By Ying Hitchcock, MD, Huntsman Cancer Hospital,
University of Utah
Christina Henson, MD, and team reported consensus recommendations for radiographic imaging-detected extranodal extension in head and neck cancer, which is to harmonize and standardize the clinical practice and research.
Background of iENE (imaging-detected ENE): extranodal extension of tumors on pathologic diagnosis is known to be a negative prognostic factor for head and neck cancer, and patients are treated with adjuvant chemoradiation, while patients with iENE may be better managed with non-surgical approaches to avoid trimodality-caused toxicities.
Multiple studies have demonstrated iENE sensitivity of 60-80% and specificity of 72-96% to predict pathologic ENE. As iENE is a relatively new concept for the radiology community, there is no expert consensus or standardization of the diagnostic criteria by which to define iENE, or the best classification reporting system to describe the extent of iENE. Although identification of iENE may significantly result in initiation of clinical management, the ability to diagnose iENE accurately on radiologic assessment has not been widely agreed upon.
All 21 members of the Head and Neck Cancer International Group (HNCIG) were invited to nominate national or international head and neck radiologist representatives to join the global consensus panel. Participating groups were DAHANCA, NWHHT, ECOG-ACRIN, GORTEC, FUSCC, IAG-KHT, JCOG-HNCSG, HeCOG, HKNPCSG, LACOG, NCCS, NCRI, NRG Oncology, and TTCC. The nominated expert head and neck radiologists completed an online questionnaire through a three-round modified Delphi process, including four main sections pertaining to iENE: diagnostic criteria, inter-observer agreement, the impact of core biopsy, and classification systems. Consensus of 80% and above indicated strong agreement for a statement; 67-79% indicated agreement; 21-66% indicated no agreement; and 20% or less of responses in agreement indicated strong agreement against a statement.
Regarding iENE features, the experts strongly agreed that indistinct nodal margin, extension into perinodal fat, extension into adjacent structures, and conglomerate/matted/coalescent nodes should all be used as criteria by which to identify iENE, while nodal necrosis and capsular thickening should not be used as criteria for identifying iENE. HNCIG proposed a new four-tier classification system to aid diagnosis; the experts strongly agreed in support of using a standardized classification system and synoptic reporting for iENE. The recommendations have been endorsed by 19 organizations, representing 34 countries.
Dr. Henson said an essential prerequisite for implementation of iENE into clinical practice is the availability of widely accepted, reliable and consistent definitions and diagnostic criteria, which for the first time is now available through these international guidelines.
Dr. Henson and HNCIG also developed an atlas which serves as an educational resource for grading iENE using the new HNCIG classification system, which is available for access and download online (www.hncig.org) and which offers detailed and specific guidance using real-life examples.
Abstract 18 -Criteria for the Diagnosis of Extranodal Extension Detected on Radiological Imaging in Head and Neck Cancer: HNCIG International Consensus Recommendations was presented during the Plenary II session at the 2024 Multidisciplinary Head and Neck Cancers Symposium on March 1, 2024.
