oedema can be used to stratify patients to joint-preserving interventions. • Absence of bone marrow oedema can justify a "wait and watch" approach.

Value of whole-body magnetic resonance imaging for screening multifocal osteonecrosis in patients with polymyositis/dermatomyositis

OBJECTIVE

To assess the value of coronal short-tau inversion recovery whole-body MRI (STIR-WBMRI) for screening osteonecrosis in patients with polymyositis (PM)/dermatomyositis (DM).

METHODS

The imaging and medical records of 129 patients with PM/DM who met the Bohan and Peter diagnostic criteria were retrospectively analyzed. STIR-WBMRI was performed in all patients. 18 patients had follow-up STIR-WBMRI. 12 patients underwent regional knee and/or hip MRI while 25 patients underwent radiography of the lower extremities.

RESULTS

STIR-WBMRI detected osteonecrosis in 15 (11.6%) patients. 38 joints were affected (mean, 2.5 per patient; range, 1-5 joints). Of the 38 joints affected by osteonecrosis, 33 had no clinical symptoms. Among the 12 patients who underwent regional MRI, STIR-WBMRI detected all 10 osteonecrotic sites seen on the regional MRI. The location, shape and size of the osteonecrotic lesions revealed on regional MRI were in accordance with those displayed on STIR-WBMRI. Of the 15 patients with osteonecrosis, 6 performed routine radiography of the affected joints and revealed no osteonecrotic lesions. Follow-up WBMRI detected new osteonecrosis in two patients whose first WBMRI revealed that there was no osteonecrosis in any skeleton.

CONCLUSION

In addition to displaying muscle inflammation, STIR-WBMRI can efficiently detect early multifocal osteonecrosis in the whole bodies of patients with PM/DM. Advances in knowledge: In patients with PM/DM, WBMRI which takes 12-15 min can display muscular involvement and detect early multisite osteonecrosis in the whole body at the same time. Osteonecrotic lesions revealed by WBMRI are in accordance with those displayed on regional WBMRI.

How PET/MR Can Add Value For Children With Cancer

PURPOSE

To review how PET/MR technology could add value for pediatric cancer patients.

RECENT FINDINGS

Since many primary tumors in children are evaluated with MRI and metastases are detected with PET/CT, integrated PET/MR can be a time-efficient and convenient solution for pediatric cancer staging. 18F-FDG PET/MR can assess primary tumors and the whole body in one imaging session, avoid repetitive anesthesia and reduce radiation exposure compared to 18F-FDG PET/CT. This article lists 10 action points, which might improve the clinical value of PET/MR for children with cancer. However, even if PET/MR proves valuable, it cannot enter mainstream applications if it is not accessible to the majority of pediatric cancer patients. Therefore, innovations are needed to make PET/MR scanners affordable and increase patient throughput.

SUMMARY

PET/MR offers opportunities for more efficient, accurate and safe diagnoses of pediatric cancer patients. The impact on patient management and outcomes has to be substantiated by large-scale prospective clinical trials.

Whole Body MR Imaging: A Useful Imaging Modality in the Management of Children With Acute Myeloid Leukemia

INTRODUCTION

To evaluate the distribution of chloromas using whole body magnetic resonance (MR) imaging in pediatric patients with acute myeloid leukemia (AML) and to assess the clinical role of whole body MR imaging in management of pediatric patients with AML.

MATERIALS AND METHODS

We retrospectively searched pediatric patients (< 18 years old) who were diagnosed with AML and underwent whole body MR imaging during their illness between January 2006 and December 2014. The presence of chloromas was defined as when it was proven pathologically or showed typical imaging features. Nonchloroma lesions that were incidentally detected and were not previously seen on other imaging studies were defined as clinically occult nonchloroma lesions.

RESULTS

Sixty-nine whole body MR scans of 40 patients with AML were included. The musculoskeletal system (42.9%) was the most commonly affected by chloromas. A total of 77 chloromas were identified in 11 (27.5%) of 40 patients. Nine (81.8%) of these 11 patients had 2 or more chloromas. There were 39 (50.6%) unexpected chloromas, which were incidentally detected, in 7 patients. Whole body MR scanning provided additional information regarding 21 clinically occult nonchloroma lesions in this patient population.

CONCLUSION

Chloromas tended to show multiplicity and be present without symptoms. The most common site of involvement was the musculoskeletal system. Whole body MR imaging provided additional information that affected the clinical management of children with AML.

Whole-body MRI reveals high incidence of osteonecrosis in children treated for Hodgkin lymphoma

Osteonecrosis is a well-recognized complication in patients treated with corticosteroids. The incidence of osteonecrosis in children treated for Hodgkin lymphoma is unknown because prospective whole-body magnetic resonance imaging (MRI) studies are lacking in this patient population. Paediatric patients with newly diagnosed Hodgkin lymphoma who were treated according to a uniform paediatric Hodgkin protocol were eligible for inclusion in this prospective study. Whole-body MRI was performed in all 24 included patients (mean age 15·1 years, 12 girls) both before treatment and after 2 cycles of chemotherapy, and in 16 patients after completion of chemotherapy. Osteonecrosis was identified in 10 patients (41·7%, 95% confidence interval: 22·0-61·4%), with a total of 56 osteonecrotic sites. Osteonecrosis was detected in 8 patients after 2 cycles of OEPA (vincristine, etoposide, prednisone, doxorubicin), and in 2 additional patients after completion of chemotherapy. Epiphyseal involvement of long bones was seen in 4 of 10 children. None of the patients with osteonecrosis had any signs of bone collapse at the times of scanning. Whole-body MRI demonstrates osteonecrosis to be a common finding occurring during therapy response assessment of paediatric Hodgkin lymphoma. Detection of early epiphyseal osteonecrosis could allow for treatment before bone collapse and joint damage may occur.

[Differential diagnosis of reduced uptake images revealed by bone scan: about a case of acute lymphoblastic leukemia]

If increased uptake during bone scan usually bring to light many bone pathologies, reduced uptakes are a rare occurrence and they require careful analysis to avoid erroneous interpretations. We report the case of a 17-year old admitted with diffuse bone pain, hypercalcemia and thrombopenia. Bone scan showed areas of low uptakes. Bone marrow tests allowed the diagnosis of acute lymphoblastic leukemia. This case report aims to discuss the main differential diagnoses based on such bone scan abnormalities.

The pathogenesis of multifocal osteonecrosis

Our objective was to study the incidence, etiology, and diagnosis of multifocal osteonecrosis (MFON) and its treatment options to facilitate an earlier diagnosis and to optimize treatment. A radiological investigation was performed in osteonecrosis patients with a high risk of MFON for a more accurate diagnosis between January 2010 and June 2015. For patients with osteonecrosis of both the hip and knee joints or for patients with a history of corticosteroid use or alcohol abuse who had osteonecrosis of one or more joints in the shoulder, ankle, wrist or elbow, magnetic resonance imaging (MRI) was also performed on other joints, regardless of whether these joints were symptomatic. Furthermore, we performed a radiological screening of 102 patients who had a negative diagnosis of MFON but were at a high risk; among them, another 31 MFON cases were successfully identified (30.4%). Thus, the incidence of MFON during the study period increased from 3.1% to 5.2%. Patients diagnosed with osteonecrosis and who are at a high risk of MFON should have their other joints radiologically examined when necessary. This will reduce missed diagnosis of MFON and facilitate an earlier diagnosis and treatment to achieve an optimal outcome.

Pediatric whole-body MRI: A review of current imaging techniques and clinical applications

There are many congenital, neoplastic, inflammatory, and infectious processes in the pediatric patient for which whole-body imaging may be of benefit diagnostically and prognostically. With recent improvements in magnetic resonance imaging (MRI) hardware and software and resultant dramatically reduced scan times, imaging of the whole body with MRI has become a much more practicable technique in children. Whole-body MRI can provide a high level of soft tissue and skeletal detail while avoiding the exposure to ionizing radiation inherent to computed tomography and nuclear medicine imaging techniques. This article reviews the more common current whole-body MRI techniques in children and the primary pathologies for which this imaging modality may be most useful to the radiologists and referring clinicians. J. MAGN. RESON. IMAGING 2016;44:783-793.

Imaging of acute and subacute toxicities of cancer therapy in children

Effective cancer therapies have resulted in significant improvement in survival. However, treatment-related acute and subacute complications are a cause of significant morbidity and mortality. Effects of cancer therapy in children can be seen early in the survival period or later in life in almost all organ systems of the body. Many of these conditions are evaluated by imaging and some are diagnosed based on characteristic imaging features. This article aims to discuss acute and subacute toxicities of cancer therapy in children involving multiple organ systems, pulmonary, gastrointestinal, hepatobiliary, genitourinary and musculoskeletal systems with emphasis on those in which imaging plays a role in diagnosis or management. We also discuss the role of imaging and choice of imaging modalities in these conditions.

The classification of osteonecrosis in patients with cancer: validation of a new radiological classification system

AIM

To validate a new, non-joint-specific radiological classification system that is suitable regardless of the site of the osteonecrosis (ON) in patients with cancer.

MATERIAL AND METHODS

Critical deficiencies in the existing ON classification systems were identified and a new, non-joint-specific radiological classification system was developed. Seventy-two magnetic resonance imaging (MRI) images of patients with cancer and ON lesions were graded, and the validation of the new system was performed by assessing inter- and intra-observer reliability.

RESULTS

Intra-observer reliability of ON grading was good or very good, with kappa values of 0.79-0.86. Interobserver agreement was lower but still good, with kappa values of 0.62-0.77. Ninety-eight percent of all intra- or interobserver differences were within one grade. Interobserver reliability of assessing the location of ON was very good, with kappa values of 0.93-0.98.

CONCLUSION

All the available radiological ON classification systems are joint specific. This limitation has spurred the development of multiple systems, which has led to the insufficient use of classifications in ON studies among patients with cancer. The introduced radiological classification system overcomes the problem of joint-specificity, was found to be reliable, and can be used to classify all ON lesions regardless of the affected site.

Whole-Body MRI in Children: Current Imaging Techniques and Clinical Applications

Whole-body magnetic resonance imaging (MRI) is increasingly used in children to evaluate the extent and distribution of various neoplastic and non-neoplastic diseases. Not using ionizing radiation is a major advantage of pediatric whole-body MRI. Coronal and sagittal short tau inversion recovery imaging is most commonly used as the fundamental whole-body MRI protocol. Diffusion-weighted imaging and Dixon-based imaging, which has been recently incorporated into whole-body MRI, are promising pulse sequences, particularly for pediatric oncology. Other pulse sequences may be added to increase diagnostic capability of whole-body MRI. Of importance, the overall whole-body MRI examination time should be less than 30-60 minutes in children, regardless of the imaging protocol. Established and potentially useful clinical applications of pediatric whole-body MRI are described.

Utility of early screening magnetic resonance imaging for extensive hip osteonecrosis in pediatric patients treated with glucocorticoids

PURPOSE

Hip osteonecrosis frequently complicates treatment with glucocorticoids. When extensive (affecting ≥ 30% of the epiphyseal surface), 80% of joints collapse within 2 years, so interventions are needed to prevent this outcome.

PATIENTS AND METHODS

This prospective cohort magnetic resonance imaging (MRI) screening study included all consecutive children treated for acute lymphoblastic leukemia on a single protocol. Hip MRI was performed at 6.5 and 9 months from diagnosis (early screening) and at completion of chemotherapy (final evaluation) to determine whether screening could identify extensive hip osteonecrosis before symptom development.

RESULTS

Of 498 patients, 462 underwent screening MRI. Extensive asymptomatic osteonecrosis was identified by early screening in 26 patients (41 hips); another four patients (seven hips) were detected after the screening period, such that screening sensitivity was 84.1% and specificity was 99.4%. The number of joints screened to detect one lesion was 20.1 joints for all patients, 4.4 joints for patients older than 10 years, and 198 joints for patients ≤ 10 years old (P < .001). Of the 40 extensive lesions in patients older than 10 years, 19 required total hip arthroplasty and none improved. Of eight extensive lesions in younger patients, none required arthroplasty and four improved.

CONCLUSION

In patients age 10 years old or younger who require prolonged glucocorticoid therapy, screening for extensive hip osteonecrosis is unnecessary because their risk is low and lesions tend to heal. In children older than 10 years, early screening successfully identifies extensive asymptomatic lesions in patients who would be eligible for studies of interventions to prevent or delay joint collapse.

Bone morbidity in childhood leukemia: epidemiology, mechanisms, diagnosis, and treatment

Skeletal abnormalities are commonly seen in children and adolescents with leukemia. The spectrum ranges from mild pain to debilitating osteonecrosis (ON) and fractures. In this review, we summarize the skeletal manifestations, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life observed in children and adolescents with leukemia.

Update on pediatric leukemia and lymphoma imaging

Together, leukemia and lymphoma account for half of all childhood malignancies. Leukemia and lymphoma arise from similar cell lines and can have overlapping imaging features; however, the clinical presentation, imaging strategies, and treatment protocols can vary substantially based on the specific subtype. Although imaging does not play a central role in staging or monitoring disease in childhood leukemia, findings on imaging may be the first indication of the diagnosis. Advanced imaging, especially positron emission tomography/computed tomography, has moved to the forefront of staging and treatment response evaluation in Hodgkin's disease and non-Hodgkin's lymphoma. Imaging also plays a key role in evaluating the myriad of treatment complications that are commonly seen with chemotherapy and associated neutropenia. Future efforts will be largely focused on decreasing radiation exposure to these children, utilizing reduced or radiation-free modalities, such as positron emission tomography/magnetic resonance and diffusion-weighted whole-body imaging with background suppression, as well as refining surveillance imaging strategies. The purpose of this article is to briefly review the classification of pediatric leukemia and lymphoma, illustrate common imaging findings at presentation throughout the body, describe staging and therapeutic response evaluation, and show a spectrum of commonly encountered complications of treatment.