Serial multiparametric MRI in head and neck cancer treated with radical radiotherapy

Abstract

Purpose: The Magnetic Resonance in Mucosal Primary Head and Neck Cancer (MR in MPHNC) study aims to measure and track changes in functional MRI parameters in head and neck cancer patients undergoing radical radiotherapy, in order to inform decisions regarding prognosis and treatment approach. Methods and Materials: The study opened for recruitment in May 2016. Patients receiving radical radiotherapy (RT) are being prospectively recruited. All patients are scanned on a Siemens Skyra at 3 T with functional studies as follows: diffusion weighted imaging (DWI) using RESOLVE sequences with b-values 50, 800 and calculated 1400 s mm-2, dynamic contrast enhanced imaging (DCE) using a TWIST sequence, and blood oxygen level-dependent (BOLD) imaging using a multiple-echo gradient echo sequence for calculation of transverse relaxation rate R2∗ (1/T2∗). Study scans are carried out at baseline, at weeks 2, 3, 5 and 6 during RT and at weeks 4 and 12 following RT. Parametric maps are created using Siemens Mapit and Tissue4D software, then exported to MIM. Contours are created for primary tumour and nodal volumes on the anatomical images, then transferred to parametric maps, where they are manually edited for any mismatches and analysed. Data extracted from parametric maps includes capillary transfer constant (Ktrans), apparent diffusion coefficient (ADC) and transverse relaxation rate R2∗. Results: Five patients have been recruited and 22 scan sets have been carried out. Early analysis of the data reveals results consistent with other published series. Mean ADC values have shown increases early during treatment consistent with earlier work from our group. Mean Ktrans and mean R2∗ measurements do not exhibit discernible trends in the first patients to complete serial scans. Conclusion: Serial functional imaging including dynamic contrast enhanced sequences is feasible in a prospective study. Initial analysis confirms previously observed trends in ADC values during radiotherapy. Further images will be analysed for prognostic value as recruitment continues and more mature outcome data become available.L618977028 <br />