PET and PET/CT of the Neck Lymph Nodes Improves Risk Prediction in Patients with Squamous Cell Carcinoma of the Oral Cavity

Development and Validation of a 3D Resnet Model for Prediction of Lymph Node Metastasis in Head and Neck Cancer Patients

The accurate diagnosis and staging of lymph node metastasis (LNM) are crucial for determining the optimal treatment strategy for head and neck cancer patients. We aimed to develop a 3D Resnet model and investigate its prediction value in detecting LNM. This study enrolled 156 head and neck cancer patients and analyzed 342 lymph nodes segmented from surgical pathologic reports. The patients' clinical and pathological data related to the primary tumor site and clinical and pathology T and N stages were collected. To predict LNM, we developed a dual-pathway 3D Resnet model incorporating two Resnet models with different depths to extract features from the input data. To assess the model's performance, we compared its predictions with those of radiologists in a test dataset comprising 38 patients. The study found that the dimensions and volume of LNM + were significantly larger than those of LNM-. Specifically, the Y and Z dimensions showed the highest sensitivity of 84.6% and specificity of 72.2%, respectively, in predicting LNM + . The analysis of various variations of the proposed 3D Resnet model demonstrated that Dual-3D-Resnet models with a depth of 34 achieved the highest AUC values of 0.9294. In the validation test of 38 patients and 86 lymph nodes dataset, the 3D Resnet model outperformed both physical examination and radiologists in terms of sensitivity (80.8% compared to 50.0% and 91.7%, respectively), specificity(90.0% compared to 88.5% and 65.4%, respectively), and positive predictive value (77.8% compared to 66.7% and 55.0%, respectively) in detecting individual LNM + . These results suggest that the 3D Resnet model can be valuable for accurately identifying LNM + in head and neck cancer patients. A prospective trial is needed to evaluate further the role of the 3D Resnet model in determining LNM + in head and neck cancer patients and its impact on treatment strategies and patient outcomes.

Diagnostic Accuracy of Up-Front PET/CT and MRI for Detecting Cervical Lymph Node Metastases in T1-T2 Oral Cavity Cancer-A Prospective Cohort Study

The diagnostic accuracy of up-front 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for detecting cervical lymph node metastases in patients with T1-T2 oral squamous cell carcinoma is reported with large discrepancies across the literature. We investigated the sensitivity, specificity, positive and negative predictive value, and accuracy of up-front PET/CT for detecting cervical lymph node metastases in this patient group and compared the performance to magnetic resonance imaging (MRI). In this prospective cohort study, 76 patients with T1-T2 oral squamous cell carcinoma underwent an up-front PET/CT and MRI at the Odense University Hospital from September 2013 to February 2016. Sentinel node biopsy and elective neck dissection were used for histopathological verification of the imaging modalities. Up-front PET/CT was significantly more sensitive than neck MRI (74% vs. 27%, p = 0.0001), but less specific (60% vs. 88%, p = 0.001). The accuracy of PET/CT and neck MRI was comparable (66% vs. 63%, p = 0.85), the PPV was slightly in favor of neck MRI (56% vs. 62%, p = 0.73), the NPV was slightly in favor of PET/CT (77% vs. 63%, p = 0.16). Neither PET/CT nor neck MRI should stand alone for N-staging T1-T2 oral cavity cancer.

The Prognostic and Diagnostic Value of [18F]FDG PET/CT in Untreated Laryngeal Carcinoma

This study aims to determine the diagnostic accuracy of staging PET/CT and neck MRI in patients with laryngeal carcinoma and to assess the value of PET/CT in predicting progression-free survival (PFS) and overall survival (OS). Sixty-eight patients who had both modalities performed before treatment between 2014 and 2021 were included in this study. The sensitivity and specificity of PET/CT and MRI were evaluated. PET/CT had 93.8% sensitivity, 58.3% specificity, and 75% accuracy for nodal metastasis, whereas MRI had 68.8%, 61.1%, and 64.7% accuracy, respectively. At a median follow-up of 51 months, 23 patients had developed disease progression and 17 patients had died. Univariate-survival analysis revealed all utilized PET parameters as significant prognostic factors for OS and PFS (p-value < 0.03 each). In multivariate analysis, metabolic-tumor volume (MTV) and total lesion glycolysis (TLG) predicted better PFS (p-value < 0.05 each). In conclusion, PET/CT improves the accuracy of nodal staging in laryngeal carcinoma over neck MRI and adds to the prognostication of survival outcomes through the use of several PET metrics.

Improved prognostic stratification of patients with pN3b oral cavity cancer based on maximum standardized uptake value of metastatic nodes, lymph node ratio, and level of cervical nodal metastases

OBJECTIVES

The prognosis of pN3b oral cavity squamous cell carcinoma (OCSCC) remains heterogeneous. We sought to improve the prognostic stratification of patients with pN3b OCSCC through a combined analysis of FDG-PET parameters and clinicopathological risk factors (RFs).

METHODS

From 2001 to 2019, complete data on maximum standardized uptake values derived from FDG-PET of neck metastatic nodes (SUV-nodal-max) and clinicopathological RFs were available for 257 patients with pN3b disease.

RESULTS

Using the 5-year disease-free survival (DFS) as the outcome of interest, the optimal cutoff points for SUV-nodal-max and lymph node ratio (LNR) were 15.9 and 0.17, respectively. The 5-year DFS rates/(number of cases) for patients with pN3b disease were as follows: SUV-nodal-max < 15.9 versus ≥ 15.9, 49%(226)/21%(31), p = 0.000003; LNR < 0.17 versus ≥ 0.17, 49%(230)/17%(27), p = 0.000117; absence versus presence of neck level IV/V metastases, 49%(230)/15%(27), p = 0.000004. Multivariable analyses revealed that SUV-nodal-max ≥ 15.9, LNR ≥ 0.17, and level IV/V metastases were independent prognosticators for 5-year distant metastases (DM), DFS, disease-specific survival (DSS), and overall survival (OS) rates. Based on these variables, we devised a scoring system that identified three distinct prognostic subgroups at low (score 0, n = 190), intermediate (score 1, n = 51), and high (scores 2-3, n = 16) risk. The 5-year rates of patients with pN3b disease deemed to be at low/intermediate/high risk were as follows: DM, 31%/52%/89%; DFS, 54%/26%/0%; DSS, 59%/36%/8%; OS, 42%/31%/6%, respectively; all p < 0.001.

CONCLUSIONS

A scoring system based on SUV-nodal-max, LNR, and level IV/V metastases improves the prognostic stratification of OCSCC patients with pN3b disease.

The Clinical Potential of Oral Microbiota as a Screening Tool for Oral Squamous Cell Carcinomas

Introduction

The oral squamous cell carcinoma (OSCC) is detrimental to patients’ physical and mental health. The prognosis of OSCC depends on the early diagnosis of OSCC in large populations.

Objectives

Here, the present study aimed to develop an early diagnostic model based on the relationship between OSCC and oral microbiota.

Methods

Overall, 164 samples were collected from 47 OSCC patients and 48 healthy individuals as controls, including saliva, subgingival plaque, the tumor surface, the control side (healthy mucosa), and tumor tissue. Based on 16S rDNA sequencing, data from all the five sites, and salivary samples only, two machine learning models were developed to diagnose OSCC.

Results

The average diagnostic accuracy rates of five sites and saliva were 98.17% and 95.70%, respectively. Cross-validations showed estimated external prediction accuracies of 96.67% and 93.58%, respectively. The false-negative rate was 0%. Besides, it was shown that OSCC could be diagnosed on any one of the five sites. In this model, Actinobacteria, Fusobacterium, Moraxella, Bacillus, and Veillonella species exhibited strong correlations with OSCC.

Conclusion

This study provided a noninvasive and inexpensive way to diagnose malignancy based on oral microbiota without radiation. Applying machine learning methods in microbiota data to diagnose OSCC constitutes an example of a microbial assistant diagnostic model for other malignancies.

Sentinel Lymph Node Biopsy in Early Stages of Oral Squamous Cell Carcinoma Using the Receptor-Targeted Radiotracer 99mTc-Tilmanocept

Neck management in patients with early-stage, clinically node-negative oral squamous cell carcinoma (OSCC) remains a matter of discussion. Sentinel lymph node biopsy (SLNB) represents a treatment alternative to avoid elective neck dissection (END) in this cohort and different protocols and tracers exist. Here we present the clinical outcome of SLNB using ^99mTc-tilmanocept in a two-day protocol in patients suffering from early-stage OSCC. A total of 13 patients (males: 6; females: 7; mean age: 65.7 years, ranging from 47 to 89 years) were included in this study. Most of the patients suffered from an OSCC of the floor of mouth (n = 6), followed by tongue (n = 5) and upper alveolar crest/hard palate (n = 2). Sentinel lymph nodes (SLNs) were successfully identified in all cases (range: 1–7). The average length of hospital stay was 4.7 days (range: 3–8 days) and mean duration of surgical intervention was 121 min (range: 74–233 min). One patient who suffered from an OSCC of the tongue was sentinel lymph node positive (SLN+). The mean follow-up for all sentinel lymph node negative (SLN-) patients (n = 12) was 20.3 months (range: 10–28 months). No local or nodal recurrences were observed within the observation period. In our patient cohort, SLNB using ^99mTc-tilmanocept in a two-day protocol proved to be a reliable and safe staging method for patients suffering from early-stage, clinically node-negative OSCC. These results and their possible superiority to colloid tracers have to be confirmed in a prospective randomized controlled study.

Cervical Lymph Node Metastases in Oral Squamous Cell Carcinoma-How Much Imaging Do We Need?

Cervical lymph node metastases in oral squamous cell carcinoma (OSCC) are key predictors of disease specific survival. It was therefore the aim of this study to evaluate how much imaging is minimally needed for reliable and efficient identification of cervical lymph node metastases. In this retrospective cross-sectional study, results (metastasis yes/no) of ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) were compared to the final histopathological results of the corresponding neck dissection (ND) specimens (metastasis yes/no). A score was calculated to account for cervical lymph node size, shape, clustering, peripheral enhancement, hilus sign, architecture, blood flow, and central necrosis. Sensitivity and specificity were analyzed for each imaging technique separately. In 164 patients diagnosed with OSCC, 96 underwent uni- or bilateral ND (122 ND in total). One hundred percent sensitivity was achieved by CT+MRI, MRI+PET, US+CT+MRI, US+MRI+PET, CT+MRI+PET, and US+CT+MRI+PET. The highest specificity was realized by US with 79% (95% CI [0.698–0.890]). Specificity for CT+MRI and PET+MRI was 51% (95% CI [0.359–0.665]) and 70% (95% CI [0.416–0.984]), respectively. Regarding 100% sensitivity with acceptable specificity, the combination of CT+MRI or PET+MRI appeared to be suitable for staging cervical lymph nodes in primary OSCC.

Significance of SUV Max for Predicting Occult Lymph Node Metastasis and Prognosis in Early-Stage Tongue Squamous Cell Carcinoma

Objective

Our goal was to clarify the significance of SUV max for predicting occult lymph node metastasis and prognosis in early-stage tongue squamous cell carcinoma (SCC).

Methods

cT1-2N0 tongue SCC patients who underwent a preoperative PET-CT examination were prospectively enrolled. The association between SUV max and occult lymph node metastasis was analyzed. The main study endpoint was locoregional control (LRC). The Cox model was used to determine the independent factors.

Results

A total of 120 patients were included for analysis, and the median SUV max was 9.7. In 60 patients with an SUV max ≤9.7, 5 patients had occult metastasis; in 60 patients with an SUV max >9.7, 13 patients had occult metastasis, and the difference was significant (p=0.041). In patients with an SUV max ≤9.7, the 5-year LRC rate was 93%; in patients with an SUV max >9.7, the 5-year LRC rate was 81%, and the difference was significant (p=0.045).

Conclusion

An SUV max >9.7 was a marker for occult lymph node metastasis and could decrease LRC in patients with cT1-2N0 tongue SCC.

A combined analysis of maximum standardized uptake value on FDG-PET, genetic markers, and clinicopathological risk factors in the prognostic stratification of patients with resected oral cavity squamous cell carcinoma

OBJECTIVE

Clinical outcomes of patients with resected oral cavity squamous cell carcinoma (OCSCC) chiefly depend on the presence of specific clinicopathological risk factors (RFs). Here, we performed a combined analysis of FDG-PET, genetic markers, and clinicopathological RFs in an effort to improve prognostic stratification.

METHODS

We retrospectively reviewed the clinical records of 2036 consecutive patients with first primary OCSCC who underwent surgery between 1996 and 2016. Of them, 345 underwent ultra-deep targeted sequencing (UDTS, between 1996 and 2011) and 168 whole exome sequencing (WES, between 2007 and 2016). Preoperative FDG-PET imaging was performed in 1135 patients from 2001 to 2016. Complete data on FDG-PET, genetic markers, and clinicopathological RFs were available for 327 patients.

RESULTS

Using log-ranked tests based on 5-year disease-free survival (DFS), the optimal cutoff points for maximum standardized uptake values (SUV-max) of the primary tumor and neck metastatic nodes were 22.8 and 9.7, respectively. The 5-year DFS rates were as follows: SUVtumor-max ≥ 22.8 or SUVnodal-max ≥ 9.7 (n = 77) versus SUVtumor-max < 22.8 and SUVnodal-max < 9.7 (n = 250), 32%/62%, P < 0.001; positive UDTS or WES gene panel (n = 64) versus negative (n = 263), 25%/62%, P < 0.001; pN3b (n = 165) versus pN1-2 (n = 162), 42%/68%, P < 0.001. On multivariate analyses, SUVtumor-max ≥ 22.8 or SUVnodal-max ≥ 9.7, a positive UDTS/WES gene panel, and pN3b disease were identified as independent prognosticators for 5-year outcomes. Based on these variables, we devised a scoring system that identified four distinct prognostic groups. The 5-year rates for patients with a score from 0 to 3 were as follows: loco-regional control, 80%/67%/47%/24% (P < 0.001); distant metastases, 13%/23%/55%/92% (P < 0.001); DFS, 74%/58%/28%/7% (P < 0.001); and disease-specific survival, 80%/64%/35%/7% (P < 0.001) respectively.

CONCLUSIONS

The combined assessment of tumor and nodal SUV-max, genetic markers, and pathological node status may refine the prognostic stratification of OCSCC patients.

Diagnostic accuracy of F-18 FDG PET or PET/CT for detection of lymph node metastasis in clinically node negative head and neck cancer patients; A systematic review and meta-analysis

OBJECTIVE

The purpose of the current study was to investigate the diagnostic performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) for the detection of cervical lymph node (LN) metastasis in clinically node negative head and neck squamous cell cancer (cN0 HNSCC) patients through a systematic review and meta-analysis.

METHODS

The PubMed and EMBASE database, from the earliest available date of indexing through April 30, 2018, were searched for studies evaluating the diagnostic performance of F-18 FDG PET or PET/CT for the detection of LN metastasis in cN0 HNSCC patients. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic (SROC) curves.

RESULTS

Across 18 studies (1044 patients), the pooled sensitivity for F-18 FDG PET or PET/CT for the detection of LN metastasis was 0.58 and a pooled specificity of 0.87 for patient based analysis. Neck side based analysis showed the pooled sensitivity of 0.67 and a pooled specificity of 0.85. Level based study demonstrated the pooled sensitivity of 0.53 and a pooled specificity of 0.97 (95% CI; 0.95-0.98). In meta-regression analysis, no definite variable was the source of the study heterogeneity.

CONCLUSION

The current meta-analysis showed the low sensitivity and moderate specificity of F-18 FDG PET/CT for the detection of cervical LN metastasis in cN0 HNSCC patients. Level based analysis of F-18 FDG PET or PET/CT has a high specificity and NPV for the detection of cervical metastatic LN detection.

The value of whole-body contrast-enhanced 18F-FDG PET/CT imaging in the diagnosis and staging of patients with laryngeal carcinoma

PURPOSE

This study aimed to determine whether intravenous contrast-enhanced dual-phase fluorine-18--fluorodeoxyglucose (F-FDG) PET/CT scans provide additional diagnostic information compared with the MRI/CT in patients with laryngeal carcinoma during the initial staging.

PATIENTS AND METHODS

Forty-five consecutive patients (44 men, one woman; mean age±SD, 67.0±9.0 years, range: 45-80 years) with carcinoma of the larynx who had MRI/CT and intravenous contrast-enhanced PET/CT were enrolled. Each patient was scanned on the PET/CT system 1 h (early) and 2 h (delayed) after injection. The maximum standardized uptake values of the primary tumor, nodal, and distant metastatic lesions were measured using the dual-time-point method. Double-blinded F-FDG PET/CT and MRI/CT staging data were compared. The diagnostic accuracy of each modality was compared for primary tumors, nodal metastasis, and the tumor staging.

RESULTS

For primary tumor detection, the sensitivity of PET/CT was higher (100%) than MRI/CT (93.3%). The accuracy for N status was 88.8% for PET/CT, being superior to MRI, which had an accuracy of 66.6%. The sensitivity and specificity for the detection of nodal metastasis were 100 and 84.6% for PET/CT compared with 100 and 50% for MRI/CT, respectively. As an initial TNM-staging method, the PET/CT had a diagnostic accuracy of 86.6% compared with 44.4% for MRI/CT.

CONCLUSION

The results suggest that contrast-enhanced dual-phase PET/CT imaging contributes additional diagnostic information compared with the conventional methods for the initial evaluation of primary laryngeal tumors. F-FDG PET/CT has a good diagnostic performance for the detection of regional nodal and distant metastasis, and also synchronous tumors in patients with laryngeal carcinoma.

Clinical usefulness of 2-deoxy-2-[18F] fluoro-d-glucose-positron emission tomography/computed tomography for assessing early oral squamous cell carcinoma (cT1-2N0M0)

Background

Positron emission tomography with 2-deoxy-2-[18F] fluoro-d-glucose integrated with computed tomography (FDG-PET/CT) is a useful method to evaluate patients with oral squamous cell carcinoma (OSCC). However, the prognostic significance of FDG-PET/CT for assessing early OSCC remains unclear.

Methods

Pretreatment FDG-PET/CT of 205 consecutive patients (125 men, 80 women, mean age 59.7 year old) with early OSCC (cT1-2N0M0) between June 2010 and December 2014 were retrospectively analyzed. FDG avidity in primary lesions was assessed by visual interpretation. Thereafter, maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were measured in primary lesions. The relationship between each parameter and recurrence free survival (RFS) was assessed using the log-rank test. The performance of FDG-PET/CT for diagnosing metastatic lesions and synchronous cancer was also assessed.

Results

During the follow-up period (mean 32.9 months), 43 patients developed recurrences (21.0%). Patients with visually positive FDG uptake in primary lesions showed significantly shorter RFS than the others (63.0 months vs. 52.9 months, P = 0.005). In those patients, greater SUVmax, MTV, and TLG did not significantly predict shorter RFS. The sensitivity and specificity of FDG-PET/CT for cervical nodal metastases detection were 32.3% and 77.6%, respectively. FDG-PET/CT detected eight synchronous cancers (3.9%) and overlooked six synchronous cancers (2.9%).

Conclusions

Although its utility for detecting cervical nodal metastases and synchronous cancers is limited, FDG-PET/CT is a potentially prognostic indicator in early OSCC.

Chapter 8 On the Horizon: Advanced Imaging Techniques to Improve Noninvasive Assessment of Cervical Lymph Nodes

Conventional imaging modalities are limited in the evaluation of lymph nodes as they predominantly rely on size and morphology, which have suboptimal sensitivity and specificity for malignancy. In this review we will explore the role of "on the horizon" advanced imaging modalities that can look beyond the size and morphologic features of a cervical lymph node and explore its molecular nature and can aid in personalizing therapy rather than use the "one-size-fits-all" approach.

Molecular Imaging and Oral Cancer Diagnosis and Therapy

Oral cancer is known as one of relatively common type of cancer worldwide. Despite the easy access of the oral cavity to examination, oral tumors are diagnosed in more advanced stages of the disease. Imaging techniques have been recently emerged as non-invasive approaches to detect molecular and cellular changes in living cells and organisms. These techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) could help physicians to screen patients with oral tumors particularly oral squamous cell carcinoma (OSCC) in early stage of the disease. In this review, we discuss that early detection and diagnosis of oral tumors through using more robust and precise imaging techniques and a variety of cellular/molecular biomarkers not only could lead to more effective and less aggressive form of treatment for the disease but also could improve survival rates and lower treatment costs. J. Cell. Biochem. 118: 3055-3060, 2017. © 2017 Wiley Periodicals, Inc.

Prognostic significance of standardized uptake value and metabolic tumour volume on ¹⁸F-FDG PET/CT in oropharyngeal squamous cell carcinoma

PURPOSE

Standardized uptake value (SUV) and metabolic tumour volume (MTV) measured by (18)F-FDG PET/CT are emerging prognostic biomarkers in human solid cancers. However, their prognostic significance in oropharyngeal squamous cell carcinoma (OPSCC) has been investigated in only a few studies and with small cohorts. In the present study we evaluated the ability of SUV, MTV, and total lesion glycolysis (TLG) measured on pretreatment (18)F-FDG PET/CT to predict recurrence and survival outcomes in OPSCC.

METHODS

The study included 221 patients with OPSCC who underwent pretreatment (18)F-FDG PET/CT imaging and received definitive treatment at our tertiary referral centre. The PET imaging parameters SUVmax, SUVpeak, MTV and TLG were measured in primary tumours with focal (18)F-FDG uptake. Clinical and imaging variables significantly associated with overall survival (OS) and disease-free survival (DFS) were identified by univariate and multivariate analyses using the Cox proportional hazards model.

RESULTS

Overall 5-year OS and DFS rates were 72.0 % and 79.5 %, respectively, during a median follow-up of 61 months (range 18 - 122 months). The cut-off values of tumour SUVmax, SUVpeak, MTV and TLG for prediction of DFS were 7.55, 6.80, 11.06 mL and 78.56 g, respectively. Univariate analyses showed that age >60 years, advanced tumour stage, and high tumour SUVmax, SUVpeak, MTV and TLG were significantly associated with decreased OS and DFS (P < 0.05 each). Age, tumour SUVmax and MTV remained independent variables for OS and DFS (P < 0.05 each) in the multivariate analyses.

CONCLUSION

SUVmax and MTV measured on pretreatment (18)F-FDG PET/CT may be useful in predicting the clinical outcomes in OPSCC patients. This study investigated the clinical prognostic value of imaging parameters from pretreatment (18)F-FDG PET/CT in 221 patients who underwent definitive treatment for oropharyngeal squamous cell carcinoma. High maximum standardized uptake value and metabolic tumour volume were independently associated with decreased disease-free and overall survival outcomes.

The Role of PET-CT in Evaluation of Cervical Lymph Node Metastases in Oral Cavity Squamous Cell Carcinomas

Objective

The aim of this study is to determine the sensitivity and specificity of positron emission tomography-computed tomography (PET-CT) in the evaluation of cervical lymph node metastasis in oral cavity squamous cell cancers (SCCs) and to determine the SUV-max values in differentiating reactive and metastatic lymph nodes as a supportive parameter.

Methods

In this study, 23 patients were included who were diagnosed with oral cavity SCC and treated with surgery between 2006 and 2013 in our department. All the patients were scanned with PET-CT during the pretreatment evaluation. Detailed pretreatment PET-CT (retention sites and SUV-max values) and histopathological examination results were obtained. SPSS 17.0 software package was used for statistical analysis of the data. Categorical measurement was summarized as number and percentage and continuous measurements as mean and standard deviation (median and minimum-maximum where necessary). Chi-square test or Fisher's test were used in the comparison of categorical variables. Compliance of methods was assessed by Kappa coefficient analysis. In this study, the advantages of PET-CT were determined by the calculation of sensitivity and specificity values with histopathological examination results considered as the gold standard, and SUV-max value was assessed by examining the area under the ROC curve. In all tests, the level of statistical significance was accepted as 0.05.

Results

The threshold value for SUV-max depending on the data of the histopathological examination and results of PET-CT of the 23 patients was 2.50. The reliability of this threshold was determined as AUC=0.819. In demonstrating neck metastasis in patients with cancer of the oral cavity, PET-CT has a sensitivity of 89% and specificity of 98%. Compliance between the histopathological examination and PET-CT for metastatic cervical lymph nodes was determined to be 0.416 by kappa coefficient analysis.

Conclusion

There was FDG uptake on PET-CT in the cervical lymph node regions of all patients with metastatic cervical lymph nodes. There were no metastases in any of the patients with no FDG retention. The sensitivity and specificity of PET-CT in determining cervical lymph node metastasis were 89% and 98%, respectively, with a threshold SUV-max value considered as 2.50 in patients with FDG retention.

Use of PET in Head and Neck Cancers

Head and neck cancer imaging is especially necessary for staging. Computed tomography and magnetic resonance imaging are the techniques frequently used for this purpose. These methods are valuable for displaying detailed anatomical structures; however, they may be inadequate for making the distinction between recurrence, residual tumor, fibrosis, and normal tissues with an altered anatomy after treatments such as surgery, radiotherapy, and chemotherapy and for the detection of metastases. From this point, positron emission tomography may be a promising imaging method. Scanning the entire body with a single method is an important advantage of positron emission tomography. It may be useful in the detection of synchronous tumors, which are a serious problem in head and neck cancers. Positron emission tomography may provide additional contribution for neck metastases, where the primary site is unknown and is undetectable by other imaging techniques.

PET imaging biomarkers in head and neck cancer

In locally advanced head and neck squamous cell carcinoma (HNSCC), the role of imaging becomes more and more critical in the management process. In this framework, molecular imaging techniques such as PET allow noninvasive assessment of a range of tumour biomarkers such as metabolism, hypoxia and proliferation, which can serve different purposes. First, in a pretreatment setting they can influence therapy selection strategies and target delineation for radiation therapy. Second, their predictive and/or prognostic value could help enhance the therapeutic ratio in the management of HNSCC. Third, treatment modification can be performed through the generation of a molecular-based heterogeneous dose distribution with dose escalation to the most resistant parts of the tumour, a concept known as dose painting. Fourth, they are increasingly becoming a tool for monitoring response to therapy. In this review, PET imaging biomarkers used in the routine management of HNSCC or under investigation are discussed.

Positive clinical impact of an additional PET/CT scan before adjuvant radiotherapy or concurrent chemoradiotherapy in patients with advanced oral cavity squamous cell carcinoma

The aim of this single-center study was to investigate whether obtaining an additional PET/CT scan before adjuvant radiotherapy or concurrent chemoradiotherapy (CCRT) could meaningfully improve 2-y disease-free survival (DFS) and disease-specific survival (DSS) rates.

METHODS

Six hundred seventy-four patients with oral cavity squamous cell carcinoma who received adjuvant therapy after radical surgery were included. Of these, 152 patients were initially scheduled to receive an additional preradiotherapy/CCRT PET/CT scan within 1 wk of starting adjuvant therapy. However, 16 patients were excluded because of either medical problems or refusal. Therefore, 136 patients underwent a preradiotherapy/CCRT PET/CT scan (PET group), and 522 did not (NO-PET group). All of the participants were followed up for at least 2 y or censored at the last follow-up. The impact of preradiotherapy/CCRT PET/CT imaging was examined using Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

Two-year DFS (80% vs. 70%, P = 0.033) and DSS (84% vs. 75%, P = 0.010) rates were significantly higher in the PET than in the NO-PET group. In the PET group, both DFS and DSS were higher in patients with negative findings than in those without (88% vs. 22% and 91% vs. 36%, respectively; both P < 0.001). A prognostic scoring system based on the presence of the 2 independent risk factors in the PET group (extracapsular spread and lymphatic invasion) predicted both DFS (P = 0.001 and P < 0.001, respectively) and DSS (P = 0.001 and P < 0.001, respectively). Nineteen patients (14%) had their treatment modified by preradiotherapy/CCRT PET/CT findings. Of these, 15 were treated with curative intent due to the presence of locoregional disease, and 4 received palliative care due to distant metastases. Seven of the 15 patients are currently alive without disease.

CONCLUSION

An additional preradiotherapy/CCRT PET/CT scan improves both DFS and DSS in patients with advanced oral cavity squamous cell carcinoma.

Priority of fibular reconstruction in patients with oral cavity cancer undergoing segmental mandibulectomy

Background

The fibula osteoseptocutaneous free flap is generally used for segmental mandibular reconstructions following resection of oral cavity squamous cell carcinoma (OSCC). However, less complex reconstructions may be feasible for patients with predicted poor survival. Herein, we sought to identify the main risk factors (RFs) associated with poor prognosis in OSCC patients undergoing segmental mandibulectomy to help decide between fibular and non-fibular reconstructions.

Methods

Between 1996 and 2011, we examined the 5-year control, distant metastases, and survival rates in 310 consecutive, previously untreated patients with primary OSCC who underwent segmental mandibulectomy.

Results

Margin status was the only independent RF for 5-year local control. Level IV/V metastases, extracapsular spread, and tumor depth ≥15 mm were independent RFs for poor 5-year survival. In the entire study cohort, 23% of the patients had 2 or 3 adverse RFs; such a high-risk group was characterized by a poor prognosis and may be suitable for non-fibular reconstructions. Overall, 70% of the study patients were cT1-4N0, cT1N2, cT2N1, or had tumor depth <15 mm; less than 5% of patients in this subgroup had 2 or 3 adverse RFs and were thus candidates for fibular reconstructions. Among the remaining 30% of patients who showed both advanced clinical stage (cT2N2, cT3-4N1-2) and tumor depth ≥15 mm, 70% exhibited 2 or 3 adverse RFs.

Conclusions

Level IV/V metastases, extracapsular spread, and tumor depth ≥15 mm were independent predictors of poor prognosis in OSCC patients undergoing segmental mandibulectomy. The preoperative or intraoperative identification of adverse RFs may help decide between fibular and non-fibular mandibular reconstruction. High-risk patients bearing 2 or 3 adverse RFs have poor prognosis and should not be considered as candidates for fibular reconstructions.

18F-fluorodeoxyglucose--positron emission tomography/computed tomography aids staging and predicts mortality in patients with muscle-invasive bladder cancer

OBJECTIVE

To investigate the association between extravesical (18)F-fluorodeoxyglucose (FDG) avid lesions on FDG-positron emission tomography/computed tomography (PET/CT) and mortality in patients with muscle-invasive bladder cancer.

METHODS

An international, bi-institutional cohort study of 211 patients with muscle-invasive bladder cancer who underwent staging CT and FDG-PET/CT imaging. On the basis of the presence of extravesical FDG-avid lesions suspicious for malignancy on PET/CT images, patients were divided into a PET/CT-positive and PET/CT-negative group. Data on staging and mortality were retrospectively analyzed from prospective databases. Kaplan-Meier analyses were performed to compare overall (OS) and disease-specific survival (DSS) between the groups. Multivariable Cox regression models were used to investigate the association between extravesical PET/CT lesions and mortality. Extravesical lesions suspicious for malignancy on conventional CT were included in the models.

RESULTS

Of the 211 patients, 98 (46.4%) had 1 or more extravesical lesions on PET/CT, 113 (53.5%) had a negative PET/CT. Conventional CT revealed extravesical lesions in 51 patients (24.4%). Median follow-up was 18 months. Patients with a positive PET/CT had a significantly shorter OS and DSS (median OS: 14 vs 50 months, P = .001; DSS: 16 vs 50 months, P <.001). In multivariable analysis, the presence of extravesical lesions on PET/CT was an independent prognostic indicator of mortality (OS: hazard ratio = 3.0, confidence interval 95% 1.7-5.1). This association was not statistically significant for conventional CT (hazard ratio = 1.6 (95% confidence interval 0.9-2.7).

CONCLUSION

On the basis of our results, the presence of extravesical FDG-avid lesions on PET/CT might be considered an independent indicator of mortality.

A comparison of positron emission tomography and colonoscopy for the detection of advanced colorectal neoplasms in subjects undergoing a health check-up

Background & Aims

There is no agreement as to whether F-18 fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) screening for advanced colorectal neoplasms is meaningful. This retrospective study was undertaken to determine whether FDG PET/CT may be a valuable screening tool for the detection of advanced colorectal neoplasms.

Methods

A retrospective review of the records of 1,109 FDG PET/CT scans acquired from January 2007 to December 2011 was performed. Colonoscopy and FDG PET/CT imaging were performed within two days of each other. The results of colonoscopy were taken as the gold standard, either with or without the results of the histopathological examination. An advanced neoplasm was defined as the presence of a malignant tumor, an adenoma ≥1 cm, or histological evidence of high-grade dysplasia or significant villous components.

Results

A total of 36 subjects had advanced colorectal neoplasms detected by colonoscopy (totaling 38 neoplasms). Six of the 38 neoplasms were also detected by FDG PET/CT. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of FDG PET/CT in the detection of advanced colorectal neoplasms were 15.8% (6/38), 99.1% (1063/1073), 37.5% (6/16), 97.1% (1063/1095), and 96.2% (1069/1111) respectively. The presence of lesions with an endoscopic size ≤1.5 cm (P<0.001) and low-grade dysplasia (P<0.001) were the main predictors of false-negative FDG PET/CT findings.

Conclusions

We conclude that FDG PET/CT screening of advanced colorectal neoplasms is unwarranted, especially in the presence of lesions with an endoscopic size ≤1.5 cm or low-grade dysplasia.

Prognostic value of (18)F-fluorodeoxyglucose positron emission tomography, computed tomography and magnetic resonance imaging in oral cavity squamous cell carcinoma with pathologically positive neck lymph node

Purpose

To evaluate the prognostic value of preoperative neck lymph node (LN) assessment with ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET), computed tomography (CT), and magnetic resonance imaging (MRI) in oral cavity squamous cell carcinoma (OSCC) patients with pathologically positive LN.

Materials and Methods

In total, 47 OSCC patients with pathologically positive LN were retrospectively reviewed with preoperative ¹⁸F-FDG PET and CT/MRI. All patients underwent surgical resection, neck dissection and postoperative adjuvant radiotherapy and/or chemotherapy between March 2002 and October 2010. Histologic correlation was performed for findings of ¹⁸F-FDG PET and CT/MRI.

Results

Thirty-six (76.6%) of 47 cases were correctly diagnosed with neck LN metastasis by ¹⁸F-FDG PET and 32 (68.1%) of 47 cases were correctly diagnosed by CT/MRI. Follow-up ranged from 20 to 114 months (median, 56 months). Clinically negative nodal status evaluated by ¹⁸F-FDG PET or CT/MRI revealed a trend toward better clinical outcomes in terms of overall survival, disease-free survival, local recurrence-free survival, regional nodal recurrence-free survival, and distant metastasis-free survival rates even though the trends were not statistically significant. However, there was no impact of neck node standardized uptake value (SUV_max) on clinical outcomes. Notably, SUV_max showed significant correlation with tumor size in LN (p < 0.01, R² = 0.62). PET and CT/MRI status of LN also had significant correlation with the size of intranodal tumor deposit (p < 0.05, R² = 0.37 and p < 0.01, R² = 0.48, respectively).

Conclusion

¹⁸F-FDG PET and CT/MRI at the neck LNs might improve risk stratification in OSCC patients with pathologically positive neck LN in this study, even without significant prognostic value of SUV_max.

Current oncologic concepts and emerging techniques for imaging of head and neck squamous cell cancer

The incidence of head and neck squamous cell carcinoma (HNSCC) is increasing and currently they account for 5% of all malignancies worldwide. Inspite of ongoing developments in diagnostic imaging and new therapeutic options, HNSCC still represents a multidisciplinary challenge.One of the most important prognostic factors in HNSCC is the presence of lymph node metastases. Patients with confirmed nodal involvement have a considerable reduction of their 5-year overall survival rate. In the era of individually optimised surgery, chemotherapy and intensity modulated radiotherapy, the main role of pre- and posttherapeutic imaging remains cancer detection at an early stage and accurate follow-up. The combined effort of early diagnosis and close patient monitoring after surgery and/or radio-chemotherapy influences disease progression and outcome predicition in patients with HNSCC.This review article focuses on currrent oncologic concepts and emerging tools in imaging of head and neck squamous cell cancer. Besides the diagnostic spectrum of the individual imaging modalities, their limitations are also discussed. One main part of this article is dedicated to PET-CT which combines functional and morphological imaging. Furthermore latest developments in MRI are presented with regard to lymph node staging and response prediction. Last but not least, a clinical contribution in this review explains, which information the head and neck surgeon requires from the multimodality imaging and its impact on operation planning.

Evidence-based guideline recommendations on the use of positron emission tomography imaging in head and neck cancer

AIMS

To provide evidence-based practice guideline recommendations on the use of fluoro-2-deoxy-D-glucose positron emission tomography (PET) for diagnosis, staging and assessing treatment response, restaging or recurrence of head and neck cancer.

MATERIALS AND METHODS

A systematic review by Facey et al. (Health Technology Assessment 2007;11(44):iii-iv, xi-267) was used as the evidence base for recommendation development. As the review was limited to August 2005, the evidence base was updated to July 2011 using the same search strategies for MEDLINE and EMBASE used in the original review. The authors of the current systematic review drafted recommendations, which were reviewed, adapted and accepted by consensus by the Ontario provincial Head and Neck Disease Site Group and a special meeting of clinical experts.

RESULTS

The results of the Facey et al. review for head and neck cancer included five other systematic reviews and 31 primary studies. The 2005 to 2011 update search included four additional systematic reviews and 53 primary studies. Recommendations were developed based on this evidence and accepted by consensus.

CONCLUSIONS

PET is recommended in the M and bilateral nodal staging of all patients with head and neck squamous cell carcinoma where conventional imaging is equivocal, or where treatment may be significantly modified. PET is recommended in all patients after conventional imaging and in addition to, or prior to, diagnostic panendoscopy where the primary site is unknown. PET is recommended for the staging and assessment of recurrence of patients with nasopharyngeal carcinoma if conventional imaging is equivocal. PET is recommended for restaging patients who are being considered for major salvage treatment, including neck dissection.

18F-FDG metabolic tumor volume and total glycolytic activity of oral cavity and oropharyngeal squamous cell cancer: adding value to clinical staging

(18)F-FDG metabolic tumor volume (MTV) and total glycolytic activity (TGA) have been proposed as potential prognostic imaging markers for patient outcome in human solid tumors. The purpose of this study was to establish whether MTV and TGA add prognostic information to clinical staging in patients with oral and oropharyngeal squamous cell carcinomas (SCCs).

METHODS

The Institutional Review Board approved this Health Insurance Portability and Accountability Act-compliant single-institution retrospective study. Forty-five patients with histologically proven oral or oropharyngeal SCC underwent PET/CT for initial cancer staging and were included in the study. MTV was measured using a gradient-based method (PET Edge) and fixed-threshold methods at 38%, 50%, and 60% of maximum standardized uptake value (SUV). The TGA is defined as MTV × mean SUV. Bland-Altman analysis was used to establish the reliability of the methods of segmentation. Outcome endpoints were overall survival (OS) and progression-free survival. Cox proportional hazards univariate and multivariate regression analyses were performed.

RESULTS

In Cox regression models, MTV and TGA were the only factors significantly associated with survival outcome after adjusting for all other covariates including American Joint Committee on Cancer (AJCC) stage, with hazards ratio of 1.06 (95% confidence interval, 1.01-1.10; P = 0.006) and 1.00 (95% confidence interval, 1.00-1.01; P = 0.02). The model fit was significantly better when MTV was added to AJCC stage in model I (χ(2) value change, 1.16-6.71; P = 0.01) and when TGA was added to AJCC stage in model II (χ(2) value change, 1.16-4.37; P = 0.04). The median cutoff point of 7.7 mL for primary tumor MTV was predictive of time to OS (log rank P = 0.04). The median cutoff point of 55 g for PET Edge primary tumor TGA was predictive of time to OS (log rank P = 0.08), though the result was not statistically significant.

CONCLUSION

Gradient-based segmentations of primary tumor MTV and TGA are potential (18)F-FDG markers for time to survival in patients with oral and oropharyngeal SCC and may provide prognostic information in addition to AJCC stage. These exploratory imaging markers need validation in larger cohort studies.

Radiological imaging of the neck for initial decision-making in oral squamous cell carcinomas--a questionnaire survey in the Nordic countries

BACKGROUND

Fast and accurate work-up is crucial to ensure the best possible treatment and prognosis for patients with head and neck cancer. The presence or absence of neck lymph node metastases is important for the prognosis and the choice of treatment. Clinical lymph node (N)-staging is done by palpation and diagnostic imaging of the neck. We investigated the current practice of the initial radiological work-up of patients with oral squamous cell carcinomas (OSCC) in the Nordic countries.

METHODS

A questionnaire regarding the availability and use of guidelines and imaging modalities for radiological N-staging in OSCC was distributed to 21 Head and Neck centres in Denmark (n = 4), Finland (n = 5), Iceland (n = 1), Norway (n = 4) and Sweden (n = 7). We also asked for a description of the radiological criteria for determining the lymph nodes as clinical positive (cN+) or negative (cN0).

RESULTS

All 21 Head and Neck centres responded to the questionnaire. Denmark and Finland have national guidelines, while Norway and Sweden have local or regional guidelines. Seventeen of the 19 centres with available guidelines recommended computed tomography (CT) of the cN0 neck. The waiting time may influence the imaging modalities used. Lymph node size was the most commonly used criteria for radiological cN+, but the cut-off measures vary from 0.8 to 2.0 cm.

CONCLUSION

Overall, CT is the most commonly recommended and used imaging modality for OSCC. Despite availability of national guidelines the type and number of radiological examinations vary between centres within a country, but the implementation of a fast-track programme may facilitate fast access to imaging. The absence of uniform criteria for determining the lymph nodes of the neck as cN+ complicates the comparison of the accuracy of the imaging modalities. Well-defined radiological strategies and criteria are needed to optimise the radiological work-up in OSCC.