Staging of squamous cell carcinoma of the oral cavity and oropharynx: a comparison of MRI and CT in T- and N-staging

Diagnostic accuracy of contrast-enhanced computed tomography in assessing bone invasion in patients with oral squamous cell carcinoma

OBJECTIVES

This study aimed to evaluate the diagnostic accuracy of contrast-enhanced computed tomography (CT) in detecting bone invasion in oral squamous cell carcinoma (OSCC) patients and to explore clinicopathological factors associated with its reliability.

MATERIALS AND METHODS

417 patients underwent preoperative contrast-enhanced CT followed by radical surgery. The presence or absence of bone invasion served as the outcome variable, with histopathologic examination of the resection specimen considered the gold standard. Statistical analyses, comprising correlation analyses and the determination of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were conducted.

RESULTS

CT exhibited 76.85% sensitivity, 82.20% specificity, 47.14% PPV, and 89.67% NPV. False-positive and false-negative rates were 11.27% and 5.99%, respectively. Artifacts affected assessment in 44 patients, but not in those with bone invasion. Tumor size, depth of invasion (DOI), tumor localization at the upper jaw, lymphatic invasion, and perineural invasion correlated with incorrect identification of bone invasion (Chi-square, p < 0.05).

CONCLUSIONS

Despite utilizing thin-section CT, notable false-positive and false-negative results persisted. Patients with T3 tumors, DOI ≥ 10 mm, or upper jaw tumors are at higher risk for misidentification of bone invasion. Combining multiple methods may enhance diagnostic accuracy, and the integration of artificial intelligence or tracking electrolyte disturbances by tumor depth profiling shows promise for further assessment of bone invasion before histopathology.

CLINICAL RELEVANCE

Surgeons should consider these insights when planning tumor resection. Supplementary imaging may be warranted in cases with high risk factors for misidentification. Further methodological advancements are crucial for enhancing diagnostic precision.

Deep Learning Reconstruction Plus Single-Energy Metal Artifact Reduction for Supra Hyoid Neck CT in Patients With Dental Metals

Purpose: We investigated the effect of deep learning reconstruction (DLR) plus single-energy metal artifact reduction (SEMAR) on neck CT in patients with dental metals, comparing it with DLR and with hybrid iterative reconstruction (Hybrid IR)-SEMAR. Methods: In this retrospective study, 32 patients (25 men, 7 women; mean age: 63 ± 15 years) with dental metals underwent contrast-enhanced CT of the oral and oropharyngeal regions. Axial images were reconstructed using DLR, Hybrid IR-SEMAR, and DLR-SEMAR. In quantitative analyses, degrees of image noise and artifacts were evaluated. In one-by-one qualitative analyses, 2 radiologists evaluated metal artifacts, the depiction of structures, and noise on five-point scales. In side-by-side qualitative analyses, artifacts and overall image quality were evaluated by comparing Hybrid IR-SEMAR with DLR-SEMAR. Results: Artifacts were significantly less with DLR-SEMAR than with DLR in quantitative (P < .001) and one-by-one qualitative (P < .001) analyses, which resulted in significantly better depiction of most structures (P < .004). Artifacts in side-by-side analysis and image noise in quantitative and one-by-one qualitative analyses (P < .001) were significantly less with DLR-SEMAR than with Hybrid IR-SEMAR, resulting in significantly better overall quality of DLR-SEMAR. Conclusions: Compared with DLR and Hybrid IR-SEMAR, DLR-SEMAR provided significantly better supra hyoid neck CT images in patients with dental metals.

Iterative Metal Artifact Reduction in Head and Neck CT Facilitates Tumor Visualization of Oral and Oropharyngeal Cancer Obscured by Artifacts From Dental Hardware

RATIONALE AND OBJECTIVES

The purpose of this study was to evaluate the diagnostic utility of iterative metal artifact reduction (iMAR) in computed tomography (CT)-imaging of oral and oropharyngeal cancers when obscured by dental hardware artifacts and to determine the most appropriate iMAR settings for this purpose.

MATERIALS AND METHODS

The study retrospectively enrolled 27 patients (8 female, 19 male; mean age 64±12.7years) with histologically confirmed oral or oropharyngeal cancer obscured by dental artifacts in contrast-enhanced CT. Raw CT data were reconstructed with ascending iMAR strengths (levels 1/2/3/4/5) and one reconstruction without iMAR (level 0). For subjective analysis, two blinded radiologists rated tumor visualization and artifact severity on a five-point Likert scale. For objective analysis, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and artifact index (AI) were determined.

RESULTS

iMAR reconstructions improved the subjective image quality of tumor edge and contrast, and the objective parameters of tumor SNR and CNR, reaching their optimum at iMAR levels 4 and 5 (P<.001). AI decreased with iMAR reconstructions reaching its minimum at iMAR level 5 (P<.001). Tumor detection rates increased 2.4-fold with iMAR 5, 2.1-fold with iMAR 4, and 1.9-fold with iMAR 3 compared to reconstructions without iMAR. Disadvantages such as algorithm-induced artifacts increased significantly with higher iMAR strengths (P<.05), reaching a maximum with iMAR 5.

CONCLUSION

iMAR significantly improves CT imaging of oral and oropharyngeal cancers, as confirmed by both subjective and objective measures, with best results at highest iMAR strengths.

Magnetic resonance imaging based radiomics prediction of Human Papillomavirus infection status and overall survival in oropharyngeal squamous cell carcinoma

OBJECTIVES

Human papillomavirus- (HPV) positive oropharyngeal squamous cell carcinoma (OPSCC) differs biologically and clinically from HPV-negative OPSCC and has a better prognosis. This study aims to analyze the value of magnetic resonance imaging (MRI)-based radiomics in predicting HPV status in OPSCC and aims to develop a prognostic model in OPSCC including HPV status and MRI-based radiomics.

MATERIALS AND METHODS

Manual delineation of 249 primary OPSCCs (91 HPV-positive and 159 HPV-negative) on pretreatment native T1-weighted MRIs was performed and used to extract 498 radiomic features per delineation. A logistic regression (LR) and random forest (RF) model were developed using univariate feature selection. Additionally, factor analysis was performed, and the derived factors were combined with clinical data in a predictive model to assess the performance on predicting HPV status. Additionally, factors were combined with clinical parameters in a multivariable survival regression analysis.

RESULTS

Both feature-based LR and RF models performed with an AUC of 0.79 in prediction of HPV status. Fourteen of the twenty most significant features were similar in both models, mainly concerning tumor sphericity, intensity variation, compactness, and tumor diameter. The model combining clinical data and radiomic factors (AUC = 0.89) outperformed the radiomics-only model in predicting OPSCC HPV status. Overall survival prediction was most accurate using the combination of clinical parameters and radiomic factors (C-index = 0.72).

CONCLUSION

Predictive models based on MR-radiomic features were able to predict HPV status with sufficient performance, supporting the role of MRI-based radiomics as potential imaging biomarker. Survival prediction improved by combining clinical features with MRI-based radiomics.

Lessons learnt from the global iodinated contrast media shortage in head and neck imaging

A recent shortage in the global supply of iodinated contrast media (ICM) has required health service providers to review their contrast administration policies and implement strategies to conserve inventory. This article will review the current best practices in head and neck imaging for a variety of common presentations and provide examples where alternative imaging can be considered due to the recent ICM shortage. Ultrasound and MRI techniques can feature heavily in many diagnostic processes in head and neck pathology, and a variety of common presentations can be appropriately investigated through clinical evaluation or naso-endoscopy. In many instances, for the routine assessment of non-acute adult and paediatric head and neck presentations, the use of contrast-enhanced CT can be safely minimised to conserve ICM if required.

Increased rate of pseudarthrosis in the anterior intersegmental gap after mandibular reconstruction with fibula free flaps: a volumetric analysis

OBJECTIVES

Pseudarthrosis after mandibular reconstruction leads to chronic overload of the osteosynthesis and impedes dental rehabilitation. This study evaluates the impact of gap site on osseous union in mandible reconstruction using a new volumetric analysis method with repeated cone-beam computed tomography (CBCT).

METHODS

The degree of bone regeneration was evaluated in 16 patients after mandible reconstruction with a fibula free flap and patient-specific reconstruction plates. Percentual bone volume and width changes in intersegmental gaps were retrospectively analyzed using a baseline CBCT in comparison to a follow-up CBCT. Patients' characteristics, plate-related complications, and gap sites (anterior/posterior) were analyzed. Detailed assessments of both gap sites (buccal/lingual/superior/inferior) were additionally performed.

RESULTS

Intersegmental gap width (p = 0.002) and site (p < 0.001) significantly influence bone volume change over two consecutive CBCTs. An initial larger gap width resulted in a lower bone volume change. In addition, anterior gaps showed significantly less bone volume changes. Initial gap width was larger at posterior segmental gaps (2.97 vs 1.65 mm, p = 0.017).

CONCLUSIONS

A methodology framework has been developed that allows to quantify pseuarthrosis in reconstructed mandibles using CBCT imaging. The study identifies the anterior segmental gap as a further risk factor for pseudarthrosis in reconstructions with CAD/CAM reconstruction plates. Future research should evaluate whether this outcome is related to the biomechanics induced at this site.

Detectability of Head and Neck Cancer via New Computed Tomography Reconstruction Tools including Iterative Reconstruction and Metal Artifact Reduction

State-of-the-art technology in Computed Tomography (CT) includes iterative reconstruction algorithms (IR) and metal artefact reduction (MAR) techniques. The objective of the study is to show the benefits of this technology for the detection of primary and recurrent head and neck cancer. A total of 131 patients underwent contrast-enhanced CT for diagnosis of primary and recurrent Head and Neck cancer; 110 patients were included. All scans were reconstructed using iterative reconstruction, and metal artifact reduction was applied when indicated. Tumor detectability was evaluated dichotomously. Histopathological findings were used as a standard of reference. Data were analyzed retrospectively, statistics was performed through diagnostic test characteristics. State-of-the-art Head and Neck CT showed a sensitivity of 0.83 (95% CI; 0.61–0.95) with 0.93 specificity (95% CI; 0.84–0.98) for primary tumor detection. Recurrent tumors were identified with a 0.94 sensitivity (95% CI; 0.71–0.99) and 0.93 specificity (95% CI; 0.84–0.98) in this study. Conclusion: State-of-the-art reconstruction tools improve the diagnostic quality of Head and Neck CT, especially for recurrent tumor detection, compared with data published for standard CT. IR and MAR are easily implemented in routine clinical settings and improve image evaluation by reducing artifacts and image noise while lowering radiation exposure.

Detecting Bone Invasion of the Maxilla by Oral Squamous Cell Carcinoma: Diagnostic Accuracy of Preoperative Computed Tomography Versus Magnetic Resonance Imaging

PURPOSE

For planning of the surgical resection, computed tomography (CT) and magnetic resonance imaging (MRI) are commonly used for the preoperative assessment of bone invasion of the maxilla. The purpose of this study was to compare the diagnostic test accuracy of CT and MRI for detecting bone invasion of the maxilla in patients with squamous cell carcinoma of the maxilla (MSCC).

MATERIALS AND METHODS

We conducted a retrospective cross-sectional study and enrolled a consecutive number of patients with primary MSCC between 2000 and 2017 who underwent either preoperative CT or MRI scans. The outcome variable was the absence or presence of bone invasion, with histopathologic examination of the resection specimen as the gold standard. The predictor variable was the imaging technique (CT and MRI). The imaging results on bone invasion were compared with the histopathologic results. Sensitivity and specificity were calculated, and the 2-sided Fisher exact test was used to calculate statistically significant differences between the unpaired CT and MRI results. Receiver operating characteristic curves were computed, and the area under the curve (AUC) was calculated.

RESULTS

The study included 72 patients (29 male and 43 female patients) with a mean age of 72 years. A total of 41 CT scans and 31 MRI scans were available. Histopathologic examination showed bone invasion in 45 cases: 26 of 41 patients with CT scans (63%) and 19 of 31 patients with MRI scans (61%). CT yielded 2 false-positive and 2 false-negative results, with a sensitivity of 92%, specificity of 87%, and AUC of 0.895. MRI yielded 5 false-positive and 2 false-negative results, with a sensitivity of 89%, specificity of 58%, and AUC of 0.739. No significant differences were observed for sensitivity (P > .999) and specificity (P = .185).

CONCLUSIONS

In the absence of metallic dental restorations, CT could detect bone invasion more accurately than MRI in this study; however, the difference was not statistically significant. The imaging method of choice may depend on other situational factors.

Is integrated 18F-FDG PET/MRI superior to 18F-FDG PET/CT in the differentiation of incidental tracer uptake in the head and neck area?

PURPOSE

We aimed to investigate the accuracy of 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (18F-FDG PET/MRI) compared with contrast-enhanced 18F-FDG PET/computed tomography (PET/CT) for the characterization of incidental tracer uptake in examinations of the head and neck.

METHODS

A retrospective analysis of 81 oncologic patients who underwent contrast-enhanced 18F-FDG PET/CT and subsequent PET/MRI was performed by two readers for incidental tracer uptake. In a consensus reading, discrepancies were resolved. Each finding was either characterized as most likely benign, most likely malignant, or indeterminate. Using all available clinical information including results from histopathologic sampling and follow-up examinations, an expert reader classified each finding as benign or malignant. McNemar's test was used to compare the performance of both imaging modalities in characterizing incidental tracer uptake.

RESULTS

Forty-six lesions were detected by both modalities. On PET/CT, 27 lesions were classified as most likely benign, one as most likely malignant, and 18 as indeterminate; on PET/MRI, 31 lesions were classified as most likely benign, one lesion as most likely malignant, and 14 as indeterminate. Forty-three lesions were benign and one lesion was malignant according to the reference standard. In two lesions, a definite diagnosis was not possible. McNemar's test detected no differences concerning the correct classification of incidental tracer uptake between PET/CT and PET/MRI (P = 0.125).

CONCLUSION

In examinations of the head and neck area, incidental tracer uptake cannot be classified more accurately by PET/MRI than by PET/CT.

Oral leukoplakia and oral cavity squamous cell carcinoma

Oral leukoplakia is defined as a white oral lesion not related to another disease process. These lesions are largely asymptomatic, and the clinical relevance of oral leukoplakia is primarily tied to its association with oral cavity squamous cell carcinoma. Timely workup and effective management of these lesions can reduce the risk of malignant transformation and promote early diagnosis of invasive tumors. A biopsy should be performed promptly of any persistent or suspicious leukoplakia with subsequent management dictated by histologic findings. Benign lesions can be observed or treated with topical therapy, and dysplastic lesions should be excised. Some risk of malignant transformation remains even after treatment, and close follow-up is required. Oral cavity squamous cell carcinoma is an aggressive malignancy that can result from malignant conversion of oral leukoplakia or occur de novo. These tumors are primarily treated with surgical resection and adjuvant radiation or chemoradiation as dictated by histopathologic findings.

Metal artefact reduction for patients with metallic dental fillings in helical neck computed tomography: comparison of adaptive iterative dose reduction 3D (AIDR 3D), forward-projected model-based iterative reconstruction solution (FIRST) and AIDR 3D with single-energy metal artefact reduction (SEMAR)

OBJECTIVES

To compare the differences in metal artefact degree and the depiction of structures in helical neck CT, in patients with metallic dental fillings, among adaptive iterative dose reduction three dimensional (AIDR 3D), forward-projected model-based iterative reconstruction solution (FIRST) and AIDR 3D with single-energy metal artefact reduction (SEMAR-A).

METHODS

In this retrospective clinical study, 22 patients (males, 13; females, 9; mean age, 64.6 ± 12.6 years) with metallic dental fillings who underwent contrast-enhanced helical CT involving the oropharyngeal region were included. Neck axial images were reconstructed with AIDR 3D, FIRST and SEMAR-A. Metal artefact degree and depiction of structures (the apex and root of the tongue, parapharyngeal space, superior portion of the internal jugular chain and parotid gland) were evaluated on a four-point scale by two radiologists. Placing regions of interest, standard deviations of the oral cavity and nuchal muscle (at the slice where no metal exists) were measured and metal artefact indices were calculated (the square root of the difference of the squares of them).

RESULTS

In SEMAR-A, metal artefact was significantly reduced and depictions of all structures were significantly improved compared with those in FIRST and AIDR 3D (p ≤ 0.001, sign test). Metal artefact index for the oral cavity in AIDR 3D/FIRST/SEMAR-A was 572.0/477.7/88.4, and significant differences were seen between each reconstruction algorithm (p < 0.0001, Wilcoxon signed-rank test).

CONCLUSIONS

SEMAR-A could provide images with lesser metal artefact and better depiction of structures than AIDR 3D and FIRST.

Added value of a single-energy projection-based metal-artifact reduction algorithm for the computed tomography evaluation of oral cavity cancers

PURPOSE

The purpose of our study was to investigate the added value of the single-energy projection-based metallic artifact reduction (SEMAR) technique on the visualization and diagnostic confidence of oral cavity cancers.

MATERIALS AND METHODS

Contrast-enhanced CT was performed on 40 patients with dental metalwork. Of these, 18 patients had pathologically confirmed oral cavity cancer, and the other 22 patients had no lesions. CT attenuation and noise in the oral cavity were compared between the conventional and SEMAR images. Two radiologists visually graded the diagnostic confidence on a 5-point scale from 1 (definitely absent) to 5 (definitely present). The value of the SEMAR was assessed in a receiver-operating characteristic curve analysis.

RESULTS

The artifact of the SEMAR images was significantly lower than that of the conventional images (38.4 ± 18.0 HU vs. 187.7 ± 162.7 HU; P < 0.01). Reviewers 1 and 2 detected 10 and 7 more lesions with the SEMAR, respectively. Areas under the curve for the conventional and SEMAR reconstruction were 0.761 and 0.942, respectively, for reviewer 1 and 0.701 and 0.864, respectively, for reviewer 2.

CONCLUSION

The SEMAR significantly improved the oral cavity cancer visualization and diagnostic confidence.

Locoregional tumour evaluation of squamous cell carcinoma in the head and neck area: a comparison between MRI, PET/CT and integrated PET/MRI

PURPOSE

To evaluate the accuracy of integrated (18)F-FDG PET/MR imaging for locoregional tumour evaluation compared to (18)F-FDG PET/CT and MR imaging in initial tumour and recurrence diagnosis in histopathologically confirmed head and neck squamous cell carcinoma (HNSCC).

METHODS

(18)F-FDG PET/CT and integrated (18)F-FDG PET/MR imaging were performed for initial tumour staging or recurrence diagnosis in 25 patients with HNSCC. MR, fused (18)F-FDG PET/CT and fused (18)F-FDG PET/MR images were analysed by two independent readers in separate sessions in random order. In initial tumour staging, T and N staging was performed while individual lesions were analysed in patients with suspected cancer recurrence. In T and N staging, histopathological results after tumour resection served as the reference standard while histopathological sampling as well as cross-sectional and clinical follow-up were accepted in cancer recurrence diagnosis. The diagnostic accuracy of each modality was calculated separately for T and N staging as well as for tumour recurrence, and compared using McNemar's test. Values of p <0.017 were considered statistically significant after Bonferroni correction.

RESULTS

In 12 patients undergoing (18)F-FDG PET/CT and (18)F-FDG PET/MR for initial tumour staging, T staging was accurate in 50 % with MRI, in 59 % with PET/CT and in 75 % with PET/MR while N staging was accurate in 75 % with MRI, in 77 % with PET/CT and in 71 % with PET/MR in relation to the reference standard. No significant differences were observed in T and N staging among the three modalities (p > 0.017). In 13 patients undergoing hybrid imaging for cancer recurrence diagnosis, diagnostic accuracy was 57 % with MRI and in 72 % with (18)F-FDG PET/CT and (18)F-FDG PET/MR, respectively. Again, no significant differences were found among the three modalities (p > 0.017).

CONCLUSION

In this initial study, no significant differences were found among (18)F-FDG PET/MR, (18)F-FDG PET/CT and MRI in local tumour staging and cancer recurrence diagnosis.

Ultrashort echo time (UTE) MRI for the assessment of caries lesions

OBJECTIVE

Direct in vivo MRI of dental hard tissues by applying ultrashort echo time (UTE) MRI techniques has recently been reported. The objective of the presented study is to clinically evaluate the applicability of UTE MRI for the identification of caries lesions.

METHODS

40 randomly selected patients (mean age 41 ± 15 years) were enrolled in this study. 39 patients underwent a conventional clinical assessment, dental bitewing X-ray and a dental MRI investigation comprising a conventional turbo-spin echo (TSE) and a dedicated UTE scan. One patient had to be excluded owing to claustrophobia. In four patients, the clinical treatment of the lesions was documented by intraoral pictures, and the resulting volume of the cavity after excavation was documented by dental imprints and compared with the MRI findings.

RESULTS

In total, 161 lesions were identified. 157 (97%) were visible in the UTE images, 27 (17%) in the conventional TSE images and 137 (85%) in the X-ray images. In total, 14 teeth could not be analysed by MR owing to artefacts caused by dental fillings. All lesions appear significantly larger in the UTE images as compared with the X-ray and TSE images. In situ measurements confirm the accuracy of the lesion dimensions as observed in the UTE images.

CONCLUSION

The presented data provide evidence that UTE MR imaging can be applied for the identification of caries lesions. Although the current data suggest an even higher sensitivity of UTE MRI, some limitations must be expected from dental fillings.

Modification of staging and treatment of head and neck cancer by FDG-PET/CT prior to radiotherapy

BACKGROUND AND PURPOSE

Reliable tumor staging is a fundamental pre-requisite for efficient tumor therapy and further prognosis. The aim of this study was to compare head and neck cancer (HNC) staging before and after FDG-PET/CT, evaluating the stage modifications for radiotherapy (RT) planning.

PATIENTS AND METHODS

A total of 102 patients with untreated primary HNC, who underwent conventional staging and staging including FDG-PET/CT before RT, were enrolled in this retrospective study. Blinded pre-FDG-PET/CT and post-FDG-PET/CT staging data were compared. The impact on patient management was tested by comparing the intention before and after FDG-PET/CT.

RESULTS

Significant modifications of T, N, and M stage as well as clinical stage were detected after inclusion of FDG-PET/CT data (p = 0.002, 0.0006, 0.001, 0.03, respectively). Overall, the implementation of FDG-PET/CT led to modification of RT intention decision in 14 patients.

CONCLUSIONS

FDG-PET/CT demonstrates essential influence on tumor staging in HNC patients scheduled for irradiation. Implementation of FDG-PET/CT in imaging protocol improves selection of candidates for curative and palliative RT and allows further optimization of treatment management and therapy intention.

Transoral resection of pharyngeal cancer: summary of a National Cancer Institute Head and Neck Cancer Steering Committee Clinical Trials Planning Meeting, November 6-7, 2011, Arlington, Virginia

Recent advances now permit resection of many pharyngeal tumors through the open mouth, an approach that can greatly reduce the morbidity of surgical exposure. These transoral techniques are being rapidly adopted by the surgical community and hold considerable promise. On November 6-7, 2011, the National Cancer Institute sponsored a Clinical Trials Planning Meeting to address how to further investigate the use of transoral surgery, both in the good prognosis human papillomavirus (HPV)-initiated oropharyngeal cancers, and in those with HPV-unrelated disease. The proceedings of this meeting are summarized.

The diagnosis and treatment of oral cavity cancer

BACKGROUND

About 10,000 persons are diagnosed as having carcinoma of the oral cavity or the throat in Germany every year. Squamous-cell carcinoma accounts for 95% of cases.

METHODS

We systematically reviewed the pertinent literature on predefined key questions about these tumors (which were agreed upon by a consensus of the investigators), concerning imaging, the removal of cervical lymph nodes, and resection of the primary tumor.

RESULTS

246 clinical trials were selected for review on the basis of 3014 abstracts. There was only one randomized, controlled trial (evidence level 1-); the remaining trials reached evidence levels 2++ to 3. Patients with mucosal changes of an unclear nature persisting for more than two weeks should be examined by a specialist without delay. The diagnosis is made by computed tomography or magnetic resonance imaging along with biopsy and a standardized histopathological examination. Occult metastases are present in 20% to 40% of cases. Advanced disease (stages T3 and T4) should be treated by surgery followed by radiotherapy, with or without chemotherapy. 20% of the patients overall go on to have a recurrence, usually within 2 to 3 years of the initial treatment. The 5-year survival rate is somewhat above 50%. Depending on the radicality of surgery and radiotherapy, there may be functional deficits, osteoradionecrosis, and xerostomia. The rate of loss of implants in irradiated bone is about 10% in 3 years.

CONCLUSION

The interdisciplinary planning and implementation of treatment, based on the patient's individual constellation of findings and personal wishes, are prerequisites for therapeutic success. Reconstructive measures, particularly microsurgical ones, have proven their usefulness and are an established component of surgical treatment.

cTNM vs. pTNM: the effect of not applying ultrasonography in the identification of cervical nodal disease

Accurate clinical staging of oral squamous cell cancer can be quite difficult to achieve especially if nodal involvement is identified. Radiologically-assisted clinical staging is more accurate and informs the clinician of loco-regional and distant metastasis.In this study, we compared clinical TNM (cTNM) staging (not including ultrasonography) to pathological TNM (pTNM) staging in 245 patients presenting with carcinoma of the oral cavity and the oro-pharyngeal region. Tumour size differences and nodal involvement were highlighted. US reports of the neck were then added to the clinical staging and results compared.Tumour size was clinically underestimated in 4 T1, 2 T2 and 2 T3 oral diseases. Also 20 patients that were reported as nodal disease free had histological proven N1 or N2 nodal involvement; while 3 patients with cTNM showing N1 disease had histologically proven N2 disease.Overall the agreement between the 2 systems per 1 site was 86.6% (Kappa agreement = 0.80), per 2 sites 90.0% (Kappa agreement = 0.68) and per 3 sites 90.5% (Kappa agreement 0.62).An accurate clinical staging is of an utmost importance. It is the corner stone in which the surgical team build the surgical treatment plan and decide whether an adjuvant therapy is required to deal with any possible problem that might arise. The failure to achieve an accurate staging may lead to incomplete surgical planning and hence unforeseen problems that may adversely affect the patient's survival.

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.

CT assessment of the correlation between clinical examination and bone involvement in oral malignant tumors

Oral cancers have a tendency to invade the surrounding bone structures, and this has a direct influence on the treatment management and on outcomes. The objective of this study was to correlate the clinical parameters (location, clinical presentation and TNM staging) of oral malignant tumors that can be associated with a potential of bone invasion and determine the accuracy of clinical examination to predict bone involvement, using computed tomography (CT). Twenty five patients, with oral malignant tumors were submitted to clinical and CT examinations. CT was considered the standard parameter to evaluate the presence of bone involvement. Clinical assessment of location, presentation form and TNM staging of the tumors were then compared to the CT findings in predicting bone involvement. Bone involvement was observed in 68% of the cases. It was predicted that tumors located in the retromolar trigone and hard palate, with a clinical aspect of infiltrative ulcer or nodule and classified in stage IV had a high potential to cause bone involvement. The clinical examination assessment of these tumors showed to be a valuable tool to predict bone invasion, with high sensitivity (82%) and specificity (87.5%), based on the results found in the CT images. No statistical significance was found between the CT and clinical examinations regarding bone involvement. The identification of some clinical parameters such as location, clinical presentation, and TNM stage, associated with a detailed clinical examination, was considered a valuable tool for the assessment of bone destruction by oral malignant tumors.

Freedom from local and regional failure of contralateral neck with ipsilateral neck radiotherapy for node-positive tonsil cancer: results of a prospective management approach

PURPOSE

To review the outcomes of a prospective management approach using ipsilateral neck radiotherapy in the treatment of node-positive squamous cell carcinoma of the tonsil with a well-lateralized primary lesion.

METHODS AND MATERIALS

Between August 2003 and June 2007, 20 patients who presented with squamous cell carcinoma of the tonsil, without involvement of the base of the tongue or midline soft palate, and with Stage N1-N2b disease were prospectively treated with radiotherapy to the primary site and ipsilateral neck. In addition, 18 patients received concurrent chemotherapy. The actuarial freedom from contralateral nodal and in-field progression was determined. Acute and late toxicity were prospectively evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 3, and Radiation Therapy Oncology Group criteria.

RESULTS

The nodal disease was Stage N1 in 4 patients, N2a in 3 patients, and N2b in 13 patients. At a median follow-up 19 months (range, 12-40), no in-field or contralateral nodal recurrences had been observed. The 2-year freedom from distant metastasis rate was 87.4%. The actuarial 2-year disease-free and overall survival rates were both 79.5%. Late Radiation Therapy Oncology Group grade 2 xerostomia occurred in 1 patient (5%). No late Grade 3 or greater toxicity was observed. No patient was feeding tube dependent at their last follow-up visit.

CONCLUSION

In carefully selected patients with node-positive, lateralized tonsillar cancer, treatment of the ipsilateral neck and primary site does not appear to increase the risk of contralateral nodal failure and reduces late morbidity compared with historical controls. Although the outcomes with ipsilateral radiotherapy in the present series were promising, these findings require longer follow-up and validation in a larger patient cohort.

[Tumors of the oropharynx and oral cavity: MR, CT, PET-CT imaging]

Pretherapeutic imaging plays a central role in the management of tumors of the oropharynx and oral cavity. MR and, to a lesser extent, CT and F-18 FDG PET-CT are the imaging modalities of choice for pretherapeutic work-up of these lesions. Imaging protocols should be simple and reproducible, and should provide the key elements for treatment planning.

Patterns of locoregional failure after exclusive IMRT for oropharyngeal carcinoma

PURPOSE

To assess the patterns of failure after intensity-modulated radiotherapy (IMRT) for oropharyngeal squamous cell carcinoma (SCC).

METHODS AND MATERIALS

We analyzed patients treated at the University of Texas Medical Branch between May 2002 and February 2006 who met the following criteria: (1) definitive IMRT without chemotherapy for oropharyngeal SCC; (2) no pretreatment radical surgery; (3) minimal follow-up of 1 year. The location of each nodal/primary failure was co-registered to the pretreatment planning computed tomography scan and then expanded by 5 mm to a planning target volume (PTV) of the failure (PTV-f). We then investigated whether the prescription dose to the PTV-f had been appropriate for the amount of disease present before treatment and whether the PTV-f had been adequately covered.

RESULTS

A total of 50 patients were eligible. With a median follow-up of 32.6 months (range, 12.1-58.6), three local and six regional failures were observed in 8 patients. All but one failure, that had been neglected, were recorded within 14 months of the treatment end. Of the nine failures, four developed in the neck treated electively to the lowest dose level; in all of them, we could retrospectively identify initial positive lymph nodes that might have justified the subsequent failure. The remaining five failures developed in proximity of the high-dose volume. In all but one, the volume of region of interest receiving >/=95% of the dose of the PTV-f was >95%, suggesting adequate coverage. In 1 patient, about 20% of PTV-f was outside the 95% isodose, so that marginal underdosing could not be ruled out.

CONCLUSIONS

A potential cause could be identified in all the failures in the lowest dose level. The implications and possible remedies are discussed. Most failures around the high-dose region were "true failures" with no apparent technical cause.

Detection of cutaneous invasion by malignant head and neck tumors with MDCT

OBJECTIVE

Cutaneous invasion by direct infiltration and metastasis, in malignant head and neck tumors, has a distinct impact on therapeutic options, especially surgical procedures, curative intent, and overall prognosis. Therefore, the purpose of this study was to determine the diagnostic accuracy of MDCT in detecting cutaneous invasion by malignant head and neck tumors.

MATERIALS AND METHODS

Nineteen patients with malignant head and neck tumors and clinical suspicion of cutaneous invasion routinely underwent contrast-enhanced 16-row MDCT (Philips MDCT MX 8000) of the region of interest in the axial plane before surgical intervention. The following parameters were used: 16mmx0.75mm detector collimation; 3mm reconstructed slice thickness; 1.5mm increment; 0.75s rotation speed; 120kV, 200mAs; and 100ml non-ionic contrast agent, i.v., with a flow of 2.0ml/s and a scan delay of 50s. The studies were reconstructed with a soft tissue algorithm (W400, L100 HU), and coronal and sagittal planes were also reconstructed. The axial images were retrospectively reviewed in consensus by two radiologists for the evidence of cutaneous invasion blinded to the histological results. The MDCT results were correlated with histology that was obtained by punch biopsy or surgery.

RESULTS

MDCT correctly revealed 11 of 11 cases with cutaneous invasion, and correctly excluded 4 of 8 cases without cutaneous invasion. The diagnostic accuracy of MDCT in detecting cutaneous invasion showed a sensitivity of 100%, a specificity of 50%, and an overall accuracy of 79%.

CONCLUSION

MDCT reconstructed with a soft tissue algorithm has a good sensitivity and moderate overall accuracy in detecting cutaneous invasion by malignant head and neck tumors.

Imaging of oral cancer

This article reviews imaging modalities commonly used to evaluate oral cavity cancers and their metastases to lymph nodes. It discusses how the studies are performed and their relative merits. It also presents new techniques for evaluating these neoplasms.

Advanced imaging applied to radiotherapy planning in head and neck cancer: a clinical review

Head and neck squamous cell carcinoma represents an ideal model to investigate the application of recent advances in medical imaging to radiotherapy planning. Tumours usually remain localized, and are potentially curable with local radiation. The steep radiation dose-response relationships support the strategies of radiation dose escalation to increase local control. Two-dimensional simulator-based planning and CT planning have significant drawbacks in terms of accurate target volume definition. MRI has enhanced soft tissue delineation, but has to be fused with CT to allow dose calculation. Functional imaging using dynamic contrast enhanced CT or MRI sequences may allow improved knowledge of tumour function. Positron emission tomography (PET) may allow further physiological information to be determined. This review summarizes the current techniques in clinical development in this area.

Comparison of 16-slice MSCT and MRI in the assessment of squamous cell carcinoma of the oral cavity

The goal of this retrospective study was to assess the accuracy of 16-slice multislice CT (MSCT) and MRI in staging of patients with primary squamous cell carcinoma (SCC) of the oral cavity. Fifty-two patients with histologically proven primary SCC were examined with contrast enhanced MSCT and MRI at 1.5 T with a combined head and surface neck coil. Image modalities were evaluated in a blinded fashion by two radiologists and an oral-maxillofacial surgeon in consensus concerning tumour depiction, local tumour infiltration and cervical lymph node metastases. Results of the radiological assessment were correlated with the intraoperative and histopathological findings in all patients. 36 of 52 primary tumours (69.2%) were depicted by MSCT while 44 were localized by MRI (84.6%). Regarding muscle infiltration MRI versus MSCT had a sensitivity of 81.8% versus 72.7%, but a low specificity and an accuracy of 63.4% versus 61% and 67.3% versus 63.5%, respectively, were found. There was a trend towards a better detection of bony infiltration by MRI than MSCT with a sensitivity of 100% versus 71.4%, a specificity of 93.3% versus 95.5% and an accuracy 94.2% versus 92.3%, respectively. Detection of cervical lymph node involvement was similar for MRI and MSCT with a sensitivity of 84.2% and 78.9%, a specificity of 63.6% and 75.7% and an accuracy of 71.1% and 76.9%, respectively. For N-staging both methods failed to detect small metastasis. For T-staging MRI was superior to MSCT, because there was a tendency to underestimate the tumour size by MSCT more often (19.4% versus 6.8% by MRI). Therefore, pre-operative MRI is recommended as the basic imaging modality of choice for treatment planning of oral SCC. MSCT is a valid alternative imaging method especially in cases with low patient compliance.

Image fusion between 18FDG-PET and MRI/CT for radiotherapy planning of oropharyngeal and nasopharyngeal carcinomas

PURPOSE

Accurate diagnosis of tumor extent is important in three-dimensional conformal radiotherapy. This study reports the use of image fusion between (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET) and magnetic resonance imaging/computed tomography (MRI/CT) for better targets delineation in radiotherapy planning of head-and-neck cancers.

METHODS AND MATERIALS

The subjects consisted of 12 patients with oropharyngeal carcinoma and 9 patients with nasopharyngeal carcinoma (NPC) who were treated with radical radiotherapy between July 1999 and February 2001. Image fusion between 18FDG-PET and MRI/CT was performed using an automatic multimodality image registration algorithm, which used the brain as an internal reference for registration. Gross tumor volume (GTV) was determined based on clinical examination and 18FDG uptake on the fusion images. Clinical target volume (CTV) was determined following the usual pattern of lymph node spread for each disease entity along with the clinical presentation of each patient.

RESULTS

Except for 3 cases with superficial tumors, all the other primary tumors were detected by 18FDG-PET. The GTV volumes for primary tumors were not changed by image fusion in 19 cases (89%), increased by 49% in one NPC, and decreased by 45% in another NPC. Normal tissue sparing was more easily performed based on clearer GTV and CTV determination on the fusion images. In particular, parotid sparing became possible in 15 patients (71%) whose upper neck areas near the parotid glands were tumor-free by 18FDG-PET. Within a mean follow-up period of 18 months, no recurrence occurred in the areas defined as CTV, which was treated prophylactically, except for 1 patient who experienced nodal recurrence in the CTV and simultaneous primary site recurrence.

CONCLUSION

This preliminary study showed that image fusion between 18FDG-PET and MRI/CT was useful in GTV and CTV determination in conformal RT, thus sparing normal tissues.

Single-bolus technique for spiral CT of laryngopharyngeal squamous cell carcinoma: comparison of different contrast material volumes, flow rates, and start delays

PURPOSE

To evaluate different contrast material volumes, flow rates, and start delays for contrast material enhancement of neck structures and squamous cell carcinoma to determine the most effective examination protocol.

MATERIALS AND METHODS

Seventy patients with squamous cell carcinoma were prospectively randomized into four groups for examination with different protocols (125 mL of contrast material administered at a flow rate of 2.5 mL/sec, 100 mL at 2.0 mL/sec, 90 mL at 1.5 mL/sec, or 70 mL at 1.0 mL/sec). Dynamic series were performed on the tumors and relevant anatomic structures to obtain time-attenuation curves. The protocols were compared (analysis of variance and Tukey-Kramer tests) with regard to time and level of maximum tumor enhancement and carotid arterial enhancement of more than 150 HU. One selected protocol was tested in 30 additional routine examinations with start delays of 40 seconds (for laryngeal and/or hypopharyngeal tumors, 3-mm collimation) and 45 seconds (for oropharyngeal tumors, 5-mm collimation).

RESULTS

Except for the 70-mL bolus administered at 1.0 mL/sec, the other protocols performed similarly well, yielding comparable maximum tumor enhancement at 52 seconds and later. In spite of a smaller volume of 90 mL, due to the prolonged flow time at 1.5 mL/sec, carotid arterial enhancement of more than 150 HU was prolonged (when compared with that in 100- or 125-mL protocols). As a result of these circumstances, injection of 90 mL at 1.5 mL/sec was considered more effective, providing no significant differences in tumor (P =.39) or carotid arterial (P =.52) enhancement between routine examinations and dynamic series.

CONCLUSION

A single bolus of 90 mL administered at 1.5 mL/sec appears to be the most desirable protocol for contrast enhancement.

MRI of the teeth

The teeth and periapical structures were demonstrated on MRI using an open MRI system. There was good visualization of normal structures including crowns of teeth, pulp chambers and the neurovascular bundle of the inferior dental nerve. Dental and periapical pathology was shown.

Oral cavity and oropharynx

Cross-sectional imaging has become an essential element in the evaluation of disease processes involving the oral cavity and oropharynx. This article is an overview of the anatomy and typical pathology of the these areas. The radiologist, working in conjunction with the physical examination and the clinical evaluation of a careful head and neck surgeon, can provide information that is critical to the treatment of patients with oral cavity and oropharyngeal disease.