Changes in functional imaging parameters following induction chemotherapy have important implications for individualised patient-based treatment regimens for advanced head and neck cancer.

Abstract

When induction chemotherapy (IC) is used prior to chemoradiotherapy (CRT) in head and neck cancer (HNC), functional imaging (FI) may inform adaptation of treatment plans with the aim of optimising outcomes. Understanding the impact of IC on FI parameters is, therefore, essential. To prospectively evaluate the feasibility of acquiring serial FI ((18)F-FDG-PET, diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI) and its role in defining individualised treatment regimens following IC in HNC. Ten patients with stage III and IV HNC underwent conventional (CT and MRI) and functional (DW, DCE-MRI and (18)F-FDG-PET/CT) imaging at baseline and following two cycles of IC prior to definitive CRT. One patient withdrew due to claustrophobia. Seven out of nine patients had a complete metabolic response to IC on (18)F-FDG-PET imaging. DCE-MRI showed a significant fall in transfer constant (K(trans)) (0.209 vs 0.129 min(-1)P<0.01) and integrated area under gadolinium curve at 60s (IAUGC6O) (18.4 vs 11.9 mmol/min, P<0.01) and DW-MRI a rise in ADC (0.89 vs 1.06 × 10(-3) mm(2)/s, P<0.01) following IC. Acquiring FI sequences is feasible in HNC. There are marked changes in FI parameters following IC which may guide adaptation of individualised treatment regimens.