Whole-Body Diffusion-Weighted MRI Compared to ^{18 F}FDG PET/CT in Initial Staging and Therapy Response Assessment of Hodgkin Lymphoma in Pediatric Patients

Abstract

Purpose: The aim of our study was to compare whole-body diffusion-weighted MRI (WB-DWI-MRI) to fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the assessment of initial staging and treatment response in pediatric patients with Hodgkin lymphoma. Materials and Methods: This prospective study comprised 11 children with Hodgkin lymphoma. Whole-body DWI-MRI and FDG-PET/CT were obtained at baseline and after 2 cycles of chemotherapy. Two radiologists measured the apparent diffusion coefficient (ADC) values of the sites of involvement agreed upon in consensus and 1 nuclear medicine physician assessed the PET/CT. Reliability of radiologists’ ratings was assessed by intraclass correlation coefficients (ICC2,1). The sensitivity and positive predictive value (PPV) of DW-MRI relative to PET/CT were calculated for nodal and extranodal sites. The patients were staged according to both modalities. Association of treatment responses was assessed through the Pearson correlation between the ADC ratios and the change standardized uptake value (SUV) between baseline and follow-up. Results: There was good agreement between the raters for nodal and extranodal ADC measurements. The sensitivity and PPV of DW-MRI relative to PET/CT of nodal disease was 0.651 and 1.0, respectively, at baseline, and 0.697 and 0.885 at follow-up. The sensitivity and PPV of extranodal disease were 0.545 and 0.6 at baseline, and 0.167 and 0.333 at follow-up. Diffusion-weighted MRI determined correct tumor stage in 8 of 11 examinations. There was poor correlation between the ADC ratios and the absolute change in SUV between baseline and follow-up (0.348). Conclusion: Our experience showed that WB-DWI-MRI is inferior to PET/CT for initial staging and assessment of treatment response of Hodgkin lymphoma in pediatric patients.

Single-center experience of childhood Hodgkin lymphoma treated without radiotherapy

“…However, it contains ionizing radiation. Nevertheless, in a study comparing magnetic resonance imaging and PET CT, PET CT was shown to be more sensitive in staging at the time of diagnosis and evaluating the response to treatment (20). We used PET CT for staging and evaluation of response to treatment in all of our patients.…”

[18F]FDG PET/MRI in children suffering from lymphoma: does MRI contrast media make a difference?

“…Nonetheless, not all study results support the use of whole-body DWI for pediatric lymphoma staging. Thus, a study of Shapira-Zaltsberg and colleagues with focus on pediatric HL highlights the superiority of PET/CT at initial staging and assessment of therapy response [ 66 ]. However, at comprehensive [ 18 F]FDG PET/MRI staging of pediatric lymphoma patients, whole-body DWI seems to have no beneficial effect for staging [ 13 ].…”

18F-FDG PET/MR Assessment of Pediatric Langerhans Cell Histiocytosis

“…The lack of a significant reduction in ADC values in most patients with LCH may provide some clues for the differential diagnosis of other tumors, such as lymphoma. 21 …”

“…The lack of a significant reduction in ADC values in most patients with LCH may provide some clues for the differential diagnosis of other tumors, such as lymphoma. 21 The skeletal system is the most frequently involved system in LCH. Most of the images show bone destruction with soft tissue mass formation, surrounding soft tissue exudation and edema, and compression of the adjacent spinal cord.…”