Assessment of mandibular invasion of squamous cell carcinoma by various modes of imaging: constructing a diagnostic algorithm

Performance of cone-beam computed tomography (CBCT) in comparison to conventional computed tomography (CT) and magnetic resonance imaging (MRI) for the detection of bone invasion in oral squamous cell cancer (OSCC): a prospective study

BACKGROUND

Oral squamous carcinoma (OSCC) is often diagnosed at late stages and bone erosion or invasion of the jawbone is frequently present. Computed tomography (CT) and magnetic resonance imaging (MRI) are known to have high diagnostic sensitivities, specificities, and accuracies in detecting these bone affections in patients suffering from OSCC. To date, the existing data regarding the impact of cone-beam computed tomography (CBCT) have been weak. Therefore, this study aimed to investigate whether CBCT is a suitable tool to detect bone erosion or invasion in patients with OSCC.

METHODS

We investigated in a prospective trial the impact of CBCT in the diagnosis of bone erosion or invasion in patients with OSCC who underwent surgery. Every participant received a CBCT, CT, and MRI scan during staging. Imaging modalities were evaluated by two specialists in oral and maxillofacial surgery (CBCT) and two specialists in radiology (CT and MRI) in a blinded way, to determine whether a bone affection was present or not. Reporting used the following 3-point system: no bony destruction ("0"), cortical bone erosion ("1"), or medullary bone invasion ("2"). Histological examination or a follow-up served to calculate the sensitivities, specificities, and accuracies of the imaging modalities.

RESULTS

Our results revealed high diagnostic sensitivities (95.6%, 84.4%, and 88.9%), specificities (87.0%, 91.7%, and 91.7%), and accuracies (89.5%, 89.5%, and 90.8%) for CBCT, CT, and MRI. A pairwise comparison found no statistical difference between CBCT, CT, and MRI.

CONCLUSION

Our data support the routine use of CBCT in the diagnosis of bone erosion and invasion in patients with OSCC as diagnostic accuracy is equal to CT and MRI, the procedure is cost-effective, and it can be performed during initial contact with the patient.

The utility of cone-beam computed tomography and multislice computed tomography scan for the evaluation of invasion versus erosion by mandibular squamous cell carcinoma as viewed on medical PACS

Introduction

The degree of bone involvement in mandibular squamous cell carcinoma has a significant impact on surgical planning. The purpose of this study was to determine the utility of cone-beam computed tomography (CBCT) for the evaluation of invasion by mandibular squamous cell carcinoma.

Methods

A retrospective review was conducted to identify subjects treated for oral squamous cell carcinoma (OSCC). All subjects had OSCC adjacent or fixed to the mandible, received preoperative CBCT and multislice computed tomography scan (MSCT), and had resection specimens that included bone.

Results

Twenty-one subjects met the inclusion criteria. The sensitivity of CBCT was 100% (95% CI 0.75-1), the specificity was 75% (95% CI 0.35-0.97), the positive predictive value was 87% (95% CI 0.66-0.98), and the calculated test accuracy was 91%. The sensitivity of MSCT was 92% (95% CI 0.64-1), the specificity was 100% (95% CI 0.63-1), and the calculated test accuracy was 95%.

Discussion

CBCT provides meaningful data that may be useful in identifying bony involvement in patients with mandibular squamous cell carcinoma. The utility in delineating erosion versus invasion is limited.

Intraoperative Assessment of Resection Margin in Oral Cancer: The Potential Role of Spectroscopy

In parallel with the increasing number of oncological cases, the need for faster and more efficient diagnostic tools has also appeared. Different diagnostic approaches are available, such as radiological imaging or histological staining methods, but these do not provide adequate information regarding the resection margin, intraoperatively, or are time consuming. The purpose of this review is to summarize the current knowledge on spectrometric diagnostic modalities suitable for intraoperative use, with an emphasis on their relevance in the management of oral cancer. The literature agrees on the sensitivity, specificity, and accuracy of spectrometric diagnostic modalities, but further long-term prospective, multicentric clinical studies are needed, which may standardize the intraoperative assessment of the resection margin and the use of real-time spectroscopic approaches.

Marginal versus Segmental Mandibulectomy in the Treatment of Oral Cavity Cancer: A Systematic Review and Meta-analysis

Introduction  Oral cavity squamous cell carcinoma (OCSCC) is the most common malignancy in the oral cavity. Two types of mandibular resections have been described: the segmental mandibulectomy and the marginal mandibulectomy. Both may have a different impact over the quality of life, oncological prognosis, and functional or aesthetic result. Objectives  The aim of this study was to systematically explore the literature to determine the survival outcomes and disease control rates in patients who underwent segmental or marginal mandibulectomy for OCSCC with histological evidence of cortical and medullary bone invasion. Data Synthesis  This review involved a systematic search of the electronic databases MEDLINE/PUBMED, Google Scholar, Ovid Medline, Embase, and Scopus including articles from 1985 to 2019. Fifteen articles were included for qualitative analysis and 11 articles were considered for meta-analysis calculations. All of them correspond to retrospective cohort studies. Conclusion  This systematic review reveals the low-level evidence regarding the impact over local control or survival according to the type of mandibulectomy. Our results need to be considered with precaution according to the limited evidence available. We just found difference regarding the 5-year disease-free survival, and a tendency in favor of segmental mandibulectomy was confirmed when medullary invasion was evident.

Dual-energy CT for the detection of skull base invasion in nasopharyngeal carcinoma: comparison of simulated single-energy CT and MRI

BACKGROUND

Skull base invasion in nasopharyngeal carcinoma (NPC) was shown to be a poor negative prognostic factor, and dual-energy CT (DECT) has heralded a new approach to detect this condition. The study aims to evaluate the value of DECT for detection of skull base invasion in NPC and compare the diagnostic performance of DECT with those of simulated single-energy CT (SECT) and MRI.

METHODS

The imaging findings of 50 NPC patients and 31 participants in control group which underwent DECT examinations were assessed in this retrospective study. The skull base invasions were evaluated using 5-point scale by two blind observers. ROC analysis, Mcnemar test, paired t test, weighted K statistics and intraclass correlation coefficient were performed to evaluate the diagnostic performance of simulated SECT, MRI and DECT.

RESULTS

Quantitative analysis of DECT parameters showed higher normalized iodine concentration and effective atomic number values in sclerosis and lower values in erosion than those in normal bones (both p < 0.05). Compared with simulated SECT and MRI, the diagnostic sensitivity for DECT was significantly improved from 75% (simulated SECT) and 84.26% (MRI) to 90.74% (DECT) (both p < 0.001), specificity from 93.23% and 93.75% to 95.31 (both p < 0.001), accuracy from 86.67% and 90.33% to 93.67%, and AUC from 0.927 and 0.955 to 0.972 (both p < 0.05), respectively.

CONCLUSIONS

DECT demonstrates better diagnostic performance than simulated SECT and MRI for detecting skull base invasions in NPC, even those slight bone invasions in early stage, with higher sensitivity, specificity and accuracy.

Accuracy of preoperative clinical examination and imaging for mandibular resection in oral cancer: a systematic review of diagnostic test accuracy studies

The aim of this systematic review is not only to analyse the accuracy of clinical examination and radiological preoperative assessment of mandibular invasion reported in isolation, but to highlight those reports that have combined them. A total of 1636 titles and abstracts published between 1995 - 2000 were screened following a literature search in PubMed. Keywords were "mandible" and "squamous cell carcinoma". A total of 90 full manuscripts were reviewed with 24 meeting defined inclusion/exclusion criteria and yielding the data reported. The most sensitive test was single photon emission tomography with eight out of the 10 studies reporting sensitivity higher than 95%. Magnetic resonance imaging (MRI) demonstrated superior sensitivity but was less specific than computed tomography (CT). A single report attempted to report the combined CT and MRI scans with a separate expert reporting but did not result in more reliable detection. Periosteal stripping was not reported, and there was insufficient data to establish the value of new technologies. This review confirms that, to our knowledge, there are no reliable data on the results of combining imaging techniques with or without clinical examination. It emphasises the lack of data for the combination of preoperative techniques to enhance safe oncological resection of the mandible. Based on the evidence gathered in this review an algorithm of assessment of possible mandibular invasion is proposed. With new technologies available and 3-dimensional models to help plan the mandibular resection and reconstruction, the potential of combining preoperative investigations should be fully realised through prospective research.

Biomechanical behavior of mandible with posterior marginal resection using finite element analysis

This study aims to characterize biomechanical behavior of various designs of posterior mandibular marginal resection under functional loadings using finite element method. The ultimate goal of this work is to provide clinically relevant information to prevent postoperative fracture and to stipulate prophylactic internal fixation for planning of marginal mandibulectomy. A 3D mandibular master model was reconstructed from cone beam computed tomography images. Different marginal resection models were created based on three design parameters, namely, defect curvilinear radius, anterior-posterior defect width and residual height of the mandibular body. Functional loadings from incisors (60 N) and contralateral first molar area (200 N) were applied to designed models and stress patterns were compared of five groups with curvilinear radius from 0 (conventional rectangular shape), 2.5, 3.5, 5, and 6 mm. Models with 25, 35 and 45 mm defect width mimic defects varied from canine to 3rd molar were tested. Residual height range from 10 to 4 mm was assessed. The results show high stresses predominated in the occlusal area and the posterior inferior border near the resection corner. The average maximum stress decreased by 29.8% (r = 2.5 mm), 51.9% (r = 3.5 mm), 54.4% (r = 5 mm), and 59.3% (r = 6 mm) compared to the baseline of r = 0 mm. The results from the combined defect width/residual height models demonstrate the increase of defect width and the decrease in residual height resulted in the increase of maximum stress. Our data also confirm that the factor of residual height supersedes defect width in terms of prevention of postoperative fracture when considering resection design.

Diagnostic efficacy of PET-CT, CT, and MRI in preoperative assessment of mandibular invasion caused by head and neck cancer: A systematic review and meta-analysis

OBJECTIVE

This study aims to conduct a systematic review and meta-analysis of the performance of PET-CT, CT, and MRI in diagnosing mandible invasion induced by head and neck cancer (HNC).

MATERIALS AND METHODS

The MEDLINE, Embase, Science Direct, CNKI and CQVIP databases were searched from inception until August 1, 2020. Then, a meta-analysis was conducted to calculate the combined diagnostic values with the corresponding 95% CIs. Two independent researchers completed the full text screening, data abstraction, and risk assessment.

RESULTS

This meta-analysis included 53 studies (N = 2 946 participants). For the pooled sensitivity (SEN), MRI (SEN: 0.88, 95% CI: 0.81-0.93) was found to have a significantly higher SEN (P = 0.0045), when compared to CT (SEN: 0.77, 95% CI: 0.71-0.82), while compared with PET-CT (SEN: 0.88, 95% CI: 0.64-0.97), the SEN was approximately equal (P > 0.05). The analysis revealed that the combined specificity (SPE) of MRI (SPE: 0.83, 95% CI: 0.74-0.89) and PET-CT (SPE: 0.81, 95% CI: 0.57-0.93) was lower than that of CT (SPE: 0.87, 95% CI: 0.83-0.90), but there was no statistical significance among these (P > 0.05). The comparison of the area under curve (AUC) reflected that PET-CT, CT and MRI have approximately equal summary diagnostic power in detecting mandibular invasion (P > 0.05).

CONCLUSION

The findings suggest that compared with CT, MRI is significantly superior for higher SEN in diagnosing mandibular invasion. The SEN of MRI and PET-CT were approximately equal. For the summary of diagnostic power, more prospective clinical trials that directly compare these three methods are needed in the future.

Locoregional recurrence rate and disease-specific survival following marginal vs segmental resection for oral squamous cell carcinoma with mandibular bone invasion

BACKGROUND AND OBJECTIVES

To determine locoregional recurrence rate (LRR) and disease-specific survival (DSS) following marginal vs segmental mandibulectomy.

METHODS

Included were 210 patients, who had marginal or segmental mandibulectomy between 2000 and 2017. Marginal resection was performed when complete removal of the tumor was deemed feasible on the condition that at least 1 cm bone height of the inferior border of the mandible could be preserved. Segmental resection was performed in case less than 1 cm bone height of the mandible would remain. Clinical and histopathological data were collected from medical records. LRR and DSS were computed using Kaplan-Meier analysis. Cox-regression analysis was used to identify risk factors for LRR and DSS.

RESULTS

A total of 59 marginal and 151 segmental resections had been performed. There was no significant difference in 3- and 5-year LRR (P = .904) and no significant difference in 3- and 5-year DSS (P = .362) between the marginal and segmental resection group. Cox-regression analysis showed a trend for surgical margin less than equal to 1 mm, to affect LRR (P = .05) and surgical margin less than equal 1 mm, perineural invasion and lymph node metastasis to affect DSS (P < .05).

CONCLUSIONS

There was no difference in outcome between the two types of mandibulectomy.

Diagnostic value of intraoperative bone marrow assessment for bone margins in patients with head and neck squamous cell carcinoma: a systematic review and meta-analysis

A clear bone margin is essential for complete resection of the bone-involved tumour, but the evaluation of hard tissue takes time and is impractical intraoperatively. Bone marrow assessment remains controversial. The aim of this study was to investigate the diagnostic value of intraoperative bone marrow assessment for bone margins. PubMed and Web of Science were searched for studies published between 1990 and 2017. A systematic review was conducted. After quality assessment, 10 articles with 11 cohorts and 404 patients were identified. Sensitivity, specificity, and other measures were pooled for meta-analysis; the estimates for intraoperative bone marrow assessment were as follows: sensitivity 0.82 (95% confidence interval (CI) 0.62-0.93), specificity 0.99 (95% CI 0.96-1.00), positive likelihood ratio 109.79 (95% CI 22.99-524.34), negative likelihood ratio 0.18 (95% CI 0.08-0.42), and diagnostic odds ratio 241.82 (95% CI 90.33-647.38). Furthermore, sensitivity and specificity at the summary operating point of the summary receiver operating characteristic curve were 0.82 and 0.99, respectively, and the area under the curve was 0.99. Intraoperative bone marrow assessment was investigated by meta-analysis and shown to have a high level of overall accuracy for the diagnosis of bone margins.

Accuracy of the Cone Beam Computed Tomography in the Detection of Bone Invasion in Patients with Oral Cancer: A Systematic Review

This review article aims to analyze the diagnostic accuracy of the cone beam computed tomography (CBCT) with respect to other imaging methods in detection of bone tissue invasion by oral squamous cell carcinoma (OSCC). The review was carried out of English language studies in PubMed Search, National Library of Medicine, between 1990 and 2017. For each study, sensitivity, specificity, and positive (LR+) and negative (LR-) likelihood ratio, as well as the diagnostic accuracy, and positive and negative predictive values were calculated. Of the 62 collected articles, 7 fulfilled the inclusion criteria. Tests and respective articles included were computed tomography (CT, four studies), magnetic resonance imaging (MRI, five studies), C (two studies), single-photon emission tomography (SPECT, two studies), multi-slice computed tomography (MSCT, two studies), and panoramic radiography (PR, two studies). The analytic data show values of LR+ were 14.4 (CT), 37.9 (MRI), 27.8 (CBCT), 25.5 (SPECT), 37.0 (MSCT), 4.8 (PR), respectively. The values of LR- were 0.35 (CT), 0.24 (MRI), 0.10 (CBCT), 0.06 (SPECT), 0.31 (MSCT), and 0.36 (PR), respectively. The positive and negative predictive values for bone tissue invasion by OSCC were 90.31%-74.91% (CT), 90.63%-78.69% (MRI), 80.05%-89.83% (CBCT), 72.97%-95.53% (SPECT), 87.44%-73.74% (MSCT), and 84.245%-69.18% (PR), respectively. The level of scientific evidence available today is weak. To better define the impact of CBCT on clinical decision-making, further studies with uniform methodological approach are needed.

What Is a Safe Distance for Preservation of the Inferior Alveolar Nerve in Lower Gingival Squamous Cell Carcinoma? A Radiographic and Histopathological Study

PURPOSE

Involvement of the inferior alveolar nerve (IAN) is important in the prognosis and treatment of gingival squamous cell carcinoma (SCC).

METHODS

In this cross sectional study, patients with gingival SCC (T4a), undergoing hemimandibulectomy or subtotal hemimandibulectomy, were examined. The distance between the lesion and inferior alveolar canal (IAC) was measured, using axial computed tomography scans before resection. Following that, histopathological evaluation of IAN was conducted. The receiver operating characteristic curve was plotted to determine the association of IAN involvement in histopathological evaluation with various distances between the lesion and IAC.

RESULTS

A total of 29 patients were examined in this study. The mean distance between the lesion and IAC was 9.40 ± 2.21 mm. Nerve involvement was documented in 9 (45%) out of 20 males, while 11 (55%) men showed no involvement. Thirteen (44.82%) patients showed IAN involvement. The receiver operating characteristic curve demonstrated a cut-off point of 9.75 mm for the lesion-IAN distance. The possibility of IAN involvement was 23.33 times higher in patients who reported paresthesia, compared with patients without nerve involvement (odds ratio, 23.33; 95% CL; P = 0.001) CONCLUSION:: It seems that in a CT scan view, a 9.75-mm safe margin is associated with high accuracy for preserving IAN in patients with gingival SCC. Also, neurosensory disturbance can be considered a strong predictor of IAN involvement.

Clinical value of 3D SPECT/CT imaging for assessing jaw bone invasion in oral cancer patients

PURPOSE

This study compared the diagnostic accuracy of jaw bone invasion (JBI) of oral cancer observed with three-dimensional (3D) SPECT/CT, CT, and MRI, and evaluated the clinical advantages of 3D SPECT/CT compared to conventional two-dimensional (2D) SPECT/CT.

MATERIALS AND METHODS

From April 2014 to January 2018, consecutive 16 oral cancer patients with suspected JBI, who had preoperatively undergone the imaging tests, were retrospectively enrolled. The likelihood of JBI was independently scored by a radiologist and oral surgeon. Using 2D or 3D SPECT/CT images, 20 oral surgeons delineated virtual surgical areas on 3D-printed jaws for 3 cases in which the extent of JBI was fully pathologically confirmed. The surgeons completed questionnaires regarding surgical planning and explanations for patients using Likert scales.

RESULTS

JBI was found in 9 patients including 5 (56%) with initial bone invasion. 3D SPECT/CT showed very high negative predictive value (100%) and inter-observer agreement (kappa = 0.917). 3D SPECT/CT was more sensitive than CT and MRI when inconclusive findings for JBI were considered negative. Compared to 2D SPECT/CT, 3D SPECT/CT had greater clinical advantages such as surgical planning and explanation to patients (p < 0.005).

CONCLUSION

3D SPECT/CT is useful not only for detecting JBI but also for surgical planning.

Performance of different imaging techniques in the diagnosis of head and neck cancer mandibular invasion: A systematic review and meta-analysis

BACKGROUND

To assess diagnostic efficacy of imaging techniques for mandibular invasion by head and neck cancer.

METHODS

Thirteen databases were searched. Study inclusion, data-extraction and quality assessment were performed independently. STATA 14.0 were mainly used for meta-analysis.

RESULTS

Forty-nine studies were included. For mandibular invasion (cortex and marrow), CBCT, SPECT, CT, MRI, orthopantomography, PET-CT and bone-scintigraphy showed pooled sensitivities of 90%, 97%, 73%, 88%, 75%, 90%, 92%, specificities of 85%, 69% 91%, 90%, 83%, 89%, 79%, AUC of 0.9461, 0.9434, 0.8995, 0.9296, 0.8761, 0.9290, 0.9207, respectively. The combined SROC curves indicated CBCT and SPECT were superior to other techniques. For mandibular medullary invasion (marrow), CT and MRI showed pooled sensitivities of 85% and 93%, specificities of 86% and 84%.

CONCLUSIONS

CBCT was top-priority choice for bone invasion diagnosis. SPECT was recommended for exclusion, CT and MRI were suitable for conformation. Further investigations are needed for mandibular medullary involvement.

Value of PET/CT 3D visualization of head and neck squamous cell carcinoma extended to mandible

PURPOSE

To study an original 3D visualization of head and neck squamous cell carcinoma extending to the mandible by using [18F]-NaF PET/CT and [18F]-FDG PET/CT imaging along with a new innovative FDG and NaF image analysis using dedicated software. The main interest of the 3D evaluation is to have a better visualization of bone extension in such cancers and that could also avoid unsatisfying surgical treatment later on.

PATIENTS AND METHODS

A prospective study was carried out from November 2016 to September 2017. Twenty patients with head and neck squamous cell carcinoma extending to the mandible (stage 4 in the UICC classification) underwent [18F]-NaF and [18F]-FDG PET/CT. We compared the delineation of 3D quantification obtained with [18F]-NaF and [18F]-FDG PET/CT. In order to carry out this comparison, a method of visualisation and quantification of PET images was developed. This new approach was based on a process of quantification of radioactive activity within the mandibular bone that objectively defined the significant limits of this activity on PET images and on a 3D visualization. Furthermore, the spatial limits obtained by analysis of the PET/CT 3D images were compared to those obtained by histopathological examination of mandibular resection which confirmed intraosseous extension to the mandible.

RESULTS

The [18F]-NaF PET/CT imaging confirmed the mandibular extension in 85% of cases and was not shown in [18F]-FDG PET/CT imaging. The [18F]-NaF PET/CT was significantly more accurate than [18F]-FDG PET/CT in 3D assessment of intraosseous extension of head and neck squamous cell carcinoma. This new 3D information shows the importance in the imaging approach of cancers. All cases of mandibular extension suspected on [18F]-NaF PET/CT imaging were confirmed based on histopathological results as a reference.

CONCLUSIONS

The [18F]-NaF PET/CT 3D visualization should be included in the pre-treatment workups of head and neck cancers. With the use of a dedicated software which enables objective delineation of radioactive activity within the bone, it gives a very encouraging results. The [18F]-FDG PET/CT appears insufficient to confirm mandibular extension. This new 3D simulation management is expected to avoid under treatment of patients with intraosseous mandibular extension of head and neck cancers. However, there is also a need for a further study that will compare the interest of PET/CT and PET/MRI in this indication.

[Single-photon emission computed tomography for the diagnosis of mandibular invasion caused by oral cancers: a systematic review and Meta-analysis]

Objective This review aimed at assessing the diagnostic efficacy of contrast-enhanced single-photon emission computed tomography (SPECT) in the diagnosis of mandibular invasion by oral cancers. Methods Five databases were searched electronically on August 5, 2016. The reference lists of included studies were hand searched. Quality assessment was performed by two reviewers in duplicate with tools suggested by Cochrane's handbook. Furthermore, the data extraction of included studies was delivered. Meta-analysis was performed using STATA 11.0. Results Ten studies with 460 participants were included. One study had a low risk of bias, and two studies had a high risk of bias. The remaining seven studies had an unclear risk of bias. Meta-analysis results showed that SPECT had a pooled sensitivity of 0.99 [95% confidence interval=0.87-
1.00]. Sensitivity was 0.99 on Q* point. The specificity of 0.61 and the area under summary receiver operating characteristic curve (SROC) were 0.93 [95% confidence interval=0.90-
0.95]. The pooled positive likelihood ratio was 2.555. The negative likelihood ratio was 0.015. The diagnostic odd ratio was 5.115. Conclusion SPECT had high sensitivity, which became suitable for excluding bone invasion by oral cancers. However, its specificity was relatively low, indicating its limited capability in confirming diagnosis. Therefore, surgeons should perform this method under certain conditions.

Dual-Energy CT in Head and Neck Imaging

PURPOSE OF REVIEW

To explain the technique of Dual-energy CT (DECT) and highlight its applications and advantages in head and neck radiology.

RECENT FINDINGS

Using DECT, additional datasets can be created next to conventional images. In head and neck radiology, three material decomposition algorithms can be used for improved lesion detection and delineation of the tumor. Iodine concentration measurements can aid in differentiating malignant from nonmalignant lymph nodes and benign posttreatment changes from tumor recurrence. Virtual non-calcium images can be used for detection of bone marrow edema. Virtual mono-energetic imaging can be useful for improved iodine conspicuity at lower keV and for reduction of metallic artifacts and increase in signal-to-noise ratio at higher keV.

SUMMARY

DECT and its additional reconstructions can play an important role in head and neck cancer patients, from initial diagnosis and staging, to therapy planning, evaluation of treatment response and follow-up. Moreover, it can be helpful in imaging of infections and inflammation and parathyroid imaging as supplementary reconstructions can be obtained at lower or equal radiation dose compared with conventional single energy scanning.

Magnetic resonance imaging for diagnosis of mandibular involvement from head and neck cancers: a systematic review and meta-analysis

Background

Diagnosis of mandibular involvement caused by head and neck cancers is critical for treatment. We performed a meta-analysis to determine the diagnostic efficacy of MR for distinguishing mandibular involvement caused by head and neck cancers.

Methods

Thirteen databases were searched electronically and hand-searching was also done. Two reviewers conducted study inclusion, data extractions, and quality assessment of the studies independently. Meta-disc 1.4 and STATA 11.0 were used to conduct the meta-analysis.

Results

16 studies involving a total of 490 participants underwent MR examinations and were accounted for in this meta-analysis. Among the included studies, 2 had high risk of bias, while the rest had unclear risk of bias. Meta-regression showed that the slight clinical and methodological heterogeneities did not influence the outcome (P>0.05). Meta-analysis indicated that the MR for the diagnosis of mandibular involvement had a pooled sensitivity (SEN) of 78%, specificity (SPE) of 83%, positive likelihood ratio (+LR) of 3.80, negative likelihood ratio (-LR) of 0.28, diagnostic odds ratio (DOR) of 28.94, area under curve (AUC) of 0.9110, and Q* of 0.8432. Two studies detected the diagnostic efficacy of MR for the mandibular medullar invasion, and only one study reported the inferior alveolar canal invasion, which made it impossible to include it in our meta-analysis. In comparing to CT, MR had a higher SEN without statistical significance (P = 0.08), but a significantly lower SPE (P = 0.04). The synthesized diagnostic efficacy (AUC and Q*) on mandibular involvement was similar between the two modalities (P>0.05).

Conclusions

Present clinical evidence showed that MR had an acceptable diagnostic value in detecting mandibular involvement caused by head and neck cancers. MR exceeded CT in diagnosing patients with mandibular invasion (higher sensitivity than CT) but was less efficacious to exclude patients without the mandibular invasion (lower specificity than CT).

Technetium-99m bone scan and panoramic radiography in detection of bone invasion by oral carcinoma

OBJECTIVE

The correct extension of cancer in the bone usually remains undetected on static imaging which may lead to inadequate or over excision. The conventional radiography as well as other anatomical imaging modalities like computed tomography, magnetic resonance imaging often fails to detect functional changes in the bone. However, bone scinitigraphy is highly sensitive in detecting earlier changes in the bone but lack anatomical definition. The purpose of the study was to evaluate the accuracy of combining technetium-99m bone scan and panoramic radiography (Tc scan/PR) over using single diagnostic modality in detection of jaw bone invasion by oral carcinomas. The accuracy of these imaging modalities either alone or in combination were determined by comparing with the histopathological findings.

MATERIALS AND METHODS

Twenty patients with biopsy-proven oral malignant tumors were randomly selected from Oral Medicine and Radiology department over a period of two years. All patients were investigated preoperatively by Tc scan and PR. Lewis - Jones's designed diagnostic criterion was applied on Tc scan/PR to evaluate bone involvement by cancer. To test the accuracy of Tc scan, PR and Tc scan/PR, their results were compared with the histopathological findings of resected specimen.

RESULTS

Hybrid Tc scan/PR had higher specificity, accuracy and positive predictive value (83.3%, 94.7%, 92.8%) than Tc scan alone (50%, 84.2%, 81.2%) and higher sensitivity and negative predictive value (100%, 100%) than PR (69.2%, 55.5%).

CONCLUSION

Combination of Tc scan and PR was more accurate in detecting jaw bone invasion by oral squamous cell carcinoma than Tc scan and PR alone.

Evaluation of intraoperative cytological assessment of bone resection margins in patients with oral squamous cell carcinoma

BACKGROUND

Frozen sections are routinely applied to control for adequate resection margins. In cases in which carcinoma infiltrates bone, the intraoperative microscopic assessment of bone margins remains challenging due to technical difficulties to section native bone. The objective of the current study was to evaluate an intraoperative cytological approach to control bone resection margins in patients with bone-infiltrating oral squamous cell carcinomas.

METHODS

A total of 174 cytological preparations obtained from bone margins of bone-infiltrating oral squamous cell carcinomas (28 patients) were assessed intraoperatively and compared with the corresponding histological findings. In a validation cohort (45 patients) the intraoperative cytological assessment of bone resection margins (ICAB) (104 margins) was evaluated as a diagnostic tool for routine clinical application.

RESULTS

In the first patient cohort, the ICAB revealed 95.3% sensitivity and 96% specificity. The results provided an accuracy of 95.7% with a significant correlation noted between cytological and histological results (κ, 0.91; P < .001), and a positive predictive value and negative predictive value of 93.8% and 96.9%, respectively. In the validation cohort, ICAB revealed 80% sensitivity and 98.9% specificity with 98% accuracy. There was a significant correlation found between cytological and histological results (κ, 0.91; P < .001), providing a positive predictive value and negative predictive value of 80% and 98%, respectively. ICAB could predict final resection status at bone margins with 80% sensitivity and 97.5% specificity. A significant correlation was found between the cytological and histological resection status at bone margins (κ, 0,75; P < .001).

CONCLUSIONS

ICAB could supplement intraoperative frozen sections of soft tissue margins as a standard procedure to control for adequate resection at bone margins.

Accuracy of imaging methods for detection of bone tissue invasion in patients with oral squamous cell carcinoma

The objective of this review is to evaluate the diagnostic accuracy of imaging methods for detection of mandibular bone tissue invasion by squamous cell carcinoma (SCC). A systematic review was carried out of studies in MEDLINE, SciELO and Science Direct, published between 1960 and 2012, in English, Spanish or German, which compared detection of mandibular bone tissue invasion via different imaging tests against a histopathology reference standard. Sensitivity and specificity data were extracted from each study. The outcome measure was diagnostic accuracy. We found 338 articles, of which 5 fulfilled the inclusion criteria. Tests included were: CT (four articles), MRI (four articles), panoramic radiography (one article), positron emission tomography (PET)/CT (one article) and cone beam CT (CBCT) (one article). The quality of articles was low to moderate and the evidence showed that all tests have a high diagnostic accuracy for detection of mandibular bone tissue invasion by SCC, with sensitivity values of 94% (MRI), 91% (CBCT), 83% (CT) and 55% (panoramic radiography), and specificity values of 100% (CT, MRI, CBCT), 97% (PET/CT) and 91.7% (panoramic radiography). Available evidence is scarce and of only low to moderate quality. However, it is consistently shown that current imaging methods give a moderate to high diagnostic accuracy for the detection of mandibular bone tissue invasion by SCC. Recommendations are given for improving the quality of future reports, in particular provision of a detailed description of the patients' conditions, the imaging instrument and both imaging and histopathological invasion criteria.

Initial staging of squamous cell carcinoma of the oral cavity, larynx and pharynx (excluding nasopharynx). Part I: Locoregional extension assessment: 2012 SFORL guidelines

OBJECTIVES

To set out good practice guidelines for locoregional extension assessment of squamous cell carcinoma of the head and neck (excluding nasopharynx, nasal cavities and sinuses).

MATERIALS AND METHODS

A critical multidisciplinary review of the literature on locoregional extension assessment of squamous cell carcinoma of the head and neck was conducted, applying levels of evidence in line with the French health authority's (HAS) literature analysis guide of January 2000.

CONCLUSION

Based on the levels of evidence of the selected articles and on work-group consensus, graded guidelines are set out for clinical, endoscopic and imaging locoregional extension assessment of head and neck cancer.

Molecular pathways involved in crosstalk between cancer cells, osteoblasts and osteoclasts in the invasion of bone by oral squamous cell carcinoma

AIMS

This study investigates whether matrix metalloproteinases (MMPs), specifically MMP-2 and MMP-9, interacting with other molecules important in osteoblast differentiation and osteoclastogenesis, could play important roles in the invasion of bone by oral squamous cell carcinoma (OSCC).

METHODS

Supernatant (conditioned medium, CM) was collected from OSCC cell lines (SCC15 and SCC25), and from cultured osteoblasts (hFOB cell line and a primary culture, OB), and used for indirect co-culture: OSCC cells were treated with CM from osteoblasts and vice versa. Zymogenic activities of MMP-2 and -9, and protein quantities of all molecules studied, were detected by gelatine zymography and Western blotting, respectively. Real-time polymerase chain reaction (PCR) analysed mRNA of these molecules. Targeted molecules were examined by immunohistochemistry in tissue sections of bone-invasive OSCCs.

RESULTS

Zymogenic activities of both MMPs were increased in OSCC cells following culture with CM from hFOB: Twist1 protein expression was increased while Runx2 did not alter. The RANKL/OPG ratio, zymogen and protein expression of MMP-9 were increased in hFOB cells cultured with CM from OSCC lines, while zymogen expression of MMP-2 was decreased. Real-time PCR showed generally similar changes in expression of these molecules. All targeted molecules were expressed in invading malignant keratinocytes, and all but OPG were expressed in osteoclasts of clinical samples.

CONCLUSIONS

Crosstalk between different cell types appears to exist in the invasion of bone by OSCC. Understanding and ultimately interfering with the molecules involved may provide therapeutic approaches to inhibit such bone invasion.

Mandibular conservation in oral cancer

Surgery is one of the established modes of initial definitive treatment for a majority of oral cancers. Invasion of bony or cartilaginous structures by advanced upper aero-digestive tract cancer has been considered an indication for primary surgery on the basis of historic experience of poor responsiveness to radiation therapy [1]. The mandible is a key structure both in the pathology of intra-oral tumours and their surgical management. It bars easy surgical access to the oral cavity, yet maintaining its integrity is vital for function and cosmesis. Management of tumours that involve or abut the mandible requires specific understanding of the pattern of spread and routes of tumour invasion into the mandible. This facilitates the employment of mandibular sparing approaches like marginal mandibulectomy and mandibulotomy, as opposed to segmental or hemimandibulectomy which causes severe functional problems, as the mandibular continuity is lost. Accurate preoperative assessment that combines clinical examination and imaging along with the understanding of the pattern of spread and routes of invasion is essential in deciding the appropriate level and extent of mandibular resection in oral squamous cell carcinoma. Studies have shown that local control rates achieved with marginal mandibulectomy are comparable with that of segmental mandibulectomy. In carefully selected patients, marginal mandibulectomy is an oncologically safe procedure to achieve good local control and provides a better quality of life. This article aims to review the mechanism of spread, evaluation and prognosis of mandibular invasion, various techniques and role of mandibular conservation in oral squamous cell carcinoma.

Removal of an oral squamous cell carcinoma including parts of osseointegrated implants in the marginal mandibulectomy. A case report

Purpose

The incidence of oral squamous cell carcinomas (OSCC) arising around dental implants will increase because of the rising popularity of dental implants. In this case, a novel surgical treatment of an OSCC in the vicinity of endosseous implants is reported.

Materials and methods

In a 69-year-old woman, a recurrent OSCC (cT₂N₀M₀) developed in the floor of the mouth extending to the attached keratinized peri-implant mucosa of both interforaminal-placed dental implants. Radiographically, no bone invasion could be observed.

Results

To radically remove the tumor, a marginal mandibulectomy was performed including the cranial parts of both dental implants by cutting them into two parts. Three years after tumor resection and one year after reimplantation, the patient is disease free and has a good oral function.

Conclusions

In case of an OSCC, traditional bone and soft margins for oncologic safety are 1.0 cm. If a dental implant is present within this safety zone, on condition, there is no massive bone invasion, and the original mandible has sufficient vertical height; a marginal mandibulectomy including part of the implants can be considered.

Contemporary management of cancer of the oral cavity

Oral cancer represents a common entity comprising a third of all head and neck malignant tumors. The options for curative treatment of oral cavity cancer have not changed significantly in the last three decades; however, the work up, the approach to surveillance, and the options for reconstruction have evolved significantly. Because of the profound functional and cosmetic importance of the oral cavity, management of oral cavity cancers requires a thorough understanding of disease progression, approaches to management and options for reconstruction. The purpose of this review is to discuss the most current management options for oral cavity cancers.