Definitive radiotherapy for head-and-neck cancer with radiographically positive retropharyngeal nodes: incomplete radiographic response does not necessarily indicate failure.
OBJECTIVE
Our aim was to report the control rate of radiographically positive retropharyngeal (RP) nodes with radiation therapy (RT) and to correlate posttreatment imaging with clinical outcome.


METHODS
Sixteen patients treated with definitive RT for head-and-neck cancer had radiographically positive RP nodes (size >1 cm in largest axial dimension, or presence of focal enhancement, lucency, or calcification), and both pre-RT and post-RT image sets available for review. An additional 21 patients with unconfirmed radiographically positive RP nodes had post-RT imaging, which consisted of computed tomography (CT) at a median of 4 weeks after completing RT. Patients with positive post-RT RP nodes underwent observation with serial imaging.


RESULTS
Of 16 patients with pre-RT and post-RT images available for review, 9 (56%) had a radiographic complete response, and of 21 patients with unconfirmed positive RP nodes with post-RT images available for review, 14 (67%) had a radiographic complete response. In all, 14 patients with incomplete response on post-RT imaging experienced control of their disease with no further therapy, and no RP node or neck failures were noted during a median follow-up of 2.8 years. Six patients with positive post-RT RP nodes had serial imaging available for review, and none demonstrated radiographic progression of disease.


CONCLUSIONS
Radiographic response at 4 weeks may not accurately reflect long-term locoregional control, as RP nodes may continue to resolve over time. The highest index of suspicion should be reserved for patients with progressive changes in size, focal lucency, or focal enhancement on serial imaging after RT.
Liauw
Stanley L
SL
Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL, USA.
Mancuso
Anthony A
AA
Morris
Christopher G
CG
Amdur
Robert J
RJ
Mendenhall
William M
WM
D000328:Adult; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000528:radiation effects; D008207:Lymphatic Metastasis; D008297:Male; D010614:Pharynx / Q000000981:diagnostic imaging; D011379:Prognosis; D011859:Radiography; D020266:Radiotherapy, Conformal / Q000379:methods*; D018570:Risk Assessment / Q000379:methods*; D017211:Treatment Failure; D016896:Treatment Outcome