Roles of Therapeutic Selective Neck Dissection in Multidisciplinary Treatment

Abstract

In the treatment of head and neck squamous cell carcinoma (HNSCC), management of cervical lymph nodal metastases has a crucial impact on the prognosis of patients. The “radical neck dissection (RND)”, which was proposed by Crile (Crile, 1906) in 1906, had long been played a role of standard treatment for neck metastases due to its high curability. However, during the last two to three decades, modified neck dissection (MND), also called as “functional neck dissection”, which preserves non-lymphatic structures, has replaced the position of RND, because patients as well as surgeons have become more aware of the significance of the quality of life. In addition, it has become apparent that under current multimodality treatment protocols, MND can achieve improved functional results without compromising oncological outcomes, compared to the conventional RND (Ferlito et al., 2003). Of note, in this study, MND implies the comprehensive (I-V) ND that is generally termed as “modified radical neck dissection (MRND)”, unless described otherwise. Moreover, the detailed studies on the patterns of potential neck metastases clearly demonstrated that the laryngeal and pharyngeal cancers seldom metastasize to the level I and V, while the oral cavity cancers to the level IV and V (Lindberg, 1972; Shah, 1990). These data have strongly encouraged the application of selective neck dissection (SND) that spares the dissection of at least one level in the treatment of clinically N0 neck as “elective” SND (ESND). It is now widely accepted that ESND can achieve similar regional control rates compared to comprehensive neck dissection (CND) (i.e., RND or MRND) in this N0 clinical setting with improved functional outcomes as summarized in a comprehensive review (Ferlito et al., 2006). Recent remarkable advancements in chemoradiation have further extended the application of SND to clinically N+ cases as “therapeutic” SND (TSND) instead of therapeutic CND (TCND). Efficacy of TSND performed either as an initial treatment or as a planed ND (PND) in the course of multidisciplinary treatments has been reported by an increasing number of studies (Ambrosch et al., 2001; Byers et al., 1999; Ferlito et al., 2009; Lohuis et al., 2004; Muzaffar, 2003; Patel et al., 2008; Shepard et al., 2010). Moreover, a recent study by Robins et. al., (Robbins et al., 2005) demonstrated that super selective (i.e., only two levels) neck dissection can achieve quite favorable outcomes, when performed as a PND after RADPLAT. In view of these observations, neck dissection (ND)