Accuracy of 18F-FDG-PET/CT for staging of oral squamous cell carcinoma

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.

Contribution of Open Mouth Technique in 18F-FDG PET/CT Imaging in Patients with Malignant Lip Neoplasm

Objectives:

¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) plays an important role in evaluating head and neck cancers. However, localization and size evaluation in this region can be rough due to the multitude of the anatomic structures and physiologic uptakes. The aim of this study was to evaluate malignant lip lesions with the contribution of open mouth (OM) imaging technique at PET/CT.

Methods:

Fifty-six patients with malignant lip neoplasm underwent ¹⁸F-FDG PET/CT imaging. Each patient was imaged twice as whole-body PET/CT with routine closed mouth (CM) position; and OM head and neck image, standardized with a special device. Lesion maximum standard uptake value (SUV_max), localization, size, and involvement of lymph nodes were evaluated.

Results:

Lesion localization was correctly detected in 100% of the OM images. Lesion size in PET/CT was compared with clinical, radiological (magnetic resonance imaging and CT) and/or histopathological results and the size measurement was coherent at 47.1% and 95.6% for CM and OM images, respectively. It was observed that OM acquisition did not contribute additionally in detecting regional lymph node metastasis. Forty-one PET/CT scans with CT artifacts due to dental amalgams were evaluated and 46.3% dimensional and 53.7% localization errors were detected in the CM position. There was no statistically significant difference between OM and CM SUV_max (p>0.05).

Conclusion:

We concluded that additional OM head and neck imaging is useful and necessary to accurately determine the localization and size of the tumor, thus enhancing the value of PET/CT in staging, treatment response assessment, and restaging of patients with malignant lip cancer with or without dental amalgam

Evaluation of Proton MR Spectroscopy for the Study of the Tongue Tissue in Healthy Subjects and Patients With Tongue Squamous Cell Carcinoma: Preliminary Findings

Purpose

To noninvasively assess spectroscopic and metabolic profiles of healthy tongue tissue and in an exploratory objective in nontreated and treated patients with tongue squamous cell carcinoma (SCC).

Methods

Fourteen healthy subjects (HSs), one patient with nontreated tongue SCC (NT-SCC), and two patients with treated tongue SCC (T-SCC) underwent MRI and single-voxel proton magnetic resonance spectroscopy (1H-MRS) evaluations (3 and 1.5T). Multi-echo-times 1H-MRS was performed at the medial superior part (MSP) and the anterior inferior part (AIP) of the tongue in HS, while 1H-MRS voxel was placed at the most aggressive part of the tumor for patients with tongue SCC. 1H-MRS data analysis yielded spectroscopic metabolite ratios quantified to total creatine.

Results

In HS, compared to MSP and AIP, 1H-MRS spectra revealed higher levels of creatine, a more prominent and well-identified trimethylamine-choline (TMA-Cho) peak. However, larger prominent lipid peaks were better differentiated in the tongue MSP. Compared to HS, patients with NT-SCC exhibited very high levels of lipids and relatively higher values of TMA-Cho peak. Interestingly, patients with T-SCC showed almost nonproliferation activity. However, high lipids levels were measured, although they were relatively lower than lipids levels measured in patients with NT-SCC.

Conclusion

The present study demonstrated the potential use of in-vivo1H-MRS to noninvasively assess spectroscopic and metabolic profiles of the healthy tongue tissue in a spatial location-dependent manner. Preliminary results revealed differences between HS and patients with tongue NT-SCC as well as tongue T-SCC, which should be confirmed with more patients. 1H-MRS could be included, in the future, in the arsenal of tools for treatment response evaluation and noninvasive monitoring of patients with tongue SCC.

Comparison of different diagnostic imaging techniques for the detection of bone invasion in oral cancers

OBJECTIVES

To evaluate the ability of different imaging modalities to accurately detect bone invasion in oral squamous cell carcinomas.

PATIENTS AND METHODS

Patients with oral squamous cell carcinoma, who were scheduled for mandibulectomy or maxillectomy, underwent clinical evaluation using five preoperative imaging diagnosis methods-contrast-enhanced MRI, CT, ^99mTc scintigraphy (Tc scan), FDG-PET CT (PET/CT), and panoramic radiography. The sensitivity and specificity of each modality in detecting bone invasion were calculated by comparing the findings on the images with postoperative histopathological findings. In a subgroup of patients, we further assessed the ability of MRI and CT to detect the accurate extent of bone invasion, including the height, width, and depth in patients with pathological mandibular invasion.

RESULTS

Overall, 50 patients were enrolled in this study, and nine patients with pathological mandibular invasion were included in our subgroup analysis. MRI was found to be the most useful method in detecting bone invasion, showing the highest sensitivity (88.9%) and negative predictive values (92.3%). CT (87.5% specificity and 77.8% sensitivity) was more specific than MRI, though less sensitive. Combined PET/CT was more sensitive (83.3%) and less specific (71.9%) than CT. Tc scan had high sensitivity (88.9%); however, the specificity was relatively low (71.9%).

CONCLUSION

MRI was the most useful method in detecting bone invasion. A negative MRI result definitively excludes bone marrow invasion. In patients with positive MRI findings, a negative CT may be useful in ruling out bone marrow invasion.

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.

Targeting fibroblast activation protein in newly diagnosed squamous cell carcinoma of the oral cavity - initial experience and comparison to [18F]FDG PET/CT and MRI

Purpose

While [¹⁸F]-fluorodeoxyglucose ([¹⁸F]FDG) is the standard for positron emission tomography/computed tomography (PET/CT) imaging of oral squamous cell carcinoma (OSCC), diagnostic specificity is hampered by uptake in inflammatory cells such as neutrophils or macrophages. Recently, molecular imaging probes targeting fibroblast activation protein α (FAP), which is overexpressed in a variety of cancer-associated fibroblasts, have become available and might constitute a feasible alternative to FDG PET/CT.

Methods

Ten consecutive, treatment-naïve patients (8 males, 2 females; mean age, 62 ± 9 years) with biopsy-proven OSCC underwent both whole-body [¹⁸F]FDG and [⁶⁸Ga]FAPI-04 (FAP-directed) PET/CT for primary staging prior to tumor resection and cervical lymph node dissection. Detection of the primary tumor, as well as the presence and number of lymph node and distant metastases was analysed. Intensity of tracer accumulation was assessed by means of maximum (SUV_max) and peak (SUV_peak) standardized uptake values. Histological work-up including immunohistochemical staining for FAP served as standard of reference.

Results

[¹⁸F]FDG and FAP-directed PET/CT detected all primary tumors with a SUV_max of 25.5 ± 13.2 (FDG) and 20.5 ± 6.4 (FAP-directed) and a SUV_peak of 16.1 ± 10.3 ([¹⁸F]FDG) and 13.8 ± 3.9 (FAP-directed), respectively. Regarding cervical lymph node metastases, FAP-directed PET/CT demonstrated comparable sensitivity (81.3% vs. 87.5%; P = 0.32) and specificity (93.3% vs. 81.3%; P = 0.16) to [¹⁸F]FDG PET/CT. FAP expression on the cell surface of cancer-associated fibroblasts in both primary lesions as well as lymph nodes metastases was confirmed in all samples.

Conclusion

FAP-directed PET/CT in OSCC seems feasible. Future research to investigate its potential to improve patient staging is highly warranted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05422-z.

PET/CT Variants and Pitfalls in Head and Neck Cancers Including Thyroid Cancer

PET/CT imaging is a dual-modality diagnostic technology that merges metabolic and structural imaging. There are several currently available radiotracers, but ¹⁸F-FDG is the most commonly utilized due to its widespread availability. ¹⁸F-FDG PET/CT is a cornerstone of head and neck squamous cell carcinoma imaging. ⁶⁸Ga-DOTA-TOC is another widely used radiotracer. It allows for whole-body imaging of cellular somatostatin receptors, commonly expressed by neuroendocrine tumors and is the standard of reference for the characterization and staging of neuroendocrine tumors. The normal biodistribution of these PET radiotracers as well as the technical aspects of image acquisition and inadequate patient preparation affect the quality of PET/CT imaging. In addition, normal variants, artifacts and incidental findings may impede accurate image interpretation and can potentially lead to misdiagnosis. In order to correctly interpret PET/CT imaging, it is necessary to have a comprehensive knowledge of the normal anatomy of the head and neck and to be cognizant of potential imaging pitfalls. The interpreter must be familiar with benign conditions which may accumulate radiotracer potentially mimicking neoplastic processes and also be aware of malignancies which can demonstrate low radiotracer uptake. Appropriate use of structural imaging with either CT, MR or ultrasound can serve a complimentary role in several head and neck pathologies including local tumor staging, detection of bone marrow involvement or perineural spread, and classification of thyroid nodules. It is important to be aware of the role of these complementary modalities to maximize diagnostic accuracy and patient outcomes. The purpose of this article is to outline the basic principles of PET/CT imaging, with a focus on ¹⁸F-FDG PET/CT and ⁶⁸Ga-DOTA PET/CT. Basic physiology, variant imaging appearances and potential pitfalls of image interpretation are presented within the context of common use cases of PET technology in patients with head and neck cancers and other pathologies, benign and malignant.

Accuracy of 18-F Fluorodeoxyglucose Positron Emission Tomographic/Computed Tomographic Imaging in Primary Staging of Squamous Cell Carcinoma of the Oral Cavity

IMPORTANCE

Squamous cell carcinoma (SCC) of the oral cavity is one of the most common tumor entities worldwide. Precise initial staging is necessary to determine a diagnosis, treatment, and prognosis.

OBJECTIVE

To examine the diagnostic accuracy of preoperative 18-F fluorodeoxyglucose (FDG) positron emission tomographic/computed tomographic (PET/CT) imaging in detecting cervical lymph node metastases.

DESIGN, SETTING, AND PARTICIPANTS

This prospective diagnostic study was performed at a single tertiary reference center between June 1, 2013, and January 31, 2016. Data were analyzed from April 7, 2018, through May 31, 2019. Observers of the FDG PET/CT imaging were blinded to patients' tumor stage. A total of 150 treatment-naive patients with clinical suspicion of SCC of the oral cavity were enrolled.

EXPOSURES

All patients underwent FDG PET/CT imaging before local tumor resection with selective or complete neck dissection.

MAIN OUTCOMES AND MEASURES

The accuracy of FDG PET/CT in localizing primary tumor, lymph node, and distant metastases was tested. Histopathologic characteristics of the tissue samples served as the standard of reference.

RESULTS

Of the 150 patients enrolled, 135 patients (74 [54.8%] men) with a median age of 63 years (range, 23-88 years) met the inclusion criteria (histopathologically confirmed primary SCC of the oral cavity/level-based histopathologic assessment of the resected lymph nodes). Thirty-six patients (26.7%) in the study cohort had neck metastases. Use of FDG PET/CT detected cervical lymph node metastasis with 83.3% sensitivity (95% CI, 71.2%-95.5%) and 84.8% specificity (95% CI, 77.8%-91.9%) and had a negative predictive value of 93.3% (95% CI, 88.2%-98.5%). The specificity was higher than for contrast-enhanced cervical CT imaging (67.0%; 95% CI, 57.4%-76.7%; P < .01) and cervical magnetic resonance imaging (62.6%; 95% CI, 52.7%-72.6%; P < .001). Ipsilateral lymph node metastasis in left- or right-sided primary tumor sites was detected with 78.6% sensitivity (95% CI, 63.4%-93.8%) and 83.1% specificity (95% CI, 75.1%-91.2%), and contralateral metastatic involvement was detected with 66.7% sensitivity (95% CI, 28.9%-100.0%) and 98.6% specificity (95% CI, 95.9%-100.0%). No distant metastases were observed.

CONCLUSIONS AND RELEVANCE

In this study, FDG PET/CT imaging had a high negative predictive value in detecting cervical lymph node metastasis in patients with newly diagnosed, treatment-naive SCC of the oral cavity. Routine clinical use of FDG PET/CT might lead to a substantial reduction of treatment-related morbidity in most patients.

Relationship between Standard Uptake Values of Positron Emission Tomography/Computed Tomography and Salivary Metabolites in Oral Cancer: A Pilot Study

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) is usually used for staging or evaluation of treatment response rather than for cancer screening. However, ¹⁸F-FDG PET/CT has also been used in Japan for cancer screening in people with no cancer symptoms, and accumulating evidence supports this application of ¹⁸F-FDG PET/CT. Previously, we have observed a correlation between the saliva and tumor metabolomic profiles in patients with oral cancer. Hence, if salivary metabolites demonstrate a significant correlation with PET parameters such as the maximum standardized uptake value (SUV_max), they may have the potential to be used as a screening tool before PET/CT to identify patients with high SUV_max. Hence, in this study, we aimed to explore the relationship between salivary metabolites and SUV_max of ¹⁸F-FDG PET/CT using previously collected data. ¹⁸F-FDG PET/CT was performed for staging 26 patients with oral cancer. The collected data were integrated and analyzed along with quantified salivary hydrophilic metabolites obtained from the same patients with oral cancer and controls (n = 44). In total, 11 metabolites showed significant correlations with SUV_max in the delayed phases. A multiple logistic regression model of the two metabolites showed the ability to discriminate between patients with oral cancer and controls, with an area under the receiver operating characteristic curve of 0.738 (p = 0.001). This study uniquely confirmed a relationship between salivary metabolites and SUV_max of PET/CT in patients with oral cancer; salivary metabolites were significantly correlated with SUV_max. These salivary metabolites can be used as a screening tool before PET/CT to identify patients with high SUV_max, i.e., to detect the presence of oral cancer.

PET/CT in Surgical Planning for Head and Neck Cancer

Fluorine-18 (¹⁸F)-fluorodeoxyglucose (FDG) positron emission tomography fused with computed tomography (PET/CT) is a valuable tool in surgical planning for head and neck squamous cell carcinoma (HNSCC). If performed prior to biopsy or other surgical intervention, FDG-PET/CT has high sensitivity for the detection of the primary site in patients with cervical lymph node metastases from unknown primary origin and can be used to direct the surgical workup. FDG-PET/CT is superior to CT alone for detection of nodal metastases outside the expected pattern or distant metastases or second primary cancers and can greatly affect determination of appropriate management including surgical eligibility. Prior to the advent of PET/CT, many patients undergoing (chemo)radiation-based therapy had planned post-treatment neck dissection; FDG-PET/CT now has a proven role in the evaluation of recurrent or persistent disease amenable to salvage surgery and enables safe avoidance of planned postradiation neck dissection with a high negative predictive value. Specifically for this important application, two standardized reporting metrics may be used in the head and neck anatomic region: the "Hopkins criteria" and the "Neck Imaging Reporting and Data System"; both systems produce a formalized evaluation and recommendation based on PET/CT findings. The role of PET/CT as a replacement for elective neck dissection or examination under anesthesia remains controversial but deserves further study. FDG-PET/CT has a wide-ranging impact on the surgical management of patients with HNSCC and should be used routinely in patients with unknown primary nodal disease and those presenting with advanced-stage cancers at initial staging and to assess treatment response.

Time between Diagnosis and Treatment of Hypopharynx and Larynx Cancer: Are Longer Delays Associated with Higher Discrepancy between Clinical and Pathological Staging?

Introduction  At the time of diagnosis, treatment strategies for cancer are largely based upon clinical staging. However, discrepancy between clinical and pathological staging has been reported.

Objective  To assess the rate of staging discrepancy in Laryngeal and Hypopharyngeal Squamous Cell Carcinoma (LHSCC), the potential influence of higher interval of time from diagnosis to primary surgical treatment, and whether this has any impact on survival outcomes.

Methods  Retrospective study of patients with LHSCC proposed for primary surgical treatment.

Results  The study population included 125 Caucasian patients with LHSCC. The level of agreement between clinical and pathological tumor staging was moderate (Cohen’s Kappa: 0.400; p  < 0.001) and similar result was found for node staging (Cohen’ Kappa: 0.520; p  < 0.001). The mean time between diagnosis and surgical treatment was 26.66 days and no statistically significant influence was found with staging discrepancy. The sample presented a 5-year Overall Survival (OS) of 58.2% and a Disease-specific survival (DSS) of 72.6%. No statistically significant impact of staging discrepancy on survival was found.

Conclusion  For advanced LHSCC, based on the findings of physical examination, endoscopy and imaging, is possible to achieve a moderate accuracy between clinical and pathological staging which allows a reliable counselling and treatment planning. Interval of time under 3–4 weeks between diagnosis and surgical treatment does not influence the rate of discrepancy. However, almost 30% of staging discrepancy is expected due to false negatives of imaging and limitations of physical exams.

Value of SUVmax for the Prediction of Bone Invasion in Oral Squamous Cell Carcinoma

In advanced oral squamous cell carcinoma (OSCC), accurate planning of surgical resection and reconstruction are crucial for outcome and postoperative function. For OSCC close to the maxilla or mandible, prediction of bone invasion is necessary. The aim of this study was to examine whether metabolic tumor imaging obtained by fluorodeoxyglucose positron emission tomography (FDG-PET) could enhance preoperative predictability of bone invasion. We performed an analysis of 84 treatment-naïve OSCCs arising from gum (upper and lower), hard palate, floor of mouth, and retromolar trigone treated at the University Hospital Zurich, Switzerland, who underwent wide local excision with free flap reconstruction between 04/2010 and 09/2018 and with available preoperative FDG-PET. Prediction of bone invasion by metabolic tumor imaging such as maximum standardized uptake value (SUV_max) was examined. On definitive histopathology, bone invasion was present in 47 of 84 cases (56%). The probability of bone infiltration increased with a higher pretherapeutic SUV_max in an almost linear manner. A pretherapeutic SUV_max of primary tumor below 9.5 ruled out bone invasion preoperatively with a high specificity (97.6%). The risk of bone invasion was 53.6% and 71.4% for patients with SUV_max between 9.5-14.5 and above 14.5, respectively. Patients with bone invasion had worse distant metastasis-free survival compared to patients without bone invasion (log-rank test, p = 0.032). In conclusion, metabolic tumor imaging using FDG-PET could be used to rule out bone invasion in oral cancer patients and may serve in treatment planning.

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

OBJECTIVE

To measure the efficacy of positron emission tomography/computed tomography (PET/CT) in the diagnosis of neck metastases of oral squamous cell carcinoma (OSCC) in patients without enlarged lymph nodes and to determine the threshold of maximum standardized uptake values (SUV_max) in diagnosis.

STUDY DESIGN

In total, 78 OSCC patients without large palpable lymph nodes were included. PET/CT findings were compared with histopathologic neck status.

RESULTS

Neck dissection was performed in 78 patients with 98 neck sides, and 31 neck sides harbored metastases. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT were 83.9%, 73.1%, 76.5%, 59.1%, and 90.7%, respectively. The area under the curve in receiver operating characteristic analysis was 0.76, which indicated that SUV_max of lymph nodes was useful in diagnosis of pathologic neck status. The threshold SUV_max was 2.21, which was the best diagnosis threshold of neck metastasis.

CONCLUSIONS

PET/CT is valuable in diagnosis of neck status. The probability of neck metastasis increased with increasing SUV_max values, but the threshold SUV_max should not be the sole criterion for determining the presence of neck metastases. Fluorodeoxyglucose PET/CT is recommended for evaluation of neck status in OSCC patients without large palpable lymph nodes.

Role of Positron Emission Tomography in Imaging of Non-neurologic Disorders of the Head, Neck, and Teeth in Veterinary Medicine

Positron Emission Tomography (PET) is an imaging technique that provides functional information, in addition to structural information obtained with computed tomography (CT). The most common application is cancer staging, using ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG), a radioactive analog of glucose. Although limited data are available in the veterinary literature, human studies have demonstrated benefit with the addition of PET both for assessment of the primary tumor and for detection of metastatic disease. ¹⁸F-FDG PET appears to be more accurate at detecting the margin of oral neoplasia, in particular for tumors arising from highly vascularized tissue, such as the lingual and laryngeal areas. ¹⁸F-FDG PET has a high sensitivity for the detection of lymph node metastasis, however the specificity is variable between studies. Tracers beyond ¹⁸F-FDG can also be used for oncology imaging. ¹⁸F-Fluoride (¹⁸F-NaF) is an excellent osseous tracer, useful in assessing bone involvement of primary tumors or osseous metastasis. Other specific tracers can be used to assess cell proliferation or hypoxia for tumor characterization. ¹⁸F-FDG is also an excellent tracer for detection of inflammation. Human studies have demonstrated its value for the assessment of periodontitis and dental implant infection. ¹⁸F-NaF has been used to assess disorders of the temporomandibular joint in the human literature, demonstrating good correlation with arthralgia and therapeutic outcome. Both ¹⁸F-NaF and ¹⁸F-FDG had good concordance with localization of cervical pain in people. PET will likely have a growing role in veterinary medicine not only for oncologic imaging but also for assessment of inflammation and pain.

AHNS Series: Do you know your guidelines? Evidence-based management of oral cavity cancers

Oral cavity squamous cell carcinoma (OCSCC) is the most common nonmelanoma head and neck cancer in the world, with an estimated 405 000 new cases expected each year. Subsites of the oral cavity include the alveolar ridge, buccal mucosa, anterior tongue, tonsillar pillar, retromolar trigone, hard palate, gingiva, and floor of the mouth. In this issue of the AHNS "Do you know your guidelines?" series, we review the evidence-based approach to the management of oral cavity carcinomas based on the framework provided by the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology.

Clinical Practice in PET/CT for the Management of Head and Neck Squamous Cell Cancer

OBJECTIVE

The purpose of this article is to summarize the evidence for the value of PET/CT for the management of patients with head and neck squamous cell cancer and suggest best clinical practices.

CONCLUSION

FDG PET/CT is a valuable imaging tool for identifying unknown primary tumors in patients with known cervical node metastases leading to management change and is the standard of care for the initial staging of stage III and IV head and neck squamous cell carcinomas (HNSCCs), for assessing therapy response when performed at least 12 weeks after chemoradiation therapy, and for avoiding unnecessary planned neck dissection. Neck dissection is avoided if PET/CT findings are negative-regardless of the size of the residual neck nodes-because survival outcomes are not compromised. FDG PET/CT is valuable in detecting recurrences and metastases during follow-up when suspected because of clinical symptoms and serves as a prognostic marker for patient survival outcomes, for 5 years. Using FDG PET/CT for routine surveillance of HNSCC after 6 months of treatment without any clinical suspicion should be discouraged.

FDG uptake in cervical lymph nodes in children without head and neck cancer

BACKGROUND

Reactive cervical lymphadenopathy is common in children and may demonstrate increased ¹⁸F-fluoro-deoxyglucose (¹⁸F-FDG) uptake on positron emission tomography/computed tomography (PET/CT).

OBJECTIVE

We sought to evaluate the frequency and significance of ¹⁸F-FDG uptake by neck lymph nodes in children with no history of head and neck cancer.

MATERIALS AND METHODS

The charts of 244 patients (114 female, mean age: 10.4 years) with a variety of tumors such as lymphoma and post-transplant lymphoproliferative diseases (PTLD), but no head and neck cancers, who had undergone ¹⁸F-FDG PET/CT were reviewed retrospectively. Using the maximum standardized uptake value (SUVmax), increased ¹⁸F-FDG uptake by neck lymph nodes was recorded and compared with the final diagnosis based on follow-up studies or biopsy results.

RESULTS

Neck lymph node uptake was identified in 70/244 (28.6%) of the patients. In 38 patients, the lymph nodes were benign. In eight patients, the lymph nodes were malignant (seven PTLD and one lymphoma). In 24 patients, we were not able to confirm the final diagnosis. Seven out of the eight malignant lymph nodes were positive for PTLD. The mean SUVmax was significantly higher in malignant lesions (4.2) compared with benign lesions (2.1) (P = 0.00049).

CONCLUSION

¹⁸F-FDG uptake in neck lymph nodes is common in children and is frequently due to reactive lymph nodes, especially when the SUVmax is <3.2. The frequency of malignant cervical lymph nodes is higher in PTLD patients compared with other groups.

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.

The role of PET/CT in the management of patients affected by head and neck tumors: a review of the literature

The management of head and neck tumor (HNSCC) has been changing over the years, especially due to the aid of imaging techniques that help physicians to attain a correct diagnosis. These techniques represent a valuable tool to help tailor treatment and during follow-up of patients affected by malignancies. The aim of this review is to summarize the results of the most recent and relevant studies about the use of PET imaging in HNSCCs. This review is divided into six chapters: (1) The role of PET/CT in the pre-treatment phase; (2) PET/CT and radiotherapy planning; (3) PET/CT in the post-treatment setting; (4) PET/CT and SUVmax for prediction of prognosis; (5) miscellanea on the utility of PET in specific HNSCCs; (6) non-FDG PET tracers used in HNSCC. Promising results have been obtained so far. Despite the encouraging outcomes, more investigations are needed to warrant the value of this technique, especially in the pre-treatment setting.

To evaluate disparity between clinical and pathological tumor-node-metastasis staging in oral cavity squamous cell carcinoma patients and its impact on overall survival: An institutional study

Background:

Accurate clinical staging is important for patient counseling, treatment planning, prognostication, and rational design of clinical trials. In head and neck squamous cell carcinoma, discrepancy between clinical and pathological staging has been reported.

Objective:

To evaluate any disparity between clinical and pathological tumor-node-metastasis (TNM) staging in oral cavity squamous cell carcinoma (OCSCC) patients and any impact of the same on survival.

Materials and Methods:

Retrospective chart review from year 2007 to 2013, at a tertiary care center.

Statistical Analysis:

All survival analyses were performed using SPSS for Windows version 15 (Chicago, IL, USA). Disease-free survival curves were generated using Kaplan–Meier algorithm.

Results:

One hundred and twenty-seven patients with OCSCC were analyzed. Seventy-nine (62.2%) were males and 48 (37.8%) females with a mean age at presentation 43.6 years (29–79 years). The highest congruence between clinical and pathological T-staging seen for clinical stage T1 and T4 at 76.9% and 73.4% with pathological T-stage. Similarly, the highest congruence between clinical and pathological N-stage seen for clinical N0 and N3 at 86.4% and 91.7% with pathological N-stage. Of clinically early stage patients, 67.5% remained early stage, and 32.5% were upstaged to advanced stage following pathological analysis. Of the clinically advanced stage patients, 75% remained advanced, and 25% were pathologically downstaged. This staging discrepancy did not significantly alter the survival.

Conclusion:

Some disparity exists in clinical and pathological TNM staging of OCSCC, which could affect treatment planning and survival of patients. Hence, more unified and even system of staging for the disease is required for proper decision-making.

The role of 18F-FDG PET/CT in pediatric lymph-node acute lymphoblastic leukemia involvement

In pediatric oncology, positron emission tomography/computed tomography (PET/CT) is emerging as an essential diagnostic tool in characterizing suspicious neoplastic lesions and staging malignant diseases. Most studies regarding the possible role of FDG-PET/CT in the management of acute lymphoblastic leukemia (ALL) patients are limited to adults. Here we report a pediatric patient with recurrent ALL, in which FDG-PET/CT was used both to define more precisely the cause of lymphadenopathy and to assess the effect of the second-line therapy.

Correlation of PET-CT nodal SUVmax with p16 positivity in oropharyngeal squamous cell carcinoma

Background

The incidence of human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) has been rising in recent years. Given the clinical impact of HPV/p16 positivity in OPSCC, identifying surrogate markers of this disease early in the diagnostic work-up of these patients could improve patient care.

Methods

Demographic, pathologic, staging and PET-CT data from patients diagnosed with OPSCC from 2009–2014 were obtained from a prospectively collected provincial cancer registry. Tumor HPV/p16 status was correlated to the maximum standard uptake value (SUVmax) of the primary tumor and cervical nodes. Comparisons of means and multinomial regression models were used to determine associations between p16 status and SUVmax. A diagnostic odds ratio was calculated using a cut off value for predicting HPV/p16 positivity based on nodal SUVmax.

Results

PET-CT and HPV/p16 data was obtained for 65 patients treated surgically for OPSCC. Significantly higher nodal SUVmax was associated with HPV/p16 positive nodes (SUVmax 10.8 vs 7.9). No significant differences were seen between HPV/p16 positive vs negative primary tumor SUVmax (10.3 vs 13.7). In combination with other clinical parameters, higher nodal SUVmax was highly correlated with HPV/p16 positivity.

Conclusion

Elevated nodal SUVmax is a significant predictor of HPV/p16 positive disease.

Is 18F-fluorodeoxyglucose positron emission tomography/computed tomography helpful in the decision-making process for neck dissection in patients with T1-T2 lingual cancer?

CONCLUSION

The usefulness of addition of positron emission tomography/computed tomography (PET/CT) in decisions as to whether to perform neck dissection in patients with T1-T2 lingual squamous cell carcinoma (SCC) might be limited, but adding the condition of lymph nodes with a maximum standardized uptake value (SUVmax) >4.5 to existing criteria would be helpful.

OBJECTIVES

The purpose of this study was to investigate the usefulness of PET/CT for performing neck dissection in patients with T1-T2 lingual SCC.

METHODS

This retrospective review surveyed 19 patients with T1-T2 lingual SCC who underwent neck dissection after meeting one or more of the following criteria: (1) clinically positive nodes; (2) >4 mm thickness; (3) ≥ 3 cm longest diameter of the primary tumor. Focal 18F-fluorodeoxyglucose (FDG) uptake was considered to indicate PET-positive nodes (PET + Ns). The relation between pathologically positive nodes (p + Ns) and PET + Ns was estimated.

RESULTS

There were 14 PET + Ns at 12 of 66 levels (18%) in 8 of the 19 (42%) patients. There were also 6 p + Ns (1%) among 412 nodes at 5 cervical lymph node levels (8%) in 5 patients (26%). The sensitivity and specificity for PET/CT were 80% and 64%, respectively. The SUVmax was measured, and receiver operating characteristic (ROC) analysis was undertaken to obtain better accuracy. The sensitivity and specificity were 60% and 100% when the SUVmax cut-off value was set at 4.5.

(18)FDG-PET/CT for the detection of regional nodal metastasis in patients with head and neck cancer: a meta-analysis

We performed a meta-analysis to evaluate the role of (18)FDG-PET/CT for detection of regional nodal metastasis in patients with head and neck cancer (HNC). Studies about (18)FDG-PET/CT were systematically searched in the MEDLINE and EMBASE databases. The Stata software was used to obtain pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for (18)FDG-PET/CT. We also compared the performance of (18)FDG-PET/CT with that of conventional imaging (CT, MRI, and CT/MRI) by analyzing studies that had also used conventional imaging on the same patients. 24 articles bulled all inclusion criteria (1270 patients). The pooled per-patient, per-neck-side, and per-neck-level sensitivities/specificities for (18)FDG-PET/CT were 0.91/0.87, 0.84/0.83, and 0.80/0.96, respectively. Across 13 studies (3460 neck levels) with per-neck-level data, the sensitivity and specificity of PET-CT were 0.84 and 0.96, and of conventional imaging were 0.63 and 0.96, respectively. (18)FDG-PET/CT has good diagnostic performance for the detection of regional nodal metastasis in HNC patients. Compared with conventional imaging, (18)FDG-PET/CT may have higher per-neck-level sensitivity.

Imaging evaluation of lymphadenopathy and patterns of lymph node spread in head and neck cancer

Accurate and consistent characterization of metastatic cervical adenopathy is essential for the initial staging, treatment planning and surveillance of head and neck cancer patients. While enlarged superficial nodes may be clinically palpated, imaging allows identification of deeper adenopathy as well as clinically unsuspected pathology and thus imaging has become an integral part of the evaluation of most head and neck cancers patients. This review will focus on the evaluation of cervical adenopathy, summarizing the currently used nomenclature and imaging approach for determining cervical lymph node metastases in head and neck malignancies. The imaging-based classification, which has also been adopted by the American Joint Committee on Cancer, will be presented, the morphologic characteristics used to identify metastatic nodes will be reviewed and the typical nodal spread patterns of the major mucosal cancers of the head and neck will be examined.

The impact of clinical versus pathological staging in oral cavity carcinoma--a multi-institutional analysis of survival

Objectives

To evaluate any disparity in clinical versus pathological TNM staging in oral cavity squamous cell carcinoma (OCSCC) patients and any impact of this on survival.

Design

Demographic, survival, staging, and pathologic data on all patients undergoing surgical treatment for OCSCC in Alberta between 1998 and 2006 was collected. Clinical and pathological TNM staging data were compared. Patients were stratified as pathologically downstaged, upstaged or unchanged.

Setting

Tertiary care centers in Alberta, Canada.

Main outcome measures

Survival differences between groups were analyzed using Kaplan-Meier and Cox regression models.

Results

Patients with clinically early stage tumors were pathologically upstaged in 21.9% of cases and unchanged in 78.1% of cases. Patients with clinically advanced stage tumors were pathologically downstaged in 7.9% of cases and unchanged in 92.1% of cases. Univariate and multivariate estimates of disease-specific survival showed no statistically significant differences in survival when patients were either upstaged or downstaged.

Conclusions

Some disparity exists in clinical versus pathological staging in OCSCC, however, this does not have any significant impact on disease specific survival.

18FDG-PET/CT for the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment: a meta-analysis

BACKGROUND

We performed a meta-analysis to evaluate the role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)FDG-PET/CT) in the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment.

MATERIALS AND METHODS

Studies about (18)FDG-PET/CT for the detection of regional nodal metastasis in patients with primary HNC were systematically searched in the MEDLINE, EMBASE, and EBM Review databases from January 1, 2000 to July 25, 2012. A software called "Stata 12.0" was used to obtain pooled estimates of sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for PET/CT. We also calculated hierarchic summary receiver operating characteristic (HSROC) curves and area under the curves.

RESULTS

14 articles (742 patients) fulfilled all inclusion criteria. The pooled sensitivity, and specificity with 95% confidence interval for PET/CT on a per-neck-side analysis were 0.84 (0.77-0.89) and 0.84 (0.78-0.89). The corresponding values for PET/CT on a per-nodal-level analysis 0.84 (0.78-0.88) and 0.96 (0.94-0.98).

CONCLUSIONS

(18)FDG-PET/CT had good diagnostic performance for the detection of regional nodal metastasis in patients with primary head and neck cancer before treatment.

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.

Diffusion-weighted imaging in head and neck cancers

This article reviews the utility of diffusion-weighted imaging (DWI) in the diagnosis, prognosis and monitoring of treatment response in tumors arising in the head and neck region. The apparent diffusion coefficient (ADC) value, determined from DWI, can help in cancer staging and detection of subcentimeter nodal metastasis. The ADC value also discriminates carcinomas from lymphomas, benign lesions from malignant tumors and tumor necrosis from abscesses. Low pretreatment ADC values typically predict a favorable response to chemoradiation therapy. These promising reports indicate the potential of DWI as a potential biomarker for diagnosis and monitoring of treatment response in head and neck cancers. In view of the overlapping ADC values between different salivary gland tumors, care should be taken when interpreting these results and other imaging parameters should be considered for a better diagnosis. Susceptibility and motion-induced artifacts may sometimes degrade DWI image quality; however, novel techniques are being developed to overcome these drawbacks.

18F-Fluorodeoxyglucose-PET/CT to evaluate tumor, nodal disease, and gross tumor volume of oropharyngeal and oral cavity cancer: comparison with MR imaging and validation with surgical specimen

INTRODUCTION

The purpose of this paper is to evaluate the impact of adding combined 18F-PET/CT to MRI for T and N staging of the oral and oropharyngeal cancer and calculation of the gross tumor volume (GTV) having histopathology as reference standard.

METHODS

PET/CT and MRI were performed in 66 patients with suspected oral and oropharyngeal cancer (41 primary tumors/25 recurrent tumors) and nodal disease (114 nodes). Statistical analysis included the McNemar test, sensitivity, specificity for the diagnostic modalities as well as regression analysis, and Bland-Altman graphs for calculated tumor volumes.

RESULTS

There was no statistically significant difference between the two modalities compared to pathological findings regarding detection of disease (P > or =0.72). The sensitivity/specificity for tumor detection were 100/80% and 96.72/60% for MRI and PET/CT, respectively. The sensitivity/specificity for nodal metastases were 88.46/75% and 83.81/73.91% for MRI and PET/CT, respectively. In 18% of cases, the MRI-based T staging resulted in an overestimation of the pathologic tumor stage. The corresponding rate for PET/CT was 22%. Regarding the treated necks, both modalities showed 100% sensitivity for detection of the recurrent lesions. In necks with histologically N0 staging, MRI and PET/CT gave 22% and 26% false positive findings, respectively. The mean tumor volume in the pathologic specimen was 16.6 +/- 18.6 ml, the mean volume derived by the MR imaging was 17.6 +/- 19.1 ml while the estimated by PET/CT volume was 18.8 +/- 18.1 ml (P < or =0.007 between the three methods). The Bland-Altman analysis showed a better agreement between PET/CT and MRI.

CONCLUSION

The diagnostic performance of FDG-PET/CT in the local staging of oral cancer is not superior to MRI.

Incidental head and neck (18)F-FDG uptake on PET/CT without corresponding morphological lesion: early predictor of cancer development?

PURPOSE

To retrospectively determine whether increased/asymmetric FDG uptake on PET without a correlating morphological lesion on fully diagnostic CT indicates the development of a head and neck malignancy.

METHODS

In 590 patients (mean age 55.4 +/- 13.3 years) without a head and neck malignancy/inflammation FDG uptake was measured at (a) Waldeyer's ring, (b) the oral floor, (c) the larynx, and (d) the thyroid gland, and rated as absent (group A), present (group B), symmetric (group B1) or asymmetric (group B2). Differences between groups A and B and between B1 and B2 were tested for significance with the U-test (p < 0.05). An average follow-up of about 2.5 years (mean 29.5 +/- 13.9 months) served as the reference period to determine whether patients developed a head and neck malignancy.

RESULTS

Of the 590 patients, 235 (40%) showed no evidence of enhanced FDG uptake in any investigated site, and 355 (60%) showed qualitatively elevated FDG uptake in at least one site. FDG uptake values (SUV(max), mean+/-SD) for Waldeyer's ring were 3.0 +/- 0.89 in group A (n = 326), 4.5 +/- 2.18 in group B (n = 264; p < 0.01), 5.4 +/- 3.35 in group B1 (n = 177), and 4.1 +/- 1.7 in group B2 (n = 87; p < 0.01). Values for the oral floor were 2.8 +/- 0.74 in group A (n = 362), 4.7 +/- 2.55 in group B (n = 228; p < 0.01), 4.4 +/- 3.39 in group B1 (n = 130), and 5.1 +/- 2.69 in group B2 (n = 98, p = 0.01). Values for the larynx were 2.8 +/- 0.76 in group A (n = 353), 4.2 +/- 2.05 in group B (n = 237; p < 0.01), 4.0 +/- 2.02 in group B1 (n = 165), and 4.6 +/- 2.8 in group B2 (n = 72; p = 0.027). Values for the thyroid were 2.4 +/- 0.63 in group A (n = 404), 3.0 +/- 1.01 in group B (n = 186; p < 0.01), 2.6 +/- 0.39 in group B1 (n = 130), and 4.0 +/- 1.24 in group B2 (n = 56; p < 0.01). One patient developed a palatine tonsil carcinoma (group B1, SUV(max) 3.2), and one patient developed an oral floor carcinoma (group B1, SUV(max) 3.7).

CONCLUSION

Elevated/asymmetric head and neck FDG accumulation without a correlating morphological lesion can frequently be found and does not predict cancer development. In populations in which goitre is endemic, FDG uptake by the thyroid is common and not associated with thyroid cancer.