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Summary: We evaluated the clinical utility of combined [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT), as well as CT and magnetic resonance imaging (MRI) in identifying nodal metastases in the contralateral neck in patients with head and neck squamous cell carcinoma (HNSCC). A total of 114 patients were preoperatively evaluated with PET/CT and CT/MRI. Histopathologic analysis from bilateral neck dissection tissues was used as the gold standard in assessing these imaging techniques. Of the 114 patients, 63 (55%) had neck metastases and 26 (23%) had contralateral neck metastases. On a per-level basis, FDG PET/CT was significantly more sensitive and accurate than CT/MRI in the ipsilateral (88% vs. 70%, P <0.01 and 93% vs. 89%, P <0.01, respectively) and contralateral (52% vs. 36%, P <0.01 and 91% vs. 90%, P =0.039, respectively) neck. PET/CT and CT/MRI were less sensitive in detecting contralateral than ipsilateral neck metastases due to the lower incidence of metastases and smaller nodes on the contralateral side. Combined PET/CT is superior to CT/MRI in detecting metastatic neck nodes in HNSCC patients. However, PET/CT may not abrogate the need for contralateral neck surgery or radiotherapy in these patients. [ABSTRACT FROM AUTHOR]

Objectives: Current guidelines recommend chest computed tomography (CT) with locoregional CT/magnetic resonance imaging for patients with head and neck squamous cell carcinoma (HNSCC), and 18F-fluorodeoxyglucose (FDG) positron-emission tomography (PET)/CT is suggested for stage III-IV patients. However, whole body screening with 18F-FDG PET/CT may provide better detection of distant metastases and synchronous cancer than conventional imaging. We evaluated the utility of 18F-FDG PET/CT in detecting distant metastasis and synchronous cancer.Methods: This prospective study enrolled 740 consecutive patients with previously untreated HNSCC diagnosed between September 2010 and December 2015. Synchronous cancer was histologically confirmed and distant metastases were confirmed by biopsy or serial imaging follow-ups. McNemar test was used to compare the true-positive detection rates of chest radiography (CXR) + head and neck CT (hnCT) (A) versus 18F-FDG PET/CT (C) and chest CT + hnCT (B) versus 18F-FDG PET/CT.Results: Distant metastases and synchronous cancer were found in 23 (3.1%) and 55 (7.4%) patients, respectively. A, B, and C detected distant metastases in 10 (1.3%), 19 (2.6%), and 21 (2.8%) patients, respectively. The absolute differences were 1.5% (A versus C, P = 0.003) and 0.3% (B versus C, P = 0.687). A, B, and C detected synchronous cancer in 15 (2.0%), 22 (2.9%), and 36 (4.9%) patients, respectively. The absolute differences were 2.8% (A versus C, P < 0.001) and 1.4% (B versus C, P = 0.013).Conclusions: 18F-FDG PET/CT detected more distant metastases and synchronous cancer than CXR + hnCT and more synchronous cancer than chest CT + hnCT. [ABSTRACT FROM AUTHOR]

Objectives: Adenoid cystic carcinoma (AdCC) in the salivary gland shows a high rate of distant metastasis, which is related to the resulting poor prognosis. We therefore examined the role of pretreatment 18F-FDG PET/CT for prediction of distant metastasis, recurrence/progression, and survival in AdCC.Methods: This study included 52 patients who underwent pretreatment 18F-FDG PET/CT scanning and subsequent treatments for AdCC. Maximum, mean, and peak standardized uptake value (SUVmax, SUVmean, and SUVpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured on 18F-FDG PET/CT. Univariate and multivariate Cox proportional hazards regression analyses were used to identify associations between the quantitative measurements of 18F-FDG PET, and progression-free survival (PFS), distant metastasis-free survival (DMFS), and disease-specific survival (DSS).Results: Distant metastases were found in 20 (39%) patients: 6 (12%) at initial diagnosis and 14 (27%) during the median follow-up of 72 months after treatment. Univariate analyses showed that all the 18F-FDG PET parameters of SUVmax, SUVmean, SUVpeak, MTV, and TLG were significantly associated with overall PFS, DMFS, and OS (all P < .05). After controlling for clinicopathological variables, SUVmax remained an independent factor predictive of PFS (P = .001), while MTV and TLG were independent predictors of DMFS (P = .009) and DSS (P = .017). Patients with MTV > 14.8 mL showed a 5.9-fold higher risk of distant metastasis and a 4.2-fold higher risk of disease-specific death than those with a lower MTV.Conclusions: Quantitative measurements using 18F-FDG PET/CT are useful for predicting tumor progression, distant metastasis, and survival in patients with AdCC. [ABSTRACT FROM AUTHOR]

Summary: Objectives: Central compartment lymph node metastasis (CLNM) in patients with laryngeal, hypopharyngeal, or cervical esophageal squamous cell carcinoma is associated with unfavorable clinical outcomes, but cannot be reliably detected using computed tomography (CT)/magnetic resonance imaging (MRI). Therefore, we assessed the clinical utility of using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT to identify CLNM in these patients. Patients and methods: A total of 62 patients were preoperatively evaluated using 18F-FDG PET/CT and CT/MRI. Histopathologic analysis of the dissected neck tissues was used as the gold standard for assessing these imaging techniques. The diagnostic value of 18F-FDG PET/CT for detecting CLNM was calculated and compared with CT/MRI. Univariate and multivariate analyses were utilized to determine the factors predictive of CLNM. Results: Of the 62 patients in the study cohort, 12 (19%) had CLNM. Compared with histology, both 18F-FDG PET/CT and CT/MRI demonstrated low sensitivity for detecting CLNM (58% vs 42%, respectively, P =0.625). The specificities of 18F-FDG PET/CT and CT/MRI for the detection of CLNM were 88% and 90%, respectively (P =1.000). Univariate and multivariate analyses showed that clinical metastasis to any cervical lymph node was significantly associated with CLNM (P =0.018). Conclusions: Neither 18F-FDG PET/CT nor CT/MRI is a sensitive diagnostic imaging modality for detecting CLNM. Routine elective central compartment dissection or radiotherapy should be advocated for the treatment of these patients. [ABSTRACT FROM AUTHOR]

Summary: 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) has been reported to identify primary tumors in patients with cervical metastases from cancer of unknown primary (CUP). However, few reports have assessed the use of combined FDG-PET/computed tomography (CT) in this setting. We therefore examined the utility of combined FDG-PET/CT in the detection of primary tumors and unrecognized metastases in these patients. Patients with previously untreated CUPs underwent head and neck CT and whole-body FDG-PET/CT before panendoscopy and guided biopsy. The diagnostic accuracy of CT and FDG-PET/CT in detecting primary tumors and cervical metastases was compared with that of histopathology. The ability of FDG-PET/CT to detect distant metastases was also tested. Of the 44 eligible patients, 16 had occult primary tumors in the head and neck. FDG-PET/CT was significantly more sensitive than CT for detecting primary tumors (87.5% vs. 43.7%, P =.016), but their specificity did not differ (82.1% vs. 89.3%, P =.500). Thirty-four of 44 patients underwent neck dissection; 67 of 182 dissected cervical levels had metastatic nodal diseases. On a level-by-level basis, FDG-PET/CT was significantly more sensitive than CT (94.0% vs. 71.6%, P <.001), but the two methods were equally specific (94.8% vs. 96.5%). FDG-PET/CT correctly detected distant metastases in 6 of 6 patients. Combined FDG-PET/CT is a useful screening method for primary tumor detection, accurate nodal staging, and distant metastases in patients with CUPs. [Copyright &y& Elsevier]

Summary: The role of 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) in identifying bone metastases in patients with head and neck cancer is not clear. We compared the ability of FDG-PET and bone scintigraphy (BS) to detect bone metastases in patients with upper aerodigestive tract (UADT) malignancies. Patients with histologically confirmed malignancies in the UADT underwent both FDG-PET and BS at initial staging or follow-up. The two methods were compared in patients and in seven skeletal regions. Maximum standard uptake value (SUVmax) on PET was calculated in each lesion and compared between true- and false-positive lesions. This study included 564 eligible patients, of whom 17 had bone metastases. The spine was the most frequently involved site, followed by the lungs and liver. Both FDG-PET and BS had high specificity, accuracy, and negative predictive values for detecting bone metastases (>95% each), and the two methods did not differ in sensitivity, specificity, and predictive values (P >0.05). Both FDG-PET (n =15) and BS (n =14) yielded a significant number of false-positive results, which could be corrected by further work-ups and follow-up imaging. Compared with true-positive lesions, the false-positive lesions on FDG-PET were usually single (86.7% vs. 12.5%, P <0.001) and had lower mean SUVmax (2.4 vs. 5.6, P <0.001). FDG-PET is not more accurate than BS for detecting bone metastasis in patients with UADT cancer. Positive findings on FDG-PET or BS require further confirmation. [Copyright &y& Elsevier]

Summary: The combination of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) has been reported to be more accurate than CT or PET alone in a preoperative setting. We compared the diagnostic utility of preoperative PET/CT, PET and CT/MRI in 167 patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC), of whom 104 underwent FDG PET and 63 underwent combined PET/CT with all receiving CT/MRI. These preoperative PET, PET/CT, and CT/MRI results were reviewed and their accuracies were compared in patients in whom diagnosis was confirmed histopathologically. Age, sex, primary sites and stage, and nodal involvement were comparable between two groups. The accuracy of PET and PET/CT for detecting primary tumors and cervical metastases was comparable, but significantly higher than that of CT/MRI (98%–97% vs. 86–88% for primary; 92%–93% vs. 85%–86% for neck on a level-by-level basis; P <.05). PET and PET/CT gave false negative results: in 2 (2%) and 2 (3%) patients for primary tumors; in 6 (6%) and 3 (5%) patients for neck metastases, respectively. PET and PET/CT also gave false-positive results for cervical metastases in 5 (5%) and 4 (6%) patients, respectively. Compared with PET alone, preoperative FDG PET/CT may not yield significantly improved diagnostic accuracy in patients with HNSCC. Moreover, despite their high accuracy, PET and PET/CT may not abrogate the need for conventional imaging and pathologic staging based on primary resection and neck dissection. [Copyright &y& Elsevier]

Summary: Few studies have used positron emission tomography (PET) to identify metastases or simultaneous thoracic malignancies in patients with head and neck cancer (HNC). We retrospectively investigated the role of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in detecting thoracic malignancies in patients with previously untreated HNC. Patients (n =86) with HNC and intrathoracic lesions on PET were divided into those who had abnormal FDG uptake in the mediastinum (n =29), lungs (n =34), or both (n =23). Whole body PET and chest computed tomography (CT) results were blindly reviewed and scored by two observers. The accuracy of FDG PET and CT were drawn from patients in whom diagnosis was confirmed, by histopathology or follow-up imaging, and risk factors for thoracic malignancy were analyzed. Malignancy was suspected in 23 of 86 patients (27%) with FDG uptake. Most of the lesions (83%) with abnormal FDG uptake were benign, with thoracic malignancy confirmed in 15 patients (17%). The overall sensitivity, specificity, and accuracy of FDG PET for intrathoracic malignancy in these patients were 80%, 85%, and 84%, respectively. The likelihood of thoracic malignancy in the HNC patients was associated with high FDG uptake of thoracic lesions. FDG PET may reveal lung and mediastinal malignancies with high accuracy in patients with HNC. The thoracic staging by FDG PET may be helpful in therapeutic planning for these patients. [Copyright &y& Elsevier]

Summary: The aim was to evaluate the efficacy of positron emission tomography (PET) with 2-[F-18]fluoro-2-deoxy-d-glucose (FDG) in early discrimination of response to definitive radiotherapy (RT) in patients with squamous cell carcinoma of the head and neck (SCCHN). Twenty-four patients who underwent FDG-PET scans before and after radiotherapy for nondisseminated SCCHN at the Asan Medical Center between August 2001 and September 2002 were prospectively evaluated. Initial FDG-PET scans were performed within 1month before RT, and follow-up FDG-PET scans were performed 1month after completion of RT. FDG-PET images were analyzed by standard uptake value (SUV). All patients were followed for more than 6months. Pretreatment SUV ranged from 3.4 to 14.0 (median, 6.0), while posttreatment SUV ranged from ground level to 7.7 (median, 2.0). In evaluating residual tumors in these SCCHN patients, the overall sensitivity of FDG-PET was 100%, while its overall specificity was 87%. FDG-PET is effective in evaluating the response to radiation in patients with SCCHN. Timing the follow-up FDG-PET scan 1month after completion of RT was not too rapid for evaluating the response to radiation. [Copyright &y& Elsevier]

Objectives: Pre- and post-treatment 18F-FDG PET/CT may have a prognostic role in human cancers. 18F-FDG PET/CT after primary surgery for head and neck cancer might also predict survival. Therefore, we evaluated the prognostic value of post-treatment 18F-FDG PET/CT in primary surgical patients with advanced-stage head and neck squamous cell carcinoma (HNSCC).Materials and Methods: This prospective study involved 225 patients with previously untreated advanced-stage HNSCC who underwent primary surgery with or without postoperative radiotherapy or chemoradiotherapy. The patients also had 18F-FDG PET/CT scanning at a median 6 months after surgery. Post-treatment 18F-FDG PET/CT was considered positive, based on interpretation by experienced nuclear medicine physicians with integrating clinical information. Positive and negative predictive values (PPV and NPV) for positive 18F-FDG PET/CT in association with recurrence were calculated. Predictors for positive post-treatment 18F-FDG PET/CT were evaluated using binary logistic regression. Survival analysis was performed using Cox proportional hazard regression analysis.Results: PPV and NPV for post-treatment PET/CT for overall recurrence were 75.8% and 98.7%, respectively. A positive post-treatment PET/CT was an independent predictive factor for overall and disease-free survival (both P < 0.001). Five-year overall survival rates for patients with positive and negative PET/CT were 48.1% and 92.3%, respectively. Corresponding 5-year disease-free survival rates were 22.5% and 82.4%, respectively. Perineural invasion, positive resection margin, positive pathological node, and extranodal extension were the independent predictors of positive 18F-FDG PET/CT (all P < 0.05).Conclusions: Post-treatment 18F-FDG PET/CT predicts survival and recurrence in patients undergoing curative surgery for advanced-stage HNSCC. [ABSTRACT FROM AUTHOR]