Analysis of Lymph Nodes Number according to Various Modifications of Neck Dissection / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: The type of neck dissection performed for head and neck cancers depends on the experience of the surgeon and the status of the neck metastasis. The purpose of this study was to quantify the extent of lymphadenectomy achieved according to the various modifications of neck dissection based on microscopic pathologic analysis and to analyze the difference in the number of lymph nodes between the types of neck dissection. MATERIALS AND METHODS: Charts and pathologic finding of patients who underwent neck dissection from June 1994 to October 1999 were reviewed. Patients who received selective neck dissection or preoperative radiotherapy to the neck were excluded. The samples were 65 necks and were divided into four groups based on Medina's classification radical neck dissection (group 1), Type I modified radical neck dissection (group 2), Type II modified radical neck dissection (group 3), and Type III modified neck dissection (group 4). The number of lymph nodes was counted by a pathologic microscopic examination for each region of specimens. The intergroup difference was analyzed by a one-way between-group analysis of variance (ANOVA). RESULTS: The mean number of dissected lymph nodes per specimen was 43.6 in group 1, 38.8 in both groups of 2 and 3, and 30.3 in group 4. Group 4 was significantly different from group 1 (p<0.05). Especially, the number of dissected lymph nodes from level II, III, IV of group 4 was significantly different from those of group 1 (p<0.05). There was no significant difference between other groups. CONCLUSIONS: The number of dissected lymph nodes decreases as the number of preserved non-lymphatic tissue structures increases. Level II, III, IV are less completely operated regions in functional neck dissection.