Expert consensus statements for Waldeyer's ring involvement in pediatric Hodgkin lymphoma: The staging, evaluation, and response criteria harmonization (SEARCH) for childhood, adolescent, and young adult Hodgkin lymphoma (CAYAHL) group

Abstract

Waldeyer's ring (WR) involvement in pediatric Hodgkin lymphoma (HL) is extremely rare and criteria for determining involvement and response to treatment are unclear. The international Staging, Evaluation, and Response Criteria Harmonization for Childhood, Adolescent and Young Adult Hodgkin Lymphoma (SEARCH for CAYAHL) Group performed a systematic review of the literature in search of involvement or response criteria, or evidence to support specific criteria. Only 166 cases of HL with WR involvement were reported in the literature, 7 of which were pediatric. To date no standardized diagnostic or response assessment criteria are available. Given the paucity of evidence, using a modified Delphi survey technique, expert consensus statements were developed by the SEARCH group to allow for a more consistent definition of disease and response evaluation related to this rare site of involvement among pediatric oncologists. The available evidence and expert consensus statements are summarized.

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

“…About 1% of the patients enrolled into the EuroNet‐PHL‐C1 trial had WR involvement which is compatible with other reports showing that the WR is rarely involved by Hodgkin's lymphoma 8,9 . Nevertheless, precise staging of the WR including the differentiation between directly adjacent lymph nodes and the WR is crucial when radiotherapy is a component of the treatment.…”

“…Currently, assessment of the WR at staging in HL patients is commonly performed by clinical assessment, sometimes involving a detailed examination by an ENT specialist. However, especially in the absence of biopsies, clinical assessment remains highly subjective, and is therefore not recommendable as the sole method of diagnosis 9 …”

“…Otherwise, a no‐lymphoma‐like response was determined, potentially attributable to upper respiratory tract infection or inflammation. The latter two are frequently found in young patients both before and during HL treatment 9 Application of the imaging‐based algorithm to patients with WR involvement according to clinical assessment …”

“…Clinical assessment obviously only assesses the appearance of the mucosal surface and possibly a displacement of the WR but not the three‐dimensional involvement of deeper adjacent structures. Furthermore, clinical findings used to conclude WR involvement are not specific which makes clinical assessment prone to high interobserver variability 8,9 . Still, prior to the introduction of modern imaging technologies, clinical assessment was considered the staging method of choice to evaluate the entire WR 10 .…”

“…However, cross‐sectional imaging technologies have improved much during the last 30 years and computed tomography (CT), magnetic resonance imaging (MRI), and 18 F‐flurorodeoxyglucose positron emission tomography ( 18 F‐FDG‐PET) are widely available nowadays. Thus, it seems reasonable to include these modalities into the staging procedure and to assess their performance for a more adequate assessment of WR involvement 9 …”