Abstract
ObjectivesTo investigate the optimal timing for post-chemoradiotherapy (CRT) reference magnetic resonance imaging (MRI) in head and neck cancer, so as to demonstrate a maximal treatment response. To assess whether this differs in human papillomavirus–related oropharyngeal cancer (HPV-OPC) and whether the MRI timing impacts on the ability to predict treatment success.MethodsFollowing ethical approval and informed consent, 45 patients (40 male, mean age 59.7 ± 7.9 years, 33 HPV-OPC) with stage 3 and 4 HNSCC underwent pre-treatment, 6- and 12-week post-CRT MRIs in this prospective cohort study. Primary tumour (n = 39) size, T2w morphology and diffusion weight imaging (DWI) scores, together with nodal (n = 42) size and necrotic/cystic change, were recorded. Interval imaging changes were analysed for all patients and according to HPV-OPC status. MRI descriptors and their interval changes were also compared with 2-year progression-free survival (PFS).ResultsAll MRI descriptors significantly changed between pre-treatment and 6-week post-treatment MRI studies (p < .001). Primary tumour and nodal volume decreased between 6- and 12-week studies; however, interval changes in linear dimensions were only evident for HPV-OPC lymph nodes. Nodal necrosis scores also evolved after 6 weeks but other descriptors were stable. The 6-week nodal necrosis score and the 6- and 12-week nodal volume were predictive of 2-year PFS.ConclusionApart from HPV-OPC patients with nodal disease, the 6-week post-CRT MRI demonstrates maximal reduction in the linear dimensions of head and neck cancer; however, a later reference study should be considered if volumetric analysis is applied.Key Points• This study provides guidance on when early post-treatment imaging should be performed in head and neck cancer following chemoradiotherapy, in order to aid subsequent detection of recurrent tumour.• Lymph nodes in HPV-related oropharyngeal cancer patients clearly reduced in size from 6 to 12 weeks post-treatment. However, other lymph node disease and all primary tumours showed only a minor reduction in size beyond 6 weeks, and this required a detailed volumetric analysis for demonstration.• Timing of the reference MRI following chemoradiotherapy for head and neck cancer depends on whether the patient has HPV-related oropharyngeal cancer and whether there is nodal disease. MRI as early as 6 weeks post-treatment may be performed unless volumetric analysis is routinely performed.
Highlights
MethodsChemoradiotherapy (CRT) is the principal treatment option for stage 3 and 4 head and neck squamous cell carcinoma (HNSCC)
This study provides guidance on when early post-treatment imaging should be performed in head and neck cancer following chemoradiotherapy, in order to aid subsequent detection of recurrent tumour
The detection of residual or recurrent HNSCC by clinical examination maybe challenging due to posttreatment changes, whilst biopsies may be unreliable and add to morbidity [3,4,5,6]. 18F-Fluorodeoxygluocose (18F-FDG) positron emission tomography (PET) [7], quantitative diffusion-weighted (DW) magnetic resonance imaging (MRI) [8,9,10,11,12] and qualitative MRI descriptors have all been used to aid tumour detection in the post-treatment setting
Summary
MethodsChemoradiotherapy (CRT) is the principal treatment option for stage 3 and 4 head and neck squamous cell carcinoma (HNSCC). MRI descriptors such as T2w and DWI signal, morphology and dimensions have been demonstrated to contribute to both the early post-treatment and later symptomatic assessment of recurrent disease [13,14,15,16,17,18,19,20,21,22,23]. It would be useful to ascertain the earliest point at which the successfully treated tumour demonstrates the greatest response on imaging. This would allow for earlier post-treatment reference imaging and potentially earlier detection of recurrent tumour during imaging surveillance. The impact of human papillomavirus oropharyngeal cancer (HPV-OPC) status on the timing of post-treatment change should be explored since it is a potential confounding factor, with its differing morphological features and improved clinical outcomes [24, 25]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have