Standardizing the extent of resection in nonradical neck dissections: the final report of the Japan Neck Dissection Study Group prospective study

Because there are few exchanges of doctors and surgical techniques among leading Japanese hospitals, neck dissections in Japan have become so highly diverse that the uniformity and comparability of nonradical neck dissections have become questionable.

The Japan Neck Dissection Study Group (JNDSG) was organized in 2002 and includes 22 leading Japanese hospitals as members. To enhance exchanges among member hospitals and standardize nonradical neck dissections, JNDSG planned and conducted a prospective study, in which surgeons from participating hospitals were directed to observe neck dissections conducted by surgeons in other hospitals. To standardize the observation method, JNDSG created a specialized form consisting of 79 questions regarding details of neck dissection.

A total of 235 patients were enrolled between February 18, 2004 and November 22, 2006. Of the 79 questions, difference among participating hospitals was confirmed in 13 details and strongly suspected in 7 details. To standardize these 20 details, JNDSG established a manual, "Standard Surgical Maneuvers for Each Detail of Neck Dissection," based on the discussion about the optimal procedures concerning each detail. As the study proceeded from the first to the second stage, the intensity of difference among the hospitals decreased in 11 details and increased in 6 details. Because there were more details showing decreased intensity, this study was concluded to have contributed to some extent to the standardization of nonradical neck dissections in Japan.

Although standardization of a surgical procedure in a multi-institutional setting is a very rare undertaking, this study achieved noteworthy success.