Use, Accuracy, and Implications for Patient Management of [18F]-2-Fluorodeoxyglucose-Positron Emission/Computerized Tomography for Head and Neck Tumors

Latin American Consensus on the Treatment of Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is well known as a serious health problem worldwide, especially in low-income countries or those with limited resources, such as most countries in Latin America. International guidelines cannot always be applied to a population from a large region with specific conditions. This study established a Latin American guideline for care of patients with head and neck cancer and presented evidence of HNSCC management considering availability and oncologic benefit. A panel composed of 41 head and neck cancer experts systematically worked according to a modified Delphi process on (1) document compilation of evidence-based answers to different questions contextualized by resource availability and oncologic benefit regarding Latin America (region of limited resources and/or without access to all necessary health care system infrastructure), (2) revision of the answers and the classification of levels of evidence and degrees of recommendations of all recommendations, (3) validation of the consensus through two rounds of online surveys, and (4) manuscript composition. The consensus consists of 12 sections: Head and neck cancer staging, Histopathologic evaluation of head and neck cancer, Head and neck surgery-oral cavity, Clinical oncology-oral cavity, Head and neck surgery-oropharynx, Clinical oncology-oropharynx, Head and neck surgery-larynx, Head and neck surgery-larynx/hypopharynx, Clinical oncology-larynx/hypopharynx, Clinical oncology-recurrent and metastatic head and neck cancer, Head and neck surgery-reconstruction and rehabilitation, and Radiation therapy. The present consensus established 48 recommendations on HNSCC patient care considering the availability of resources and focusing on oncologic benefit. These recommendations could also be used to formulate strategies in other regions like Latin America countries.

The impact of multimodality integrated positron emission tomography-computed tomography on improving the staging and management of head and neck malignancy: a cross- sectional study

BACKGROUND

Clinical assessment of head and neck cancers is highly challenging owing to the complexity of regional anatomy and wide range of lesions. The diagnostic evaluation includes detailed physical examination, biopsy and imaging modalities for disease extent and staging. Appropriate imaging is done to enable determination of precise tumor extent and involvement of lymph nodes, and detection of distant metastases and second primary tumors.

OBJECTIVE

To evaluate the initial staging discrepancy between conventional contrasted computed tomography (CT) and 18F-fluorodeoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) and its impact on management plans for head and neck malignancies.

DESIGN AND SETTING

Prospective cross-sectional study in two tertiary-level hospitals.

METHODS

This study included 30 patients with primary head and neck malignant tumors who underwent contrasted computed tomography and whole-body 18F-FDG PET/CT assessments. The staging and treatment plans were compared with the incremental information obtained after 18F-FDG PET/CT.

RESULTS

18F-FDG PET/CT was found to raise the stage in 33.3% of the cases and the treatment intent was altered in 43.3% of them, while there was no management change in the remaining 56.7%. 18F-FDG PET/CT had higher sensitivity (96% versus 89.2%) and accuracy (93% versus 86.7%) than conventional contrast-enhanced computed tomography.

CONCLUSION

Our study demonstrated that 18F-FDG PET/CT had higher sensitivity and accuracy for detecting head and neck malignancy, in comparison with conventional contrast-enhanced computed tomography. 18F-FDG PET/CT improved the initial staging and substantially impacted the management strategy for head and neck malignancies.

Comparison of PET-CT, CT and MRI scan in initial staging and management of head and neck cancers

BACKGROUND

To evaluate the utility of positron-emission tomography (FDG PET) in initial staging and management of head and neck cancers.

METHODS

This is a retrospective study of 99 treatment naïve head and neck cancer patients treated between January 2017 and December 2020 at a tertiary teaching centre. Change in initial staging and management was noted based on PET scan compared to cross-sectional imaging (CT and MRI).

RESULTS

There were 73 (73.7%) males and 26 (26.2%) females with male-to-female ratio of 2.8:1.Overall, change in management was seen in 36/99 (36.4%) patients due to PET scan. With regards to initial staging, T, N and M stage was changed in 14/99 (14.1%), 19/99 (19.1%) and 3/99 (3%) patients, respectively. These changes were significantly higher in patients with unknown primary (63.3%, p value -0.001) and N3 (41%, p -0.045) nodal disease.

CONCLUSION

PET-CT plays an important role in appropriate initial staging and subsequent treatment planning of head and neck cancers.

ADVANCES IN KNOWLEDGE

Initial staging PETCT changes management in 36.4% cases. Accuracy of various different imaging modalities have been compared.

Prediction model for cervical lymph node metastasis in human papillomavirus-related oropharyngeal squamous cell carcinomas

OBJECTIVES

To develop and validate a risk scoring system based on clinical and imaging findings to predict lymph node metastasis from HPV-related oropharyngeal squamous cell carcinomas.

METHODS

This study population who had undergone neck dissections or lymph node biopsies in patients with HPV+ OPSCC was obtained from a historical cohort from two tertiary referral hospitals. The training set from one hospital included 455 lymph nodes from 82 patients, and the test set from the other hospital included 150 lymph nodes from 42 patients. The baseline clinical and imaging findings on pretreatment CT or MR were investigated and the reference standards were the histopathologic results. A risk scoring system was constructed based on logistic regression and validated both internally and externally.

RESULTS

A 7-point risk scoring system was developed based on the following variables: central necrosis, infiltration of adjacent planes, lymph node level, and the maximal axial diameter of the lymph node. This risk scoring system showed good discriminative ability for metastasis in the training set (C-statistic 0.952; 95% CI, 0.931-0.972) and test set (C-statistic 0.968, 95% CI, 0.936-0.999) and good calibration ability in the training set (p = 0.723) and test set (p = 0.253).

CONCLUSIONS

We developed and validated a reliable risk scoring system that predicts lymph node metastasis from HPV+ OPSCCs based on the clinical data and pretreatment imaging findings. We expect this risk scoring system to be a useful guide for better decision-making in practice.

KEY POINTS

• It is important to diagnose lymph node metastasis from HPV+ OPSCC for treatment planning; however, there has been little research on that. • We developed and externally validated a new scoring system for stratifying the risk of lymph node metastasis from HPV+ OPSCC based on clinical and imaging data. • A predictive model combining both clinical and imaging data showed high diagnostic accuracy and efficiency for lymph node metastasis from HPV+ OPSCC.

Diagnostic accuracy of 18F-FDG PET/CT and MR imaging in patients with adenoid cystic carcinoma

Background

The aim of this study was to evaluate the value of 18F–FDG PET/CT (PET/CT) and MRI for local and/or whole-body restaging of adenoid cystic carcinoma of the head and neck (ACC).

Methods

Thirty-six patients with ACC underwent conventional MRI of the head and neck and a whole-body PET/CT and were analysed with regards to detection of a local tumor recurrence, lymph node or distant metastases. A consensus interpretation of all available imaging data was used as reference standard. Sensitivity, specificity, diagnostic accuracy, positive and negative predictive values were calculated for MRI and PET/CT.

Results

The sensitivity of PET/CT and MRI was 96% (89%), specificity 89% (89%), PPV 96% (96%), NPV 89% (73%) and accuracy 94% (89%) for detection of local tumors. Additionally, PET/CT revealed lymph node metastases in one patient and distant metastases in 9/36 patients. In three patients secondary primaries were found.

Conclusions

Whole-body PET/CT in addition to MRI of the head and neck improves detection of local tumour and metastastic spread in ACC.

Up-front PET/CT changes treatment intent in patients with head and neck squamous cell carcinoma

PURPOSE

In patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC), we wanted to examine the differences in overall treatment decisions, i.e. curative versus palliative treatment intent, reached by a multidisciplinary team conference (MDTC) based on 18F-fluoro-deoxy-glucose-positron emission tomography/computed tomography (PET/CT) or chest X-ray + MRI of the head and neck (CXR/MRI).

PATIENTS AND METHODS

This was a prospective blinded cohort study based on paired data. Consecutive patients with histologically verified primary HNSCC were invited to participate. All included patients underwent CXR/MRI and PET/CT before diagnostic biopsy. An ordinary MDTC using all available imaging was conducted as per standard practice. After at least 3 months (to eliminate recall bias in the team), the first project MDTC was conducted, based on either CXR/MRI or PET/CT, and the tumor board drew conclusions regarding treatment. After an additional 3 months, a second project MDTC was conducted using the complementary imaging modality.

RESULTS

A total of 307 patients were included. Based on CXR/MRI, 303 patients (99%) were recommended for curative treatment and only four patients (1%) for palliative treatment. Based on PET/CT, the MDTC concluded that 278 (91%) patients were suitable for curative treatment and 29 (9%) patients for palliative treatment. The absolute difference of 8% was statistically significant (95% CI: 4.8%-11.5%, p < 0.001).

CONCLUSIONS

A PET/CT-based imaging strategy significantly changed the decisions regarding treatment intent made by a MDTC for patients diagnosed with HNSCC, when compared with the standard imaging strategy of CXR/MRI.

AHNS Series: Do you know your guidelines? Review of current knowledge on laryngeal cancer

The following article is part of a series in an initiative by the American Head and Neck Society's Education Committee and will review clinical practice guidelines for head and neck oncology. The primary goal is to increase awareness of current best practices pertaining to head and neck surgery and oncology. This manuscript is a review of current knowledge in laryngeal cancer with a focus on anatomy, epidemiology, diagnosis, evaluation, and treatment.

Coexistence of sarcoidosis and metastatic lesions: A diagnostic and therapeutic dilemma

Sarcoidosis, a chronic, inflammatory disease that affects various different organs, is characterized by noncaseating epitheloid granulomas. This systemic inflammatory process is associated with an increased risk of cancer. Several cases of sarcoidosis that mimic metastatic tumor progression in radiological findings have been reported so far. However, there are also cases that have presented a coexistence of sarcoidosis and metastasis, which have caused a diagnostic and therapeutic dilemma. Due to inadequate current therapies, a reliable differentiation between benign and malignant lesions is crucial. This review focuses on the residual risk of the coexistence of metastases within radiological suspicious lesions in patients with a history of solid tumors and sarcoidosis, as well as immunological findings, in order to explain the potential associations. Sarcoidosis has the potential to promote metastasis as it includes tumor-promoting and immune-regulating cell subsets. Notably, myeloid derived suppressor cells may serve a pivotal role in metastatic progression in patients with sarcoidosis. In addition, the present review also evaluates the potential novel diagnostic approaches, which may be able to differentiate between metastatic lesions and sarcoidosis. The risk of coexistent metastasis in sarcoidosis lesions must be considered by clinical practitioners, and a multidisciplinary approach may be required to avoid misdiagnosis and the subsequent unnecessary surgery or insufficient treatments.

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.

Influence of FDG-PET on primary nodal target volume definition for head and neck carcinomas

BACKGROUND

The role of 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in routine diagnostic staging remains controversial. In case of discordance between FDG-PET and CT, a compromise has to be made between the risk of false positive FDG-PET and the risk of delaying appropriate salvage intervention. Second, with intensity modulated radiation therapy (IMRT), smaller radiation fields allow tissue sparing, but could also lead to more marginal failures.

METHODS

We retrospectively studied 283 patients with head and neck carcinoma scheduled for radiotherapy between 2002 and 2010. We analyzed the influence of FDG-PET/CT versus CT alone on defining nodal target volume definition and evaluated its long-term clinical results. Second, the location of nodal recurrences was related to the radiation regional dose distribution.

RESULTS

In 92 patients, CT and FDG-PET, performed in mold, showed discordant results. In 33%, nodal staging was altered by FDG-PET. In 24%, FDG-PET also led to an alteration in nodal treatment, including a nodal upstage of 18% and downstage of 6%. In eight of these 92 patients, a regional recurrence occurred. Only two patients had a recurrence in the discordant node on FDG-PET and CT and both received a boost (high dose radiation).

CONCLUSION

These results support the complementary value of FDG-PET/CT compared to CT alone in defining nodal target volume definition for radiotherapy of head and neck cancer.

The Role of FDG-PET/CT Imaging in Head and Neck Malignant Conditions: Impact on Diagnostic Accuracy and Patient Care

BACKGROUND: To assess the value of positron emission tomography/computed tomography (PET/CT) with 18 F-Fluorodeoxyglucose (FDG) in patients with head and neck carcinoma as compared with PET and conventional imaging alone, and to assess the impact of PET/CT on further clinical management.

STUDY DESIGN: Prospective nonrandomized study.

SETTING: Ninety patients with head and neck tumors had 107 PET/CT examinations.

RESULTS: The study analysis showed that PET/CT had a sensitivity of 89%, specificity 95%, PPV 94%, NPV 90%, and accuracy of 92%. PET/CT altered management in 51 patients (56%). PET/CT eliminated the need for previously planned diagnostic procedures in 24 patients, induced a change in the planned therapeutic approach in 21 patients and guided biopsy in 6 patients.

CONCLUSIONS: PET/CT is an imaging modality with high diagnostic performance in the assessment of head and neck cancer, and induced a change in further clinical management in more than half of the study population.

Tumor Volumes and Prognosis in Laryngeal Cancer

Tumor staging systems for laryngeal cancer (LC) have been developed to assist in estimating prognosis after treatment and comparing treatment results across institutions. While the laryngeal TNM system has been shown to have prognostic information, varying cure rates in the literature have suggested concern about the accuracy and effectiveness of the T-classification in particular. To test the hypothesis that tumor volumes are more useful than T classification, we conducted a retrospective review of 78 patients with laryngeal cancer treated with radiation therapy at our institution. Using multivariable analysis, we demonstrate the significant prognostic value of anatomic volumes in patients with previously untreated laryngeal cancer. In this cohort, primary tumor volume (GTV_P), composite nodal volumes (GTV_N) and composite total volume (GTV_P + GTV_N = GTV_C) had prognostic value in both univariate and multivariate cox model analysis. Interestingly, when anatomic volumes were measured from CT scans after a single cycle of induction chemotherapy, all significant prognosticating value for measured anatomic volumes was lost. Given the literature findings and the results of this study, the authors advocate the use of tumor anatomic volumes calculated from pretreatment scans to supplement the TNM staging system in subjects with untreated laryngeal cancer. The study found that tumor volume assessment after induction chemotherapy is not of prognostic significance.

Cystic squamous cell carcinoma of the neck: could a second metastatic focus help?

Squamous cell carcinoma of the neck presenting clinically as predominantly cystic lesion has often been considered as branchiogenic carcinoma in the past. However, such cystic lesions presently constitute a distinct form of head-neck metastasis, and a co-existent second metastatic focus could supposedly help distinguish them from branchiogenic carcinoma. We here present a case where, although the primary remained elusive, the associated spinal metastasis precluded us from diagnosing a cystic squamous cell carcinoma as branchiogenic carcinoma. Thus a second metastatic focus, if found, could add to the existing knowledge to distinguish between a cystic squamous cell carcinoma and the so-called branchiogenic carcinoma, especially when the primary could not be found.

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.

Positron emission tomography and stage migration in head and neck cancer

IMPORTANCE

Since 2001, there has been a rapid adoption of positron emission tomography (PET) for diagnosis and American Joint Committee on Cancer (AJCC) staging of head and neck cancer (HNC) without data describing improved clinical outcomes.

OBJECTIVE

To determine the association between increased use of PET and stage and/or survival for patients with HNC in the managed care environment.

DESIGN, SETTING, AND PARTICIPANTS

Adult patients diagnosed as having HNC (n = 958) from 2000 to 2008 at 4 integrated health systems were identified via tumor registries linked to administrative data. The AJCC stage distribution, patient and treatment characteristics, and survival between pre-PET era (2000-2004) vs PET era (2005-2008) and use of PET vs no use of PET during the PET era were compared. The AJCC stages were categorized to represent localized (stage I or II), locally advanced (stage III, IVA, or IVB), and metastatic (stage IVC) disease.

INTERVENTIONS

Treatments were determined by billing codes for surgery, radiation treatment, and chemotherapy.

MAIN OUTCOMES AND MEASURES

The primary outcome for this study was the use of PET. Secondary outcomes included treatment received and 2-year survival. A logit model estimated the effects of PET on diagnosis of locally advanced disease. Kaplan-Meier estimates described overall survival differences between PET and non-PET. Cox regression evaluated the association of PET on survival in patients with locally advanced disease.

RESULTS

An association between PET and locally advanced disease was found (odds ratio, 2.86 [95% CI, 1.90-4.29) (P < .001). Two-year overall survival for patients with locally advanced disease with and without PET was 52% and 32%, respectively (P = .004), but there was no difference for all stages (P = .69). On Cox proportional hazard regression, PET had no association with survival in patients with locally advanced disease (hazard ratio, 1.208 [95% CI, 0.778-1.877]) (P = .40).

CONCLUSIONS AND RELEVANCE

The increasing use of PET among patients with HNC is associated with a greater number of patients with higher-stage disease and a dilution of the population with higher-stage disease with patients who have a better prognosis. Thus, the improved survival in patients with locally advanced disease likely reflects selection bias and stage migration. Further research on PET use among patients with HNC is necessary to determine if it results in improved treatment for individual patients.

Chapter 10: Sinonasal malignancies

Malignant tumors of the sinonasal tract are uncommon tumors of the head and neck. Patients often present in the later years of life with unilateral symptoms and potential involvement of nearby structures such as the orbit, brain, or cranial nerves. Presenting symptoms are similar to patients suffering from inflammatory sinonasal disease and thus early diagnosis relies heavily on a high clinical suspicion. There are established risk factors based on exposure to the by-products of woodworking, metal, textile, and leather industries. Sinonasal malignancies are generally divided into those of epithelial origin (squamous cell carcinoma, adenocarcinoma, and adenoid cystic carcinoma) and nonepithelial origin (olfactory neuroblastoma, chondrosarcoma, and mucosal melanoma). Accurate histopathology confirmation and staging of the tumor is critical prior to making treatment decisions. Both computed tomography and magnetic resonance imaging are required to accurately determine the extent of local disease. Treatment is based on multimodality therapy, primarily surgical excision, and postoperative radiotherapy. This article reviews the classification of malignant tumors of the paranasal sinuses, their clinical presentation, relevant diagnostic investigations, and the principals of therapy and management.

Predictive value of pre-therapy (18)F-FDG PET/CT for the outcome of (18)F-FDG PET-guided radiotherapy in patients with head and neck cancer

PURPOSE

The aim of this study was to evaluate the predictive role of pre-therapy fluorodeoxyglucose (FDG) uptake parameters of primary tumour in head and neck cancer (HNC) patients undergoing intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) on FDG-positive volume-positron emission tomography (PET) gross tumour volume (PET-GTV).

METHODS

This retrospective study included 19 patients (15 men and 4 women, mean age 59.2 years, range 23-81 years) diagnosed with HNC between 2005 and 2011. Of 19 patients, 15 (79 %) had stage III-IV. All patients underwent FDG PET/CT before treatment. Metabolic indexes of primary tumour, including metabolic tumour volume (MTV), maximum and mean standardized uptake value (SUVmax, SUVmean) and total lesion glycolysis (TLG) were considered. Partial volume effect correction (PVC) was performed for SUVmean and TLG estimation. Correlations between PET/CT parameters and 2-year disease-free survival (DFS), local recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) were assessed. Median patient follow-up was 19.2 months (range 4-24 months).

RESULTS

MTV, TLG and PVC-TLG predicting patients' outcome with respect to all the considered local and distant disease control endpoints (LRFS, DMFS and DFS) were 32.4 cc, 469.8 g and 547.3 g, respectively. SUVmean and PVC-SUVmean cut-off values predictive of LRFS and DFS were 10.8 and 13.3, respectively. PVC was able to compensate errors up to 25 % in the primary HNC tumour uptake. Moreover, PVC enhanced the statistical significance of the results.

CONCLUSION

FDG PET/CT uptake parameters are predictors of patients' outcome and can potentially identify patients with higher risk of treatment failure that could benefit from more aggressive approaches. Application of PVC is recommended for accurate measurement of PET parameters.

The Value of F-18 FDG PET for Planning Treatment and Detecting Recurrence in Malignant Salivary Gland Tumors: Comparison with Conventional Imaging Studies

PURPOSE

To assess the value of F-18 FDG PET/CT for detecting cervical lymph node (LN) metastasis and recurrence, as well as planning treatment, and to compare the accuracy of PET/CT with conventional imaging studies (CIS) in patients with malignant salivary gland tumor (SGT).

METHODS

Staging and follow-up PET/CT for SGT were retrospectively reviewed. Enhanced CT and/or MRI of the neck were performed within 1 month of PET/CT. Final diagnosis was based on histology from cervical LN dissection and biopsy or a minimum 6 months of clinical and imaging follow-up. We compared the performance of PET/CT in initial cervical LN staging and recurrence detection with that of CIS.

RESULTS

A total of 184 PET/CT exams of 66 patients were included, and 34 initial staging and 150 surveillance PET/CT exams were performed. The initial cervical LN detection sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 60.9 %, 89.2 %, 84.0 %, 56.0 %, and 91.0 % for visual analysis on PET/CT, 39.1 %, 95.0 %, 84.8 %, 64.3 %, and 87.4 % for semiquantitative analysis on PET/CT, and and 43.5 %, 94.1 %, 84.8 %, 62.5 %, and 88.1 % for CIS. The sensitivity of visual analysis on PET/CT was significantly higher than that of semiquantitative analysis on PET/CT and CIS (p = 0.0009 and 0.0086). In 5 of 34 initial staging patients (14.7 %), the treatment plan was changed from curative surgery to palliative therapy. The performance of follow-up PET/CT showed no significant difference compared with CIS.

CONCLUSION

PET/CT showed comparable performance with CIS for cervical LNs staging. Initial PET/CT changed treatment plans in 14.7 % of patients. However, PET/CT offered no additional advantage for detecting locoregional recurrence.

Valor da PET/CT na abordagem do câncer de cabeça e pescoço

OBJETIVO: Avaliar a PET/CT na abordagem de pacientes com câncer de cabeça e pescoço. MATERIAIS E MÉTODOS: Estudo retrospectivo de 63 prontuários e exames de PET/CT de pacientes com câncer de cabeça e pescoço. RESULTADOS: Foram encontradas alterações em 76% dos exames. Destes, 7 (11%) foram considerados falso-positivos, com SUV < 5,0. A PET/CT mostrou-se negativa em 15 situações (24%). Dos 14 casos nos quais se utilizou o exame para estadiamento, em 3 (22%) houve aumento no estadiamento. CONCLUSÃO: A PET/CT mostra-se como exame de potencial valor na rotina de avaliação de pacientes com câncer de cabeça e pescoço, entretanto, necessitamos de maior número de casos para definirmos protocolo de uso.

Prognostic value of volume-based (18)F-fluorodeoxyglucose PET/CT parameters in patients with clinically node-negative oral tongue squamous cell carcinoma

Objective

To evaluate the prognostic value of volume-based metabolic parameters measured with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) in patients with clinically node-negative (cN0) oral tongue squamous cell carcinoma (OTSCC) as compared with other prognostic factors.

Materials and Methods

In this study, we included a total of 57 patients who had been diagnosed with cN0 tongue cancer by radiologic, ¹⁸F-FDG PET/CT, and physical examinations. The maximum standardized uptake value (SUV_max), average SUV (SUV_avg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumors were measured with ¹⁸F-FDG PET. The prognostic significances of these parameters and other clinical variables were assessed by Cox proportional hazards regression analysis.

Results

In the univariate analysis, pathological node (pN) stage, American Joint Committee on Cancer (AJCC) stage, SUV_max, SUV_avg, MTV, and TLG were significant predictors for survival. On a multivariate analysis, pN stage (hazard ratio = 10.555, p = 0.049), AJCC stage (hazard ratio = 13.220, p = 0.045), and MTV (hazard ratio = 2.698, p = 0.033) were significant prognostic factors in cN0 OTSCC patients. The patients with MTV ≥ 7.78 cm³ showed a worse prognosis than those with MTV < 7.78 cm³ (p = 0.037).

Conclusion

The MTV of primary tumor as a volumetric parameter of ¹⁸F-FDG PET, in addition to pN stage and AJCC stage, is an independent prognostic factor for survival in cN0 OTSCC.

Value of fluoro-2-deoxy-D-glucose-positron emission tomography for detecting metastatic lesions in head and neck cancer

OBJECTIVES

The role of positron emission tomography (PET) scans in the staging of head and neck cancer (HNC) is unclear. The National Comprehensive Cancer Network guidelines do not recommend routine metastatic workup beyond physical examination, chest x-ray, and laboratory tests. The purpose of this report is to examine the accuracy of staging PET scans for detecting distant metastatic disease in patients with HNC.

METHODS

Retrospective review of 182 consecutive newly diagnosed HNC patients who had a staging PET scan at Thomas Jefferson University Hospital between 2003 and 2007.

RESULTS

The overall incidence of confirmed distant metastatic disease in this population was 5.0%. About 26 of the staging PET scans had areas suspicious for a metastatic lesion(s). Of total, 23 patients were further evaluated with imaging and/or biopsy, revealing 9 (39%) true positives, and 14 (60%) false positives. Of the 156 negative PET scans, there was 1 false negative and 155 true negatives. Thus, the sensitivity of PET was 90% and specificity was 92%. Positive predictive value was 39% and negative predictive value was 99.4%. No patients with pre-PET clinical stage I or II cancer had confirmed distant metastases. The only statistically significant predictor for metastatic disease was clinical stage IV versus all other stages (P=0.03).

CONCLUSIONS

Given the marked differences in the treatment of locally advanced/nonmetastatic HNC versus metastatic HNC, we recommend PET for clinical stage IV disease. Although the sensitivity, specificity, and negative predictive value rates were acceptable, the positive predictive value was suboptimal. Patients found to have a PET scan "positive" for metastatic disease require confirmatory imaging or ideally biopsy.

The Impact of (18)F-FDG PET CT Prior to Chemoradiotherapy for Stage III/IV Head and Neck Squamous Cell Carcinoma

Introduction. To determine the value of a FDG-PET-CT scan in patients with locally advanced head and neck squamous cell carcinoma (HNSCC) prior to chemoradiotherapy. Materials and Methods. Consecutive patients with stage III or IV HNSCC who had undergone a staging FDG-PET-CT scan prior to chemoradiotherapy between August 2008 and April 2011 were included. Clinical details and conventional imaging (CT and/or MRI) were, retrospectively, reviewed, a TNM stage was assigned, and levels of cervical lymph node involvement were documented. This process was repeated with the addition of FDG-PET-CT. Radiotherapy plans were reviewed for patients with an alteration identified on TNM staging and/or nodal level identification with FDG-PET-CT and potential alterations in radiotherapy planning were documented. Results. 55 patients were included in the analysis. FDG-PET-CT altered the TNM stage in 17/55 (31%) of patients, upstaging disease in 11 (20%) and downstaging in 6 (11%); distant metastases were identified by FDG-PET-CT in 1 (2%) patient. FDG-PET-CT altered the lymph node levels identified in 22 patients (40%), upclassifying disease in 16 (29%) and downclassifying in 6 (11%). Radiotherapy plans were judged retrospectively to have been altered by FDG-PET-CT in 10 patients (18%). Conclusions. The use of FDG-PET-CT potentially impacts upon both treatment decisions and radiotherapy planning.

Prognostic value of 18F-FDG PET/CT in patients with squamous cell carcinoma of the tonsil: comparisons of volume-based metabolic parameters

BACKGROUND

The prognostic significance of volume-based metabolic parameters measured by (18)F-fluorodeoxyglucose positron emission tomography/CT ((18) F-FDG PET/CT) is not established. We evaluated the prognostic value of metabolic parameters in patients with squamous cell carcinoma (SCC) of the tonsil.

METHODS

We enrolled a total of 69 patients with SCC of the tonsil who underwent pretreatment (18)F-FDG PET/CT. We measured maximum standardized uptake value (SUV(max)), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and asymmetry indices (of SUV(max), MTV, and TLG). The prognostic significance of these parameters and clinical variables was assessed by Cox proportional hazards regression analysis.

RESULTS

Multivariate analyses with adjustments for age, sex, and American Joint Committee on Cancer stage showed that only TLG (hazard ratio = 1.020, 95% confidence interval 1.003-1.037, p = .023) was an independent predictive factor associated with decreased overall survival.

CONCLUSION

TLG is a significant independent metabolic prognostic factor for overall survival in patients with SCC of the tonsil.

(18)FDG-PET/CT for detecting distant metastases and second primary cancers in patients with head and neck cancer. A meta-analysis

We performed a meta-analysis to evaluate the role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)FDG-PET/CT) in detecting distant metastases and second primary cancers in patients with head and neck cancer (HNC) at staging. Studies about (18)FDG-PET/CT for detecting distant metastases and second primary cancers in patients with HNC were systematically searched in the MEDLINE, EMBASE, and EBM Review databases from January 1, 2000 to March 1, 2011. A software called "Meta-DiSc" was used to obtain pooled estimates of sensitivity, specificity, diagnostic odds ratios, summary receiver operating characteristic curves, and Q* index. Twelve articles fulfilled all inclusion criteria. The pooled sensitivity, specificity, and Q* index estimates with 95% confidence interval for PET/CT were 0.888 (0.827-0.928), 0.951 (0.936-0.963), and 0.937 (0.844-0.964). Subgroup analysis showed similar pooled estimates of sensitivity, specificity, and Q* index for initial staging and restaging, nasopharyngeal cancer and all other sites of HNC. (18)FDG-PET/CT has good diagnostic performance in detecting distant metastases and second primary cancers in patients with HNC.

Accuracy of whole-body PET and PET-CT in initial M staging of head and neck cancer: a meta-analysis

BACKGROUND

A meta-analysis was conducted to evaluate the accuracy of whole-body positron emission tomography (PET) and PET-CT in initial M staging of head and neck cancer.

METHODS

After a systematic review of English language studies, sensitivity, specificity, and other measures of whole-body PET and PET-CT were pooled. Summary receiver operating characteristic (SROC) curves were also used to summarize overall test performance.

RESULTS

Eight PET and 7 PET-CT studies were identified. The pooled sensitivity estimates for PET and PET-CT were 0.848 (95% confidence interval [CI], 0.776-0.905) and 0.875 (95% CI, 0.787-0.936). The pooled specificity estimates were 0.952 (95% CI, 0.933-0.967) and 0.950 (95% CI, 0.931-0.964). The Q* index estimates for PET-CT (0.9409) were not significantly higher than for PET (0.9154; p > .05).

CONCLUSION

Whole-body PET and PET-CT have good diagnostic performance in initial M staging of head and neck cancer; although PET-CT tends to have higher accuracy than PET.

18F-FDG PET/CT imaging in oncology

Accurate diagnosis and staging are essential for the optimal management of cancer patients. Positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography (18F-FDG PET/CT) has emerged as a powerful imaging tool for the detection of various cancers. The combined acquisition of PET and CT has synergistic advantages over PET or CT alone and minimizes their individual limitations. It is a valuable tool for staging and restaging of some tumors and has an important role in the detection of recurrence in asymptomatic patients with rising tumor marker levels and patients with negative or equivocal findings on conventional imaging techniques. It also allows for monitoring response to therapy and permitting timely modification of therapeutic regimens. In about 27% of the patients, the course of management is changed. This review provides guidance for oncologists/radiotherapists and clinical and surgical specialists on the use of 18F-FDG PET/CT in oncology.

Preoperative combined 18-fluorodeoxyglucose positron emission tomography and computed tomography imaging in head and neck cancer: does it really improve initial N staging?

CONCLUSION

In our experience PET-CT cannot yet reliably predict the need for surgical neck dissection in patients with N0 neck. According to the results of PET-CT the neck dissection should be extended towards unusual lymph node areas.

OBJECTIVE

To analyze the value of PET-CT for the initial N staging, comparing PET-CT data with histopathological results of the modified radical neck dissection.

METHODS

Fifty patients with previously untreated head and neck squamous cell carcinoma were eligible for inclusion in this study. Modified radical unilateral or bilateral neck dissection was performed in all patients. PET-CT findings and histological findings were compared to determine their diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value.

RESULTS

In all, 105 levels had pathologically diagnosed metastases: PET-CT was positive in 87 levels and negative in 18 levels. Also, 399 levels had negative postoperative histology findings: PET-CT was positive in 24 levels and negative in 375 levels. The false-positive over-staged and the false-negative under-staged rates were 27% and 12%, respectively.

FDG-PET staging and importance of lymph node SUV in head and neck cancer

Objectives

The role of positron emission tomography (PET) with fluoro-deoxy-glucose (FDG) in the staging of head and neck cancer (HNC) is unclear. The NCCN guidelines do not recommend FDG-PET as a part of standard workup. The purpose of this report is to examine the role of FDG-PET imaging in altering management and providing prognostic information for HNC.

Methods

Retrospective review of HNC patients who had a staging FDG-PET scan performed at either Thomas Jefferson University or University of Kansas Medical Center between the years 2001 and 2007. A total of 212 PET scans were performed in patients who went on to receive radiotherapy.

Results

The median follow-up time for all patients was 469 days. The PPV and NPV of PET imaging to correctly identify lymph node status was 94% and 89% respectively. Lymph nodes with extracapsular extension (ECE) had higher SUVs than nodes without ECE, 11.0 vs. 5.0 (p < 0.0007). Maximum SUV for the primary tumor > 8.0 was predictive of worse overall survival (p < 0.045), while the SUV of the lymph nodes was predictive for distant recurrence at one year--with a mean SUV value of 10.4 for patients with distant failure vs. 7.0 without (p < 0.05).

Conclusions

FDG-PET staging in head and neck cancer has good positive and negative predictive values in determining lymph node status. The maximum SUV of the primary tumor is predictive of overall survival. This is the first report to find that the SUV of a lymph node is predictive for ECE and also for distant recurrence.

Positron emission tomography with [18F]fluorodeoxyglucose improves staging and patient management in patients with head and neck squamous cell carcinoma: a multicenter prospective study

PURPOSE To address the impact of positron emission tomography with [(18)F]fluorodeoxyglucose (PET-FDG) on the initial staging and management of patients with head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS This multicenter, prospective study included 233 patients with newly diagnosed and untreated HNSCC. TNM stage and therapeutic decision were first determined based on the conventional work-up (including physical examination, computed tomography [CT]/magnetic resonance imaging of the head and neck region, and thoracic CT) and sealed in envelope 1. Whole-body PET-FDG was then performed, and subsequent TNM stage and therapeutic decision were written in envelope 2. Changes in TNM stages and in patient management as a result of PET-FDG imaging were recorded. Clinical outcome and histopathology were used as gold standards to validate the TNM stage. Conventional and PET stages were compared using the McNemar test. Results Conventional and PET stage were discordant in 100 (43%) of 233 patients. PET proved to be accurate in 47 patients and inaccurate in 13 patients. TNM status was left unconfirmed in 40 patients because no therapeutic change was expected from the stage difference. Conventional + PET TNM classification (envelope 2) was significantly more accurate than conventional classification (envelope 1; P < .0001, McNemar test). PET-FDG altered the therapeutic plan in 32 (13.7%) of 233 patients. CONCLUSION Adding whole-body PET-FDG to the pretherapeutic conventional staging of HNSCC improved the TNM classification of the disease and altered the management of 13.7% of patients. These findings support the implementation of PET-FDG in the routine imaging work-up of HNSCC.

PET Lesion Segmentation Using Automated Iso-intensity Contouring in Head and Neck Cancer

To improve the objectivity of the integration of positron emission tomography (PET), we used the conformality index (CI) to measure the goodness of fit of a given PET iso-SUV (standardized uptake value) level with the GTV defined on PET (GTVPET) and CT (GTVCT). Twenty-two datasets involving 20 head and neck cancer patients were identified. GTVPET and GTVCT were delineated manually. An iso-intensity method was developed to automatically segment GTVPET-ISO using (a) SUV and (b) maximum intensity thresholding (%Max), over a range of intensities. For each intensity, GTVPET-ISO was compared to GTVPET using the conformality index CIPET (and, similarly, to GTVCT using CICT). Comparing GTVPET to GTVPET-ISO vs comparing GTVCT to GTVPET-ISO, the average peak CI was 0.68 ± 0.09 vs 0.49 ± 0.12 (p<0.001), the optimum iso-SUV was 2.7 ± 0.7 vs 2.9 ± 1.0 (p=0. 253), and the %Max SUV was 21.8% ± 7.6% vs 23.8% ± 8.6% (p=0. 310), respectively. The radiation oncologist's volumes corresponded to a lower iso-SUV (3.02 ± 0.58 vs 4.36 ± 0.77, p < 0.001) and lower %Max SUV (24.1 ± 9.1% vs 34.3 ± 11.2%, p<0.001) than those drawn by the nuclear medicine physician. Though manual editing may still be necessary, PET iso-contouring is one method to improve the objectivity of GTV definition in head and neck cancer patients. Iso-SUV's can also be used to study the differences between PET's role as a nuclear medicine diagnostic test versus a radiation oncology treatment planning tool.

PET/CT-MR Imaging in Head and Neck Cancer Including Pitfalls and Physiologic Variations

This article emphasizes the strengths and potential pitfalls of functional and anatomic imaging in patients who have head and neck cancer with an emphasis on the treated neck, including patients who have undergone surgery and/or radiation therapy. Anatomic and molecular imaging together allow optimal evaluation and interpretation of a patient who has cancer. Effective assessment of patients who have head and neck cancer can be achieved through a careful review of pertinent anatomy, with awareness of the physiologic variations (especially those in the treated head and neck) seen in PET imaging, and analysis of both the PET and cross-sectional images.

Accuracy of positron emission tomography in the evaluation of patients treated with chemoradiotherapy for mucosal head and neck cancer

BACKGROUND

The aim of this study was to evaluate the accuracy of positron emission tomography (PET) in assessing the patients treated with primary chemoradiotherapy for mucosal carcinoma of the head and neck.

METHODS

A retrospective review of patients with biopsy-proven cancer of mucosal head and neck sites receiving chemoradiotherapy with curative intent was undertaken.

RESULTS

Seventy-eight patients met the study criteria. Staging PET identified unsuspected distant metastatic disease in 11% of patients. Sixty-one patients (78%) had a complete metabolic response on PET, with 17 showing residual disease. Sensitivity of PET was 82% (positive predictive value: 82%) and specificity was 95% (negative predictive value: 95%). Accuracy of PET response was significantly better than clinical assessment and conventional imaging (p < .002, p < .001, respectively).

CONCLUSION

PET has been found to be significantly better than clinical examination or conventional imaging in restaging patients after chemoradiotherapy. Patients with a complete response on posttreatment PET have a significant survival advantage and can be safely observed.

Evaluation of different methods of 18F-FDG-PET target volume delineation in the radiotherapy of head and neck cancer

OBJECTIVE

To quantify differences between the alternative methods of F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)-based delineation of the gross tumor volume in patients with head and neck cancer.

MATERIALS AND METHODS

Twelve patients with locally-advanced head and neck carcinomas were studied. The reference gross tumor volume (GTVref) was established by a radiation oncologist, along with a neuroradiologist, using the computed tomography-simulation and diagnostic magnetic resonance imaging data. With the GTVref obscured, a second radiation oncologist and a nuclear medicine physician determined the following contours: (1) high FDG uptake based on visual inspection (GTVvis), (2) the contour derived from the 50% maximum standardized uptake value (SUV) threshold (GTV50), (3) the contour derived from a 2.5 SUV absolute threshold (GTV2.5), and (4) the contours derived from an iterative segmentation algorithm (GTViter). These volumes were compared with the GTVref using a signed-ranks test with the exact reference distribution.

RESULTS

The average GTVref was 75.5 mL (median 72.8 mL, range 22.2-138.4 mL). The average GTVvis was 57.6 (median 55.4 mL, range 12-115.8 mL). Overall, a 21% reduction in volume size was observed with GTVvis versus GTVref. When the signed-ranks test with the exact reference distribution was applied, the difference was not statistically significant (P = 0.32). The average GTV2.5 was 60 mL (median 64.5, range 8.8-90.3 mL). The differences between GTV2.5 and GTVref were not statistically significant (P = 0.35). The use of GTV50 and GTViter produced significantly smaller volumes with respect to GTVref (P < 0.005).

CONCLUSIONS

PET-based tumor volumes are strongly affected by the choice of threshold level. Quantitatively, GTVs derived from visual inspection of the region of high FDG uptake do not significantly differ from GTVref in this cohort of patients. The inclusion of alternative FDG-PET segmentation data, other than visual inspection, may reduce target volumes significantly.

Combined FDG-PET/CT for the detection of unknown primary tumors: systematic review and meta-analysis

The aim of this study was to systematically review and meta-analyze published data on the diagnostic performance of combined 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the detection of primary tumors in patients with cancer of unknown primary (CUP). A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Methodological quality of the included studies was assessed. Reported detection rates, sensitivities and specificities were meta-analyzed. Subgroup analyses were performed if results of individual studies were heterogeneous. The 11 included studies, comprising a total sample size of 433 patients with CUP, had moderate methodological quality. Overall primary tumor detection rate, pooled sensitivity and specificity of FDG-PET/CT were 37%, 84% (95% CI 78–88%) and 84% (95% CI 78–89%), respectively. Sensitivity was heterogeneous across studies (P = 0.0001), whereas specificity was homogeneous across studies (P = 0.2114). Completeness of diagnostic workup before FDG-PET/CT, location of metastases of unknown primary, administration of CT contrast agents, type of FDG-PET/CT images evaluated and way of FDG-PET/CT review did not significantly influence diagnostic performance. In conclusion, FDG-PET/CT can be a useful method for unknown primary tumor detection. Future studies are required to prove the assumed advantage of FDG-PET/CT over FDG-PET alone and to further explore causes of heterogeneity.

PET changes management and improves prognostic stratification in patients with head and neck cancer: results of a multicenter prospective study

The primary aim of this study was to determine the impact of PET in changing initial management plans in patients with untreated head and neck cancer. Secondary aims were to determine the incremental staging information provided by PET and to document the effect of PET on treatment outcomes.

METHODS

Patients with untreated head and neck cancer underwent PET scans. Pre-PET management plans were documented by referring clinicians unaware of the PET results, and management plan changes due to PET scan findings were documented. Follow-up to 12 mo after treatment was performed to determine actual management and clinical outcomes.

RESULTS

A total of 71 patients (median age, 56 y; 69% male) were studied. PET scans resulted in management change in 33.8% of patients. Moreover, PET was able to detect additional sites of disease in 39.4% of patients. Follow-up data showed that PET improved the classification of patients into curative and palliative categories. Trends toward inferior disease-free survival and lower complete response rates in patients with additional lesions detected on PET were demonstrated. In addition, a trend toward inferior disease-free survival in patients with a higher maximum standardized uptake value was shown.

CONCLUSION

These data unequivocally demonstrate the significant impact of PET on management and outcomes in patients with untreated head and neck cancer.

Staging of untreated nasopharyngeal carcinoma with PET/CT: comparison with conventional imaging work-up

PURPOSE

We prospectively compared PET/CT and conventional imaging for initial staging of nasopharyngeal carcinoma (NPC).

METHODS

A total of 111 patients with histologically proven NPC were investigated with PET/CT and conventional imaging (head-and-neck MRI, chest X-ray, abdominal ultrasound, and bone scan) before treatment. The respective findings were reviewed independently and then compared with each other.

RESULTS

With regard to T staging, PET/CT showed a discrepancy with head-and-neck MRI in 36 (32.4%) of the study subjects. With regard to N staging, PET/CT showed a discrepancy with head-and-neck MRI in 15 (13.5%) patients. Among the discordant cases, MRI was superior in demonstrating tumor involvement in the parapharyngeal space, skull base, intracranial area, sphenoid sinus, and retropharyngeal nodes while PET/CT was superior in demonstrating neck nodal metastasis. PET/CT disclosed 13 of 16 patients with distant malignancy compared with four patients disclosed by conventional imaging work-up. The false-positive rate of PET/CT was 18.8%. PET/CT correctly modified M staging in eight patients (7.2%) and disclosed a second primary lung malignancy in one patient (0.9%).

CONCLUSION

In NPC patients, MRI appears to be superior to PET/CT for the assessment of locoregional invasion and retropharyngeal nodal metastasis. PET/CT is more accurate than MRI for determining cervical nodal metastasis and should be the better reference for the neck status. PET/CT has an acceptable diagnostic yield and a low false-positive rate for the detection of distant malignancy and can replace conventional work-up to this aim. PET/CT and head-and-neck MRI are suggested for the initial staging of NPC patients.

Primary lung cancer after treatment of head and neck cancer without lymph node metastasis: is there a role for autofluorescence bronchoscopy?

BACKGROUND

Head and neck cancer (HNC) is the 5th most common cancer worldwide. As good locoregional tumor control can be achieved with current treatment strategies, patients who develop second primary tumors from field cancerization have poorer prognosis.

OBJECTIVES

To determine if autofluorescence bronchoscopy (AF) played a role in the detection of second primary lung cancer (SPLC), and impact of SPLC on survival of patients with HNC and no cervical lymph node metastasis (N0).

METHODS

Patients with HNC(N0) referred for symptoms and/or radiology suspicious for lung cancer were assessed with AF. Data on patient demographics, smoking, cancer characteristics, and outcome were prospectively collected.

RESULTS

Fifty-one patients (44 males) with curatively treated HNC(N0) were evaluated. Median age was 70 years, all were current or former smokers of 35 pack years, and 25 had chronic obstructive lung disease. Over a median follow up of 60 months, 8 patients were diagnosed with synchronous and 26 with metachronous SPLC. Forty-two SPLC were found; 12 (29%) affected the tracheobronchial tree and 30 (71%) involved the lung parenchyma. Median time to metachronous SPLC was 22 months. Most of SPLC were surgically resectable. Five radiographically occult lung cancers detected by AF were successfully treated with endobronchial therapy. Lung cancer mortality was 24%. HNC patients who developed synchronous and metachronous SPLCs had significantly shorter survival (51 and 144 months) compared to those without (240 months) (p=0.0005).

CONCLUSION

SPLC impacted negatively on the survival of patients with HNC. Close surveillance with AF and CT for SPLC combined with aggressive treatment of early stage lung cancer might be a strategy to improve outcome.

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

BACKGROUND

Positron emission tomography using 18F-fluorodeoxyglucose (18F-FDG PET) has been proposed to enhance preoperative assessment of cervical lymph node status in patients with head and neck squamous cell carcinoma (HNSCC). Management is most controversial for patients with a clinically negative (cN0) neck. We aimed to assess the diagnostic accuracy of 18F-FDG PET in detecting lymph node metastases in patients with HNSCC.

METHODS

We performed a meta-analysis of all available studies of the diagnostic performance of 18F-FDG PET in patients with HNSCC. We determined sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic curves using hierarchical regression models. We also compared the performance of 18F-FDG PET with that of conventional diagnostic methods (ie, computed tomography, magnetic resonance imaging, and ultrasound with fine-needle aspiration) by analyzing studies that had also used these diagnostic methods on the same patients.

RESULTS

Across 32 studies (1236 patients), 18F-FDG PET sensitivity was 79% (95% confidence interval [CI] = 72% to 85%) and specificity was 86% (95% CI = 83% to 89%). For cN0 patients, sensitivity of 18F-FDG PET was only 50% (95% CI = 37% to 63%), whereas specificity was 87% (95% CI = 76% to 93%). Overall, LR+ was 5.84 (95% CI = 4.59 to 7.42) and LR- was 0.24 (95% CI = 0.17 to 0.33). In studies in which both 18F-FDG PET and conventional diagnostic tests were performed, sensitivity and specificity of 18F-FDG PET were 80% and 86%, respectively, and of conventional diagnostic tests were 75% and 79%, respectively.

CONCLUSION

18F-FDG PET has good diagnostic performance in the overall pretreatment evaluation of patients with HNSCC but still does not detect disease in half of the patients with metastasis and cN0.