Controversies in surgical management of the node-positive neck after chemoradiation

The addition of chemotherapy to radiation in the treatment of advanced-staged head and neck cancer has improved local-regional control and increased complete clinical and pathologic response rates in the neck. However, for those patients with residual neck disease on a posttreatment computed tomography (CT) scan, there remains significant controversy as to how to further assess the neck for the presence of a viable tumor and when to perform a neck dissection. Recently, investigators from Australia have assembled level I evidence to support the use of positron-emission tomography (PET) scanning to assess treatment response and have shown a very high negative predictive value for patients with a negative PET at 12 weeks after the completion of therapy. These data support the practice of observing PET-negative necks and intervening with neck dissection in PET-positive necks. However, not all investigators, practitioners, and patients are comfortable with delaying intervention for such a long time interval after treatment. The authors favor assessment of the neck with a CT scan at 6 weeks after the completion of chemoradiotherapy and recommend neck dissection for patients with radiographic residual disease at this time point. One rationale is that 6 weeks is an optimal window for operative intervention after acute treatment effects have subsided and before extensive fibrosis and scarring, which translates to less morbidity for the patient who is treated surgically. Another rationale is that those who develop regional recurrence can be hard to salvage surgically, and waiting an additional 6 weeks could allow for the expansion of resistant clones. The significance of this is unclear, however, because patients with residual disease are at a higher risk for local and distant as well as regional failure. Thus, further prospective studies of the role of postchemoradiotherapy PET scanning and neck dissection are needed.