18F-fluorodeoxyglucose positron emission tomography to evaluate cervical node metastases in patients with head and neck squamous cell carcinoma: a meta-analysis

Impact of positron emission tomography with computed tomography for image-guided radiotherapy

Therapeutic effectiveness in radiotherapy is partly related to correct staging of the disease and then precise therapeutic targeting. Positron emission tomography (PET) allows the stage of many cancers to be determined and therefore is essential before deciding on radiation treatment. The definition of the therapeutic target is essential to obtain correct tumour control and limit side effects. The part of adaptive radiotherapy remains to be defined, but PET by its functional nature makes it possible to define the prognosis of many cancers and to consider radiotherapy adapted to the initial response allowing an increase over the entire metabolic volume, or targeted at a subvolume at risk per dose painting, or with a decrease in the dose in case of good response at interim assessment.

A Review of Modern Radiation Therapy Dose Escalation in Locally Advanced Head and Neck Cancer

The management of head and neck cancer is complex and often involves multimodality treatment. Certain groups of patients, such as those with inoperable or advanced disease, are at higher risk of treatment failure and may therefore benefit from radiation therapy dose escalation. This can be difficult to achieve without increasing toxicity. However, the combination of modern treatment techniques and increased research into the use of functional imaging modalities that assist with target delineation allows researchers to push this boundary further. This review aims to summarise modern dose escalation trials to identify the impact on disease outcomes and explore the growing role of functional imaging modalities. Studies experimenting with dose escalation above standard fractionated regimens as outlined in National Comprehensive Cancer Network guidelines using photon therapy were chosen for review. Seventeen papers were considered suitable for inclusion in the review. Eight studies investigated nasopharyngeal cancer, with the remainder treating a range of subsites. Six studies utilised functional imaging modalities for target delineation. Doses as high as 85.9 Gy in 2.6 Gy fractions (EQD2 90.2 Gy₁₀) were reportedly delivered with the aid of functional imaging modalities. Dose escalation in nasopharyngeal cancer resulted in 3-year locoregional control rates of 86.6-100% and overall survival of 82-95.2%. For other mucosal primary tumour sites, 3-year locoregional control reached 68.2-85.9% and 48.4-54% for overall survival. There were no clear trends in acute or late toxicity across studies, regardless of dose or addition of chemotherapy. However, small cohort sizes and short follow-up times may have resulted in under-reporting. This review highlights the future possibilities of radiation therapy dose escalation in head and neck cancer and the potential for improved target delineation with careful patient selection and the assistance of functional imaging modalities.

Current Standards for Organ Preservation in Locoregionally Advanced Non-nasopharyngeal Head and Neck Cancer and Evolving Strategies for Favorable-Risk and Platinum-Ineligible Populations

OPINION STATEMENT

Standard-of-care treatment for the majority of patients with locoregionally advanced squamous cell carcinoma of the head and neck (SCCHN) is either upfront surgery followed by adjuvant treatment as indicated by intraoperative or pathologic findings or concurrent chemoradiation reserving surgical salvage for non-responsive disease. An attempt at upfront complete resection should be pursued if feasible in patients with oral cavity or paranasal sinus primary tumors. Given multimodality treatment paradigms, patients with locoregionally advanced SCCHN should be managed in a multidisciplinary setting. Modern radiation therapy, whether postoperative or definitive in intent, is based on target delineation guided by high-quality imaging, using an intensity-modulated radiation technique to spare organs at risk. In select groups of low-risk patients, most notably those with HPV-associated oropharyngeal SCC (OPSCC), several treatment deintensification approaches are currently under investigation. Major experimental strategies within this non-surgical organ preservation domain include reductions in the intensity of the chemotherapy or radiation therapy components of the chemoradiation program, use of induction chemotherapy, or imaging-based selection of patients eligible for deintensified radiation-based treatment. Of note, recent efforts to substitute cetuximab for cisplatin in low-risk HPV-associated OPSCC have demonstrated the inferiority of cetuximab to cisplatin in cisplatin-eligible patients, re-confirming cisplatin as the standard systemic therapy of choice in HNSCC. In patients who are not candidates for any type of cisplatin administration, carboplatin-based therapy or cetuximab remain options, and other non-cisplatin therapies are under investigation. Altered fractionation may be considered in patients who are not candidates for any type of systemic therapy. The role of immunotherapy in the management of locoregional SCCHN remains investigational.

Clinical value of 18F-FDG-PET/CT in staging cutaneous squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin malignancy. Computed tomography (CT) and/or MRI are commonly used for staging, however, the role of fluorine-18-fluorodeoxyglucose (F-FDG)-PET is not clearly established. In this study, we evaluated F-FDG-PET/CT imaging for initial staging of cSCC.

PATIENTS AND METHODS

F-FDG-PET/CT scans performed in patients with newly diagnosed cSCC were reviewed retrospectively. Images were visually assessed for lesions and F-FDG uptake [standardized uptake value (SUV)] in primary and secondary sites was measured. Suspected lesions on F-FDG-PET/CT were correlated with histopathology when available, follow-up imaging or clinical data in others.

RESULTS

Twenty-three cSCC patients who underwent F-FDG-PET/CT at diagnosis were evaluated. Primary sites were in head/neck (n=21), chest (n=1), and foot (n=1). All patients had F-FDG-positive scans with a total of 51 F-FDG-positive lesions. All primary lesions (n=24) were F-FDG-positive (SUV: 2.3-22.8; mean 10.2), and additional 27 F-FDG-positive lesions, including 21 nodes, four cutaneous, one osseous and one lung lesion, were noted in 13 patients. Mean size of F-FDG-positive nodes was 0.9 cm (range: 0.4-2.5 cm), predominantly clinically impalpable. Pathology was available for 40/51 lesions; 31 sites positive for malignancy. SUV (mean±SD) was 9.2±6.2 for malignant and 2.7±1.2 for benign lesions. Sensitivity, positive predictive value, and accuracy of F-FDG-PET/CT scan were 100, 77.5, and 77.5%, respectively. F-FDG detected seven additional lesions in three patients, compared to CT/MRI. Overall, staging F-FDG-PET/CT detected nine prior unknown lesions in five patients that were proven metastatic disease by histopathology or follow-up; F-FDG-PET/CT modified management in 5/23 (21.7%) patients.

CONCLUSION

F-FDG-PET/CT has high sensitivity in the detection of cSCC lesions, including small cutaneous and nodal disease, and has a potential role in initial staging and management.

Rational choice of neck dissection in clinically N0 patients with supraglottic cancer

BACKGROUND

The mainstay treatment of the neck for clinically negative neck (cN0) supraglottic laryngeal carcinoma (SGLC) is neck dissection. However, the optimal extent remains controversial. This study's purpose is to determine whether ipsilateral level II-III neck dissection is appropriate for cN0SGLC patients.

METHODS

The records of 220 consecutive untreated cN0SGLC patients were retrospectively reviewed. Relevant factors related to occult and contralateral neck metastasis were analyzed and the distribution of metastasis was described.

RESULTS

Seventy-seven and 143 patients underwent unilateral and bilateral neck dissection, respectively. The rate of occult neck metastases was 21.4%. The histologic differentiation was an independent risk factor for occult neck metastasis. In the bilateral neck dissection group, the incidence of contralateral neck metastasis of patients with noncentral tumors was 0.7%. Moreover, only 1.7% of patients had positive nodes at level IV, and no isolated nodal metastases existed in level IV.

CONCLUSION

Ipsilateral level II-III neck dissection is feasible for patients with noncentral cN0SGLC.

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.

[Individualization of dose and fractionation of radiotherapy for head and neck cancers]

Head and neck cancers comprise a variety of tumours depending on the sub-site, for which target volumes and the prescribed doses need to be individualized according to each patient's history and presentation. This article aims at describing the main factors involved in decision-making regarding dose and volume, as well as ongoing research. Contouring and treatment guidelines, use of altered fractionation, major prognostic factors, the role of Human papillomavirus and of functional imaging will be presented and discussed.

18F-FDG-PET/CT-based treatment planning for definitive (chemo)radiotherapy in patients with head and neck squamous cell carcinoma improves regional control and survival

BACKGROUND AND PURPOSE

Multimodality imaging including ¹⁸F-FDG-PET has improved the detection threshold of nodal metastases in head and neck squamous cell carcinoma (HNSCC). The aim of this retrospective analysis is to investigate the impact of FDG-PET/CT-based nodal target volume definition (FDG-PET/CT-based NTV) on radiotherapy outcomes, compared to conventional CT-based nodal target volume definition (CT-based NTV).

MATERIALS AND METHODS

Six-hundred-thirty-three patients treated for HNSCC with definitive (chemo)radiotherapy using IMRT/VMAT techniques between 2008 and 2017 were analyzed. FDG-PET/CT-based NTV was performed in 46% of the patients. The median follow-up was 31 months. Diagnostic imaging depicting the regional recurrence was co-registered with the initial CT-scan to reconstruct the exact site of the recurrence. Multivariate Cox regression analysis was performed to identify variables associated with radiotherapy outcome.

RESULTS

FDG-PET/CT-based NTV improved control of disease in the CTV_{elective-nodal} (HR: 0.33, p = 0.026), overall regional control (HR: 0.62, p = 0.027) and overall survival (HR: 0.71, p = 0.033) compared to CT-based NTV. The risk for recurrence in the CTV_{elective-nodal} was increased in case of synchronous local recurrence of the primary tumor (HR: 12.4, p < 0.001).

CONCLUSION

FDG-PET/CT-based NTV significantly improved control of disease in the CTV_{elective-nodal}, overall regional control and overall survival compared to CT-based NTV. A significant proportion of CTV_{elective-nodal} recurrences are potentially new nodal manifestations from a synchronous local recurrent primary tumor. These results support the concept of target volume transformation and give an indication of the potential of FDG-PET to guide gradual radiotherapy dose de-escalation in elective neck treatment in HNSCC.

Imaging at diagnosis impacts cancer-specific survival among patients with cancer of the oropharynx

BACKGROUND

The optimal imaging for the staging of oropharyngeal cancer is not well defined.

METHODS

The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database for 2006 through 2011 was used to compare patient characteristics and hospital region by the initial imaging modality used for patients with oropharyngeal cancer. The primary outcome was 3-year cancer-specific survival (CSS). Cox proportional hazards models were adjusted for imaging, age, sex, region, education, race, American Joint Committee on Cancer stage of disease, and treatment, which were examined using backward elimination. The authors also explored how initial imaging use varied by patient characteristics and hospital region.

RESULTS

A total of 1765 patients underwent initial diagnostic imaging. Of those, approximately 11.4% (202 patients) received computed tomography (CT) alone as their initial imaging modality, 5.2% (91 patients) underwent magnetic resonance imaging (MRI) without positron emission tomography (PET), and 83.3% (1472 patients) had initial imaging that included PET. The overall 3-year CSS rate for the entire population was 63.7%. In the adjusted survival models compared by initial imaging modality, patients who underwent a PET examination were found to have higher survival than those who underwent CT alone or MRI, respectively (hazard ratio, 1.337 [95% CI, 1.001-1.785; P = .0491]; and hazard ratio, 1.748 [95% CI, 1.2-2.545; P = .0036]).

CONCLUSIONS

Among patients with oropharyngeal cancer, initial staging with PET imaging was associated with improved 3-year CSS compared with initial staging with MRI or CT.

A Bayesian network model of lymphatic tumor progression for personalized elective CTV definition in head and neck cancers

Many tumors including head and neck squamous cell carcinoma (HNSCC) spread along the lymphatic network. Current imaging modalities can only detect sufficiently large metastases. Therefore, adjacent lymph node levels (LNL) are irradiated electively since they may harbor microscopic tumors. We apply Bayesian Networks (BN) to model lymphatic tumor progression. The model can subsequently be used to personalize the risk estimation of microscopic lymph node metastases in newly diagnosed patients based on their distribution of macroscopic metastases. A BN is a graphical representation of a joint probability distribution. We represent LNLs by binary random variables corresponding to the BN nodes. Each LNL is associated with a hidden microscopic state and an observed macroscopic state (e.g. ¹⁸F-FDG-PET/CT imaging). The primary tumor is represented by network input nodes. We demonstrate the concept for early T-stage oropharyngeal carcinomas and their spread to ipsilateral lymph node levels (LNL) Ib to IV. We show that the BN parameters can be efficiently learnt by merging pathology findings on microscopic tumor progression (which is limited to a few published studies) and imaging data on macroscopic tumor progression such as CT and ¹⁸F-FDG-PET (which are widely available in clinical practice). The trained network can be used to quantify how the distribution of macroscopic metastases impacts the probability of microscopic involvement of the remaining LNLs. The analysis suggests that the risk of microscopic involvement of level IV exceeds 5% only if level III harbors metastases. Excluding level IV from the elective CTV for other patients would reduce the integral dose delivered to the patient and potentially reduce acute and late side effects.

Predictive Value of Pretherapeutic Maximum Standardized Uptake Value (Suvmax) In Laryngeal and Hypopharyngeal Cancer

The aim of the study was to evaluate whether pretherapeutic metabolic tumor parameters from 18-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging could predict larynx preservation in laryngeal and hypopharyngeal cancer patients prior to primary chemoradiation. Tumor metabolic parameters [maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), and total lesion glycolysis (TLG)] were retrospectively assessed in a consecutive cohort of laryngeal and hypopharyngeal cancer patients undergoing primary (chemo-)radiation. Main outcome measures were larynx preservation and survival. The study included 97 patients with a median follow-up of 32 months (IQR 20-54.5). For hypopharyngeal cancer, multivariable analysis showed that patients with a primary tumor's SUV_max > 9.5 entailed a higher risk of undergoing salvage pharyngolaryngectomy after chemoradiation (HR = 8.64, 95% CI = 1.1-67.3, P = 0.040). In laryngeal cancer, SUV_max did not predict the need for salvage laryngectomy. The only predictor for larynx preservation in laryngeal cancer patients was T-classification at initial diagnosis (HR = 6.67, 95% CI = 0.82-53.9, P = 0.039). In conclusion, SUV_max of primary tumor could be used as a predictor of larynx preservation prior to primary chemoradiation in hypopharyngeal cancer patients. This information may be important for patient counseling, as high SUV_max was correlated with reduced probability of larynx preservation. However, in laryngeal cancer patients, SUV_max does not seem to be predictive of outcome.

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.

CT Texture Analysis of Cervical Lymph Nodes on Contrast-Enhanced [18F] FDG-PET/CT Images to Differentiate Nodal Metastases from Reactive Lymphadenopathy in HIV-Positive Patients with Head and Neck Squamous Cell Carcinoma

BACKGROUND AND PURPOSE

Differentiating nodal metastases from reactive adenopathy in HIV-infected patients with [¹⁸F] FDG-PET/CT can be challenging because lymph nodes in HIV-positive patients often show increased [¹⁸F] FDG uptake. The purpose of this study was to assess CT textural analysis characteristics of HIV-positive and HIV-negative lymph nodes on [¹⁸F] FDG-PET/CT to differentiate nodal metastases from disease-specific nodal reactivity.

MATERIALS AND METHODS

Nine HIV-positive patients with head and neck squamous cell carcinoma (7 men, 2 women; 29-62 years of age; median age, 48 years) with 22 lymph nodes (≥1 cm) who underwent contrast-enhanced CT with [¹⁸F] FDG-PET followed by pathologic evaluation of cervical lymph nodes were retrospectively reviewed. Twenty-six HIV-negative patients with head and neck squamous cell carcinoma with 61 lymph nodes were evaluated as a control group. Each lymph node was manually segmented, and an in-house-developed Matlab-based texture analysis program extracted 41 texture features from each segmented volume. A mixed linear regression model was used to compare the pathologically proved malignant lymph nodes with benign nodes in the 2 enrolled groups.

RESULTS

Thirteen (59%) lymph nodes in the HIV-positive group and 22 (36%) lymph nodes in the HIV-negative control group were confirmed as positive for metastases. There were 7 histogram features (P = .017-0.032), 3 gray-level co-occurrence features (P = .009-.025), and 9 gray-level run-length features (P < .001-.033) that demonstrated a significant difference in HIV-positive patients with either benign or malignant lymph nodes.

CONCLUSIONS

CT texture analysis may be useful as a noninvasive method of obtaining additional quantitative information to differentiate nodal metastases from disease-specific nodal reactivity in HIV-positive patients with head and neck squamous cell carcinoma.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

Update 2018: 18F-FDG PET/CT and PET/MRI in Head and Neck Cancer

There are recent advances, namely, a standardized method for reporting therapy response (Hopkins criteria), a multicenter prospective cohort study with excellent negative predictive value of F-FDG PET/CT for N0 clinical neck, a phase III multicenter randomized controlled study establishing the value of a negative posttherapy F-FDG PET/CT for patient management, a phase II randomized controlled study demonstrating radiation dose reduction strategies for human papilloma virus-related disease, and Food and Drug Administration approval of nivolumab for treatment of recurrent head and neck squamous cell carcinoma.

Prognostic value of metabolic tumor burden calculated using dual-time-point 18F-fluorodeoxyglucose positron emission tomography/CT in patients with oropharyngeal or hypopharyngeal cancer

BACKGROUND

This study investigates the prognostic value of metabolic tumor burden calculated using dual-time-point 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT in patients with locally advanced cancer.

METHODS

This study examines 42 patients (35 men and 7 women, 38-73 years old) with locally advanced oropharyngeal or hypopharyngeal cancer who had undergone FDG-PET/CT before receiving chemoradiotherapy. Maximum standardized uptake value (SUV_max ), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured for the early and delayed phases. Statistical analyses included receiver operating characteristic curve, univariate and multivariate analysis.

RESULTS

ΔSUV_max , both phases of MTV_2.5 and TLG_2.5 , early TLG_40% , ΔTLG_2.5 , and ΔTLG_40% were significantly associated with progression-free survival (PFS). In multivariate analysis, early TLG_2.5 (P = .005) was an independent prognostic factor of PFS.

CONCLUSION

Not the percent change but the value calculated in the early phase in several parameters using dual-time-point FDG-PET/CT is significantly associated with the outcomes of patients with locally advanced oropharyngeal or hypopharyngeal cancer.

Current State of Image Guidance in Radiation Oncology: Implications for PTV Margin Expansion and Adaptive Therapy

Image guidance technology has evolved and seen widespread application in the past several decades. Advancements in the diagnostic imaging field have found new applications in radiation oncology and promoted the development of therapeutic devices with advanced imaging capabilities. A recent example is the development of linear accelerators that offer magnetic resonance imaging for real-time imaging and online adaptive planning. Volumetric imaging, in particular, offers more precise localization of soft tissue targets and critical organs which reduces setup uncertainty and permit the use of smaller setup margins. We present a review of the status of current imaging modalities available for radiation oncology and its impact on target margins and use for adaptive therapy.

Oral cancers: Current status

Oral cancer is a global disease. Despite a well elucidated tumour progression model, these cancers present late. Attempts at early detection by way of adjunctive diagnostic technologies and screening have not lived up to expectations in spite initial promise. Surgery is the mainstay of treatment. Treatment intensification by way of adjuvant radiation/chemo radiation is warranted for those with high risk features. Recent studies have explored intensification in those with intermediate risk factors in an attempt to improve outcomes. There has been generation of recent robust evidence that has influenced the need and extent of neck dissection. Neoadjuvant chemotherapy (NACT) may have a potential role in organ preservation and borderline resectable oral cancers. Recurrent tumours should be offered surgery whenever feasible while the addition of biological agents to chemotherapy gives best results in the palliative settings.

Differential impact of circulating tumor cells on disease recurrence and survivals in patients with head and neck squamous cell carcinomas: An updated meta-analysis

Purpose

The prognostic impact of circulating tumor cells (CTC) on disease recurrence, progression and survivals in patients with head and neck squamous cell carcinoma (HNSCC) has not been adequately described. The objective of this study was to determine the impacts of the presence of CTC on loco-regional recurrence and survival of HNSCC patients by conducting a systematic review and meta-analysis.

Methods

A comprehensive search for articles published between 1990 and 2016 was conducted and data from these studies were extracted, using the MEDLINE, Cochrane Library, and EMBASE databases. The main outcomes were overall survival (OS) and recurrence-free survival (RFS) of HNSCC patients. Pooled hazard ratio (HR) and 95% confidence intervals (95%CI) were calculated using the random effect model for outcomes. The quality of the studies, heterogeneity and publication bias were assessed with the appropriate statistical methods.

Results

Six eligible studies with 429 patients were identified. The presence of CTC was significantly associated shorter RFS (HR = 4.88 [95%CI: 1.93–12.35], P < 0.001). However, it could not predict patients’ OS (HR = 1.92 [95%CI: 0.93–3.96], P = 0.078). The following analyses using univariable values of each study also made the similar results (HR = 1.70 [95%CI: 0.83–3.45] for OS, HR = 3.79 [95%CI: 2.02–7.13] for RFS). Heterogeneity and publication bias were not significant, except one enrolled study.

Conclusions

The presence of CTC is not a significant prognostic indicator for OS of patients with HNSCC, although it could reflect the outcomes of loco-regional disease.

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.

The effectiveness of the follow-up of patients after surgery due to cancer of the head and neck

Aim: The aim of this study was to assess the effectiveness of the follow-up (FU) of patients after head and neck cancer treatment. Materials & methods: This is a retrospective cross-sectional study and concerns the analysis of outpatient records of 85 women and 355 men who reported at FU visits between 2011 and 2016 in ENT Department in the University Of Medical Sciences in Poznan, Poland. Results: The value of the FU scheme was confirmed by a high rate of recurrence detected in a medical examination (60%) and routine imaging studies (27%), as opposed to only 13% in spontaneous reports. Conclusion: The FU therapeutic profit in the form of high percentages of preclinical relapse at a reasonable cost is justified medically and socially.

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.

Dual-Energy CT-Derived Iodine Content and Spectral Attenuation Analysis of Metastatic Versus Nonmetastatic Lymph Nodes in Squamous Cell Carcinoma of the Oropharynx

The presence of a single nodal metastasis has significant prognostic and treatment implications for patients with head and neck cancer. This study aims to investigate whether dual-energy computed tomography (DECT)-derived iodine content and spectral attenuation curve analysis can improve detection of nodal metastasis in oropharyngeal carcinoma. Eight patients with newly diagnosed oropharyngeal squamous cell carcinoma and pathologically proven nodal metastatic disease (n = 13 metastatic nodes; n = 16 nonmetastatic nodes) who underwent contrast-enhanced DECT of the neck were retrospectively evaluated. DECT-derived iodine content (mg/mL) and monoenergetic attenuation values at 40 keV and 100 keV were obtained via circular regions of interest within metastatic and nonmetastatic cervical lymph nodes. Iodine content was significantly lower in metastatic nodes (0.96 ± 0.28 mg/mL) than in nonmetastatic nodes (1.65 ± 0.38 mg/mL; P = .002). Iodine spectral attenuation slope was significantly lower in metastatic nodes (1.33 ± 0.49 mg/mL) than in nonmetastatic nodes (1.91 ± 0.64 mg/mL; P = .015). A nodal iodine threshold of ≤1.3 mg/mL showed a sensitivity of 84.6% and a specificity of 75.0%, with an area under the curve of 0.839, P < .0001. At a threshold value of ≤1.95 for nodal spectral attenuation slope, an optimized specificity of 92.3% and specificity of 50.0% was achieved, with an area under the curve of 0.68 (P = .049). DECT-derived quantitative iodine data and spectral attenuation curves may improve the diagnostic accuracy of computed tomography for nodal metastasis in patients with squamous cell carcinoma of the oropharynx.

Molecular Imaging-Guided Radiotherapy for the Treatment of Head-and-Neck Squamous Cell Carcinoma: Does it Fulfill the Promises?

With the routine use of intensity modulated radiation therapy for the treatment of head-and-neck squamous cell carcinoma allowing highly conformed dose distribution, there is an increasing need for refining both the selection and the delineation of gross tumor volumes (GTV). In this framework, molecular imaging with positron emission tomography and magnetic resonance imaging offers the opportunity to improve diagnostic accuracy and to integrate tumor biology mainly related to the assessment of tumor cell density, tumor hypoxia, and tumor proliferation into the treatment planning equation. Such integration, however, requires a deep comprehension of the technical and methodological issues related to image acquisition, reconstruction, and segmentation. Until now, molecular imaging has had a limited value for the selection of nodal GTV, but there are increasing evidences that both FDG positron emission tomography and diffusion-weighted magnetic resonance imaging has a potential value for the delineation of the primary tumor GTV, effecting on dose distribution. With the apprehension of the heterogeneity in tumor biology through molecular imaging, growing evidences have been collected over the years to support the concept of dose escalation/dose redistribution using a planned heterogeneous dose prescription, the so-called "dose painting" approach. Validation trials are ongoing, and in the coming years, one may expect to position the dose painting approach in the armamentarium for the treatment of patients with head-and-neck squamous cell carcinoma.

Cell-Free Plasma DNA for Disease Stratification and Prognosis in Head and Neck Cancer

BACKGROUND

Clinicians face many challenges in disease stratification and outcome prediction in head and neck squamous cancer cell (HNSCC) patients. Given the limitations of currently used clinical scoring, repetitive biopsies, and imaging techniques, liquid biopsy approaches may provide valuable additional diagnostic and prognostic information.

METHODS

A noninterventional, single-center observational study was performed with clinical data and plasma samples from HNSCC patients. Cell-free tumor DNA-derived copy number aberrations (CNAs) were determined in 116 patients by low-coverage next-generation sequencing (NGS). Significant CNAs were combined in a genome-wide copy number instability score (CNI), which was evaluated with respect to conventional clinical staging and patient outcome.

RESULTS

Receiver-operating characteristic (ROC) curve analysis comparing the presurgery CNI in patients (n = 103) with that in tumor-free controls (n = 142) yielded an area under the ROC curve of 87.2% (95% CI, 79.4%-93.3%). At a specificity of 95%, the sensitivity to detect tumors varied between 46% (pT1) and 94% (pT4). A CNI above the median (i.e., >72) had a positive predictive value of 90% (95% CI, 79%-96%) for lymph node involvement (LNI), while the negative predictive value was 57% (95% CI, 43%-70%). For a CNI >72, overall survival (OS) was worse (hazard ratio, 4.89; 95% CI, 1.39-17.17; P = 0.01) with 62% and 90% survivors 3 years after surgery for a CNI >72 and ≤72, respectively. In multivariable models, the CNI was a superior predictor of OS compared to established disease features, including LNI.

CONCLUSIONS

The CNI may assist in predicting LNI and prognosis in HNSCC with direct therapeutic implications concerning the need for neck dissection or more aggressive treatment.

The value of shear wave elastography in predicting for undiagnosed small cervical lymph node metastasis in nasopharyngeal carcinoma: A preliminary study

BACKGROUND

To investigate the diagnostic value of shear wave elastography (SWE) in identifying cervical small lymph node metastases in nasopharyngeal carcinoma (NPC) patients.

MATERIALS AND METHODS

This prospective study was approved by the local institutional review board. From July 2014 to March 2016, 114 sLNs from 62 newly diagnosed NPC patients (47 men, 15 women) were assessed. Target small lymph nodes (sLNs), which were undiagnosed by magnetic resonance imaging (MRI), were defined as scattered cervical lymph nodes that had no evidence of central necrosis or extracapsular spread and exhibited a maximum transverse diameter ≥5 mm and <10 mm in MRI. The mean (Emean), minimum (Emin) and maximum (Emax) of the elasticity indices (EIs) were measured by SWE at the stiffest part of the sLN (kPa). Biopsy pathology was served as the reference standard. Diagnostic performances were assessed using receiver operating curve (ROC) analysis on a node-by-node basis.

RESULTS

Of the 114 small cervical lymph nodes, 88 (77.2%) were benign, and 26 (22.8%) were malignant. All SWE EIs were significantly higher in malignant sLNs than in benign sLNs (p < 0.001). Emean exhibited the highest diagnostic value (area under the curve = 0.879 ± 0.036) (p < 0.001) and the corresponding sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 84.6%, 83.0%, 59.5%, 94.8% and 83.3%, respectively. The intra-observer reproducibility of all SWE EIs were significant, with intra-class correlation coefficient (ICC) of 0.745 in Emean, 0.716 in Emax and 0.702 in Emin.

CONCLUSION

Shear wave elastography is an optional supplementary imaging modality to routine MRI examination to diagnose cervical lymph nodes in NPC patients.

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.

Metabolic Tumor Volume and Total Lesion Glycolysis in Oropharyngeal Cancer Treated With Definitive Radiotherapy: Which Threshold Is the Best Predictor of Local Control?

PURPOSE

In the context of oropharyngeal cancer treated with definitive radiotherapy, the aim of this retrospective study was to identify the best threshold value to compute metabolic tumor volume (MTV) and/or total lesion glycolysis to predict local-regional control (LRC) and disease-free survival.

METHODS

One hundred twenty patients with a locally advanced oropharyngeal cancer from 2 different institutions treated with definitive radiotherapy underwent FDG PET/CT before treatment. Various MTVs and total lesion glycolysis were defined based on 2 segmentation methods: (i) an absolute threshold of SUV (0-20 g/mL) or (ii) a relative threshold for SUVmax (0%-100%). The parameters' predictive capabilities for disease-free survival and LRC were assessed using the Harrell C-index and Cox regression model.

RESULTS

Relative thresholds between 40% and 68% and absolute threshold between 5.5 and 7 had a similar predictive value for LRC (C-index = 0.65 and 0.64, respectively). Metabolic tumor volume had a higher predictive value than gross tumor volume (C-index = 0.61) and SUVmax (C-index = 0.54). Metabolic tumor volume computed with a relative threshold of 51% of SUVmax was the best predictor of disease-free survival (hazard ratio, 1.23 [per 10 mL], P = 0.009) and LRC (hazard ratio: 1.22 [per 10 mL], P = 0.02).

CONCLUSIONS

The use of different thresholds within a reasonable range (between 5.5 and 7 for an absolute threshold and between 40% and 68% for a relative threshold) seems to have no major impact on the predictive value of MTV. This parameter may be used to identify patient with a high risk of recurrence and who may benefit from treatment intensification.

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.

Chapter 3 The Role of PET/CT in Squamous Cell Carcinoma of the Head and Neck

Head and neck squamous cell carcinoma is an important cause of cancer morbidity worldwide and has been stratified into human papillomavirus-related and human papillomavirus-unrelated subgroups that affect prognosis and now staging. Conventional anatomical imaging methods are suboptimal for the detection of regional and distant metastases that are important prognosticators associated with poor outcomes. Functional imaging with (F18)-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) is a useful tool in the management of head and neck squamous cell carcinoma, providing complementary physiological and anatomical information. In this article, optimal PET/CT technique will be reviewed and the pretreatment and posttreatment applications of PET/CT will be described. A simplified approach to imaging interpretation, including review of pearls and pitfalls will be discussed. An initial framework for follow-up evaluation will be provided.

Dual-Energy Computed Tomography Applications for the Evaluation of Cervical Lymphadenopathy

There is recent interest in the use of dual-energy computed tomography (CT) in head and neck imaging, and the results are encouraging. This article reviews dual-energy CT applications as complementary tools to conventional CT scanning in the evaluation of cervical lymphadenopathy. The article cites the most relevant studies and highlights their results. Single-source and dual-source dual-energy applications including virtual noncontrast images, linear and nonlinear image blending, monochromatic images, iodine quantification, and spectral Hounsfield unit attenuation curve analysis are reviewed. Future directions and research suggestions are discussed in brief.

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 value of 18F-FDG-PET/CT in patients with nasopharyngeal carcinoma: a systematic review and meta-analysis

BACKGROUND

The prognostic role of 18F-fluorodeoxyglucose positron emission tomography CT (18F-FDG PET/CT) parameters is still controversial in nasopharyngeal carcinoma patients. We sought to perform a systematic review and meta-analysis to explore the prognostic value of maximal standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) on event-free survival (EFS) and overall survival (OS) in nasopharyngeal carcinoma patients.

RESULTS

Fifteen studies comprising 1,938 patients were included in this study. The combined hazard ratios (HRs) for EFS were 2.63 (95%CI 1.71-4.05) for SUVmax, 2.55 (95%CI 1.49-4.35) for MTV, and 3.32 (95%CI 1.23-8.95) for TLG. The pooled HRs for OS were 2.07 (95%CI 1.54-2.79) for SUVmax, 3.86 (95%CI 1.85-8.06) for MTV, and 2.60 (95%CI 1.55-4.34) for TLG. The prognostic role of SUVmax, MTV and TLG remained similar in the sub-group analyses.

METHODS

A systematic literature search was performed to identify studies which associated 18F-FDG PET/CT to clinical survival outcomes of nasopharyngeal carcinoma patients. The summarized HRs for EFS and OS were estimated by using fixed- or random-effect models according to heterogeneity between trials.

CONCLUSIONS

The present meta-analysis confirms that high values of SUVmax, MTV and TLG predicted a higher risk of adverse events or death in patients with nasopharyngeal carcinoma, despite clinically heterogeneous nasopharyngeal carcinoma patients and the various methods adopted between these studies.

[PET-CT in head and neck cancer]

The importance of ¹⁸F-fluorodesoxyglucose positron-emission tomography (FDG-PET) for the diagnosis of malignant disease is increasing. On one hand, this is due to the high sensitivity of this method, on the other, because the entire body can be examined. FDG-PET can be particularly advantageous for the diagnosis of head and neck tumors, where tumor staging is an important prognostic parameter and essentially determines the therapeutic regimen. This article presents the different possibilities for combined evaluation with PET and computed tomography (CT) for the diagnosis of patients with head and neck cancer. Special focus is placed on primary staging and tumor follow-up, as well as on the role of PET-CT in the diagnosis of patients with cancer of unknown primary origin (CUP). The use of PET-CT for radiotherapy planning and new aspects of PET technology are also discussed.

Contemporary Diagnostic Imaging of Oral Squamous Cell Carcinoma - A Review of Literature

Oral squamous cell carcinoma (OSCC) is the most common cancer of the oral cavity and constitutes 95% of all cancers of this area. Men are affected twice as commonly as women, primarily if they are over 50 years of age. Forty percent of the lesions are localized in the tongue and 30% in the floor of the oral cavity. OSCC often affects upper and lower gingiva, buccal mucous membrane, the retromolar triangle and the palate. The prognosis is poor and the five-year survival rate ranges from 20% (OSCC in the floor of the mouth) to 60% (OSCC in the alveolar part of the mandible). Treatment is difficult, because of the localization and the invasiveness of the available methods. The diagnosis is made based on a histopathological examination of a biopsy sample.

The low detection rate of early oral SCC is a considerable clinical issue. Although the oral cavity can be easily examined, in the majority of cases oral SCC is diagnosed in its late stages. It is difficult to diagnose metastases in local lymph nodes and distant organs, which is important for planning the scope of resection and further treatment, graft implantation, and differentiation between reactive and metastatic lymph nodes as well as between disease recurrence and scars or adverse reactions after surgery or radiation therapy.

Imaging studies are performed as part of the routine work-up in oral SCC. However, it is difficult to interpret the results at the early stages of the disease. The following imaging methods are used – dental radiographs, panoramic radiographs, magnetic resonance imaging with diffusion-weighted and dynamic sequences, perfusion computed tomography, cone beam computed tomography, single-photon emission computed tomography, hybrid methods (PET/CT, PET/MRI, SPECT/CT) and ultrasound. Some important clinical problems can be resolved with the use of novel modalities such as MRI with ADC sequences and PET.

The aim of this article is to describe oral squamous cell carcinoma as it appears in different imaging methods considering both their advantages and limitations.

Guidelines for the Surgical Management of Laryngeal Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to develop clinical practice guidelines for the surgical treatment of laryngeal cancer. This Task Force conducted a systematic search of the EMBASE, MEDLINE, Cochrane Library, and KoreaMed databases to identify relevant articles, using search terms selected according to the key questions. Evidence-based recommendations were then created on the basis of these articles. An external expert review and Delphi questionnaire were applied to reach consensus regarding the recommendations. The resulting guidelines focus on the surgical treatment of laryngeal cancer with the assumption that surgery is the selected treatment modality after a multidisciplinary discussion in any context. These guidelines do not, therefore, address non-surgical treatment such as radiation therapy or chemotherapy. The committee developed 62 evidence-based recommendations in 32 categories intended to assist clinicians during management of patients with laryngeal cancer and patients with laryngeal cancer, and counselors and health policy-makers.

Positron emission tomography-CT prediction of occult nodal metastasis in recurrent laryngeal cancer

BACKGROUND

The purpose of this study was to evaluate the predictive value of positron emission tomography (PET)-CT in identifying occult nodal metastasis in clinically and radiographically N0 patients with recurrent laryngeal cancer undergoing salvage laryngectomy.

METHODS

Retrospective review of 46 clinically and radiographically N0 patients with recurrent laryngeal cancer who underwent a PET-CT examination before salvage laryngectomy with neck dissection from January 1, 2002, to December 31, 2014, was performed.

RESULTS

Two patients (16.7%) had true-positive PET-CT results, whereas 10 patients (83.3%) had false-negative scans, 1 patient (2.9%) had a false-positive result and 33 patients (97.1%) had a true-negative PET-CT. The sensitivity of PET-CT was 16.7% (95% confidence interval [CI], 3.5% to 46.0%) with a specificity of 97.1% (95% CI, 83.8% to 99.9%), positive predictive value (PPV) of 66.7% (95% CI, 20.2% to 94.4%), and negative predictive value (NPV) of 76.7% (95% CI, 62.1% to 87.0%).

CONCLUSION

PET-CT has poor sensitivity and NPV making PET-CT an imperfect predictor of nodal disease in recurrent laryngeal cancer. © 2017 Wiley Periodicals, Inc. Head Neck 39: 980-987, 2017.

A PET-based nomogram for oropharyngeal cancers

PURPOSE

In the context of locally advanced oropharyngeal cancer (LAOC) treated with definitive radiotherapy (RT) (combined with chemotherapy or cetuximab), the aims of this study were: (1) to identify PET-FDG parameters correlated with overall survival (OS) from a first cohort of patients; then (2) to compute a prognostic score; and (3) finally to validate this scoring system in a second independent cohort of patients.

MATERIALS AND METHODS

A total of 76 consecutive patients (training cohort from Rennes) treated with chemoradiotherapy or RT with cetuximab for LAOC were used to build a predictive model of locoregional control (LRC) and OS based on PET-FDG parameters. After internal calibration and validation of this model, a nomogram and a scoring system were developed and tested in a validation cohort of 46 consecutive patients treated with definitive RT for LAOC in Lausanne.

RESULTS

In multivariate analysis, the metabolic tumour volume (MTV) of the primary tumour and the lymph nodes were independent predictive factors for LRC and OS. Internal calibration showed a very good adjustment between the predicted OS and the observed OS at 24 months. Using the predictive score, two risk groups were identified (median OS 42 versus 14 months, p < 0.001) and confirmed in the validation cohort from Lausanne (median OS not reached versus 26 months, p=0.008).

CONCLUSIONS

This is the first report of a PET-based nomogram in oropharyngeal cancer. Interestingly, it appeared stronger than the classical prognostic factors and was validated in independent cohorts markedly diverging in many aspects, which suggest that the observed signal was robust.

Role of Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in the Evaluation of Head and Neck Carcinoma

Fluorodeoxyglucose (FDG)-positron emission tomography-computed tomography (PET-CT) has been playing a pivotal role in tumor imaging for the past 20 years. Head and neck (HN) cancers are a good example that can illustrate such unique role of FDG imaging contributing to the patient's management. In this review article, we will describe the normal physiological distribution of FDG within HN structures focusing on its limitations and pitfalls. In addition, we will be also describing its role in the initial staging and restaging of the disease, particularly with regard to therapy response assessment. Furthermore, its role in the evaluation of patients with malignant cervical adenopathy from an unknown primary will be described. In 2016, the Royal College of Radiologists in its third edition published evidence-based guidelines for PET-CT use in HN cancer emphasizing its rule in all these clinical scenarios that are being described in this review. Finally, we will be highlighting future directions in the field of molecular imaging of HN tumors with a special emphasis on the new PET tracers.

18F-FDG PET/CT to differentiate malignant necrotic lymph node from benign cystic lesions in the neck

OBJECTIVE

Patients presenting with cystic lesions in the neck without obvious signs of malignancy constitute a diagnostic challenge since fine needle aspiration is often insufficient and a diagnosis may not be reached until surgical resection/biopsy is performed. The differential diagnosis of a cystic cervical mass comprises a variety of benign conditions, but malignancy must be ruled out. We examined the diagnostic performance of fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) PET/CT to identify malignancy.

METHODS

We retrospectively included consecutive patients referred from the Department of ENT Head and Neck Surgery for ¹⁸F-FDG PET/CT-scans because of a solitary neck cyst. Scan results were compared to histopathology and follow-up.

RESULTS

The study comprised 58 patients. Twenty patients (34%) were diagnosed with cancer during follow-up. PET/CT suggested malignancy in 34 patients (19 true positive, 15 false positive) and showed no malignancy in 24 (23 true negative, 1 false negative). The sensitivity, specificity, accuracy, positive and negative predictive values were 95% (76-99%), 61% (45-74%), 72% (60-82%), 56% (39-71%), and 96% (80-99%), respectively (95% confidence intervals in brackets). The primary tumor was identified in 14 out of the 20 patients with confirmed cancer. Increased metabolism, as evaluated by PET, was the only imaging characteristic among several others, which associated independently with malignancy in the cystic neck lesions, odds ratio 1.27 (1.07-1.50), p = 0.006.

CONCLUSION

¹⁸F-FDG PET/CT could reliably rule out malignancy (NPV 96%), albeit with a high frequency of false positive scans, requiring further diagnostic work-up. Increased metabolism was the best imaging parameter to differentiate between malignant and benign lesions.