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

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.

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.

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 Impact of PET/CT on Paediatric Oncology

This review paper will discuss the use of positron emission tomography/computed tomography (PET/CT) in paediatric oncology. Functional imaging with PET/CT has proven useful to guide treatment by accurately staging disease and limiting unnecessary treatments by determining the metabolic response to treatment. ¹⁸F-Fluorodeoxyglucose (2-[¹⁸F]FDG) PET/CT is routinely used in patients with lymphoma. We highlight specific considerations in the paediatric population with lymphoma. The strengths and weaknesses for PET/CT tracers that compliment Meta-[¹²³I]iodobenzylguanidine ([¹²³I]mIBG) for the imaging of neuroblastoma are summarized. 2-[¹⁸F]FDG PET/CT has increasingly been used in the staging and evaluation of disease response in sarcomas. The current recommendations for the use of PET/CT in sarcomas are given and potential future developments and highlighted. 2-[¹⁸F]FDG PET/CT in combination with conventional imaging is currently the standard for disease evaluation in children with Langerhans-cell Histiocytosis (LCH) and the non-LCH disease spectrum. The common pitfalls of 2-[¹⁸F]FDG PET/CT in this setting are discussed.

The DNA-topoisomerase Inhibitors in Cancer Therapy

DNA-topoisomerases are ubiquitous enzymes essential for major cellular processes. In recent years, interest in DNA-topoisomerases has increased not only because of their crucial role in promoting DNA replication and transcription processes, but also because they are the target of numerous active ingredients. The possibility of exploiting for therapeutic purposes the blocking of the activity of these enzymes has led to the development of a new class of anticancer agents capable of inducing apoptosis of tumor cells following DNA damage and its failure to repair.

Application of Anlotinib Combined With Neoadjuvant Chemotherapy in Primary EWS/PNET of Lung: A Case Report

Primary pulmonary EWS/PNET(PPES) is extremely rare and is associated with a poor prognosis. Tumor angiogenesis plays an important role in tumor, so it has become a hot topic in molecular targeted therapy. Anlotinib is a new oral small molecular multi-targeted receptor tyrosine kinase (RTK) inhibitor. This report describes a 20 year-old man with PPES. After 4 neoadjuvant chemotherapy cycles (VACwith alternating IE) combined with anlotinib, the left total pneumonectomy was performed. Then maintenance anlotinib monotherapy was continued, no sign of recurrence to date as an outcome. To our knowledge, this is the first demonstration of anlotinib combined with neoadjuvant chemotherapy efficacy in PPES.

18 F-FDG PET and PET/CT as a diagnostic method for Ewing sarcoma: A systematic review and meta-analysis

PURPOSE

The aim of this study was to evaluate the diagnostic accuracy of ¹⁸ -fluorodeoxyglucose-positron emission tomography (¹⁸ F-FDG PET) and PET/computed tomography (PET/CT) in imaging primary and metastatic lesions in Ewing sarcoma (ES).

METHODS

PubMed, Cochrane, Scopus, and Web of Science were searched for relevant studies. Data concerning ¹⁸ F-FDG PET/CT diagnostic accuracy were extracted and then analyzed using Open Meta-analyst software. Reported diagnostic accuracy outcomes included sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR), and diagnostic odds ratio.

RESULTS

Thirty-one studies with a total of 735 patients were included in this meta-analysis. The sensitivity and specificity of ¹⁸ F-FDG PET/CT were: 92.6% and 74.1% for total ES lesions, 96.7% and 68.3% for ES primary lesions, 76.1% and 92.4% for lung metastasis, 83.9% and 93.2% for bone metastasis, and 89.9% and 92.6% for ES recurrence, respectively.

CONCLUSION

¹⁸ F-FDG PET/CT is sensitive and accurate in diagnosing, staging, and detecting the recurrence of ES compared with non-PET imaging. It has high accuracy for diagnosing recurrence of ES in bone metastases; however, CT remains a superior diagnostic method for detecting lung metastasis.

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.

Diagnosis and staging of malignant bone tumours in children: what is due and what is new?

PURPOSE

Although malignant bone tumours in children are infrequent, it is important to know how to properly diagnose and stage them, in order to establish an adequate treatment.

METHODS

We present a review of the diagnostic workflow of malignant bone tumours in children, including history and clinical examination, imaging, laboratory tests and biopsy techniques. Moreover, the two most commonly used staging systems are reviewed.

RESULTS

History, clinical examination and laboratory tests are nonspecific for diagnosing malignant bone tumours in children. Radiographs remain the mainstay for initial diagnosis, with MRI the modality of choice for local assessment and staging. Fluorine-18 labelled fluoro-deoxy-glucose-positron emission tomography scans provide a noninvasive method to assess the aggressiveness of the tumour and to rule out metastasis and is replacing the use of the bone scintigraphy. Biopsy must be always performed under the direction of the surgeon who is to perform the surgical treatment and after all diagnostic evaluation has been done. Staging systems are useful to study the extent of the tumour and its prognosis. They are expected to evolve as we better understand new molecular and genetic findings.

CONCLUSION

When a malignant bone tumour is suspected in a child, it is essential to make a correct diagnosis and referral to an experienced centre. Following an appropriate workflow for diagnosis and staging facilitates, prompt access to treatment improves outcomes.

LEVEL OF EVIDENCE

Level V Expert opinion.

Computerized Tomography (CT) Updates and Challenges in Diagnosis of Bone Metastases During Prostate Cancer

Prostate cancer is one of the most common cancers in men. This cancer is often associated with indolent tumors with little or no lethal potential. Some of the patients with aggressive prostate cancer have increased morbidity and early deaths. A major complication in advanced prostate cancer is bone metastasis that mainly results in pain, pathological fractures, and compression of spinal nerves. These complications in turn cause severe pain radiating to the extremities and possibly sensory as well as motor disturbances. Further, in patients with a high risk of metastases, treatment is limited to palliative therapies. Therefore, accurate methods for the detection of bone metastases are essential. Technical advances such as single-photon emission computed tomography/ computed tomography (SPECT/CT) have emerged after the introduction of bone scans. These advanced methods allow tomographic image acquisition and help in attenuation correction with anatomical co-localization. The use of positron emission tomography/CT (PET/CT) scanners is also on the rise. These PET scanners are mainly utilized with 18F-sodium-fluoride (NaF), in order to visualize the skeleton and possible changes. Moreover, NaF PET/CT is associated with higher tracer uptake, increased target-to-background ratio and has a higher spatial resolution. However, these newer technologies have not been adopted in clinical guidelines due to lack of definite evidence in support of their use in bone metastases cases. The present review article is focused on current perspectives and challenges of computerized tomography (CT) applications in cases of bone metastases during prostate cancer.

Post-treatment FDG PET/CT predicts progression-free survival in young patients with small round blue cell tumors: Ewing sarcoma and PNET

PURPOSE

To determine if post-treatment F-18 FDG PET/CT results (overall positive findings, specific localizations) are independent predictors of disease progression in young patients with Ewing sarcoma and Primitive neuroectodermal tumor.

METHOD

A consecutive sample of 48 patients (age 14 ± 5 years, 32 male) was referred to F-18 FDG PET/CT for the suspected progression of Ewing sarcoma (39 patients) and Primitive neuroectodermal tumor (PNET) (9 patients) and followed-up clinically for 4.3 ± 2.3 years after F-18 FDG PET/CT (range 1-8 years). The diagnostic value of F-18 FDG PET/CT was determined in comparison to the biopsy. Kaplan-Meier analysis was used to compare progression-free survival between the groups with positive and negative F-18 FDG PET/CT findings. Variables included in the Cox regression for predicting the progression-free survival were sex, age, F-18 FDG PET/CT findings, MDCT findings, and MR ratio.

RESULTS

F-18 FDG PET/CT findings were positive in 32 (67 %) patients (sensitivity 93.7 %, specificity 87.5 %, accuracy 91.7 %) with an average SUVmax of 5.8 ± 3.2 (95 % CI 4.8-7.1). The progression-free survival was significantly lower (p = 0.001) in patients with positive F-18 FDG PET/CT findings (median 28 months) and when recurrence was located in bones, soft tissues, and muscles (p = 0.02, median 21 months). The significant predictors of the disease progression were the overall positive F-18 FDG PET/CT findings (HR 8.36, p = 0.004) and, specifically, the local recurrence in the bone with infiltration of soft tissue/muscles (HR 4.08, p = 0.003).

CONCLUSION

Post-treatment F-18 FDG PET/CT findings are useful for predicting the progression of Ewing sarcoma and PNET and should be included in the clinical monitoring of these patients.

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.

68Ga-PSMA-HBED-CC PET/CT and 18F-FDG PET/CT in Ewing Sarcoma

We present a case of a 19-year-old woman with Ewing sarcoma of the iliac bone in whom Ga-PSMA-HBED-CC PET/CT showed high radiotracer activity in the primary tumor. The present case documents the in vivo expression of PSMA in Ewing sarcoma family of tumors and adds on to the list of nonprostatic malignancies showing PSMA expression.

FDG PET/CT in a Case of Primary Pulmonary Ewing Sarcoma

Extraskeletal Ewing sarcoma is rare. The common locations of extraskeletal Ewing sarcoma include the paravertebral region, lower extremities, and chest wall. Primary pulmonary Ewing sarcoma is extremely rare. Because Ewing sarcoma is sensitive to specialized chemotherapy regimens, accurate diagnosis is therefore critical. The diagnosis of pulmonary Ewing sarcoma can be challenging and need immunohistochemical and cytogenetic analyses. Imaging findings of pulmonary Ewing sarcoma have been rarely reported. This report describes a case of primary pulmonary Ewing sarcoma with immunohistochemical, cytogenetic, CT, and FDG PET/CT findings.

The Value of 18F-FDG PET/CT in Detecting Bone Marrow Involvement in Childhood Cancers

BACKGROUND

The aim of this study was to assess the utility of F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT) in assessing bone marrow involvement (BMI) compared with bone marrow biopsy (BMB) in the initial staging of pediatric patients with non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), Ewing sarcoma (ES), and neuroblastoma (NB).

PROCEDURE

A total of 94 patients (57 boys, 37 girls, median age 7 y, range 1 to 18 y) with newly diagnosed NHL, HL, ES, and NB between July 2014 and December 2017, who underwent BMB and F-FDG PET/CT before chemotherapy were included in this study. There were 36 patients with NHL, 27 HL, 16 ES, and 15 NB. F-FDG PET/CT and BMB results were reviewed and compared retrospectively.

FINDINGS

Retrospective analysis of data from 94 pediatric patients (57 boys, 37 girls, median age 7 y, range 1 to 18 y) was performed. Of the 94 patients, 29 had BMI on F-FDG PET/CT. BMB was positive in 14, negative in 13, and insufficient in 2 of these 29 patients. In 65 patients negative on F-FDG PET/CT, BMB was also negative in 54 and insufficient in 7. For the whole group, sensitivity, specificity, and positive and negative predictive values of F-FDG PET/CT in detecting bone marrow metastasis at the time of diagnosis were 90.6%, 100%, 100%, and 95.4% and those of BMB were 53.1%, 87.1%, 94.4%, and 80.6%, respectively.

CONCLUSION

Our study demonstrates that F-FDG PET/CT predicts BMI better than BMB. F-FDG PET/CT may be used at initial staging of pediatric patients with NHL, HL, ES, and NB.

18F-FDG PET-CT versus MRI for detection of skeletal metastasis in Ewing sarcoma

OBJECTIVE

To determine the level of discrepancy between magnetic resonance imaging (MRI) and ¹⁸F-FDG PET-CT in detecting osseous metastases in patients with Ewing sarcoma.

METHODS

Twenty patients with histopathologically confirmed Ewing sarcoma between 2000 and 2017 who underwent ¹⁸F-FDG PET-CT and MRI within a 4-week range were included. Each imaging modality was evaluated by a separate observer. Reference diagnosis of each lesion was based on histopathology or consensus of an expert panel using all available data, including at least 6 months' follow-up. Sensitivity, specificity, and predictive values were determined. Osseous lesions were analyzed on a patient and a lesion basis. Factors possibly related to false-negative findings were evaluated using Pearson's Chi-squared or Fisher's exact test.

RESULTS

A total of 112 osseous lesions were diagnosed in 13 patients, 107 malignant and 5 benign. Seven patients showed no metastases on either ¹⁸F-FDG PET-CT or MRI. Forty-one skeletal metastases (39%) detected with MRI did not show increased ¹⁸F-FDG uptake on ¹⁸F-FDG PET-CT (false-negative). Lesion-based sensitivities and specificities were 62% (95%CI 52-71%) and 100% (48-100%) for ¹⁸F-FDG PET-CT; and 99% (97-100%) and 100% (48-100%) for MRI respectively. Bone lesions were more likely to be false-negative on ¹⁸F-FDG PET-CT if hematopoietic bone marrow extension was widespread and active (p = 0.001), during or after (neo)-adjuvant treatment (p = 0.001) or when the lesion was smaller than 10 mm (p < 0.001).

CONCLUSION

Although no definite conclusions can be drawn from this small retrospective study, it shows that caution is needed when using ¹⁸F-FDG PET-CT for diagnosing skeletal metastases in Ewing sarcoma. Poor contrast between metastases and active hematopoietic bone marrow, chemotherapeutic treatment, and/or small size significantly decrease the diagnostic yield of ¹⁸F-FDG PET-CT, but not of MRI.