Whole-body [18F]-FDG-PET/MRI for staging of pediatric non-Hodgkin lymphoma: first results from a single-center evaluation

Abstract

Aim In 2015, the revised International Pediatric Non-Hodgkin Lymphoma Staging System was published. It mentions [18F]-FDG-PET/MRI as the latest method to perform whole-body imaging. However, supporting data are pending. Our aim was to investigate the performance of whole-body [18F]-FDG-PET/MRI in pediatric non-Hodgkin lymphoma patients by using a limited number of MRI sequences. Materials and methods Ten pediatric patients with histologically proven non-Hodgkin lymphoma underwent whole-body [18F]-FDG-PET/MRI at staging. The retrospective analysis included three steps: First, [18F]-FDG-PET and MR scans were evaluated separately by a nuclear medicine physician and a pediatric radiologist. Nineteen nodal and two extranodal regions as well as six organs were checked for involvement. Second, discrepant findings were reviewed together in order to reach consensus. Third, [18F]-FDG-PET/MRI findings were correlated with the results of other clinical investigations. Results Of the 190 lymph node regions evaluated, four were rated controversial. Consensus was reached by considering metabolic, functional and morphologic information combined. Concordantly, [18F]-FDG-PET and MRI detected Waldeyer’s ring involvement in two patients whose Waldeyer’s ring was negative on clinical assessment. In four patients MRI showed pleural effusion. However, in only two of them an increased glucose metabolism as a reliable sign of pleural involvement was detectable. In six patients [18F]-FDG-PET and MRI detected skeletal lesions although bone marrow biopsy was positive in only one of them. Conclusion Despite the small number of cases evaluated, whole-body [18F]-FDG-PET turned out to be a valuable tool for staging of pediatric non-Hodgkin lymphoma.

FDG PET/CT versus Bone Marrow Biopsy for Diagnosis of Bone Marrow Involvement in Non-Hodgkin Lymphoma: A Systematic Review

“…The role of radiomic features in extracting useful information for diagnosis via BMI [ 18 F]FDG PET/CT images has been shown in recent studies for the MCL [60] and DLBCL [61]. PET/MRI can also be used as a better predictor of BMI compared to BMB for NHL [62]. Compared with PET/CT, it is expected that PET/MRI can provide comparable detectability for lymphoma imaging [63,64].…”

Editorial: Opportunities for PET imaging for the identification, staging, and monitoring of cancers

“…In addition, PET can detect metastatic lymph node lesions which are small but clinically suspected with active FDG metabolism or high signal on DWI. The early detection of distant metastases can influence the tumor staging and the following treatment strategy ( 9 , 10 ). Therefore, PET/CT and PET/MR can more accurately stage the tumor to provide more objective basis for the selection of individualized treatment.…”

Imaging recommendations in pediatric lymphoma: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

“…F18-FDG PET/MRI is recommended as an alternative imaging modality to PET/CT for tumor diagnosis where PET/MR is currently utilized and has demonstrated similar efficacy to PET/CT 30 (Grade: A; SOR 1.45). With high soft tissue contrast, it may be more valuable in NHL with extranodal involvement; large amounts of data evaluating the role in staging are lacking, but one early study is encouraging 31. Advantages: less radiation than PET/CT, excellent soft tissue differ-…”