Is planned neck dissection necessary for head and neck cancer after intensity-modulated radiotherapy?

The objective of this study was to determine regional control of local regional advanced head and neck squamous cell carcinoma (HNSCC) treated with intensity-modulated radiotherapy (IMRT), along with the role and selection criteria for neck dissection after IMRT.

A total of 90 patients with stage N2A or greater HNSCC were treated with definitive IMRT from December 1999 to July 2005. Three clinical target volumes were defined and were treated to 70 to 74 Gy, 60 Gy, and 54 Gy, respectively. Neck dissection was performed for selected patients after IMRT. Selection criteria evolved during this period with emphasis on post-IMRT [(18)F] fluorodeoxyglucose positron emission tomography in recent years.

Median follow-up for all patients was 29 months (range, 0.2-74 months). All living patients were followed at least 9 months after completing treatment. Thirteen patients underwent neck dissection after IMRT because of residual lymphadenopathy. Of these, 6 contained residual viable tumor. Three patients with persistent adenopathy did not undergo neck dissection: 2 refused and 1 had lung metastasis. Among the remaining 74 patients who were observed without neck dissection, there was only 1 case of regional failure. Among all 90 patients in this study, the 3-year local and regional control was 96.3% and 95.4%, respectively.

Appropriately delivered IMRT has excellent dose coverage for cervical lymph nodes. A high radiation dose can be safely delivered to the abnormal lymph nodes. There is a high complete response rate. Routine planned neck dissection for patients with N2A and higher stage after IMRT is not necessary. Post-IMRT [(18)F] fluorodeoxyglucose positron emission tomography is a useful tool in selecting patients appropriate for neck dissection.