Response assessment and follow-up by imaging in head and neck tumours

Abstract

Accurate and timely response assessment and follow-up by imaging are pivotal for guiding radiotherapeutic management of head and neck cancer. Primarily, post-treatment imaging should aim to detect tumour recurrence as early as possible in order to maximize success of salvage surgery and determine the need for neck dissection. Second, post-treatment imaging has a pivotal role in the differentiation of tumour recurrence from toxicity-induced complication like necrosis or ulcerations and the detection of delayed onset of locoregional, metastatic recurrence and second primary cancers. With the emerging—be it currently experimental—concepts of adaptive radiation treatment strategies, there is increasing interest for imaging assessment during the course of therapy, aiming to develop a non-invasive tool to identify patients who could benefit from treatment intensification and select patients for adaptive radiotherapy (especially important in proton radiotherapy) and aiming to identify tumour regions with suspected radioresistance. The purpose of this chapter is to present an overview of the application of conventional, metabolic and microstructural imaging modalities in the response assessment and follow-up of head and neck cancer.