Bone marrow examination in patients with Ewing sarcoma/peripheral primitive neuroectodermal tumor without metastasis based on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography

Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/PNET) is an aggressive bone tumor. Bone marrow aspiration and biopsy (BMAB) has been recognized as the gold standard for assessing bone marrow status. While the latest guideline suggests the need to omit bone marrow aspiration in patients with no findings on ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) based on one retrospective report, there is no study using ¹⁸F-FDG PET/computed tomography (CT). We retrospectively reviewed 26 consecutive, previously untreated, ES/PNET patients. We compare the results of bone marrow aspiration and biopsy (BMAB) and those of ¹⁸F-FDG PET/CT in ES/PNET patients. All of the 21 patients without metastases on ¹⁸F-FDG PET/CT had negative BMAB. The sensitivity of bone marrow involvement in bone metastases positive patients on ¹⁸F-FDG PET/CT was 75% (3/4), and the specificity was 100% (22/22). In addition to the metastatic findings on ¹⁸F-FDG PET/CT, tumor diameter, lactate dehydrogenase level at diagnosis, and the presence or absence of bone metastasis were factors related to bone marrow involvement. It may be a reasonable option to omit BMAB in ES/PNET patients with no distant metastasis based on ¹⁸F-FDG PET/CT findings.