Correlating MRI and Histologic Tumor Thickness in the Assessment of Oral Tongue Cancer

Tumor thickness and depth of invasion in squamous cell carcinoma of tongue as indicators of the loco-regional spread of the disease: A preliminary study

Background

Magnetic resonance imaging (MRI) is a routinely used imaging modality for pre-treatment radiologic evaluation of tongue carcinoma, providing accurate information regarding the extent of the disease.

Aims and objectives

To investigate the role of MRI-derived depth of invasion and tumor thickness evaluation in squamous cell carcinoma of the tongue, and to assess if any correlation exists between depth of invasion, tumor thickness, nodal metastasis, muscles, and space involved.

Materials and methods

Thirty-three patients with oral squamous cell carcinoma of the tongue who had undergone pre-treatment MRI and excisional biopsy were included. The tumor thickness (TT) and depth of invasion (DOI) were evaluated on MRI and histopathologic images.

Result

The relation between different methodologies for assessing showed a very high correlation for the tumor tissue thickness (r = 0.99, p < 0.05) and depth of invasion (r = 0.82, p < 0.05). The tumor thickness and the depth of invasion increased with the loss of differentiation in the carcinoma histopathologically. As the depth of invasion increases, the extent of the spread of the carcinoma to tongue musculature, lingual septum, and spaces also increases.

Conclusion

The present study has depicted a high correlation between the tumor thickness and the depth of invasion between MRI and histopathological findings and is the first of its kind to correlate DOI to the invasiveness of the disease.

Value of radiological depth of invasion in non-pT4 Oral tongue squamous cell carcinoma: implication for preoperative MR T-staging

OBJECTIVE

The prognostic stratification for oral tongue squamous cell carcinoma (OTSCC) is heavily based on postoperative pathological depth of invasion (pDOI). This study aims to propose a preoperative MR T-staging system based on tumor size for non-pT4 OTSCC.

METHODS

Retrospectively, 280 patients with biopsy-confirmed, non-metastatic, pT1-3 OTSCC, treated between January 2010 and December 2017, were evaluated. Multiple MR sequences, including axial T2-weighted imaging (WI), unenhanced T1WI, and axial, fat-suppressed coronal, and sagittal contrast-enhanced (CE) T1WI, were utilized to measure radiological depth of invasion (rDOI), tumor thickness, and largest diameter. Intra-class correlation (ICC) and univariate and multivariate analyses were used to evaluate measurement reproducibility, and factors' significance, respectively. Cutoff values were established using an exhaustive method.

RESULTS

Intra-observer (ICC = 0.81-0.94) and inter-observer (ICC = 0.79-0.90) reliability were excellent for rDOI measurements, and all measurements were significantly associated with overall survival (OS) (all p < .001). Measuring the rDOI on axial CE-T1WI with cutoffs of 8 mm and 12 mm yielded an optimal MR T-staging system for rT1-3 disease (5-year OS of rT1 vs rT2 vs rT3: 94.0% vs 72.8% vs 57.5%). Using multivariate analyses, the proposed T-staging exhibited increasingly worse OS (hazard ratio of rT2 and rT3 versus rT1, 3.56 [1.35-9.6], p = .011; 4.33 [1.59-11.74], p = .004; respectively), which outperformed pathological T-staging based on nonoverlapping Kaplan-Meier curves and improved C-index (0.682 vs. 0.639, p < .001).

CONCLUSIONS

rDOI is a critical predictor of OTSCC mortality and facilitates preoperative prognostic stratification, which should be considered in future oral subsite MR T-staging.

CLINICAL RELEVANCE STATEMENT

Utilizing axial CE-T1WI, an MR T-staging system for non-pT4 OTSCC was developed by employing rDOI measurement with optimal thresholds of 8 mm and 12 mm, which is comparable with pathological staging and merits consideration in future preoperative oral subsite planning.

KEY POINTS

• Tumor morphology, measuring sequences, and observers could impact MR-derived measurements and compromise the consistency with histology. • MR-derived measurements, including radiological depth of invasion (rDOI), tumor thickness, and largest diameter, have a prognostic impact on OS (all p < .001). • rDOI with cutoffs of 8 mm and 12 mm on axial CE-T1WI is an optimal predictor of OS and could facilitate risk stratification in non-pT4 OTSCC disease.

Accuracy of Magnetic Resonance Imaging in Detecting Tumor Depth of Invasion in Squamous Cell Carcinoma of the Tongue: A Systematic Review

Objective

The objective of the study was to detect the accuracy of Magnetic Resonance Imaging (MRI) in assessing tumor depth of invasion (DOI) in squamous cell carcinoma (SCC) of the tongue.

Material and Methods

The electronic search of PubMed (including MEDLINE), COCHRANE CENTRAL and Google Scholar search engine for articles published from January 1, 2000, to September 31, 2021, was conducted and also searched the lists of references of relevant articles and reviews for studies involving patients with squamous cell carcinoma of the tongue.

Results

A total of 5362 articles were retrieved in the initial search. After the initial search process, 13 full-text articles were reviewed. Out of these 13 articles, seven met the inclusion criteria and were thus included in this systematic review.

Conclusion

The MRI-determined DOI based on T1-weighted sequences increases with increasing T stage. There is the highest correlation between the MRI-derived DOI and the histopathological DOI with increasing T stage. Therefore, MRI provides satisfactory diagnostic accuracy for measuring tumor DOI and, thus, may be considered a predictor of tumor stage.

Magnetic resonance imaging-based prediction models for tumor stage and cervical lymph node metastasis of tongue squamous cell carcinoma

Purpose

To evaluate the ability of preoperative MRI-based measurements to predict the pathological T (pT) stage and cervical lymph node metastasis (CLNM) via machine learning (ML)-driven models trained in oral tongue squamous cell carcinoma (OTSCC).

Materials and methods

108 patients with a new diagnosis of OTSCC were enrolled. The preoperative MRI study included post-contrast high-resolution T1-weighted images acquired in all patients. MRI-based depth of invasion (DOI) and tumor dimension-together with shape-based and intensity-based features-were extracted from the lesion volume segmentation. The entire dataset was randomly divided into a training set and a validation set, and the performances of different types of ML algorithms were evaluated and compared.

Results

MRI-based DOI and tumor dimension together with several shape-based and intensity-based signatures significantly discriminated the pT stage and LN status. The overall accuracy of the model for predicting the pT stage was 0.86 (95%CI, 0.78-0.92) and 0.81 (0.64-0.91) in the training and validation sets, respectively. There was no improvement in the model performance upon including shape-based and intensity-based features. The model for predicting CLNM based on DOI and tumor dimensions had a fair accuracy of 0.68 (0.57-0.78) and 0.69 (0.51-0.84) in the training and validation sets, respectively. The shape-based and intensity-based signatures have shown potential for improving the model sensitivity, with a comparable accuracy.

Conclusion

MRI-based models driven by ML algorithms could stratify patients with OTSCC according to the pT stages. They had a moderate ability to predict cervical lymph node metastasis.

Preoperative MRI for oral tongue squamous cell carcinoma: timing and correlation to histopathology

Magnetic resonance imaging (MRI) is an integral part of the evaluation of local and regional disease in tongue squamous cell carcinoma prior to surgery. The aim of this study was to evaluate the accuracy of MRI in assessing tumour dimensions, as well as the impact of the time-lag from diagnostic biopsy on the accuracy of MRI. The medical records of 64 patients with tongue carcinoma were reviewed retrospectively. Tumour maximum diameter and tumour depth of invasion were compared between pathology and MRI (T1- and T2-weighted). MRI-derived maximum tumour diameter and depth of invasion correlated strongly with histopathology: T1-weighted (r = 0.700 and r = 0.813, respectively) and T2-weighted (r = 0.734 and r = 0.834, respectively). A significant correlation was found between measurements on T1 and T2 MRI for both parameters (P = 0.955 and P = 0.984, respectively). The accuracy rate of MRI for T-staging of early tumours was low: 10% for T1 tumours; 39.3% for T2 tumours. A time-lag of less than 2 weeks between the diagnostic biopsy and MRI adversely affected the correlation of tumour dimensions. MRI is a reliable tool for evaluating tongue carcinoma; however, it overestimates early tumours. A 2-week delay after diagnostic biopsy is desired before completing an MRI. Alternatively, if logistics allow, a pre-biopsy MRI is preferred, especially for T1-T2 tumours.

Prediction Formula for Pathological Depth of Invasion From Clinical Depth of Invasion in Tongue Squamous Cell Carcinoma (SCC) Stage I/II Cases

BACKGROUND

 The depth of invasion (DOI) of tongue squamous cell carcinoma (SCC) is an important prognostic factor. The definition is clear for pathological DOI (pDOI), but the treatment strategy is determined by the preoperative clinical DOI (cDOI). Few studies have investigated the difference between these DOIs. The purpose of this study was to obtain the correlation equation between cDOI and pDOI for Stage I/II tongue SCC and to consider the points to be noted in actual clinical practice.

METHODS

 In this retrospective study, 58 patients with clinical stage I/II tongue SCC were included. Correlations between cDOI and pDOI were obtained for all 58 cases, as well as for 39 cases which excluded superficial and exophytic lesions.

RESULTS

 The overall cDOI and pDOI median values were 8.0 and 5.5 mm, respectively; the 2.5 mm reduction was significant (p < 0.01). The correlation equation was pDOI = 0.81 × cDOI-0.23 (r = 0.73). Furthermore, re-analysis of the 39 cases revealed that pDOI = 0.84 × cDOI-0.37 (r = 0.62). Hence, a derived equation pDOI = 0.84 × (cDOI-0.44) was obtained to predict pDOI from cDOI.

CONCLUSIONS

 This study indicated that it is necessary to consider contraction due to specimen fixation by subtracting the thickness of the mucosal epithelium. Clinical T1 cases with a cDOI of 5 mm or less had a pDOI of 4 mm or less, and it would be expected to have low positive rate of neck lymph node metastasis.

Recent Development of Fluorescent Nanodiamonds for Optical Biosensing and Disease Diagnosis

The ability to precisely monitor the intracellular temperature directly contributes to the essential understanding of biological metabolism, intracellular signaling, thermogenesis, and respiration. The intracellular heat generation and its measurement can also assist in the prediction of the pathogenesis of chronic diseases. However, intracellular thermometry without altering the biochemical reactions and cellular membrane damage is challenging, requiring appropriately biocompatible, nontoxic, and efficient biosensors. Bright, photostable, and functionalized fluorescent nanodiamonds (FNDs) have emerged as excellent probes for intracellular thermometry and magnetometry with the spatial resolution on a nanometer scale. The temperature and magnetic field-dependent luminescence of naturally occurring defects in diamonds are key to high-sensitivity biosensing applications. Alterations in the surface chemistry of FNDs and conjugation with polymer, metallic, and magnetic nanoparticles have opened vast possibilities for drug delivery, diagnosis, nanomedicine, and magnetic hyperthermia. This study covers some recently reported research focusing on intracellular thermometry, magnetic sensing, and emerging applications of artificial intelligence (AI) in biomedical imaging. We extend the application of FNDs as biosensors toward disease diagnosis by using intracellular, stationary, and time-dependent information. Furthermore, the potential of machine learning (ML) and AI algorithms for developing biosensors can revolutionize any future outbreak.

The role of magnetic resonance imaging in assessing the extent of tongue squamous cell carcinoma: A prospective cohort study

PURPOSE

To assess the false-positive and false-negative MRI results in evaluating the extent of tongue squamous cell carcinoma.

METHODS

A prospective cohort series of 165 patients was enrolled to assess the false-positive and false-negative MRI results in evaluating the extent of tongue squamous cell carcinoma by comparing intraoperative tumor profile images and postoperative pathological sections. The differences between two-dimensional tumor margins were analyzed using Mimics 15.0 and Geomagic Control 16.0. A paired-samples t-test was used to analyze the agreement among MRI, intraoperative and pathological findings regarding the extent of tongue tumors. Multiple linear regression analysis was used to analyze associated factors.

RESULTS

The mean and maximum false-positive values of pathological specimens was 1.95±1.39 mm (95% limit of agreement (LoA) 1.70-2.14) and 3.21 mm, respectively; the false-negative value was 0.44±0.49 mm. The false-positive value of intraoperative specimens was 1.52±0.87 mm (95% LoA 1.36-1.64); the false-negative value was 0.35±0.20 mm. Tumor morphology (ulcer type) (p<0.01) and depth of invasion (DOI) (≤5 mm) (p<0.01) were significantly correlated with the false-positive values of intraoperative and pathology specimens.

CONCLUSION

The false-positive values are important when judging the invasion margin of tongue cancer and forming MRI-based operative plans; the false-negative value was almost negligible.

Accuracy of MRI, CT and Ultrasound imaging on thickness and depth of oral primary carcinomas invasion: a systematic review

OBJECTIVES

The aim of this study was to perform a systematic review to assess the sensitivity, specificity, and accuracy of magnetic resonance imaging (MRI), computed tomography (CT), and intraoral ultrasound (US) to determine the depth of invasion (DOI) and/or tumor thickness (TT) in oral cavity cancers, with histopathological evaluation as the gold standard.

METHODS

Articles whose primary objective was to evaluate the accuracy (sensitivity and specificity) of MRI, CT, and US imaging to assess DOI and/or TT were searched in six major electronic databases, in addition to three grey literature databases. The methodological quality of the selected studies was evaluated by using the Quality Assessment Tool for Diagnostic Accuracy Studies-2.

RESULTS

Twelve studies met the inclusion criteria and underwent qualitative analysis: six studies on MRI, three on US, and one on CT. The accuracy values for MRI ranged from 67 to 83%, with sensitivity values above 80% and specificity above 75%. For US, mean values of sensitivity ranged from 91 to 93%. For CT, accuracy was 75%.

CONCLUSIONS

For the application of US, CT, MRI, good accuracy was reported in DOI and/or TT, as evaluated in the preoperative period. US offered advantages for detection of small lesions.

The accuracy of magnetic resonance imaging to measure the depth of invasion in oral tongue cancer: a systematic review and meta-analysis

The accuracy of magnetic resonance imaging (MRI)-derived depth of invasion (DOI) compared to histopathological DOI is still controversial. A meta-analysis was performed to address this controversy and further investigate the best imaging sequence to measure DOI of tongue squamous cell carcinomas (SCC). A comprehensive literature search of five electronic databases was conducted. Stata/SE was used to establish a continuous variable model to assess the consistency between MRI-derived DOI and histopathological DOI. IBM SPSS Statistics 22.0 was used to evaluate the correlation between MRI-derived DOI and histopathological DOI. The meta-analysis showed that the weighted mean difference (WMD) of DOI measured by MRI had an acceptable overestimation compared with that measured by histopathology (WMD 1.64 mm; P < 0.001). In the subgroup analyses, there was no difference between T1-weighted imaging (T1WI) and histopathological values (WMD 0.77 mm; P = 0.273), while T2-weighted imaging (T2WI) had a major overestimation (WMD 2.09 mm; P < 0.001). The overall inter-class correlation coefficient (ICC) between MRI-derived DOI and histopathological DOI was 0.869 (95% CI 0.837-0.895), and was 0.923 (95% CI 0.894-0.944) in the T1WI subgroup and 0.790 (95% CI 0.718-0.845) in the T2WI subgroup. MRI is an accurate modality for evaluating the DOI in oral tongue SCC, and T1WI showed relatively higher validity than T2WI for DOI measurements.

Assessment of squamous cell carcinoma of the floor of the mouth with magnetic resonance imaging

PURPOSE

We aimed to use magnetic resonance imaging (MRI) to determine the relationship between the pathological depth of invasion (DOI), undetectability, and tumor thickness of squamous cell carcinoma of the floor of the mouth.

MATERIALS AND METHODS

We retrospectively evaluated the relationship between pathological DOI and MRI detectability, as well as the relationship between pathological DOI and tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging or coronal T2-weighted imaging.

RESULTS

We analyzed 30 patients with squamous cell carcinoma of the floor of the mouth; MRI revealed that the pathological DOI of the 11 undetectable lesions (median 2 mm) was smaller than that of the 19 detectable lesions (median 14 mm) (p < 0.001), and the cut-off value was 3 mm (sensitivity, 0.84; specificity, 0.91; area under the curve, 0.89). Tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging was assessed in all 19 detectable lesions; however, tumor thickness on coronal T2-weighted imaging could not be assessed in eight cases. Tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging was found to be significantly associated with the pathological DOI.

CONCLUSIONS

Undetectability on MRI indicates superficial lesions with a pathological DOI value that is less than 3 mm. In detectable lesions, tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging is associated with pathological DOI.

Diagnostic accuracy of magnetic resonance imaging in detecting depth of invasion of tongue cancers

The recent eighth edition of the American Joint Committee on Cancer (AJCC) staging system has introduced depth of invasion (DOI) as one of its important components. DOI is also important for deciding neck management in superficial tongue cancers. Magnetic resonance imaging (MRI) is mainly used to assess DOI, and in this study we have evaluated the efficacy of MRI to detect it. This is a retrospective study consisting of 60 treatment-naïve tongue cancer patients operated on between July 2017 and June 2019. Patients underwent MR imaging on an Optima MR450W 1.5T unit, and MRI was reported by two experienced ead and eck adiologistss. Postoperative histological DOI was considered the gold standard. The correlation coefficient was derived for postoperative DOI and MRI-detected DOI. A subgroup analysis of superficial tongue cancer was also done. The mean MRI DOI was 13.7 mm and the mean histological DOI 12.45 mm. The shrinkage factor was 0.6 mm. Pearson's correlation coefficient was 0.80 (p=<0.001) for Radiologist 1 and 0.85 (p=<0.001) for Radiologist 2. The interobserver variation was low, with a correlation coefficient between the two radiologists of 0.965 (p=<0.001). For superficial tongue cancers there was moderate correlation for MRI and histologically-detected DOI with a kappa value of 0.681 (p=0.03). As per the ROC curve, the cut-off value for MRI DOI to predict nodal metastasis was 4.6 mm. MRI has high reliability to predict the DOI of tongue cancers. The interobserver variation was low. The diagnostic accuracy in cases of superficial tongue cancer was moderate.

The prognostic role of the pre-treatment neutrophil to lymphocyte ratio (NLR) and tumor depth of invasion (DOI) in early-stage squamous cell carcinomas of the oral tongue

The appropriate surgical management of early-stage oral tongue squamous cell carcinoma (OTSCC) remains a debated topic. The aim of this study is to investigate the role of the pre-treatment neutrophil to lymphocyte ratio (NLR) and tumor depth of invasion (DOI) in predicting the presence of occult neck metastases in early-stage OTSCC. A retrospective analysis of patients affected by early-stage (cT1-T2 cN0) OTSCC who were submitted to elective neck dissection (END) was performed. Tumors were classified retrospectively according to the 8th TNM classification, the DOI was assessed on the pre-operative magnetic resonance imaging, and the pre-treatment NLR was calculated for each patient. A logistic regression model to estimate the probability π (x) of cervical metastases by studying the NLR and DOI was carried out. Next, the correlation between the two variables, the NLR and DOI, was preliminarily studied. A cohort of 110 patients was analyzed (mean age, 62 years old; male to female ratio 1.2:1). The patients were staged as cT1 in 53 cases and cT2 in 57 cases. A DOI greater than 5.4 mm and a NLR greater than 2.93 are associated with an increased risk of presenting occult cervical metastases. Furthermore, the variables NLR and DOI are linearly associated with a positive correlation, proved by Spearman's rank correlation coefficient rho of 0.64, with a unitary increase in the DOI of 1 mm directly associated with an increase of 0.47 in the NLR. The DOI and NLR can be effectively used to predict the occurrence of occult neck metastasis and therefore to plan an END in early-stage OTSCC.

Prognostic value of MRI-measured tumor thickness in patients with tongue squamous cell carcinoma

This study aimed to assess the prognostic value of MRI-measured tumor thickness (MRI-TT) in patients with tongue squamous cell carcinoma (SCC). This single-center retrospective cohort study included 133 pathologically confirmed tongue SCC patients between January 2009 and October 2019. MRI measurements of tongue SCC were based on axial and coronal T2-weighted (T2WI) and contrast-enhanced T1-weighted (CE-T1WI) images. Two radiologists independently measured MRI-TT. Intraclass correlation coefficients (ICC) were calculated for inter-rater agreements. Spearman's rank correlation between MRI-TT and pathologic depth of invasion (pDOI) was assessed. Cox proportional hazards analyses on recurrence-free (RFS) and overall survival (OS) were performed for MRI-TT and pDOI. Kaplan-Meier survival curves were plotted with log-rank tests. The intra- and inter-rater agreements of MRI-TT were excellent (ICC: 0.829-0.897, all P < 0.001). The correlation between MRI-TT and pDOI was good (Spearman's correlation coefficients: 0.72-0.76, P < 0.001). MRI-TT were significantly greater than pDOI in all axial and coronal T2WI and CE-T1WI (P < 0.001). In multivariate Cox proportional hazards analysis, MRI-TT measured on axial CE-T1WI yielded a significant prognostic value for OS (hazards ratio 2.77; P = 0.034). MRI-TT demonstrated excellent intra- and inter-rater agreements as well as high correlation with pDOI. MRI-TT may serve as a prognostic predictor in patients with tongue SCC.

Accuracy of Magnetic Resonance Imaging in Evaluating the Depth and Level of Invasion of Buccal Carcinoma: A Prospective Cohort Study

PURPOSE

This study evaluated the accuracy of magnetic resonance imaging (MRI) in determining the depth and level of invasion of buccal carcinoma.

METHODS

Patients with buccal squamous cell carcinoma diagnosed pathologically from July 2016 to December 2019 were included. The depth of invasion (DOI) and level of invasion (LOI) were evaluated by MRI, intraoperative specimens and pathological sections. Statistical analyses were performed using IBM SPSS software version 25.0 (IBM Corp., Armonk, NY).

RESULTS

Forty-nine patients were ultimately included. The overall difference in DOIs between MRI and pathological sections (DMP) was 5.55 ± 2.40 mm, and T category correlated with the differences in DOI measurement and LOI assessment. The threshold value of DOI by MRI to identify lymph node metastasis was 8.5 mm, and that for OS and disease-specific survival (DSS) was 14.1 mm for both. Buccinator invasion on MRI correlated with OS and DSS.

CONCLUSION

Tumors with MRI-derived DOIs larger than 8.5 mm deserve simultaneous neck dissection at initial surgery. Buccinator invasion was found to be an independent prognostic factor for buccal carcinoma patients.

A comparative study between CT, MRI, and intraoral US for the evaluation of the depth of invasion in early stage (T1/T2) tongue squamous cell carcinoma

Objectives

This study aimed to clarify the accuracy of intraoral ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) in preoperative image depth of invasion (DOI) measurement of T1/T2 tongue cancer through comparison with histopathological measurements.

Methods

Imaging of the primary lesions was performed at our hospital; the lesions were classified into T1 and T2 based on the 8th edition of the AJCC/UICC, and surgery performed. There was histopathological confirmation of lesions as squamous cell carcinoma in 48 patients with tongue cancer. T3 and T4 cases, cases in which preoperative chemotherapy and radiation therapy were performed, and cases where biopsy was performed before imaging were excluded. The radiological DOI in US, CT, and MRI and the histopathological DOI as base were comparatively investigated and statistical analyses were performed by Bland–Altman analysis and Spearman's rank correlation coefficient.

Results

Bland–Altman analysis showed that the US radiological DOI was overestimated by an average of 0.2 mm compared to the histopathological DOI, while CT and MRI radiological DOI were overestimated by an average of 2–3 mm. The comparison of CT and MRI revealed that the difference between the MRI and histopathological DOI, as well as the 95% limit of agreement, were smaller than those of the CT radiological DOI.

Conclusions

US is the most accurate preoperative diagnostic tool for T1 and T2 squamous cell carcinoma; CT and MRI tend to have an overestimation of about 2–3 mm and so caution is required.

Clinical diagnostic criteria versus advanced imaging in prediction of cervical lymph node metastasis in oral squamous cell carcinomas: A magnetic resonance imaging based study

CONTEXT AND AIM:

The inaccuracies in clinical examination have been well documented, while advanced imaging modalities, including computed tomography and magnetic resonance imaging (MRI), have been shown to have superior diagnostic accuracy in detecting occult and nodal metastasis. The aim of the present study was to identify as well as evaluate the inaccuracies in clinical examination and of clinical diagnostic criteria in known cases of oral squamous cell carcinomas (OSCCs) with the help of MRI.

MATERIALS AND METHODS:

A total of 24 patients attending as outpatients were included in the study, while clinically diagnosed and histopathologically proven cases of OSCC were examined clinically and then subjected to advanced imaging with the help of MRI.

STATISTICAL ANALYSIS USED:

Statistical analysis was done using Statistical Package for the Social Sciences (SPSS) version 17.0 (SPSS Inc., Chicago, IL, USA), while paired t-test was performed for evaluating the size of tumor and lymph node recorded on clinical and imaging findings. A P < 0.05 was considered statistically significant.

RESULTS:

Detection of tumor size and lymph node metastasis was found to be higher in case of MRI than when accomplished by clinical staging alone, while paired t-test values for difference in results were found to be statistically significant (P < 0.05).

CONCLUSIONS:

The present study showed that clinical diagnostic criteria alone were not sufficient and reliable for detecting metastatic lymphadenopathy, highlighting the significance of advanced imaging modalities such as MRI for an efficient preoperative diagnostic workup, as well a tool for planning treatment in patients with OSCCs.

MRI correlates to histopathological data in oral tongue squamous cell carcinoma diagnostics

OBJECTIVES

The purpose of this study was to compare magnetic resonance imaging (MRI) maximum tumor diameter and depth of invasion with histopathology in oral tongue squamous cell carcinoma (OTSCC) patients in our Institute. Another objective was to compare recorded nodal status between MRI and histology.

MATERIAL AND METHODS

MRI and pathological records of 45 patients diagnosed with T1-T3 OTSCC were reviewed retrospectively. Maximum tumor diameter and depth of invasion were measured and rechecked by oral radiologist and pathologist. Nodal status was recorded from both MRI and histopathology. Correlation analyses were performed using Pearson's correlation.

RESULTS

Both maximum tumor diameter and depth of invasion correlated significantly between MRI and histology (ρ = 0.874, p < .001; ρ = 0.898, p < .001). Significant correlation was found between MRI and pathological dimensions in the MRI-based T-staged subgroups of T2 and T3 but not in T1. MRI sensitivity for detecting pathologically positive nodes was 60%. MRI specificity for detecting pathologically negative nodes was 83%. Moderate correlation was found between MRI and histological nodal status (ρ = 0.44, p = .003).

CONCLUSIONS

MRI tumor dimensions correlate with histopathological data in OTSCC. Based on our Finnish patient material and results, MRI serves as an accurate tool in supporting OTSCC patient treatment in our Institute.

Machine learning-based MRI texture analysis to predict occult lymph node metastasis in early-stage oral tongue squamous cell carcinoma

OBJECTIVES

To develop and compare several machine learning models to predict occult cervical lymph node (LN) metastasis in early-stage oral tongue squamous cell cancer (OTSCC) from preoperative MRI texture features.

MATERIALS AND METHODS

We retrospectively enrolled 116 patients with early-stage OTSCC (cT1-2N0) who had been surgically treated by tumor excision and elective neck dissection (END). For each patient, we extracted 86 texture features from T2-weighted imaging (T2WI) and contrast-enhanced T1-weighted imaging (ceT1WI), respectively. Dimension reduction was performed in three consecutive steps: reproducibility analysis, collinearity analysis, and information gain algorithm. Models were created using six machine learning methods, including logistic regression (LR), random forest (RF), naïve Bayes (NB), support vector machine (SVM), AdaBoost, and neural network (NN). Their performance was assessed using tenfold cross-validation.

RESULTS

Occult LN metastasis was pathologically detected in 42.2% (49/116) of the patients. No significant association was identified between node status and patients' gender, age, or clinical T stage. Dimension reduction steps selected 6 texture features. The NB model gave the best overall performance, which correctly classified the nodal status in 74.1% (86/116) of the carcinomas, with an AUC of 0.802.

CONCLUSION

Machine learning-based MRI texture analysis offers a feasible tool for preoperative prediction of occult cervical node metastasis in early-stage OTSCC.

KEY POINTS

• A machine learning-based MRI texture analysis approach was adopted to predict occult cervical node metastasis in early-stage OTSCC with no evidence of node involvement on conventional images. • Six texture features from T2WI and ceT1WI of preoperative MRI were selected to construct the predictive model. • After comparing six machine learning methods, naïve Bayes (NB) achieved the best performance by correctly identifying the node status in 74.1% of the patients, using tenfold cross-validation.

Combination of compressed sensing and parallel imaging for T2-weighted imaging of the oral cavity in healthy volunteers: comparison with parallel imaging

OBJECTIVE

Compressed sensing (CS) and parallel imaging (PI) are magnetic resonance (MR) imaging acceleration techniques. Image quality of two-dimensional fast spin echo imaging of the oral cavity using CS or combined CS and PI has not been evaluated. The aim of this study was to compare the acquisition time and image quality between T2-weighted imaging (T2WI) with CS and PI (CSPI-T2WI) and T2WI with PI (PI-T2WI) of the oral cavity.

MATERIALS AND METHODS

Twenty healthy volunteers who underwent CSPI-T2WI and PI-T2WI of the oral cavity on a 3 T MR scanner were enrolled in the study. Contrast ratios of fat/muscle and bone/muscle on CSPI-T2WI and PI-T2WI were measured. Overall image quality, 4 kinds of artifacts, and visualization of 18 anatomical structures were independently evaluated by two radiologists with grading scales. The quantitative and qualitative measurements were compared between CSPI-T2WI and PI-T2WI by using the Wilcoxon signed-rank test.

RESULTS

Mean acquisition time of CSPI-T2WI and PI-T2WI was 72 s and 136 s, respectively (p < .001). CSPI-T2WI showed a significantly higher contrast ratio of fat/muscle than PI-T2WI (p < .01). There were no significant differences in the overall image quality, artifacts, and visualization of anatomical structures between CSPI-T2WI and PI-T2WI.

CONCLUSIONS

CSPI-T2WI of the oral cavity in healthy volunteers can provide a reduction in acquisition time without impaired image quality compared to PI-T2WI.

KEY POINTS

• The acquisition time of T2WI with the combined CS and PI provided a 47% reduction in acquisition time compared with T2WI with PI. • T2WI with the combined CS and PI did not show impaired image quality compared with T2WI with PI. • Combined CS and PI can be a useful technology to evaluate the oral cavity with high-speed acquisition.

Correlation between the magnetic resonance imaging features of squamous cell carcinoma of the buccal mucosa and pathologic depth of invasion

OBJECTIVE

The objective of this study was to determine correlations between magnetic resonance imaging (MRI) features including radiologic depth of invasion (r-DOI) and pathologic DOI (p-DOI) of squamous cell carcinoma of the buccal mucosa.

STUDY DESIGN

In total, 31 lesions were retrospectively evaluated. MRI findings included detectability, buccinator muscle invasion (positive: BMI+, negative: BMI-), buccal fat pad invasion (positive: BFPI+, negative: BFPI-), and r-DOI measured on T2-weighted images (T2-DOI) and contrast-enhanced T1-weighted images (CET1-DOI). These findings were compared to the p-DOI of the tumors.

RESULTS

The p-DOI values of undetectable lesions were smaller than those of detectable lesions (P < .001), and the cutoff value was 1 mm. BMI+ and BFPI+ lesions had significantly larger p-DOI values than the corresponding BMI- and BFPI- lesions (P < .001), with cutoff values of 5 and 6 mm, respectively. The correlation coefficient between CET1-DOI and p-DOI was 0.68 (P < .001). CET1-DOI values were larger than p-DOI (P < .001) and the average difference between them was 3.4 mm. T2-DOI was inconclusive in 50% of cases. Interobserver agreements of MRI evaluation were good to very good.

CONCLUSION

MRI-derived parameters were useful in estimating p-DOI and may be helpful in predicting the depth of invasion of tumors and the risk of lymph node metastasis.

Do we have a robust method for preoperative tumour depth assessment for oral cavity tumours with clinically negative necks?

Tumour depth is an important prognostic factor in head and neck cancer and has recently been included in the eighth edition of the Union for International Cancer Control TNM classification of malignant tumours for oral squamous cell carcinoma (OSCC). It is important to appraise the accuracy of depth assessments; however, there is little current evidence in the literature. Accurate depth assessment is particularly pertinent in cT1-T2N0 OSCC where it may influence neck management. A retrospective study was performed at two tertiary referral centres, in which surgically treated patients with cT1-T4N0 OSCC were audited. Preoperative tumour depth assessments from multimodality radiological staging scans were compared with the final histopathological depth. The predictive accuracy of intraoral ultrasound (IOUS), computed tomography (CT), and magnetic resonance imaging (MRI) for tumour depth was evaluated. Accuracy to within 3mm of the histopathological depth was seen in 56.7% of MRI scans and 57.1% of CT scans. IOUS appeared to have superior prediction, with 78.2% of measurements within 3mm. Over one third of CT and MRI imaging failed to detect a lesion; IOUS scans detected the lesions in all of these case. In conclusion, the reliability of preoperative imaging assessment of tumour depth should be considered when recommending treatment.

Dynamic manoeuvres on MRI in oral cancers - A pictorial essay

Magnetic resonance imaging has been shown to be a useful tool in the evaluation of oral malignancies because of direct visualization of lesions due to high soft tissue contrast and multiplanar capability. However, small oral cavity tumours pose an imaging challenge due to apposed mucosal surfaces of oral cavity, metallic denture artefacts and submucosal fibrosis. The purpose of this pictorial essay is to show the benefits of pre and post contrast MRI sequences using various dynamic manoeuvres that serve as key sequences in the evaluation of various small oral (buccal mucosa and tongue as well as hard/soft palate) lesions for studying their extent as well as their true anatomic relationship.

MR evaluation of tongue carcinoma in the assessment of depth of invasion with histopathological correlation: A single center experience

Introduction

Magnetic resonance imaging (MRI) has become the cornerstone for pretreatment evaluation of carcinoma tongue and provides accurate information regarding the extent of the lesion and depth of invasion that helps the clinician to optimize treatment strategy. Aim of the study is to correlate MRI and histopathological findings, to evaluate the role of MRI in loco-regional tumor node metastasis (TNM) staging, and to assess the depth of invasion of tongue carcinoma.

Materials and Methods

This study was undertaken on 30 patients with clinical diagnosis of tongue carcinoma referred for MR imaging at a tertiary care hospital over the 2-year period between July 2017 and June 2019. MRI was performed with GE 1.5 Tesla scanner, neurovascular (NV) array coil. Clinical and MRI staging of tongue carcinoma was done preoperatively and correlated. Post-surgery, histopathological TNM staging was done and correlated with clinical and MRI TNM staging. The cutoff value of histopathological (HP) depth that could determine the existence of nodal metastasis was 5 mm.

Results

In 30 patients diagnosed with tongue carcinoma, the incidence was higher in males (92%). Moderate agreement (k = 0.512) was noted for T staging between clinical and MRI staging assessments. Fair agreement (k = 0.218) was noted for N stage between clinical and MRI staging assessments. There was good agreement (k = 0.871) for M stage between the clinical and MRI staging assessments. Good agreement (k = 0.822 and k = 0.767, respectively) was noted for both T staging and Nstaging between MRI and histopathology staging assessments. The agreement for the T stage was poor (k = 0.012) between the clinical and histopathology staging assessments. Agreement for the N stage was also poor (k = 0.091) between the clinical and histopathology staging assessments. Mean depth of invasion by histology and MRI was 14.22 mm and 16.12 mm, respectively. Moderate agreement (k = 0.541) was noted between clinical and pathological tumor depth and good agreement (k = 0.844) was noted between radiological and pathological tumor depth. As for the T1WGd MRI depth with a cutoff value of 5 mm, the nodal metastasis rate in the group with values >5 mm was 52%, and for those <5 mm was 24%, both of which were significantly different (P = 0.040). Pearson's correlation coefficient of HP depth and T1WGd MRI depth was 0.851 (P < 0.001) suggesting that HP depth shows a strong correlation with T1WGd MRI depth.

Conclusion

MRI is the imaging modality of choice for evaluation of tongue carcinoma as MRI helps in accurate staging of the tumor using TNM classification which is crucial for optimizing treatment options. The current study shows a high correlation between MRI and histopathological findings regarding thickness of tumor and depth of invasion. MRI and histopathology assessments of tumor spread were equivalent to within 0.5 mm DOI. Estimation of invasion depth using MRI as a preoperative study in oral tongue carcinoma is essential in planning surgical treatment strategies such as the extent of elective neck dissection. Invasion depth, which greatly affects occult node metastases, must be included in the TNM staging of oral tongue carcinoma.

Assessing the magnetic resonance imaging in determining the depth of invasion of tongue cancer

OBJECTIVES

To assess the magnetic resonance imaging (MRI) in predicting tumour's depth of invasion (DOI) of tongue cancer by comparing to pathology and to determine the cut-off value of MRI-derived DOI for lymph node metastasis.

PATIENTS AND METHODS

In a retrospective analysis, 156 patients with newly diagnosed tongue cancer were included. Tumour's DOI was compared between MRI measurement and pathology by Pearson correlation coefficient and paired t test. The accuracy of MRI-derived DOI was compared to the pathological DOI. The relationship between MRI-derived DOI and cervical lymph node metastasis was calculated by receiver operating characteristic curve.

RESULTS

Tumour's DOI was well correlated between MRI measurement and pathology with correlation coefficients of 0.77. MRI-derived DOI was 3.4 mm (28%) larger than pathology. The accuracy of MRI in deciding pathological DOI was 67.9%. The cut-off value of MRI-derived DOI was 10.5 mm for lymph node metastasis of tongue cancer.

CONCLUSION

Magnetic resonance imaging can be used as a reference to determine tumour's DOI of tongue cancer. Tumour with MRI-derived DOI larger than 10.5 mm deserves simultaneous neck dissection at initial surgery.

Depth of invasion determined by magnetic resonance imaging in tongue cancer can be a predictor of cervical lymph node metastasis

OBJECTIVES

We evaluated the relationships between depth of invasion (DOI) of tongue cancer, as measured with preoperative T1- and T2-weighted magnetic resonance imaging (MRI) and postoperative histopathologic (Path) specimens, with cervical lymph node metastasis (CLNM) and tumor stage. We also calculated the correlation of MRI and Path DOI measurements.

STUDY DESIGN

This retrospective study included 101 patients who had squamous cell carcinoma of the tongue and were treated surgically. Two observers measured DOI on all 3 modalities.

RESULTS

DOI thresholds for predicting CLNM with high diagnostic efficacy were 6.99 mm and 8.32 mm for MRI and 5 mm for Path. DOI values from all modalities were significantly different for tumors with and without CLNM (P < .01) and for the 4 TNM stages (P ≤ .05), with increasing values corresponding to advancement in tumor stage. Addition of DOI changed the T level of many tumors based on the new TNM (tumor-node-metastasis) classification. The correlation coefficient between DOI calculated on each MRI sequence and Path was 0.90.

CONCLUSIONS

MRI-derived DOI accurately reflected the subsequent metastatic status and degree of progression of tumor stages, with a strong positive correlation to Path values, and may be considered a predictor of tumor stage and CLNM.

Management of the clinically N0 neck in early-stage oral squamous cell carcinoma (OSCC). An EACMFS position paper

Metastasis of oral squamous cell carcinoma (OSCC) to the cervical lymph nodes has a significant impact on prognosis. Accurate staging of the neck is important in order to deliver appropriate treatment for locoregional control of the disease and for prognosis. The management of the neck in early, low volume disease (clinically T₁/T₂ oral cavity tumours) has long been debated. The risk of occult nodal involvement in cT₁/T₂ OSCC is estimated around 20-30%. We describe the natural evolutionary history of OSCC and its patterns of spread and metastasis to the local lymphatic basins. We discuss most published literature and studies on management of the clinically negative neck (cN₀). Particular focus is given to prospective randomized trials comparing the outcomes of upfront elective neck dissection against the observational stance, and we summarize the results of the sentinel node biopsy studies. The paper discusses the significance of the primary tumour histological characteristics and specifically the tumour's depth of invasion (DOI) and its impact on predicting nodal metastasis. The DOI has been incorporated in the TNM staging highlighting its significance in aiding the treatment decision making and this is reflected in world-wide oncological guidelines. The critical analysis of all available literature amalgamates the existing evidence in early OSCC and provides recommendations in the management of the clinically N₀ neck.

Radiological approach for the newly incorporated T staging factor, depth of invasion (DOI), of the oral tongue cancer in the 8th edition of American Joint Committee on Cancer (AJCC) staging manual: assessment of the necessity for elective neck dissection

The 8^th edition of American Joint Committee on Cancer's (AJCC) Cancer Staging Manual was modified by incorporating depth of invasion (DOI) in the T categorization of oral cavity cancer. This is because DOI is strongly associated with cervical lymph node metastasis, which is the most important negative prognostic factor of oral cavity cancer. This major change in the AJCC Cancer Staging Manual caused re-staging of T category in several cases. Although, the DOI on MRI and CT (radiological DOI; r-DOI) strongly correlated with pathological DOI (p-DOI), it is often 2-3 mm larger than p-DOI. Due to this variance, estimation of p-DOI based on r-DOI may not be accurate. However, when a lesion is undetectable on MRI, p-DOI was often smaller than 4 mm. On the other hand, when MRI depicts lesions with styloglossus and hyoglossus muscle invasion, p-DOI was always larger than 4 mm. These correlations between MRI findings and p-DOI are important when assessing the need for elective neck dissection, as the National Comprehensive Cancer Network (NCCN) recommends elective neck dissection in cases with DOI greater than 4 mm.

Imaging in oral cancers: A comprehensive review

This review aims at simplifying the relevant imaging anatomy, guiding the optimal imaging method and highlighting the key imaging findings that influence prognosis and management of oral cavity squamous cell carcinoma (OSCC). Early OSCC can be treated with either surgery alone while advanced cancers are treated with a combination of surgery, radiotherapy and/or chemotherapy. Considering the complex anatomy of the oral cavity and its surrounding structures, imaging plays an indispensable role not only in locoregional staging but also in the distant metastatic work-up and post treatment follow-up. Knowledge of the anatomy with understanding of common routes of spread of cancer, allows the radiologist to accurately determine disease extent and augment clinical findings to plan appropriate therapy. This review aims at simplifying the relevant imaging anatomy, guiding the optimal imaging method and highlighting the key imaging findings that influence prognosis and management.

Significance of depth of invasion determined by MRI in cT1N0 tongue squamous cell carcinoma

Depth of invasion (DOI) can be calculated preoperatively by MRI, and whether MRI-determined DOI can predict prognosis as well as whether it can be used as an indicator of neck dissection in cT1N0 tongue squamous cell carcinoma (SCC) remains unknown. The main goal of the current study was to answer these unknowns. A total of 151 patients with surgically treated cT1N0 tongue SCC were retrospectively enrolled, and MRI-determined DOI was measured based on T1-weighted layers with a 3.0T scan. The Chi-square test was used to evaluate the association between clinical pathologic variables and neck lymph node metastasis, and the factors that were significant in the Chi-square test were then analyzed in a multivariate logistic regression analysis model to determine the independent predictors. The main study endpoints were locoregional control (LRC) and disease-specific survival (DSS), and the Kaplan-Meier method (log-rank test) was used to calculate the LRC and DSS rates. The factors that were significant in univariate analysis were then analyzed in the Cox model to determine the independent prognostic factors. A value of p < 0.05 was considered significant, and all statistical analyses were performed with SPSS 20.0. Occult neck lymph node metastasis was noted in 26 (17.2%) patients, and the ROC curve indicated that the optimal cutoff value of MRI-determined DOI was 7.5 mm for predicting neck lymph node metastasis, with a sensitivity of 86.9%. The factors of lymphovascular invasion, MRI-determined DOI, pathologic DOI, and pathologic tumor grade were significantly associated with the presence of neck lymph node metastasis in univariate analysis, and further logistic regression analysis confirmed the independence of lymphovascular invasion, MRI-determined DOI, and pathologic DOI in predicting neck lymph node metastasis. The 5-year LRC and DSS rates were 84% and 90%, respectively. Cox model analysis suggested the MRI-determined DOI was an independent prognostic factor for both LRC and DSS. Therefore, elective neck dissection is suggested if MRI-determined DOI is greater than 7.5 mm in cT1N0 tongue SCC, and MRI-determined DOI ≥ 7.5 mm indicates additional risk for disease recurrence and cancer-related death.

The role of MRI-derived depth of invasion in staging oral tongue squamous cell carcinoma: inter-reader and radiological-pathological agreement

Background

The 8th edition of tumor, node, metastasis (TNM) classification incorporates depth of invasion evaluation in the staging of oral cavity squamous cell carcinoma, since it is a predictor of nodal metastasis and an independent prognostic factor. Although the histopathological definition of depth of invasion is clear, an accurate method for its radiological assessment has not yet been validated.

Purpose

To investigate the role of MRI-derived depth of invasion evaluation in staging oral tongue squamous cell carcinoma and to assess the inter-reader agreement and the radiological–pathological correlation.

Material and Methods

We retrospectively reviewed 43 patients with oral tongue squamous cell carcinoma who underwent preoperative MRI. The MRI-derived depth of invasion was measured by two radiologists, each with a different degree of experience in head and neck imaging. The pathological depth of invasion was recorded from histopathological reports. The inter-reader and the radiological–histopathological correlations for the depth of invasion were evaluated with Bland–Altman plots, the intraclass correlation coefficients (ICC), and the paired samples test; agreements for T staging were assessed using the Kappa coefficient.

Results

Inter-reader reliability was excellent for the MRI-derived depth of invasion (ICC = 0.91), very good between MRI-derived depth of invasion and pathological depth of invasion (ICC = 0.89 for the experienced reader, 0.86 for the inexperienced reader). Both readers reached a good agreement regarding T staging (kappa value = 0.70). Furthermore, the agreement between radiological and pathological T staging was good (kappa value = 0.74 for the experienced reader, 0.60 for the inexperienced reader).

Conclusion

MRI-derived depth of invasion should be measured in the pretreatment assessment of oral tongue squamous cell carcinoma as it has an excellent inter-reader reliability and nearly excellent radiological–pathological correlation.

Accuracy of magnetic resonance imaging in predicting dentate line invasion in low rectal cancer

PURPOSE

To retrospectively assess the accuracy of magnetic resonance imaging (MRI) in predicting dentate line invasion in low rectal cancer.

MATERIALS AND METHODS

Eighty-one patients with primary rectal cancer were assessed by dynamic contrast-enhanced MRI. The location of the dentate line was assessed on MRI in 27 patients with upper-mid rectal cancer. Two observers independently evaluated the distance between the distal tumor edge and the MRI-defined dentate line in 54 patients with low rectal cancer, and the imaging and histological findings were compared.

RESULTS

The MRI-defined dentate line was 24.0 ± 3.8 mm above the anal verge in patients with upper-mid rectal cancer. The dentate line invasion status agreed with the histological findings in 49/54 (91%) patients (κ = 0.72 [95% CI 0.50-0.95]) for observer 1, and in 51/54 (94%) patients (κ = 0.83 [0.65-1.00]) for observer 2 in patients with low rectal cancer. Interobserver agreement was good (κ = 0.83 [0.65-1.00]). The MRI-derived distance between the distal tumor edge and the dentate line had significant correlation with the histological distance (r = 0.86 for reader 1 and 0.75 for observer 2).

CONCLUSION

MRI demonstrates high accuracy in predicting dentate line invasion in low rectal cancer.

Usefulness of contrast-enhanced CT in the evaluation of depth of invasion in oral tongue squamous cell carcinoma: comparison with MRI

OBJECTIVES

There is currently no standardized approach for assessing the depth of invasion (DOI) of oral tongue squamous cell carcinoma via diagnostic imaging. We investigated the usefulness of contrast-enhanced computed tomography (CECT) for estimating the pathological DOI of oral tongue squamous cell carcinoma by evaluating the correlation of pathological DOI with the DOIs on CECT and magnetic resonance imaging (MRI).

METHODS

We retrospectively reviewed 21 of 139 patients who underwent radical surgery for primary oral tongue squamous cell carcinoma between 2009 and 2018. The 21 cases were evaluable, without dental artifacts on CECT. DOIs on CECT and MRI, and pathological DOI were measured.

RESULTS

The median pathological DOI was 9 mm, that on CECT was 10.9 mm, that on T2-weighted MRI was 14.2 mm, and that on contrast-enhanced T1-weighted MRI was 13.1 mm. The DOIs on CECT and on MRI were larger than the pathological DOI (p = 0.003 to < 0.001). The absolute value of the difference between pathological DOI and DOI on CECT was smaller than that between pathological DOI and DOI on MRI (p = 0.01 and 0.003). DOIs on CECT and on MRI correlated with pathological DOI (r = 0.74-0.66, all p < 0.001). Spearman's correlation coefficient between DOI on CECT and pathological DOI was greater than that between DOI on MRI and pathological DOI.

CONCLUSIONS

Compared to the DOI determined on an MRI scan, the DOI determined on a CECT scan correlated with and better approximated pathological DOI. Therefore, CECT can be useful for preoperative staging of patients with oral tongue squamous cell carcinoma.

Magnetic Resonance vs. Intraoral Ultrasonography in the Preoperative Assessment of Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Background: Preoperative assessment is critical to decide the most adequate surgical strategy for oral squamous cell carcinoma (SCC). Magnetic resonance (MR) and intraoral ultrasonography (US) have been reported to be of great value for preoperative estimation of depth of invasion (DOI) and/or tumor thickness (TT). This review aims to analyze the accuracy of MR and intraoral US in determining DOI/TT in oral SCC, by assuming histological evaluation as the reference method.

Methods: The procedure was conducted following the modified 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We performed a systematic search of papers on PubMed, Scopus, Web of Science, and Cochrane Library databases until July 31st, 2019. For quantitative synthesis, we included nine studies (487 patients) focused on MR, and 12 (520 patients) focused on intraoral US. The Pearson correlation coefficient (r) between DOI/TT evaluated with MR or intraoral US was assumed as effect size. A meta-analysis (MA) for each study group (MR and US) was performed by using the random-effects models with the DerSimonian–Laird estimator and r-to-z transformation.

Results: In the MA for MR studies, a high heterogeneity was found (I² = 94.84%; Q = 154.915, P < 0.001). No significant risk of bias occurred by evaluating funnel plot asymmetry (P = 0.563). The pooled (overall) r of the MR studies was 0.87 (95% CI from 0.82 to 0.92), whereas the pooled r-to-z transformed was 1.44 (95% CI from 1.02 to 1.85). In the MA for US studies a high heterogeneity was found (I² = 93.56%; Q = 170.884, P < 0.001). However, no significant risk of bias occurred (P = 0.779). The pooled r of the US studies was 0.96 (95% CI from 0.94 to 0.97), whereas the pooled r-to-z transformed was 1.76 (95% CI from 1.39 to 2.13). These outputs were confirmed in additional MA performed by enrolling only MR (n = 8) and US (n = 11) studies that evaluated TT.

Conclusions: MR and intraoral US seem to be promising approaches for preoperative assessment of DOI/TT in oral SCC. Remarkably, a higher pooled r and r-to-z transformed were observed in the intraoral US studies, suggesting that this approach could be more closely related to histopathological findings.

Contemporary Approach to Locally Advanced Oral Cavity Squamous Cell Carcinoma

PURPOSE OF REVIEW

Surgical management of locally advanced oral cavity squamous cell carcinomas (OCSCC) has long been recognized as a primary treatment modality. Technological advances have led to significant improvements in our surgical approach, from improvement in the visualization of tumors to more efficient and precise reconstruction. Here, we review the latest technological advances in surgical extirpation and reconstruction of locally advanced OCSCCs.

RECENT FINDINGS

The focus of technological innovation in surgical extirpation has been on improving visualization, with the use of intraoperative ultrasound for margin delineation, intraoperative navigation, narrow-band imaging, and the use of fluorescence. Though early, these are promising steps to ensuring complete resection of the cancer. Advances in reconstruction have been centered on the incorporation of computer assisted design, manufacturing, and virtual surgical planning, allowing for more complex three-dimensional defects to be expeditiously reconstructed. As these technologies are still under development, their impact on oncologic outcomes are not yet robustly defined; however, as technology continues to advance and become more widely available, new technologies will undoubtedly become integrated into enhancing surgical precision and planning.

Reliability of MRI-Derived Depth of Invasion of Oral Tongue Cancer

RATIONALE AND OBJECTIVE

To evaluate the inter-rater reliability of the magnetic resonance imaging (MRI)-derived depth of invasion (DOI) and the agreement between MRI and pathological measurements of oral tongue cancer.

MATERIALS AND METHODS

The institutional review board approved this retrospective study. The study population consisted of 29 patients with clinical T2N0 oral tongue cancer treated by surgery. Routine pretreatment MRI was performed on a 3T superconducting imager. Two raters with 23 and 18 years of head-and-neck MRI experience, respectively, independently chosen MRI sequences for each patient, then delineate the tumor, and then used three protocols to measure the MRI-derived DOI: the axial reconstructed thickness (method 1), the axial invasive portion (method 2), and the coronal invasive portion (method 3). Then they consensually selected the optimal among the three methods for each patient; it was designated method 4. The Bland-Altman plots, intraclass correlation coefficients (ICCs), and the paired samples test were used. According to the median follow-up of 41 months, the relationship between the MRI-derived DOI and nodal recurrence was also investigated.

RESULTS

The inter-rater reliability of methods 2 and 4 was excellent (ICC of 0.829 and 0.807, respectively). The correlation between MRI and pathological measurements was good for method 4 (ICC of 0.611), however, all measurements recorded on MRI were 2-3 mm larger than on pathology. No patients whose MRI-derived DOI was less than 5 mm suffered nodal recurrence.

CONCLUSION

The MRI-derived DOI was valuable for the preoperative staging. The optimal measurement method should be selected on a case-by-case basis.

Magnetic resonance imaging findings of styloglossus and hyoglossus muscle invasion: Relationship to depth of invasion and clinical significance as a predictor of advisability of elective neck dissection in node negative oral tongue cancer

PURPOSE

By comparing styloglossus and hyoglossus muscle invasion (SHMI) of oral tongue squamous cell cancer (OTSCC) on MR imaging to pathological depth of invasion (DOI) and prognosis, we aimed to evaluate the clinical significance of MR imaging findings of SHMI.

METHOD

Forty-five, early stages and clinically N0 OTSCCs were retrospectively reviewed. Data included pathological DOI, DOI on MR imagings, two-year potential cervical lymph node positive, locoregional control, disease-free survival, and overall survival. Data were statistically compared between the groups with MR evidence of SHMI (SHMI+) and without MR evidence of SHMI (SHMI-).

RESULTS

There were 17 SHMI + and 28 SHMI-. Elective neck dissections performed on 13 cases revealed five node positive cases, all of which were SHMI + . Pathological DOI in SHMI + was significantly larger than SHMI- (average 9.0 vs 4.6 mm, p < 0.001). All SHMI + revealed pathological DOI larger than 4 mm. The two-year potential cervical lymph node positive rate of SHMI + was significantly higher than SHMI- (p =  0.01). Locoregional control rate and disease-free survival of SHMI+ were significantly lower than in SHMI- (p =  0.02). There was no significant difference in overall survival. Interobserver agreement in evaluation of SHMI on MR imaging was good (kappa value = 0.72, p <  0.001).

CONCLUSIONS

Pathological DOIs of SHMI + were all larger than 4 mm, which is the cut-off point that National Comprehensive Cancer Network recommends for neck dissection, and SHMI + had a worse prognosis than SHMI-. SHMI + can be used as a criterion for elective neck dissection.

Controversies in relation to neck management in N0 early oral tongue cancer

The standard local treatment for early-stage tongue cancer with no clinical lymph node metastases is partial glossectomy. The frequency of occult lymph node metastasis is ~20-30%. Thus, whether prophylactic neck dissection with glossectomy or glossectomy alone should be performed has been a controversial issue since the 1980s. Both treatments have advantages and disadvantages; however, especially in cases involving prophylactic neck dissection, surgical invasion and complications including the cosmetic disadvantage caused by neck skin incision, accessory nerve paralysis or facial nerve (mandibular marginal branch) paralysis, stiffness of the shoulder or neck and a feeling of neck tightness have been considered issues that could be solved by providing less-invasive treatment to the 70-80% of patients without occult lymph node metastasis. A more accurate preoperative diagnosis and strict follow-up are required to provide minimally invasive treatment while ensuring the therapeutic effect. It is also necessary to narrow down the target based on the risk-benefit balance. The depth of invasion should be considered in cases involving oral cavity malignancies. This was also taken into account in recent revisions of eighth edition of the TNM Classification of Malignant Tumors and it is an important factor for N0 neck management. This review article summarizes previous and recent reports on neck management, focusing on the risk-benefit and future perspectives of the diagnosis and treatment of early-stage oral tongue cancer. This effort is an attempt to establish treatment from the patient's point of view, with the patient's quality of life taken into account.

Multi-parametric effect in predicting tumor histological grade by using susceptibility weighted magnetic resonance imaging in tongue squamous cell carcinoma

BACKGROUND

Susceptibility weighted imaging (SWI) is helpful for depicting hemorrhage, calcification, and increased vascularity in some neoplasms, which may reflect tumor grade. In this study, we aimed to apply SWI in patients with oral tongue squamous cell carcinomas (OTSCCs) and relate multi-parametric effect to tumor histological grade prediction.

METHODS

Preoperative MR examinations were performed on a 1 .5T MRI scanner with T1-, T2- and contrast-enhanced (CE) T1-weighted imaging. In addition to routine head and neck MRI sequences, SWI was performed. Tumor thickness and volume were measured. Intratumoral susceptibility signal intensities (ITSSs), ITSS score and ITSS ratio on SWI were evaluated and recorded. Subjects were sub-grouped into low- and high-grade according to the histological findings post operation. Parameters such as tumor thickness, tumor volume and three ITSS related parameters were compared between low- and high-grade groups. ROC analysis was performed on above parameters to access the capability in predicting tumor histological grade. Different multi-parametric models were run to access multi-parametric combination effect.

RESULTS

Thirty patients with OTSCC were finally included in the study. Twenty of them were categorized as low-grade SCC and the other ten subjects were high-grade SCC according to the pathologic findings. No significant difference was seen for tumor thickness or tumor volume between two sub-groups. ITSSs were seen in 23/30 patients. Significant difference of ITSS scores between low- and high-grade OTSCCs was observed, with mean value of 0.95 ± 0.83 and 1.70 ± 0.95, respectively. Univariate ROC analysis demonstrated ITSSs, ITSS score and ITSS ratio were valuable parameters for predicting tumor histological grade and ITSSs was superior to the other two parameters, with an area under ROC curve of 0.790. Multi-parametric model using combination of ITSSs and tumor thickness would greatly improve the predictive capability in comparison with a univariate approach, yielding the area under ROC curve of 0.84(0.69,0.99). On contrast-enhanced SWI (CE-SWI), ITSSs were shown more clearly delineated in comparison with non-contrast enhanced SWI.

CONCLUSIONS

In conclusion, SWI was superior in depiction of internal characteristics of OTSCCs, which would potentially provide more diagnostic information. Multi-parametric model using combination of ITSSs and tumor thickness would be valuable in predicting tumor histological grade.

MRI prognostic factors of tongue cancer: potential predictors of cervical lymph nodes metastases

Background This study aimed to evaluate the efficacy of three MR imaging parameters, which are tumour thickness, para-lingual distance and apparent diffusion coefficient (ADC) value for prediction of cervical lymph nodes metastasis in cancer tongue patients. Patients and methods Fifty patients with proved cancer tongue by histopathological examination underwent MRI examination. T1 and T2- weighted MRI, diffusion-weighted images and post-contrast T1 fat suppression sequences were used. Results The patients were classified according to lymph nodes involvement as seen by MRI into two groups. Significant differences between positive and negative nodes groups were observed regarding tumour thickness and para-lingual distance (p-values = 0.008 and 0.003 respectively). ROC curve analyses revealed cut-off values >13.8 mm and ≤ 3.3 mm for tumour thickness and para-lingual distance respectively for prediction of nodes involvement. No significant differences between patients with and without cervical lymph nodes metastasis were found regarding corresponding ADC value of the tumour (p-value = 0.518). Conclusions Para-lingual distance and tumour thickness are factors that could influence pre-operative judgment and prognosis of tongue cancer patients. ADC value of the tumour itself seem not to be a reliable index of cancer progression to regional lymph nodes.

Intraoperative Depth of Invasion Is Accurate in Early-Stage Oral Cavity Squamous Cell Carcinoma

PURPOSE

Depth of invasion (DOI) is one predictor of nodal metastasis in oral cavity squamous cell carcinoma (OCSCC) and can facilitate the decision to complete an elective neck dissection (END) in early-stage disease with a clinically negative neck. The purpose of this study was to investigate the accuracy of DOI in intraoperative frozen specimens for T1N0 oral OCSCC.

MATERIALS AND METHODS

To compare the accuracy of DOI in frozen versus permanent specimens, we completed a prospective, blinded study of 30 patients with cT1N0 OCSCC who presented between October 2016 and December 2017.

RESULTS

DOI in frozen specimens was 96.8% accurate in predicting the need for END with a sensitivity of 90.9%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 95.2%. A strong correlation was found between DOIs in frozen and permanent specimens measured by head and neck (HN) pathologists (r = 0.96; 95% confidence interval [CI], 0.93 to 0.97), between HN pathologists using frozen specimens (r = 0.98; 95% CI, 0.95 to 0.99) and permanent specimens (r = 0.95; 95% CI, 0.91 to 0.98), and in DOIs in frozen specimens communicated intraoperatively versus measured by HN pathologist 1 (r = 0.93; 95% CI, 0.86 to 0.97) and HN pathologist 2 (r = 0.95; 95% CI, 0.89 to 0.98). Only 1 patient who did not undergo an END based on frozen specimens was undertreated owing to upgrading of the DOI in permanent specimens.

CONCLUSIONS

DOI in intraoperative frozen sections has an accuracy of 96.8% and may be reliably used as a clinical tool to determine the need for END in early-stage OCSCC.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

Undetectability of oral tongue cancer on magnetic resonance imaging; clinical significance as a predictor to avoid unnecessary elective neck dissection in node negative patients

METHODS:

We retrospectively reviewed early stage oral tongue cancer patients treated with radical surgery with clinically N0, between May 2009 and February 2016. Collected data include age, sex, pathological DOI, DOI on MRI, locoregional control rate, disease-free survival rate, and overall survival rate. These data were statistically compared between the detectable lesion (DL) group and undetectable lesion (UL) group on MRI. Interobserver agreement in evaluation of detectability of the oral tongue cancer was assessed by k statistics.

RESULTS:

Total of 53 patients were studied, and 28 were DLs and 25 ULs. Pathological DOI in UL was significantly smaller than that of DL (average 1.7 vs 4.6 mm, p < 0.001). Cut-off value between UL group and DL group was 3.5 mm (sensitivity 96 %, specificity 75 %). 96 % of ULs had pathological DOI smaller than 4 mm, the recommended cut-off value for neck dissection. There was no significant difference in locoregional control rate (p = 0.24), disease-free survival rate (p = 0.24) or overall survival rate (p = 0.92). Interobserver agreement in evaluation of detectability on MRI was very good ( k-value = 0.89, p < 0.001).

CONCLUSIONS:

When oral tongue cancer is not detected on MRI, it indicates pathological DOI being smaller than 4 mm, which may imply that elective neck dissection is unnecessary.

Utility of the luminance standard deviation to quantify magnetic resonance imaging motion artifact induced by tongue movement

Clear magnetic resonance imaging (MRI) is required to diagnose tongue cancer. However, the absence of occlusal support may cause tongue movements which are known to introduce artifacts on the MR image. This pilot study compared the manifest of artifacts from the tongue at rest and during motion using luminance standard deviation (LSD) to quantify the artifacts, in dentulous subjects. Participants were ten dentulous participants (5 males, 5 females; age 31.50 ± 8.38 years) with occlusal support. MRI was conducted with the tongue at rest and during lateral movement. The LSD was measured in the regions of interest (ROI) in the axial and sagittal planes. Tongue movement evoked unclear MR images, compared with the images taken at rest. Statistical analysis revealed that the LSD significantly differed between the tongue at rest and in motion in the axial (P = 0.004) and sagittal planes (ROI-A: P = 0.002, ROI-P: P = 0.006). These findings suggest that tongue movement introduces motion artifact and the LSD responds quantitatively to the magnitude of artifacts. Future studies will evaluate whether a prosthetic device used to provide occlusive support can decrease these artifacts when analyzed using LSD.

Radiologic-Pathologic Correlation of Tumor Thickness and Its Prognostic Importance in Squamous Cell Carcinoma of the Oral Cavity: Implications for the Eighth Edition Tumor, Node, Metastasis Classification

BACKGROUND AND PURPOSE

Addressing the performance of an imaging-based parameter compared to a "gold standard" pathologic measurement is essential to achieve accurate clinical T-classification. Our aim was to determine the radiologic-pathologic tumor thickness correlation and its prognostic value in oral squamous cell carcinoma.

MATERIALS AND METHODS

All pathologic T1-T3 (seventh edition of the Cancer Staging Manual of the American Joint Committee on Cancer) oral squamous cell carcinomas diagnosed between 2010 and 2015 were reviewed. Radiologic tumor thickness was measured on preoperative CT or MR imaging blinded to pathology. The radiologic-pathologic tumor thickness correlation was calculated. The impact of the imaging-to-surgery time interval and imaging technique on the correlation was explored. Intra-/interrater reliability on radiologic tumor thickness was calculated. The correlation of radiologic-versus-pathologic tumor thickness and its performance as the seventh edition T-category modifier was evaluated. Multivariable analysis assessed the prognostic value of the radiologic tumor thickness for overall survival adjusted for age, seventh edition T-category, and performance status.

RESULTS

For 354 consecutive patients, the radiologic-pathologic tumor thickness correlation was similar for the image-to-surgery interval of ≤4.0 weeks (ρ = 0.76) versus 4-8 weeks (ρ = 0.80) but lower in those with more than an 8-week interval (ρ = 0.62). CT and MR imaging had similar correlations (0.76 and 0.80). Intrarater and interrater reliability was excellent (0.88 and 0.84). Excluding 19 cases with an imaging-to-surgery interval of >8 weeks, 335 patients were eligible for further analysis. The radiologic-pathologic tumor thickness correlation was 0.78. The accuracy for upstaging the T-classification based on radiologic tumor thickness was 83% for pathologic T1 and 74% for pathologic T2 tumors. Multivariable analysis confirmed the prognostic value of radiologic tumor thickness (hazard ratio = 1.5, P = .02) for overall survival.

CONCLUSIONS

This study demonstrates a good radiologic-pathologic tumor thickness correlation. Intrarater and interrater reliability for radiologic tumor thickness was excellent. Radiologically thicker tumor was predictive of inferior survival.