A NEW CLASSIFICATION AND NOMENCLATURE SYSTEM FOR NECK DISSECTIONS

A PROPOSAL BY THE JAPAN NECK DISSECTION STUDY GROUP (JNDSG).

Abstract

The Japan Neck Dissection Study Group (JNDSG) receives support in the form of a Health and Labour Sciences Research Grant for Clinical Cancer Research from the Ministry of Health, Labour and Welfare, Japan, to conduct the “Study on Standardization of Treatment for Lymph Node Metastases of Head and Neck Cancer (H16-Gannrinshou-001).” The JNDSG's main objective is to standardize various aspects for non-radical neck dissections, such as the extent of resection of the cervical lymph nodes and non-lymphatic structures, their indication, and methods of evaluating their postoperative functions. To achieve this goal, JNDSG's first task was to invent a simple and unambiguous nomenclature system for non-radical neck dissections.
The terminology used for neck dissections is quite complicated since, a large number of non-radical neck dissections were developed by different surgeons, each of whom named their operation method in their own words, in an attempt to preserve functions that were usually lost by radical neck dissection. This complication is still causing serious confusion among head and neck surgeons throughout the world, although there have been many proposals for standardization, the most famous of which may be the terminology originally proposed in 1991 and updated in 2002 by the American Head and Neck Society and the American Academy of Otolaryngology-Head and Neck Surgery.
JNDSG has created a new classification and nomenclature system which is easy to understand, compatible with Japanese classifications of other carcinomas, and easily interchangeable with other neck dissection terminology proposals. Based on the Classification of Regional Lymph Nodes in Japan published by the Japan Society of Clinical Oncology, our new system divides the cervical lymph nodes into three basic regions and other regions. Each of the three basic regions is further divided into several sub-regions. Each region, sub-region, or principal non-lymphatic structure has its own symbol consisting of one alphabetical letter, two alphabetical letters, or one alphabetical letter plus one numeral. Each neck dissection operation is designated by a combination of these symbols. Neck dissections are classified into two groups, total neck dissection (TND) and selective neck dissection (SND), according to the extent of resection of the cervical lymph nodes.
We hope this new system will help clarify the terminology used for neck dissection, not only in Japan but throughout the world.