Assessment of Waldeyer's ring in pediatric and adolescent Hodgkin lymphoma patients—Importance of multimodality imaging: Results from the EuroNet‐PHL‐C1 trial

Abstract

Background In the EuroNet Pediatric Hodgkin Lymphoma (EuroNet‐PHL) trials, decision on Waldeyer's ring (WR) involvement is usually based on clinical assessment, that is, physical examination and/or nasopharyngoscopy. However, clinical assessment only evaluates mucosal surface and is prone to interobserver variability. Modern cross‐sectional imaging technology may provide valuable information beyond mucosal surface, which may lead to a more accurate WR staging. Patients, materials, and methods The EuroNet‐PHL‐C1 trial recruited 2102 patients, of which 1752 underwent central review including reference reading of their cross‐sectional imaging data. In 14 of 1752 patients, WR was considered involved according to clinical assessment. In these 14 patients, the WR was re‐assessed by applying an imaging‐based algorithm considering information from 18F‐fluorodeoxyglucose positron emission tomography, contrast‐enhanced computed tomography, and/or magnetic resonance imaging. For verification purposes, the imaging‐based algorithm was applied to 100 consecutive patients whose WR was inconspicuous on clinical assessment. Results The imaging‐based algorithm confirmed WR involvement only in four of the 14 patients. Of the remaining 10 patients, four had retropharyngeal lymph node involvement and six an inconspicuous WR. Applying the imaging‐based algorithm to 100 consecutive patients with physiological appearance of their WR on clinical assessment, absence of WR involvement could be confirmed in 99. However, suspicion of WR involvement was raised in one patient. Conclusions The imaging‐based algorithm was feasible and easily applicable at initial staging of young patients with Hodgkin lymphoma. It increased the accuracy of WR staging, which may contribute to a more individualized treatment in the future.

Waldeyer's ring involvement in a young patient with Hodgkin lymphoma: Challenges, interdisciplinary findings, and reliability check of the image‐based algorithm for diagnosis and response assessment

“…In our recent publication entitled "Assessment of Waldeyer's ring in pediatric and adolescent Hodgkin lymphoma patients-Importance of multimodality imaging: Results from the EuroNet-PHL-C1 trial," we showed that Waldeyer's ring (WR) involvement in pediatric Hodgkin lymphoma (HL) is rare, and that the diagnosis is easily made by applying an image-based algorithm, which considers information from morphologic and metabolic cross-sectional imaging. 1 The only weakness of this publication was that we could not substantiate our results by additional histopathological information, as in none of the analyzed subjects the WR was biopsied. 1 As a complement, we now present the case of a 16-year-old male pediatric HL patient whose WR involvement was confirmed through multidisciplinary involvement, and in whom biopsy delivered important information explaining why the diagnosis of WR involvement was made with a significant delay.…”

“…1 The only weakness of this publication was that we could not substantiate our results by additional histopathological information, as in none of the analyzed subjects the WR was biopsied. 1 As a complement, we now present the case of a 16-year-old male pediatric HL patient whose WR involvement was confirmed through multidisciplinary involvement, and in whom biopsy delivered important information explaining why the diagnosis of WR involvement was made with a significant delay. This patient presented in May 2020 to an outpatient ear-nosethroat (ENT) specialist because of prolonged nasal obstruction.…”

Differentiation between rebound thymic hyperplasia and thymic relapse after chemotherapy in pediatric Hodgkin lymphoma

“…In all patients with LR, an additional PET and morphological assessment of the thymus was re‐evaluated in consensus by a radiologist (Dietrich Stoevesandt) and a nuclear physician (Lars Kurch), both experienced in the evaluation of pediatric HL. Thymic LR was defined as a positive biopsy with proof of CHL together with one or more focal FDG uptakes in the thymus that exceeded that of the liver 24,34 . The additional reassessment of the thymic region was done to rule out an alternative explanation for the increased PET uptake.…”

“…Positron emission tomography CT (PET‐CT) was also able to distinguish between tumor entities using standardized uptake value (SUV) cutoffs 15 . HL lesions are regularly of focal and not diffuse appearance in fluorodeoxyglucose ( 18 F‐FDG)‐PET 24,25 . In MRI, chemical‐shift imaging can be used for interpretation, although certain overlap exists in early adulthood 26 …”

The Impact of PET/CT on Paediatric Oncology

“…Recent chemotherapy reduces the patient's immunity further, which increases the risk for infections [5]. The use of 2-[ 18 F]FDG PET/CT in combination with MRI is useful to identify pathology in Waldeyer's ring [7].…”