Residual neck disease management in squamous-cell carcinoma of the head and neck treated with radiotherapy plus cetuximab.

Purpose: Management of residual neck disease (RND) is one of the unsolved points after bio-radiotherapy (BRT) in loco-regional advanced squamous-cell carcinoma of the head and neck (SCCHN). The aims of the study were to characterize the radiological pattern of response by computed tomography (CT) and to assess the role of positron-emission tomography (PET)/CT in this setting for a better decision-making in the indication of neck dissection (ND).

Methods: We retrospectively reviewed 202 patients consecutively diagnosed with node-positive SCCHN (N1: 24; N2: 152; N3: 26) who had been treated with concomitant radiotherapy and cetuximab with or without previous induction chemotherapy between 2006 and 2013. Radiological evaluation after treatment was assessed by standard criteria using CT and in addition by PET/CT when RND was suspected in cases from 2010.

Results: There were 42 (21 %) patients who achieved complete response of the primary tumor persisting RND by CT. From this group, 24 patients were managed without PET/CT, leading to the performance of ND in 22 (92 %). On the other hand, 18 patients underwent PET/CT and ND was performed in only 6 (33 %). The overall survival was not different between both groups (p = 0.32). After histological examination and follow-up, PET/CT obtained a positive predictive value of 56 % and a negative predictive value of 89 %.

Conclusions: Radiological response after BRT is similar to that after treatment with chemo-radiotherapy, thereby validating in this scenario the accepted CT criteria to define complete response of the neck. However, when RND is suspected by CT, PET/CT is useful to prevent unnecessary ND.