E1253. How Do You Like Me Now? Post-Treatment Imaging in Patients With Head and Neck Cancer
  1. David Livingston; University of Tennesse Health Science Center/ Methodist University Hospital
  2. Jacqueline Angel ; University of Tennesse Health Science Center/ Methodist University Hospital
Head and neck surgical reconstructions are complex procedures requiring multidisciplinary collaboration. Microvascular free tissue transfer, also known as free flaps (FFs), are used more frequently in head and neck reconstruction than ever before. FFs are extremely reliable with a 0.8% incidence of FF failure and a 3% incidence of partial flap necrosis. With an increasing trend in these surgical procedures, radiologists play a pivotal role in patient care. Alternatively, or in addition to surgery, many patients with head and neck cancer receive chemotherapy, radiation, or a combination of these treatments for management of their disease. Thus, an understanding of free flaps and their expected appearance on cross-sectional imaging, having a knowledge of additional posttreatment changes (e.g., after radiotherapy), and knowing how to evaluate for residual or recurrent tumor are crucial for the interpreting radiologist.

Educational Goals / Teaching Points
Provide a brief overview of reconstructive techniques in head and neck cancer patients. Review pretreatment and posttreatment imaging appearances in patients with head and neck cancer. Develop a systematic approach for radiological evaluation of post-treatment head and neck cases. Review radiological features of post-treatment complications (early and late) and of post-treatment residual or recurrent tumor.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Surgical free flaps are transferred tissue with it's own blood supply. They are distinct from grafts which depend on angiogenesis. After reconstructive surgery, a systematic approach to head and neck imaging is crucial. A clear understanding of the patient's clinical background, primary site of the tumor, knowledge of regional lymph nodes and adjacent structures to evaluate for metastasis is the first step. There are key postoperative findings/complications after surgical free flap reconstruction. These can be classified as early versus late. Early complications include ischemia, infection, bleeding and dehiscence. Late complications include infection, fistula, hardware exposure or extrusion, osteoradionecrosis, ossification of vascular pedicle, residual or recurrent tumor, local or regional and distant metastasis. There can also be post-radiation changes involving the mucosa and submucosa, muscles, bones, cartilage and the nervous system which need to be assessed on imaging. CT head and neck with contrast is the chief imaging modality used.

Reviewing posttreatment imaging in patients with a history of head and neck cancer can be challenging. A clear understanding of resection and reconstructive techniques and a systematic approach to evaluation of posttreatment changes, complications, and residual or recurrent disease in patients with head and neck cancer can help interpreting radiologists provide useful imaging reports and thereby benefit both patients and clinicians.