Staging of newly diagnosed Ewing sarcoma: Results of bone marrow aspiration and biopsy versus (18)FDG-PET/CT imaging for bone marrow involvement

The Role of FDG- PET/CT in Detecting Bone Marrow Involvement in Childhood Solid Tumors

PURPOSE

To compare the results of 18F-Fluorodeoxy positron emission tomography/computed tomography (18 F-FDG-PET/CT) and bone marrow biopsy (BMB) procedures in the initial evaluation of bone marrow involvement (BMI) in pediatric solid tumors.

METHODS

We conducted a retrospective analysis of newly diagnosed pediatric cases with lymphoma, neuroblastoma, Ewing sarcoma, rhabdomyosarcoma. Each case underwent both PET-CT imaging and BMB. Presence of tumor infiltration in BMB specimens and/or positive FDG-PET/CT findings indicate as BMI were regarded as true positive results.

RESULTS

Sixty-four patients were included in the study. BMI was detected in 23/64 (36%) patients, FDG-PET/CT imaging and BMB results were concordant in 54/64 patients. In 9/64 patients the finding was FDG-PET/CT (+), BMB (-) indicating a false negative BMB result. In only 1/64 patients FDG- PET/CT (-), BMB (+), indicating a false negative FDG-PET/CT result. In the whole patient group, the sensitivity, specificity, positive predictive value and negative predictive value of PET/CT and BMB in detecting bone marrow involvement were 95.6%, 100%, 100% and 97.6% and 60.8 %, 100%, 100% and 82%, respectively.

CONCLUSION

PET/CT has a high sensitivity and specificity for the assessing marrow involvement in pediatric solid tumors. We believe that PET/CT imaging should be performed as the first step in diagnostic staging, and BMB may not be necessary in every patient, only in patients with suspicious PET/CT results for bone marrow involvement. Additionally, for a more precise determination of bone marrow involvement, it is reasonable to perform BMB from FDG-retaining areas, using PET/CT as a guide tool.

Is bone marrow biopsy and aspiration still mandatory when 18F-FDG PET/CT is available for the initial assessment of bone marrow metastasis in pediatric Ewing sarcoma?

Purpose

To compare the diagnostic value of 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) and bone marrow biopsy and aspiration (BMBA) for evaluating bone marrow metastases (BMM) in newly diagnosed pediatric Ewing sarcoma (ES).

Material and methods

To assess the diagnostic accuracy of 18F-FDG PET/CT against BMBA for marrow infiltration in ES patients, a retrospective analysis encompassed 103 ES patients from the Children's Hospital of Chongqing Medical University, spanning nine years, who underwent both 18F-FDG PET/CT and BMBA at the point of diagnosis.

Results

The median age of this study was 9.3(15 days to 17.1 years), 52(50.5%) patients were male. Among the cohort, 8 subjects received a BMM diagnosis via marrow cytology or histopathology, concomitant with positive 18F-FDG PET/CT findings. An additional 4 patients were identified with BMM solely through 18F-FDG PET/CT. No cytologically or histologically positive BMM were found in PET/CT-negative patients. Therefore, within this selected sample group, the 18F-FDG PET/CT imaging technique exhibited sensitivity of 100% and specificity of 95.8%. The five-year overall survival rate decreased from 57.5% among the entire cohort of patients to a mere 30% for individuals suffering from BMM.

Conclusion

Given these findings, the prevailing reliance on BMBA warrants reevaluation when 18F-FDG PET/CT is available, potentially heralding a shift towards less invasive diagnostic modalities in the management of ES.

Consensus recommendations in the management of Ewing sarcoma from the National Ewing Sarcoma Tumor Board

Ewing sarcoma (ES) is a malignant tumor of bone and soft tissue that most often occurs in adolescents and young adults. Despite an international coordinated approach, several nuances, discrepancies, and debates remain in defining the standard of care for treating ES. In this review, the authors leverage the expertise assembled by formation of the National Ewing Sarcoma Tumor Board, a multi-institution, multidisciplinary virtual tumor board that meets monthly to discuss complicated and challenging cases of ES. This report is focused on select topics that apply to the management of patients with newly diagnosed ES. The specific topics covered include indications for bone marrow aspirate and biopsy for initial evaluation compared with fluorodeoxyglucose-positron emission tomography, the role of interval compressed chemotherapy in patients aged 18 years and older, the role of adding ifosfamide/etoposide to vincristine/doxorubicin/cyclophosphamide for patients with metastatic disease, the data on and role of high-dose chemotherapy with autologous stem cell transplantation, maintenance therapy, and whole-lung irradiation. The data referenced are often limited to subgroup analyses and/or compiled from multiple sources. Although not intended to replace the clinical judgement of treating physicians, the guidelines are intended to provide clarity and recommendations for the upfront management of patients with ES. PLAIN LANGUAGE SUMMARY: Ewing sarcoma is a malignant tumor of bone and soft tissue that most often occurs in adolescents and young adults. For this review, the authors used the experience of the National Ewing Sarcoma Tumor Board, a multi-institution, multidisciplinary virtual tumor board that meets monthly to discuss complicated and challenging cases of Ewing sarcoma. Although not intended to replace the clinical judgement of treating physicians, the guidelines will focus on the development of consensus statements for the upfront management of patients with Ewing sarcoma.

Artificial intelligence-based radiomics in bone tumors: Technical advances and clinical application

Radiomics is the extraction of predefined mathematic features from medical images for predicting variables of clinical interest. Recent research has demonstrated that radiomics can be processed by artificial intelligence algorithms to reveal complex patterns and trends for diagnosis, and prediction of prognosis and response to treatment modalities in various types of cancer. Artificial intelligence tools can utilize radiological images to solve next-generation issues in clinical decision making. Bone tumors can be classified as primary and secondary (metastatic) tumors. Osteosarcoma, Ewing sarcoma, and chondrosarcoma are the dominating primary tumors of bone. The development of bone tumor model systems and relevant research, and the assessment of novel treatment methods are ongoing to improve clinical outcomes, notably for patients with metastases. Artificial intelligence and radiomics have been utilized in almost full spectrum of clinical care of bone tumors. Radiomics models have achieved excellent performance in the diagnosis and grading of bone tumors. Furthermore, the models enable to predict overall survival, metastases, and recurrence. Radiomics features have exhibited promise in assisting therapeutic planning and evaluation, especially neoadjuvant chemotherapy. This review provides an overview of the evolution and opportunities for artificial intelligence in imaging, with a focus on hand-crafted features and deep learning-based radiomics approaches. We summarize the current application of artificial intelligence-based radiomics both in primary and metastatic bone tumors, and discuss the limitations and future opportunities of artificial intelligence-based radiomics in this field. In the era of personalized medicine, our in-depth understanding of emerging artificial intelligence-based radiomics approaches will bring innovative solutions to bone tumors and achieve clinical application.