Accuracy of 18 F-FDG PET/CT in Detection of Neck Metastases of Oral Squamous Cell Carcinoma in Patients Without Large Palpable Lymph Nodes

Comparing the Efficacy of CT, MRI, PET-CT, and US in the Detection of Cervical Lymph Node Metastases in Head and Neck Squamous Cell Carcinoma with Clinically Negative Neck Lymph Node: A Systematic Review and Meta-Analysis

Background: Traditional imaging techniques have limited efficacy in detecting occult cervical lymph node (LN) metastases in head and neck squamous cell carcinoma (HNSCC). Positron emission tomography/computed tomography (PET-CT) has demonstrated potential for assessing HNSCC, but the literature on its efficacy for detecting cervical LN metastases is scarce and exhibits varied outcomes, hindering comparisons. Aim: To compare the efficacy of CT, MRI, PET-CT, and US for detecting LN metastasis in HNSCC with clinically negative neck lymph nodes. Methods: A systematic search was performed using Web of Science, PubMed, Scopus, Embase, and Cochrane databases. Studies comparing CT, MRI, PET-CT, or US to detect cervical metastases in HNSCC were identified. The quality of the studies was assessed using the QUADAS-2 instrument. The positive likelihood ratios (+LR) and negative likelihood ratios (-LR), sensitivity (SEN), specificity (SPE), and diagnostic odds ratio (DOR), with 95% confidence intervals (C.I.), were calculated. Analysis was stratified according to lymph node and patient basis. Results: Fifty-seven studies yielded 3791 patients. At the patient level, PET-CT exhibited the highest diagnostic performance, with a SEN of 74.5% (95% C.I.: 65.4-81.8%) and SPE of 83.6% (95% C.I.: 77.2-88.5%). PET-CT also demonstrated the highest +LR of 4.303 (95% C.I.: 3.082-6.008) and the lowest -LR of 0.249 (95% C.I.: 0.168-0.370), resulting in the highest DOR of 15.487 (95% C.I.: 8.973-26.730). In the evaluation of diagnostic parameters for various imaging modalities on node-based analysis results, MRI exhibited the highest SEN at 77.4%, and PET demonstrated the highest SPE at 96.6% (95% C.I.: 94.4-98%). PET-CT achieved the highest DOR at 24.353 (95% C.I.: 10.949-54.166). Conclusions: PET-CT outperformed other imaging modalities across the majority of studied metrics concerning LN metastasis detection in HNSCC.

Role of the FDG PET CT Scan in Pretreatment Evaluation of Oral Carcinomas

Pre-treatment role of FDG PET CT scan to evaluate- the extent of the primary lesion, nodal staging and distant metastasis in oral carcinoma in various TNM stages. Additionally, our study investigated the Correlation between SUVmax values on FDG-PET CT scans and histopathological proven positive nodes in patients undergoing surgery. In this study, all suspected cases of oral carcinoma in adults who visited the ENT clinic were examined and evaluated using various methods, including clinical examination, cytology, histopathology, and imaging tests like CECT scans, ultrasound, and CEMRI. Based on the results of these evaluations, the patients were staged. The patients were then given FDG-PET CT scans (done within 2 weeks of CECT/MRI scans), for restaging and treatment plans, such as surgery, chemotherapy, radiotherapy, or a combination of these methods, were developed. After surgery, the patients were restaged based on the histopathology report, and the results of the FDG-PET CT scans were compared to the histopathological findings and the histopathological positive nodes were compared to the SUV max value on the FDG PET CT scan and were correlated. In our study, the mean age of patients was found to be 50 years with a male: female ratio of 3.5:1. Maximum tumors presented at the buccal mucosa region. 92% of patients gave a history of tobacco addiction, and 18% were smokers. As per initial biopsy reports, maximum (62%) tumors were detected to be WDSCC, 2% were MDSCC and 6% were PDSCC. All 50 patients had normal findings on the chest x-ray and USG abdomen. 41 patients underwent CECT scans and 9 patients got CEMRI scans done. Staging after FDG PET CT scan was compared with that of radiological staging. It was found that in T staging there was upstaging in 36% of cases and downstaging in 14% of cases following the FDG PET CT scan. Likewise, N staging showed upstaging in 36% of cases and downstaging in 16% of cases after the FDG PET CT scan. In M staging, there was upstaging in 10% of cases after the FDG PET CT scan. In our study 15 cases got operated on. All 8 (53.3%) cases of postoperative histopathological positive lymph nodes had SUV max values greater than their reference value (> 2.5), and all negative histopathological lymph nodes had a low SUV max (< 2.5) value in the PET CT scan. The FDG PET CT scan is a highly effective tool for accurately diagnosing, staging, and predicting the outcome of oral cancers at all stages of the disease. The SUV max value (> 2.5) of the PET CT scan is positively correlated with the likelihood of nodal metastasis, as higher values were found to correspond with histopathological evidence of positive neck nodes.

The relationship between the uptake of alveolar bone inflammation and of cervical lymph nodes on fluoro-2-deoxy-D-glucose positron emission tomography

OBJECTIVES

To elucidate the relationships between the maximum standardized uptake value (SUVmax) of alveolar bone and those of lymph nodes (LNs) around the neck on 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET).

METHODS

The SUVmax values of alveolar bone and of level IA, level IB, and level IIA LNs of 174 patients, including those with and without active odontogenic inflammation, on PET/CT performed for a health check were retrospectively evaluated. The upper and lower jaws were divided into four blocks (right maxilla, left maxilla, right mandible, and left mandible). The SUVmax values of each block and of the LNs were calculated. The differences in the SUVmax of each LN level between patients with and without odontogenic inflammation, and the relationship between the SUVmax values of alveolar bone and of the LNs were analysed statistically.

RESULTS

Significant differences in SUVmax values of bilateral level IB and IIA LNs were found between patients with and without odontogenic inflammation (Mann-Whitney U test: right level IB, P = .008; left level IB, P = .006; right level IIA, P < .001; left level IIA, P = .002), but not in bilateral level IA LNs (Mann-Whitney U test: right level IA, P = .432; left level IA, P = .549). The inflammatory site with the highest SUVmax in level IB LNs was the ipsilateral mandible (multivariate analysis: right, beta = 0.398, P < .001; left, beta = 0.472, P < .001), and the highest SUVmax in level IIA LNs was the ipsilateral maxilla (multivariate analysis: right, beta = 0.223, P = .002; left, beta = 0.391, P < .001).

CONCLUSIONS

The SUVmax values of level IB and IIA LNs were associated with a tendency towards a higher SUVmax value of alveolar bone on 18F-FDG-PET.

FDG PET-CT for the Detection of Occult Nodal Metastases in Head and Neck Cancer: A Systematic Review and Meta-Analysis

Because of an estimated 20-30% prevalence of occult lymph node (LN) metastases in patients with head and neck squamous cell carcinoma (HNSCC), neck dissection is often proposed, despite its potential morbidity. In this systematic review and meta-analysis, the diagnostic performance of FDG PET-CT in detecting occult LN metastases was evaluated in patients with clinically negative necks (cN0) and in whom histopathology of a neck dissection specimen served as gold standard. Overall, 16 studies out of 2062 screened on PubMed and EMBASE fulfilled the inclusion criteria (n = 1148 patients). Seven of these sixteen studies were split into two or three studies because they contained data that could be processed distinctly in our meta-analysis. For this reason, a total of 25 studies were identified and included in the analysis (n total = 1918 patients). The overall prevalence of metastatic nodes per patient was 22.67%. The pooled sensitivity, specificity, diagnostic odds ratios, and negative predictive value (NPV) were 0.71 (95%CI: 0.66-0.75), 0.90 (95%CI: 0.84-0.93), 20.03 (95%CI: 13.51-29.70), and 0.92 (95%CI: 0.89-0.95), respectively. The main causes of inter-study heterogeneity included different reference standards (evaluation per patient, per neck side, or per neck level). The current meta-analysis showed that FDG PET-CT has a high specificity and NPV for ruling out nodal involvement in cN0 necks, but a limited sensitivity.

Comparing the Diagnostic Accuracy of Ultrasonography, CT, MRI, and PET/CT in Cervical Lymph Node Metastasis of Oral Squamous Cell Carcinoma

(1) Background: In oral cancer staging, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and 2-deoxy-2-[fluorine-18]fluoro-D-glucose (FDG) with positron emission tomography/computed tomography (PET/CT) are routinely used in clinical practice. The present study is a retrospective examination of the diagnostic accuracy of cervical lymph node metastasis using US, CT, MRI, and PET/CT, with histopathological diagnosis as a reference, to compare the different diagnostic imaging modalities. (2) Methods: The participants included 16 patients with oral squamous cell carcinoma who underwent US-, CT-, MRI-, and PET/CT-based preoperative diagnostic imaging and simultaneous primary lesion resection and neck dissection, including 82 level regions and 424 lymph nodes. We compared the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of each imaging modality based on the imaging results and the pathology results of metastasis. (3) Results: Of the four diagnostic imaging modalities, PET/CT exhibited the highest sensitivity but the lowest specificity and accuracy. US, CT, and MRI had high specificities. Comparing each level region and lymph node showed that differences were observed in PET/CT. (4) Conclusions: PET/CT to diagnose lymph node metastasis requires a comprehensive evaluation because it produces more false positives than other diagnostic imaging modalities. Using US, CT, and MRI, which have excellent spatial resolution, improves diagnostic accuracy at the lymph node level.

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.

Prognostic Utility of Neck Lymph Node-to-Primary Tumor Standardized Uptake Value Ratio in Oral Cavity Cancer

We investigated the prognostic utility of preoperative neck lymph node-to-primary tumor maximum standardized uptake value ratios (NTRs) in oral cavity squamous cell carcinoma (OSCC). We retrospectively reviewed the medical records of 141 consecutive patients who were diagnosed as having OSCC and had received fluorodeoxyglucose-positron emission tomography within 2 weeks prior to radical surgery between 2009 and 2018. To determine the optimal NTR cutoff, receiver operating characteristic analysis for overall survival (OS) was executed. The NTR's prognostic value for disease-free survival (DFS) and OS were determined through Cox proportional hazards analysis and the Kaplan-Meier method. We determined the median (range) follow-up duration to be 35.2 (2.1-122.4) months. The optimal NTR cutoff was 0.273, and patients with a higher NTR (≥0.273) exhibited significantly worse DFS and OS (p = 0.010 and 0.003, respectively). A higher NTR (≥0.273) predicted poorer DFS (hazard ratio: 2.696, p = 0.008) and OS (hazard ratio: 4.865, p = 0.003) in multivariable analysis. We created a nomogram on the basis of the NTR, and it could accurately predict OS (concordance index: 0.774). Preoperative NTRs may be a useful prognostic biomarker for DFS and OS in patients with OSCC who have undergone surgery. NTR-based nomograms may also be helpful prognostic tools in clinical trials.

Preoperative Determination of Depth of Invasion in Oral Cavity Squamous Cell Carcinoma by Standard Cross-Sectional Imaging With Computed Tomography and Positron Emission Tomography/Computed Tomography

Background Depth of invasion (DOI) is a known indicator of metastatic potential in oral cavity squamous cell carcinoma (SCC). Our purpose was to investigate the accuracy of preoperative determination of DOI in oral cavity SCC by computed tomography (CT) and positron emission tomography/computed tomography (PET/CT). Methodology A retrospective study was performed using consecutive patients with histologically proven oral cavity SCC presenting to our otorhinolaryngology department between January 2014 and July 2019 who underwent preoperative contrast-enhanced CT and/or PET/CT. Pathological assessment of DOI was determined by a review of pathology reports. The degree of DOI determined by radiographic studies was correlated to pathology results. Results A total of 79 patients were screened of whom appropriate radiographic studies were available for 63 patients. The mean DOI by pathological assessment was 12.3 ± 9.1 mm. CT and PET/CT determined depth both correlated with pathological DOI (r = 0.710; p < 0.001, r = 0.798; p < 0.001). No significant correlation was seen for CT-determined depth (r = 0.136; p = 0.709) or PET-determined depth (r = 0.234; p = 0.707) with pathologically confirmed superficial tumors (<5 mm). For patients with pathological tumor depth >10 mm, CT and PET determined depth both correlated with pathological depth (r = 0.577; p = 0.002, r = 0.668; p = 0.001). The sensitivity and specificity of CT and PET for the identification of deep invasion were 88.2% and 41.7% and 52.9% and 50%, respectively. Conclusions DOI measurement is feasible with routine preoperative CT and PET/CT images and is comparable to pathological measurement in patients with oral cavity SCC.

A prediction model of nodal metastasis in cN0 oral squamous cell carcinoma using metabolic and pathological variables

BACKGROUND

The efficacy of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) Positron Emission Tomography/Computed Tomography(PET/CT) in evaluating the neck status in clinically node-negative (cN0) oral squamous cell carcinoma(OSCC) patients was still unsatisfying. We tried to develop a prediction model for nodal metastasis in cN0 OSCC patients by using metabolic and pathological variables.

METHODS

Consecutive cN0 OSCC patients with preoperative ¹⁸F-FDG PET/CT, subsequent surgical resection of primary tumor and neck dissection were included. Ninety-five patients who underwent PET/CT scanning in Shanghai ninth people's hospital were identified as training cohort, and another 46 patients who imaged in Shanghai Universal Medical Imaging Diagnostic Center were selected as validation cohort. Nodal-status-related variables in the training cohort were selected by multivariable regression after using the least absolute shrinkage and selection operator (LASSO). A nomogram was constructed with significant variables for the risk prediction of nodal metastasis. Finally, nomogram performance was determined by its discrimination, calibration, and clinical usefulness.

RESULTS

Nodal maximum standardized uptake value(nodal SUVmax) and pathological T stage were selected as significant variables. A prediction model incorporating the two variables was used to plot a nomogram. The area under the curve was 0.871(Standard Error [SE], 0.035; 95% Confidence Interval [CI], 0.787-0.931) in the training cohort, and 0.809(SE, 0.069; 95% CI, 0.666-0.910) in the validation cohort, with good calibration demonstrated.

CONCLUSIONS

A prediction model incorporates metabolic and pathological variables has good performance for predicting nodal metastasis in cN0 OSCC patients. However, further studies with large populations are needed to verify our findings.

Accurate preoperative staging with [68Ga]Ga-FAPI PET/CT for patients with oral squamous cell carcinoma: a comparison to 2-[18F]FDG PET/CT

OBJECTIVE

To evaluate the potential value of [⁶⁸Ga]Ga-labelled fibroblast activation protein inhibitor ([⁶⁸Ga]Ga-FAPI) positron emission tomography/computed tomography (PET/CT) in preoperative staging for patients with oral squamous cell carcinoma (OSCC) as compared to 2-[¹⁸F]fluoro-2-deoxy-D-glucose (2-[¹⁸F]FDG) PET/CT.

METHODS

Thirty-six treatment-naïve patients with OSCC who underwent 2-[¹⁸F]FDG and [⁶⁸Ga]Ga-FAPI PET/CT for preoperative staging were enrolled. The maximum standardised uptake value (SUV_max) of the primary tumour and suspected cervical metastatic lymph nodes, and the tumour-to-background ratio (TBR) of the primary tumour, were measured. The accuracy of two imaging modalities for preoperative diagnosis of metastatic lymph nodes was analysed. Histopathology served as the standard of reference.

RESULTS

Thirty-seven primary lesions of 36 patients were accurately detected by both [⁶⁸Ga]Ga-FAPI and 2-[¹⁸F]FDG PET/CT. Regarding primary tumours, the SUV_max and TBR of the two imaging modalities in stage T3-T4 were significantly higher than those of stage T1-T2 (all p < 0.05). On the patient analysis, the accuracy for the evaluation of N1-N3 neck status was 52.6% (10/19) for [⁶⁸Ga]Ga-FAPI PET/CT and 57.9% (11/19) for 2-[¹⁸F]FDG PET/CT. Notably, the accuracy for the evaluation of the N0 neck status between [⁶⁸Ga]Ga-FAPI and 2-[¹⁸F]FDG PET/CT was 100% (17/17) and 29% (5/17), respectively. Based on the patient, neck side and neck level, [⁶⁸Ga]Ga-FAPI PET/CT resulted in higher specificity and accuracy in diagnosing metastatic neck lymph nodes than 2-[¹⁸F]FDG PET/CT (all p < 0.05).

CONCLUSION

[⁶⁸Ga]Ga-FAPI PET/CT is a promising tool for preoperative staging of OSCC, and appears to reduce the false positivity seen with 2-[¹⁸F]FDG PET/CT for the detection of neck lymph node metastases.

KEY POINTS

• [⁶⁸Ga]Ga-FAPI PET/CT is a promising tool targeting cancer-associated fibroblasts with comparable diagnostic performance to 2-[¹⁸F]FDG PET/CT for identifying the primary lesions of OSCC. • [⁶⁸Ga]Ga-FAPI PET/CT showed higher specificity and accuracy for the evaluation of neck lymph node metastases of OSCC than 2-[¹⁸F]FDG PET/CT, especially for N0 neck status.

[Modern perspectives of oral squamous cell carcinoma]

The article is devoted to the modern perspectives of the etiology, pathogenesis, diagnosis and prognostic factors in theoral squamous cell carcinoma. In the new edition of the WHO Classification of Head and Neck Tumors of 2017, the concept of potentially malignant diseases is introduced, which include erythroplakia, leukoplakia, oral submucous fibrosis, dyskeratosiscongenita, smokeless tobacco keratosis, palatallesions associated with reverse smoking, chronic candidiasis, lichen planus, discoid lupus erythematosus, syphilitic glossitis and actinic keratosis (liponly). A binary system for assessing oral epithelial dysplasia assessing is proposed. In Chapter 5, a separation of squamous cell carcinoma with a positive and negative reaction to human papillomavirus (HPV) is performed. It has been shown that patients with HPV positive squamous cell carcinoma have a better prognosis of the disease, which confirms the clinical distinction between oropharyngeal tumors and oral mucosa.