Pediatric bone sarcoma: diagnostic performance of ¹⁸F-FDG PET/CT versus conventional imaging for initial staging and follow-up

Japanese orthopaedic association (JOA) clinical practice guidelines on the management of malignant bone tumors - Secondary publication

BACKGROUND

In Japan, there are currently no general guidelines for the treatment of primary malignant bone tumors. Therefore, the Japanese Orthopaedic Association established a committee to develop guidelines for the appropriate diagnosis and treatment of primary malignant bone tumors for medical professionals in clinical practice.

METHODS

The guidelines were developed in accordance with "Minds Clinical Practice Guideline Development Handbook 2014″ and "Minds Clinical Practice Guideline Development Manual 2017". The Japanese Orthopaedic Association's Bone and Soft Tissue Tumor Committee established guideline development and systematic review committees, drawing members from orthopedic specialists leading the diagnosis and treatment of bone and soft tissue tumors. Pediatricians, radiologists, and diagnostic pathologists were added to both committees because of the importance of multidisciplinary treatment. Based on the diagnosis and treatment algorithm for primary malignant bone tumors, important decision-making points were selected, and clinical questions (CQ) were determined. The strength of recommendation was rated on two levels and the strength of evidence was rated on four levels. The recommendations published were selected based on agreement by 70% or more of the voters.

RESULTS

The guideline development committee examined the important clinical issues in the clinical algorithm and selected 22 CQs. The systematic review committee reviewed the evidence concerning each CQ and a clinical value judgment was added by experts. Eventually, 25 questions were published and the text of each recommendation was determined.

CONCLUSION

Since primary malignant bone tumors are rare, there is a dearth of strong evidence based on randomized controlled trials, and recommendations cannot be applied to all the patients. In clinical practice, appropriate treatment of patients with primary malignant bone tumors should be based on the histopathological diagnosis and degree of progression of each case, using these guidelines as a reference.

Recurrent Metastatic Ewing Sarcoma Involving Only in the Muscles of Extremities Shown on FDG PET/CT

ABSTRACT

Ewing sarcoma is the second most common osseous malignancy in pediatric patient. Metastasis is common due to its aggressive nature, with 25% of patients with metastasis at diagnosis, commonly to the lungs, bone, or bone marrow. Muscle metastasis is uncommon. We report FDG PET/CT findings of multifocal muscle metastases of recurrent Ewing sarcoma in the extremities without lung and bone involvement in a 6-year-old boy.

UK guidelines for the management of soft tissue sarcomas

Soft tissue sarcomas (STS) are rare tumours arising in mesenchymal tissues and can occur almost anywhere in the body. Their rarity, and the heterogeneity of subtype and location, means that developing evidence-based guidelines is complicated by the limitations of the data available. This makes it more important that STS are managed by expert multidisciplinary teams, to ensure consistent and optimal treatment, recruitment to clinical trials, and the ongoing accumulation of further data and knowledge. The development of appropriate guidance, by an experienced panel referring to the evidence available, is therefore a useful foundation on which to build progress in the field. These guidelines are an update of the previous versions published in 2010 and 2016 [1, 2]. The original guidelines were drawn up by a panel of UK sarcoma specialists convened under the auspices of the British Sarcoma Group (BSG) and were intended to provide a framework for the multidisciplinary care of patients with soft tissue sarcomas. This iteration of the guidance, as well as updating the general multidisciplinary management of soft tissue sarcoma, includes specific sections relating to the management of sarcomas at defined anatomical sites: gynaecological sarcomas, retroperitoneal sarcomas, breast sarcomas, and skin sarcomas. These are generally managed collaboratively by site specific multidisciplinary teams linked to the regional sarcoma specialist team, as stipulated in the recently published sarcoma service specification [3]. In the UK, any patient with a suspected soft tissue sarcoma should be referred to a specialist regional soft tissues sarcoma service, to be managed by a specialist sarcoma multidisciplinary team. Once the diagnosis has been confirmed using appropriate imaging and a tissue biopsy, the main modality of management is usually surgical excision performed by a specialist surgeon, combined with pre- or post-operative radiotherapy for tumours at higher risk for local recurrence. Systemic anti-cancer therapy (SACT) may be utilised in cases where the histological subtype is considered more sensitive to systemic treatment. Regular follow-up is recommended to assess local control, development of metastatic disease, and any late effects of treatment.

Molecular Imaging with PET-CT and PET-MRI in Pediatric Musculoskeletal Diseases

Molecular imaging has emerged as an integral part of oncologic imaging. Given the physiologic changes that precede anatomic changes, molecular imaging can enable early detection of disease and monitoring of response. [18F] Fluorodeoxyglucose (FDG) Positron emission tomography (PET) is the predominant molecular imaging modality used in oncologic assessment and can be performed using PET/CT or PET/MR. In pediatric patients, PET/MRI imaging is generally preferred due to low radiation exposure and PET/MRI is particularly advantageous for imaging musculoskeletal (MSK) diseases, as MRI provides superior characterization of tissue changes as compared to CT. In this article, we provide an overview of the typical role of PET CT/MRI in assessment of some common pediatric malignancies and benign MSK diseases with case examples. We also discuss the relative advantages of PET/MRI compared to PET/CT, and review published data with a primary focus on the use of PET/MR.

Can FDG-PET assess the response to chemotherapy and predict tissue necrosis in osteosarcoma and Ewing sarcoma?

INTRODUCTION

Osteosarcoma (OS) and Ewing sarcoma (ES) represent the pediatric population's most common malignant bone tumors. 18-Fluorodeoxyglucose positron emission tomography has been shown to be effective in both the diagnostic and staging phases of cancer treatment. In recent years, some studies have also explored the possibility that FDG-PET could have a prognostic role.

Comparative Analysis of Skip Metastasis in Pediatric Osteosarcoma: Clinical Features and Outcomes

BACKGROUND

Skip metastasis (SM) is a synchronous regional bone metastasis. Using new imaging modalities, the detection of SM is easier and possibly more common. We reviewed patients with SM and compared their characteristics and outcomes to other patients with osteosarcoma treated at our center.

METHODS

We reviewed retrospectively children (<18 years) with newly diagnosed osteosarcoma who presented from June 2006 to March 2022. Patients' characteristics, treatment modalities, and outcomes were analyzed. All cases were discussed in a multidisciplinary clinic that included 2 experienced radiologists.

RESULTS

We identified 155 patients with osteosarcoma, among which 13 (8.3%) patients had SM detected by MRI. Patients with SM had a median age at diagnosis of 11.2 years (range 7 to 17). Three patients had lung metastasis at diagnosis. Bone scan was positive for the SM in 8 patients (62%). All patients underwent primary tumor resection after neoadjuvant chemotherapy (amputation in 5, limb salvage surgery in 8). Five had postchemotherapy necrosis ≥90% in primary tumor. Seven patients relapsed/progressed (1 local and 6 in the lung), all relapsed patients died of disease. Compared to the rest of the patients, those with SM had similar clinical features to patients without SM; outcomes were similar with no significant differences in event-free survival and overall survival ( P =0.7 and 0.3, respectively).

CONCLUSION

In this study, we observed a percentage of patients with SM comparable to previous reports. Patients with SM exhibited clinical features akin to the rest of our patients. Thorough evaluation of imaging studies and multidisciplinary care, coupled with meticulous surgical planning, are crucial for achieving a cure, which remained unjeopardized in our patients with SM.

Tata Memorial Centre Evidence Based Use of Nuclear medicine diagnostic and treatment modalities in cancer

ABSTRACT

PET/CT and radioisotope therapy are diagnostic and therapeutic arms of Nuclear Medicine, respectively. With the emergence of better technology, PET/CT has become an accessible modality. Diagnostic tracers exploring disease-specific targets has led the clinicians to look beyond FDG PET. Moreover, with the emergence of theranostic pairs of radiopharmaceuticals, radioisotope therapy is gradually making it's way into treatment algorithm of common cancers in India. We therefore would like to discuss in detail the updates in PET/CT imaging and radionuclide therapy and generate a consensus-driven evidence based document which would guide the practitioners of Oncology.

Imaging of pediatric bone tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Malignant primary bone tumors are uncommon in the pediatric population, accounting for 3%-5% of all pediatric malignancies. Osteosarcoma and Ewing sarcoma comprise 90% of malignant primary bone tumors in children and adolescents. This paper provides consensus-based recommendations for imaging in children with osteosarcoma and Ewing sarcoma at diagnosis, during therapy, and after therapy.

Imaging of pediatric extremity soft tissue tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Pediatric soft tissue tumors of the extremity include rhabdomyosarcoma and nonrhabdomyosarcoma neoplasms. This manuscript provides consensus-based imaging recommendations for imaging evaluation at diagnosis, during treatment, and following completion of therapy for patients with a soft tissue tumor of the extremity.

Comparison of the different imaging modalities used to image pediatric oncology patients: A COG diagnostic imaging committee/SPR oncology committee white paper

Diagnostic imaging is essential in the diagnosis and management, including surveillance, of known or suspected cancer in children. The independent and combined roles of the various modalities, consisting of radiography, fluoroscopy, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine (NM), are both prescribed through protocols but also function in caring for complications that may occur during or subsequent to treatment such as infection, bleeding, or organ compromise. Use of a specific imaging modality may be based on situational circumstances such as a brain CT or MR for a new onset seizure, chest CT for respiratory signs or symptoms, or US for gross hematuria. However, in many situations, there are competing choices that do not easily lend themselves to a formulaic approach as options; these situations depend on the contributions of a variety of factors based on a combination of the clinical scenario and the strengths and limitations of the imaging modalities. Therefore, an improved understanding of the potential influence of the imaging decision pathways in pediatric cancer care can come from comparison among the individual diagnostic imaging modalities. The purpose of the following material to is to provide such a comparison. To do this, pediatric imaging content experts for the individual modalities of radiography and fluoroscopy, US, CT, MRI, and NM will discuss the individual modality strengths and limitations.

18F-FDG PET/CT in the Management of Osteosarcoma

Osteosarcoma is the most common type of primary malignant bone tumor. ¹⁸F-FDG PET/CT is useful for staging, detecting recurrence, monitoring response to neoadjuvant chemotherapy, and predicting prognosis. Here, we review the clinical aspects of osteosarcoma management and assess the role of ¹⁸F-FDG PET/CT, in particular with regard to pediatric and young adult patients.

PET/MR of pediatric bone tumors: what the radiologist needs to know

Integrated 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging can provide "one stop" local tumor and whole-body staging in one session, thereby streamlining imaging evaluations and avoiding duplicate anesthesia in young children. 18F-FDG PET/MR scans have the benefit of lower radiation, superior soft tissue contrast, and increased patient convenience compared to 18F-FDG PET/computerized tomography scans. This article reviews the 18F-FDG PET/MR imaging technique, reporting requirements, and imaging characteristics of the most common pediatric bone tumors, including osteosarcoma, Ewing sarcoma, primary bone lymphoma, bone and bone marrow metastases, and Langerhans cell histiocytosis.

Molecular imaging of sarcomas with FDG PET

Sarcoma comprises a heterogenous entity of musculoskeletal malignancies arising from a mesenchymal origin. The diagnosis and management of pediatric sarcoma requires a multidisciplinary approach and the use of various imaging modalities including CT, MRI and FDG PET scans. FDG PET/CT (FDG PET), as a metabolic imaging, complements and provides superior diagnostic information as against other imaging modalities alone. Advantages of FDG PET in differentiating malignant sarcomatous lesions from benign lesions, and value in staging and restaging have been noted in several studies. The use of FDG PET in clinical management has increased over the years. The data on prognostication of outcomes or predicting responders to therapy with FDG PET in patients with sarcoma is somewhat limited. This review will focus on the pearls and pitfalls of FDG PET and role of FDG PET in initial extent of disease assessment, treatment response, and surveillance imaging pertaining to osteosarcoma, chondrosarcoma, Ewing's sarcoma, and rhabdomyosarcoma. We also discuss the limitations and unmet needs of FDG PET in the management of patients with sarcoma.

The emerging applications and advancements of Raman spectroscopy in pediatric cancers

Although the survival rate of pediatric cancer has significantly improved, it is still an important cause of death among children. New technologies have been developed to improve the diagnosis, treatment, and prognosis of pediatric cancers. Raman spectroscopy (RS) is a non-destructive analytical technique that uses different frequencies of scattering light to characterize biological specimens. It can provide information on biological components, activities, and molecular structures. This review summarizes studies on the potential of RS in pediatric cancers. Currently, studies on the application of RS in pediatric cancers mainly focus on early diagnosis, prognosis prediction, and treatment improvement. The results of these studies showed high accuracy and specificity. In addition, the combination of RS and deep learning is discussed as a future application of RS in pediatric cancer. Studies applying RS in pediatric cancer illustrated good prospects. This review collected and analyzed the potential clinical applications of RS in pediatric cancers.

ACR Appropriateness Criteria® Malignant or Aggressive Primary Musculoskeletal Tumor-Staging and Surveillance: 2022 Update

Malignant or aggressive primary musculoskeletal tumors are rare and encompass a wide variety of bone and soft tissue tumors. Given the most common site for metastasis from these primary musculoskeletal tumors is to the lung, chest imaging is integral in both staging and surveillance. Extrapulmonary metastases are rarely encountered with only a few exceptions. Following primary tumor resection, surveillance of the primary tumor site is generally recommended. Local surveillance imaging recommendations differ between primary tumors of bone origin versus soft tissue origin. This document consolidates the current evidence and expert opinion for the imaging staging and surveillance of these tumors into five clinical scenarios. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Clinical Perspectives for 18F-FDG PET Imaging in Pediatric Oncology: Μetabolic Tumor Volume and Radiomics

Pediatric cancer, although rare, requires the most optimized treatment approach to obtain high survival rates and minimize serious long-term side effects in early adulthood. 18F-FDG PET/CT is most helpful and widely used in staging, recurrence detection, and response assessment in pediatric oncology. The well-known 18F-FDG PET metabolic indices of metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) have already revealed an independent significant prognostic value for survival in oncologic patients, although the corresponding cut-off values remain study-dependent and not validated for use in clinical practice. Advanced tumor “radiomic” analysis sheds new light into these indices. Numerous patterns of texture 18F-FDG uptake features can be extracted from segmented PET tumor images due to new powerful computational systems supporting complex “deep learning” algorithms. This high number of “quantitative” tumor imaging data, although not decrypted in their majority and once standardized for the different imaging systems and segmentation methods, could be used for the development of new “clinical” models for specific cancer types and, more interestingly, for specific age groups. In addition, data from novel techniques of tumor genome analysis could reveal new genes as biomarkers for prognosis and/or targeted therapies in childhood malignancies. Therefore, this ever-growing information of “radiogenomics”, in which the underlying tumor “genetic profile” could be expressed in the tumor-imaging signature of “radiomics”, possibly represents the next model for precision medicine in pediatric cancer management. This paper reviews 18F-FDG PET image segmentation methods as applied to pediatric sarcomas and lymphomas and summarizes reported findings on the values of metabolic and radiomic features in the assessment of these pediatric tumors.

Staging canine patients with appendicular osteosarcoma utilizing fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography compared to whole body computed tomography

Few studies have investigated the diagnostic performance of fluorine-18-fluorodeoxyglucose (¹⁸ F-FDG) positron emission tomography/computed tomography (PET/CT) for staging veterinary patients with appendicular osteosarcoma. The purpose of this study was to evaluate the efficacy of ¹⁸ F-FDG-PET/CT compared to whole-body CT (WBCT) for staging canine patients with appendicular osteosarcoma. The ¹⁸ F-FDG-PET/CT imaging studies of 66 dogs with appendicular osteosarcoma were anonymized and separated into two detached studies (one with whole body pre- and post-contrast CT images and the other with the whole body pre- and post-contrast CT images with the associated ¹⁸ F-FDG-PET overlay). Image assessment was performed retrospectively by five board-certified veterinary radiologists. The radiologists were instructed to assign a predefined categorical score to each pre-designated anatomic region based on a devised lesional scoring system. A score of 1 was normal, 2 abnormal but not neoplastic, 3 abnormal and concerning for neoplasia, and 4 abnormal, most likely neoplastic. Overall, the likelihood of detection of '3 or 4' was found to be significantly higher with ¹⁸ F-FDG PET/CT when compared to WBCT after adjusting for the effect of evaluator and the subject. Most significantly, 13 osseous lesions concerning for metastasis (scored 3-4) were identified in 10/66 dogs by at least one reviewer on ¹⁸ F-FDG PET/CT, which were not identified by any reviewer on WBCT. Additionally, four comorbid neoplastic lesions were identified with ¹⁸ F-FDG PET/CT and not with WBCT. The results of this study suggest that ¹⁸ F-FDG PET/CT is more efficacious in detecting metastatic and comorbid neoplastic lesions compared to WBCT in dogs with appendicular osteosarcoma. This article is protected by copyright. All rights reserved.

Is It Time to Call Time on Bone Marrow Biopsy for Staging Ewing Sarcoma (ES)?

Simple Summary

Ewing sarcoma (ES) is a rare primary bone cancer, usually found in children and adolescents, which can spread to the lungs, other bones and less commonly, the bone marrow. An accurate determination of the disease spread at baseline (staging) is important to establish prognosis, monitor treatment response and help with management decisions. There is no standard of care for staging ES, although the invasive bone marrow biopsy has traditionally been used to establish whether patients have bone marrow infiltration. Imaging techniques, including FDG-PET/CT and whole-body MRI (WB-MRI), have become established in staging other cancers with expanding use for staging ES. A number of studies have validated the accuracy, sensitivity and specificity of these modalities for detecting bone and bone marrow metastases in ES. The main aim of this review was to examine the current literature for the use of FDG-PET/CT and WB-MRI in staging ES to determine whether a bone marrow biopsy is still needed and would influence the management of patients. Hereafter, a new staging algorithm for ES recommends WB-MRI and/or FDG-PET/CT without bone marrow biopsy as the standard of care for staging localised and metastatic ES.

Abstract

Primary malignant bone sarcomas are rare and Ewing sarcoma (ES), along with osteosarcoma, predominates in teenagers and young adults. The well-established multimodality treatment incorporates systemic chemotherapy with local control in the form of surgery, with or without radiation. The presence and extent of metastases at diagnosis remains the most important prognostic factor in determining patient outcome; patients with skeletal metastases or bone marrow infiltration having a significantly worse outcome than those with lung metastases alone. There is, however, no accepted staging algorithm for ES. Large cooperative groups and national guidelines continue to advocate bone marrow biopsy (BMB) for staging but functional imaging techniques, such as 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) with computerised tomography (CT) have been increasingly used for staging cancers and whole-body magnetic resonance imaging (WB-MRI) for staging skeletal metastases. This review outlines the current literature, from which we conclude that BMB is no longer required for the staging of ES as it does not influence the standard of care management. BMB may, however, provide prognostic information and insights into the biology of ES in selected patients on prospective clinical trials.

The relation between staging fluorine-18 fluorodeoxyglucose positron emission tomog- raphy/computed tomography metabolic parameters and tumor necrosis rate in pediatric osteosarcoma patients

Background/aim

The aim of this study was to investigate the contribution of fluorine-18 (F-18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging in staging of pediatric osteosarcoma patients and also to evaluate the ability of metabolic parameters from the primary tumor to predict tumor necrosis rate (TNR).

Material and methods

F-18 FDG-PET/CT imaging was performed in staging 37 pediatric osteosarcoma patients. The metabolic parameters SUVmax (maximum standardised uptake value), MTV (metabolic tumour volume), and TLG (total lesion glycolysis) were measured from the primary tumor. TNR level of the primary tumor was histopathologically measured after standard neoadjuvant chemotherapy treatment. The contribution of F-18 FDG-PET/CT to staging of pediatric osteosarcoma patients and the accuracy of metabolic parameters of the primary tumor to predict TNR were analized by regression analysis.

Results

MTV and TLG of the primary tumor were found to efficiently predict histopathologic TNR, whereas SUVmax was not (P = 0.012, P = 0.027, P = 0.25, respectively). Also 5 of 12 patients (41.6%) who were initially defined as localised osteosarcoma were upstaged in consequence of staging F-18 FDG-PET/CT findings.

Conclusion

F-18 FDG-PET/CT staging in pediatric osteosarcoma patients can effectively distinguish metastatic-localised disease. MTV and TLG values are important parameters, which can efficiently be used to predict TNR.

PET with 18F-Fluorodeoxyglucose/Computed Tomography in the Management of Pediatric Sarcoma

The role for PET with fludeoxyglucose F 18 (¹⁸F-FDG PET)/computed tomography (CT) in the management of pediatric sarcomas continues to be controversial. The literature supports a role for PET/CT in the staging and surveillance of certain specific pediatric sarcoma subtypes; however, the data are less clear regarding whether PET/CT can be used as a biomarker for prognostication. Despite the interest in using this imaging modality in the management of pediatric sarcomas, most studies are limited by retrospective design and small sample size. Additional data are necessary to fully understand how best to use ¹⁸F-FDG PET/CT in pediatric sarcoma management.

Is 68Ga-Prostate-Specific Membrane Antigen PET/CT Superior than 18F-FDG PET/CT for Evaluation of Metastatic Osteosarcoma?

ABSTRACT

We present the case of a 75-year-old man with osteosarcoma of the sternum in whom 68Ga-prostate-specific membrane antigen (PSMA) PET/CT showed high radiotracer activity in the primary tumor and metastatic lesions than 18F-FDG PET/CT. The present case shows that 68Ga-PSMA PET/CT is very useful for staging of osteosarcoma due to in vivo expression of PSMA. 68Ga-PSMA PET/CT can have potential effects on prognosis and in response assessment following treatment in osteosarcoma. The use of PSMA-targeted radioligand treatments may be beneficial especially in metastatic chemorefractory osteosarcoma.

Recent Imaging Advancements for Lung Metastases in Children with Sarcoma

In children and adolescents affected by musculoskeletal sarcomas (both soft tissue and bone sarcomas), the presence of lung metastases is a frequent complication, that should be known since the patient's prognosis, as management, and treatment depend on it. During the staging phase, the detection of lung metastases should be sensitive and specific, and it should be carried out by minimizing the radiation exposure. To deal with this problem, imaging has reached important goals in recent years, thanks to the development of cone-beam CT or low-dose computed tomography, with some new iterative reconstruction methods, such as Veo and ASIR. Imaging is also fundamental for the possibility to perform lung biopsies under CT guidance, with less morbidity, less time-consumption, and shorter recovery time, compared to surgical biopsies.Moreover, important results have also been demonstrated in the treatment of lung metastases, due to the improvement of new mini-invasive image-guided percutaneous thermal ablation procedures, which proved to be safe and effective also in young patients.

Imaging Method for Osteosarcoma Diagnosis and Clinical Staging Information Optimization

In order to better assist clinicians in the diagnosis and treatment of osteosarcoma, and our understanding of the advantages and disadvantages of different examination techniques of DR, CT and MRI, this article collects the pathological diagnosis of the PACS Medical system of Liaocheng People’s Hospital 2015 to 2018. 130 patients with osteosarcoma and imaging examination data, retrospectively analyzed the diagnostic and clinical staging information contained in DR, CT and MRI examination data of osteosarcoma patients, and detected the diagnosis and clinical staging information of osteosarcoma by comparing various examination methods ability to obtain the optimal imaging examination method that can provide complete diagnosis and clinical staging information of osteosarcoma, and is recommended as a routine clinical examination program. Finally, we conclude that: DR, CT, and MRI examinations have no significant differences in the detection capacity of osteosarcoma bone destruction, periosteal response, and periosteal triangle; MRI has less ability to detect tumor bone than DR and CT; DR has soft tissue. The ability to detect masses is inferior to CT and MRI. Among the single DR, CT or MRI examinations, CT examinations have the best comprehensive detection ability for all imaging diagnostic signs of osteosarcoma. MR examination has the best comprehensive display of clinical staging information such as infiltration range and infiltration boundary of osteosarcoma. Combined DR, CT, and MRI examinations are optimized imaging procedures that provide complete osteosarcoma diagnosis and clinical staging information.

The Utility of 18FDG PET/CT Versus Bone Scan for Identification of Bone Metastases in a Pediatric Sarcoma Population and a Review of the Literature

BACKGROUND

Outcome of patients with osteosarcoma (OS) and Ewing sarcoma (EWS) is dependent on presence of metastases. Imaging guidelines for OS and EWS include radiographs, computed tomography (CT), and magnetic resonance imaging for primary tumor evaluation and CT chest and bone scintigraphy (BS) for metastatic detection. 18Fluorodeoxyglucose (18FDG) positron emission tomography (PET)/CT has become more common for disease evaluation, yet there is no consensus for its use in this population.

OBJECTIVE

We aimed to compare identification of osseous metastases using BS versus 18FDG PET/CT in our patient population. We hypothesized that 18FDG PET/CT is more likely to detect osseous metastases both at diagnosis and relapse.

MATERIALS AND METHODS

We performed retrospective chart reviews of pediatric sarcoma patients treated at our institution from 2008 to 2019. Paired BS and 18FDG PET/CT scans were reviewed. Review of the literature was also performed.

RESULTS

Thirty-three patients had paired BS and 18FDG PET/CT during diagnosis or treatment. Fifteen patients had distant osseous metastases. In the OS cohort, 8/16 patients had osseous metastases; 100% of these patients were detected on 18FDG PET/CT and 75% on BS. Thirty-one bony lesions were seen on imaging in OS patients; 100% of these were identified on 18FDG PET/CT but only 29% on BS. In the EWS cohort, 6/15 patients had osseous metastases; 100% of these patients were detected on 18FDG PET/CT and 50% on BS. Eighteen bony lesions were seen on imaging in EWS patients; 94% of these were identified on 18FDG PET/CT, but only 28% on BS.

CONCLUSION

For patients in our institution with OS or EWS, osseous metastases were more likely detected using 18FDG PET/CT.

The use of fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography as an effective method for staging in dogs with primary appendicular osteosarcoma

Fluorine-18-fluorodeoxyglucose (¹⁸ F-FDG) positron emission tomography/computed tomography (PET/CT) has been utilized in veterinary medicine to improve the detection and characterization of primary, recurrent, and secondary neoplasms; but its use as a staging tool for dogs diagnosed with appendicular osteosarcoma has not been published. The purpose of this retrospective, case series, descriptive study was to detail the use of ¹⁸ F-FDG PET/CT for staging a population of dogs with appendicular osteosarcoma, report the detection rate of secondary neoplastic lesions, and compare findings with published detection rates for other historically used imaging modalities. Seventy-one client-owned dogs with a confirmed diagnosis of appendicular osteosarcoma and staged with a whole-body ¹⁸ F-FDG PET/CT scan near the time of initial diagnosis were included. Each PET/CT study was re-evaluated for malignancy distinct from the primary disease entity based on a collective qualitative and quantitative assessment of ¹⁸ F-FDG uptake, CT appearance, and contrast enhancement characteristics. Following re-evaluation of each study, information pertaining to tissue sampling performed on identified lesions was retrieved from the medical record when available. Staging with ¹⁸ F-FDG PET/CT identified 17 of 71 (23.9%) and 12 of 71 (16.3%) dogs with a high suspicion or confirmation of a metastatic or comorbid malignant neoplasm respectively, with eight of 71 (11.3%) having both metastatic and comorbid lesions. The results of this study are suggestive that ¹⁸ F-FDG PET/CT is effective in identifying both osseous and soft tissue secondary neoplastic lesions in dogs afflicted with appendicular osteosarcoma, yielding an increased detection rate of all lesions compared those previously reported for skeletal scintigraphy or whole-body CT.

Clinical and Prognostic Role of 18F-FDG PET/CT in Pediatric Ewing Sarcoma

Ewing sarcoma (ES) is one of the most common pediatric solid tumors with aggressive behavior and unfavorable survival. In this study, we evaluated the diagnostic accuracy of baseline and restaging fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) scans and their possible prognostic role in pediatric ES. We evaluated 17 patients who underwent a total of 27 18F-FDG-PET/CT scans (10 for staging and 17 for restaging). The PET images were analyzed visually and semiquantitatively by measuring SUVmean, SUVmax, SUVlbm, SUVbsa, MTV, and TLG. Moreover, PET/CT results were compared with other conventional imaging (CI) results. Among 10 baseline PET/CT scan results, 9 were positive and 1 not valuable by interference; baseline PET/CT and CI were concordant in 7 cases and discordant in 2, with pulmonary micrometastases not detected by PET/CT. Among 17 restaging PET/CT scan results, 9 were positive and 8 negative; CI and restaging PET/CT were concordant in 9 cases and discordant in 8. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of restaging 18F-FDG-PET/CT were 73%, 83%, 89%, 62.5%, and 76%, respectively. After a median follow-up of 20 months, relapse/progression occurred in 8 patients and death in 5. A positive 18F-FDG-PET/CT at restaging was significantly associated with shorter overall survival compared with unremarkable PET/CT at the same timepoint, but not with progression-free survival. Instead, metabolic PET/CT features were not correlated with outcome. 18F-FDG-PET/CT showed a good diagnostic performance in pediatric ES; except for pulmonary micrometastases, PET/CT was better than CI at restaging. Only restaging PET/CT result was significantly correlated with overall survival.

Effectiveness of 18F-FDG PET/CT in the diagnosis and staging of osteosarcoma: a meta-analysis of 26 studies

BACKGROUND

Multiple trials have attempted to assess the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in osteosarcoma with results remaining inconclusive. This study aims to investigate the effectiveness of 18F-FDG PET and PET/CT in the diagnosis, staging, recurrence and metastasis formation observations of osteosarcoma through systematic review followed by meta-analysis.

METHODS

Three electronic databases, Medline/PubMed, Embase and the Cochrane Library were utilized in this study. Eligible studies that assessed the performance of 18F-FDG PET/CT for the diagnosis, staging, restaging and recurrence monitoring of osteosarcoma were retrieved utilizing specific search criteria. After screening and diluting out the non-conforming articles, all relevant articles and their data were identified and extracted to calculate the summary metrics involving sensitivity, specificity, diagnostic odd ratio (DOR), and area under the curve (AUC) to determine the effectiveness of 18F-FDG PET in diagnosing osteosarcoma clinically.

RESULTS

Out of 1976 articles searched, twenty-six studies were identified that were viable. All data from these articles, utilized in the quantitative analyses, showed after meta-analysis that when utilizing 18F-FDG PET or PET/CT it was better with a success rate of 90-100% for detecting primary lesions and distant metastases of patients with osteosarcoma. Similar results were also obtained for detecting lung and bone metastases in a subgroup analysis.

CONCLUSIONS

As such the investigation demonstrated that 18F-FDG PET and PET/CT are very accurate for the diagnosis, staging and recurrence monitoring of osteosarcoma. 18F-FDG-avid lesions should be further examined in osteosarcoma, especially for suspicious lung lesions.

18F-FDG PET-CT in paediatric oncology: established and emerging applications

Accurate staging and response assessment is vital in the management of childhood malignancies. Fluorine-18 fluorodeoxyglucose positron emission tomography/CT (FDG PET-CT) provides complimentary anatomical and functional information. Oncological applications of FDG PET-CT are not as well-established within the paediatric population compared to adults. This article will comprehensively review established oncological PET-CT applications in paediatric oncology and provide an overview of emerging and future developments in this domain.

ACR Appropriateness Criteria® Acutely Limping Child Up To Age 5

Imaging plays in important role in the evaluation of the acutely limping child. The decision-making process about initial imaging must consider the level of suspicion for infection and whether symptoms can be localized. The appropriateness of specific imaging examinations in the acutely limping child to age 5 years is discussed with attention in each clinical scenario to the role of radiography, ultrasound, nuclear medicine, computed tomography, and magnetic resonance imaging. Common causes of limping such as toddler's fracture, septic arthritis, transient synovitis, and osteomyelitis are discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Effectiveness of 18F-FDG PET/CT in the diagnosis, staging and recurrence monitoring of Ewing sarcoma family of tumors: A meta-analysis of 23 studies

BACKGROUND

To investigate the value of positron emission tomography (PET) and PET/computed tomography (CT) using fluorine-18-fluorodeoxyglucose (F-FDG) in the diagnosis, staging, restaging and recurrence monitoring of Ewing sarcoma family of tumors (ESFTs), a meta-analysis was performed through systematically searching PubMed, Embase, and Cochrane Central library to retrieve articles.

METHODS

After screening and diluting out the articles that met inclusion criteria to be used for statistical analysis the pooled evaluation indexes including sensitivity, specificity, and diagnostic odd ratio (DOR) as well as the summary receiver operating characteristic curve (SROC) were calculated involving diagnostic data (true positive, false positive, false negative, and true negative) extracted from original studies.

RESULTS

Screening determined that out of 2007, 23 studies involving a total of 524 patients were deemed viable for inclusion in the meta-analysis. The results of the analysis showed that the sensitivity and specificity were at 86% and 80%, respectively. Additionally, a satisfactory accuracy of F-FDG PET and PET/CT was observed in detecting ESFT recurrence, lung metastasis, and osseous metastasis.

CONCLUSION

This meta-analysis suggests that F-FDG PET and PET/CT with an extremely high accuracy could be considered a valuable method for detecting distant metastasis and post-operational recurrence of ESFT, which might have a profound impact on the development of treatment protocols for ESFT.

Pediatric Musculoskeletal Imaging: The Indications for and Applications of PET/Computed Tomography

The use of PET/computed tomography (CT) for the evaluation and management of children, adolescents, and young adults continues to expand. The principal tracer used is 18F-fluorodeoxyglucose and the principal indication is oncology, particularly musculoskeletal neoplasms. The purpose of this article is to review the common applications of PET/CT for imaging of musculoskeletal issues in pediatrics and to introduce the use of PET/CT for nononcologic issues, such as infectious/inflammatory disorders, and review the use of 18F-sodium fluoride in trauma and sports-related injuries.

Management of Primary Osseous Spinal Tumors with PET

Knowledge of the PET imaging findings of osseous spinal neoplasms is essential, because they are common incidental findings on PET scans done for staging of unrelated primary malignancies. Additionally, PET can help differentiate lesions that are not clearly defined by anatomic modalities alone. PET can also be used for follow-up of aggressive tumors to assess response to treatment, often proving superior to CT or MR imaging alone for this purpose. This review discusses the role of PET/CT and PET/MR imaging in the diagnosis and management of primary benign and malignant osseous tumors of the spine.

Diagnostic Accuracy of 18F-FDG PET/CT in the Staging and Assessment of Response to Chemotherapy in Children With Ewing Sarcoma

INTRODUCTION

The purpose of this study was to evaluate the potential role of fluorine-18 fluorodeoxyglucose (18F-FDG) positron-emission tomography/computed tomography (PET-CT) in the staging and assessment of chemotherapy response in Ewing sarcoma.

MATERIALS AND METHODS

For 13 patients with Ewing sarcoma, whole-body FDG PET-CT was assessed for site of primary disease, disease extent, and response to therapy. Chest CT, localized magnetic resonance imaging or CT of primary site, and bone scintigrams were evaluated for imaging features of the primary lesion and presence or absence of metastatic disease. Response to therapy was also assessed. Descriptive statistics are reported.

RESULTS

Nine patients (69%) presented metastatic disease. All metastatic lung lesions were detected by spiral CT, but some failed to be detected using FDG PET-CT. As regards bone lesions, both FDG PET-CT and bone scans were able to identify bone metastasis, but FDG PET-CT identified more lesions than bone scans. All PET-CT scans at the end of the neoadjuvant chemotherapy showed a decreased FDG uptake.

CONCLUSIONS

FDG PET-CT seems to be superior to bone scan in the detection of bone metastasis in all districts except skull bones. For pulmonary metastasis smaller than 7 mm, FDG PET-CT is less sensitive than CT. FDG PET-CT may have an important role in initial staging of Ewing sarcoma and subsequent evaluation of response to therapy.

Triple primary malignancies of surface osteosarcoma of jaw, myelodysplastic syndrome and colorectal cancer as a second primary cancer detected by PET2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography: A case report

Second primary malignancy (SPM) is a severe issue for cancer survivors, particularly for osteosarcoma (OS) survivors. To date, the associations between subsequent SPM and OS have been well reported. Hematogenic and solid malignancies tend to occur following OS treatment. Reportedly, 2-[¹⁸F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is mainly used in OS patients for initial cancer staging, to evaluate the response of neoadjuvant chemotherapy, and when recurrence or metastasis is clinically suspected. The present case report describes a 70-year-old man diagnosed with three primary malignancies: jaw OS, myelodysplastic syndrome and colorectal adenocarcinoma. To the best of our knowledge, this combination of malignancies has not been reported previously. Until now, there is no specific protocol of postoperative FDG-PET for OS patients. Few studies have described OS follow-up methods; therefore, there is no consensus on proper follow-up methods. In the present case report, the colorectal early-stage SPM was observed, without any symptoms, by FDG-PET/computed tomography. To avoid overlooking solid SPMs, it is suggested that FDG-PET should be performed in the long-term follow-up of OS patients.

Retrospective audit of 957 consecutive 18F-FDG PET-CT scans compared to CT and MRI in 493 patients with different histological subtypes of bone and soft tissue sarcoma

Background

The use of ¹⁸F-FDG PET–CT (PET–CT) is widespread in many cancer types compared to sarcoma. We report a large retrospective audit of PET–CT in bone and soft tissue sarcoma with varied grade in a single multi-disciplinary centre. We also sought to answer three questions. Firstly, the correlation between sarcoma sub-type and grade with ¹⁸FDG SUVmax, secondly, the practical uses of PET–CT in the clinical setting of staging (during initial diagnosis), restaging (new baseline prior to definitive intervention) and treatment response. Finally, we also attempted to evaluate the potential additional benefit of PET–CT over concurrent conventional CT and MRI.

Methods

A total of 957 consecutive PET–CT scans were performed in a single supra-regional centre in 493 sarcoma patients (excluding GIST) between 2007 and 2014. We compared, PET–CT SUVmax values in relation to histology and FNCCC grading. We compared PET–CT findings relative to concurrent conventional imaging (MRI and CT) in staging, restaging and treatment responses.

Results

High-grade (II/III) bone and soft tissue sarcoma correlated with high SUVmax, especially undifferentiated pleomorphic sarcoma, leiomyosarcoma, translocation induced sarcomas (Ewing, synovial, alveolar rhabdomyosarcoma), de-differentiated liposarcoma and osteosarcoma. Lower SUVmax values were observed in sarcomas of low histological grade (grade I), and in rare subtypes of intermediate grade soft tissue sarcoma (e.g. alveolar soft part sarcoma and solitary fibrous tumour). SUVmax variation was noted in malignant peripheral nerve sheath tumours, compared to the histologically benign plexiform neurofibroma, whereas PET–CT could clearly differentiate low from high-grade chondrosarcoma. We identified added utility of PET–CT in addition to MRI and CT in high-grade sarcoma of bone and soft tissues. An estimated 21% overall potential benefit was observed for PET–CT over CT/MRI, and in particular, in ‘upstaging’ of high-grade disease (from M0 to M1) where an additional 12% of cases were deemed M1 following PET–CT.

Conclusions

PET–CT in high-grade bone and soft tissue sarcoma can add significant benefit to routine CT/MRI staging. Further prospective and multi-centre evaluation of PET–CT is warranted to determine the actual predictive value and cost-effectiveness of PET–CT in directing clinical management of clinically complex and heterogeneous high-grade sarcomas.

Precision Medicine and PET-Computed Tomography in Pediatric Malignancies

Fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) PET-computed tomography (CT) plays a significant role in diagnosis, staging, therapy selection, and therapy assessment of multiple pediatric malignancies and facilitating precision medicine delivery in pediatric patients. In patients with Hodgkin lymphoma, interim fludeoxyglucose ¹⁸F-FDG PET/CT is highly sensitive and specific for predicting survival and multiple trials with FDG PET/CT-based adaptive therapies are currently ongoing. It is superior to iodine-131 metaiodobenzylguanidine (¹³¹I-MIBG) scintigraphy and bone scintigraphy for detecting metastases in neuroblastoma patients and sarcoma patients. It may predict histologic differentiation and neoadjuvant therapy assessment in Wilms tumor.

Prognostic value of FDG-PET indices for the assessment of histological response to neoadjuvant chemotherapy and outcome in pediatric patients with Ewing sarcoma and osteosarcoma

Purpose

The objective of this retrospective work was to evaluate the prognostic value on histological response and survival of quantitative indices derived from FDG-PET performed before and after chemotherapy (CHT), in a homogeneous pediatric Ewing sarcoma (EWS) and Osteosarcoma (OST) population.

Methods

Thirty-one patients with EWS and 31 with OST were included. All patients were treated with neoadjuvant CHT, and underwent surgery for local control. All patients had FDG-PET at diagnosis and after CHT, prior to surgery. Several parameters were evaluated: SUVmax, SUVpeak, SUVmean, metabolic tumor volume, total lesion glycolysis, 7 textural features and 3 shape features (SF). The segmentation was performed using an adaptive approach. Results were compared to histopathological regression of the resected tumor and to clinical follow-up for survival evaluation.

Results

For EWS, univariate analysis did not highlight any prognostic value on histological response, or survival regardless of all the considered metrics. For OST, only one of the SF, namely elongation, was significantly associated with PFS and OS on both univariate and multivariate analysis (PFS: p = 0.019, HR = 5.583; OS: p = 0.0062, HR = 7.113).

Conclusion

Only elongation determined on initial FDG-PET has a potential interest as a prognostic factor of PFS and OS in pediatric OST patients. Unlike recent studies of the literature realized in adult population, all the metrics reveal limited additional prognostic value in pediatric EWS patients. This seems to reinforce the question of whether children experience different subtypes of the same pathologies than older patients, with different outcomes.

Pictorial review of 18F-FDG PET/CT findings in musculoskeletal lesions

We herein reviewed ¹⁸F-fluoro-2-deoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) findings in a number of musculoskeletal lesions including malignant tumors, benign tumors, and tumor-like lesions with correlations to other radiographic imaging modalities, and described the diversity of the ¹⁸F-FDG PET/CT findings of this entity. Malignant primary musculoskeletal tumors are typically ¹⁸F-FDG avid, whereas low-grade malignant tumors show mild uptake. Benign musculoskeletal tumors generally show a faint uptake of ¹⁸F-FDG, and tumor-like conditions also display various uptake patterns of ¹⁸F-FDG. Although musculoskeletal tumors show various uptakes of ¹⁸F-FDG on PET/CT, its addition to morphological imaging modalities such as CT and MRI is useful for the characterization and differentiation of musculoskeletal lesions.