Follow-up in head and neck cancer. What the radiologist must know.

The management of patients with head and neck cancer implies a multidisciplinary treatment with surgery, radiotherapy and chemotherapy. Imaging is crucial in their follow-up, especially when the tumor recurrence is not clinically evident. Radiologically distinguishing post-treatment changes from a tumor recurrence is a challenge due to the anatomical alteration due to surgical techniques and their reconstructions, radiotherapy treatment and chemotherapeutic guidelines. The differential diagnosis must include the possible complications derived from radiotherapy (mucosal necrosis, osteoradionecrosis, vasculopathy, cerebral radionecrosis) and surgery (wound infections, flap necrosis, fistulas,...). A wide knowledge of the expected findings of multimodal treatment and its complications is essential for an accurate diagnosis of tumor recurrence. Finally, choosing the appropriate image study and having a baseline post-treatment study is also relevant for a suitable radiological control.