Assessment of tumour depth in early tongue cancer: Accuracy of MRI and intraoral ultrasound.

Rob Noorlag,Frank A Pameijer,Valerie E.J Delwel,Robert J.J Van Es,Stefan M Willems,Thomas J.W Klein Nulent,Remco De Bree

doi:10.1016/j.oraloncology.2020.104895

Rob Noorlag, Frank A Pameijer + Show 5 more

Open Access

https://doi.org/10.1016/j.oraloncology.2020.104895

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Journal: Oral oncology	Publication Date: Jul 9, 2020
Citations: 40	License type: cc-by

Affiliation: University Medical Center Utrecht

Abstract

Complete resection of tongue cancer is necessary to achieve local control. Unfortunately, deep resection margins are frequently inadequate. To improve deep margin control, accurate knowledge of tumour thickness is pivotal. Magnetic resonance imaging (MRI) and intraoral ultrasound (ioUS) are frequently applied for tumour staging. This study explores the accuracy of these techniques to estimate depth of invasion. The data of patients with a T1-2 tongue cancer that had been treated surgically between 2014 and 2018 were retrospectively analysed. Measurements that had been taken by either MRI or ioUS were compared with those taken during histopathology. A total of 83 patients with tongue cancer had undergone a pre-operative MRI and 107 had been studied through an ioUS. Tumour thickness measured by MRI (r=0.72) and ioUS (r=0.78) correlated significantly (p<0.001) with histopathological depth of invasion (DOI). In tumours with a DOI of 0-10mm, MRI has a mean absolute difference with histopathology of 3.1mm (SD 3.2mm) and ioUS of 1.6mm (SD 1.3mm). In tumours with a DOIgreater than10mm, MRI has a mean absolute difference of 3.5mm (SD 3.0mm) and ioUS of 4.7mm (SD 3.5mm). Estimation of histopathological DOI in tongue cancers with DOI till 10mm is very accurate through use of ioUS. ioUS tends to underestimate DOI in tumors exceeding 10mm DOI. MRI tends to overestimate DOI in both thin and thick tumours. Since ultrasound measurements can be performed during surgery, ioUS could potentially guide the surgeon in the achievement of adequate resection margins.

Highlights

Most tongue cancers are detected as early stage tumours, for which complete surgical resection is the preferred treatment [1,2]
The accuracy of the measurement of tumour thickness (TT) through use of either Magnetic resonance imaging (MRI) or intraoral ultrasound (ioUS) to estimate histopathological depth of invasion (DOI) is established in a consecutive cohort of 146 patients with clinically early-stage tongue cancers
The present results are in line with our meta-analysis on patientspecific data (r = 0.82 for T1-2 tongue cancers based on 9 studies) [10], but do not exactly match two recent meta-analyses that reported correlation coefficients of 0.96 for ioUS and 0.87 for MRI, or another meta-analysis with a correlation coefficient of 0.95 for ioUS in oral cancer [11,15]

Summary

Introduction

Most tongue cancers are detected as early stage (cT1 or cT2, cN0) tumours, for which complete surgical resection is the preferred treatment [1,2]. A retrospective analysis of 105 patients with early-stage tongue cancers who were treated in our centre revealed 11% ‘positive’ margins (i.e. tumour within resection margin) and 63% ‘close’ margins (i.e. tumour within 0 – 5 mm of resection margin) [3]. In cases of positive resection margins or close margins with unfavourable growth characteristics (i.e. non-coherent, vascular invasive and perineural growth), patients are exposed to adjuvant treatment, which consists of either re-resection or (chemo)radiotherapy. Adjuvant (chemo)radiotherapy is associated with extended morbidity effects, both locally and systemically, such as neurotoxicity, xerostomia, mucositis, fibrosis and osteoradionecrosis [6,7,8]

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