Prognostic impact of standardized uptake value of F-18 FDG PET/CT in nasopharyngeal carcinoma.

PURPOSE: We evaluated the use of metabolic parameters of F-18 fluorodeoxyglucose positron emission tomography (FDG PET) for the assessment of the primary tumor and nodal metastasis in predicting survival in nasopharyngeal carcinoma (NPC) patients. MATERIALS AND METHODS: The F-18 FDG PET/CT (computed tomography) scans of 46 consecutive newly diagnosed NPC patients were retrospectively reviewed. Maximal standardized uptake value (SUVmax) corrected for lean body mass of primary tumor (pSUVmax) and highest SUVmax of cervical lymph nodes (nSUVmax) were recorded. The association of FDG uptake and 2-year disease-free survival (DFS) was examined. RESULTS: Significantly better DFS was found in patients with pSUVmax <7.5 and nSUVmax <6.5 (P = 0.042 and P = 0.019, respectively). In multivariate analysis, both pSUVmax and nSUVmax were significant independent predictors of DFS. CONCLUSIONS: The SUVmax of the primary tumor and nodal metastasis are useful parameters for predicting DFS in NPC patients.

Nasopharyngeal carcinoma: relationship between 18F-FDG PET-CT maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis and TNM classification.

PURPOSE: We aimed to evaluate the relationships between primary tumour; maximum standardized uptake value (SUVmax), metabolic tumour volume (TV) and total lesion glycolysis (TLG) and tumour-node metastases (TNM) classification in nasopharyngeal carcinoma (NPC) patients. METHODS: Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography scans of 57 consecutive newly diagnosed NPC patients (age range, 15-80 years) were retrospectively reviewed. SUVmax, TV and TLG were recorded. Two-tailed Spearman's correlation was used to analyse the relationships between the metabolic parameters and the TNM staging system. RESULTS: Positive correlations were observed between SUVmax (P<0.001, R=0.516), TV (P<0.001, R=0.504) and TLG (P<0.001, R=0.620) and T-stage, and both TV and SUVmax were independent variables that significantly affected T-stage (P<0.001, adjusted R=0.370). No other significant correlations were found between the metabolic parameters and TNM classification system. CONCLUSION: The metabolic parameters derived from fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography were positively correlated with T-stage in primary NPC. Our findings may suggest a complementary role of these parameters to TNM staging in prognostication of NPC patients.

Dual-tracer PET/CT imaging in evaluation of metastatic hepatocellular carcinoma.

UNLABELLED: We have reported previously that (11)C-acetate ((11)C-ACT) PET was complementary to (18)F-FDG PET in the evaluation of primary hepatocellular carcinoma (HCC) in relation to the degree of tumor cellular differentiation. In this retrospective study, our goals were to further explore the complementary role of (11)C-ACT and (18)F-FDG PET in the detection of metastatic HCC disease, to evaluate the tracer characteristics of individual organ metastasis, to identify the risk factors of metastasis, and to evaluate how these results could affect patient management. METHODS: One hundred twenty-one patients were selected for this study. All patients had undergone a "dual-tracer" PET/CT same-day protocol with (11)C-ACT PET/CT followed by (18)F-FDG PET/CT. Sets of criteria were chosen to define "metastasis" and "no metastasis" on a patient basis. The patients considered as true-positive (n = 97) were then divided into 4 groups on the basis of their primary HCC tracer avidity: (18)F-FDG-avid group, (11)C-ACT-avid group, (18)F-FDG- and (11)C-ACT-avid group, and a posttreatment group with metastasis but no baseline dual-tracer PET characterization of the primary tumor and no hepatic recurrence. RESULTS: On a patient basis, dual-tracer PET/CT had a sensitivity of 98%, a specificity of 86%, a positive predictive value of 97%, a negative predictive value of 90%, and an accuracy of 96% in the detection of HCC metastasis. On a lesion basis, 273 metastatic HCC lesions considered as true-positive were detected and categorized according to the organ or site of metastasis: lymph node (abdominal and thoracic, 49%), lung (32%), bone (8%), and others (10%). The lesion-based and patient-based detection sensitivities were 60% and 64%, respectively, by (11)C-ACT and 77% and 79%, respectively, by (18)F-FDG, and they were complementary. In analyzing lesion tracer avidity, there was a positive statistical correlation between primary HCC avidity with the general tendency of metastasis. Clinically significant changes in management were found in patients with true-positive metastasis, of whom 19% were affected by (11)C-ACT PET alone. Dual-tracer PET/CT was more effective than single-tracer PET/CT in identifying candidates for curative therapy (negative predictive value of dual-tracer, (18)F-FDG, and (11)C-ACT PET/CT: 90%, 49%, and 37%, respectively). CONCLUSION: This study confirmed that (18)F-FDG PET/CT is useful in the evaluation of HCC metastasis, although its role in the diagnosis of primary HCC is more limited. Dual-tracer PET/CT had an incremental value and complementary advantage when compared with single-tracer imaging in the evaluation of HCC metastasis.

Pilot study of positron emission tomography (PET) brain glucose metabolism to assess the efficacy of tongue and body acupuncture in cerebral palsy.

We aimed to assess the efficacy of tongue and body acupuncture with clinical function and brain glucose metabolism in children with a severe type of cerebral palsy. Four children were recruited. The motor function belonged to grade 5 of the Gross Motor Function Measure (i.e., completely nonambulatory). Daily tongue and body acupuncture was applied for 5 days a week for 8 weeks. The Functional Independence Scale for Children (WeeFIM), Clinical Global Impression Scale (CGIS), and positron emission tomography of the brain with [18F]fluorodeoxyglucose (FDG) were performed at baseline and after acupuncture. None of the children had any significant change in the Functional Independence Scale for Children score, despite the fact that all mothers scored 3 on the Clinical Global Impression Scale (i.e., 25% in improvement) in overall function. The brain glucose metabolism, however, showed a >10% increase in the frontal, parietal, temporal, and occipital cortices and cerebellum. Thus, a short course of tongue and body acupuncture was shown to increase brain glucose metabolism, despite lacking any clinical functional improvement seen during the eight-week course, possibly owing to the severity of the motor dysfunction and the short duration of treatment. The objective increase in brain glucose metabolism might serve as a surrogate marker for assessing the subclinical efficacy of an alternative treatment before any objective clinical improvement is evident. A larger-scale study for different degrees of severity of cerebral palsy and an impairment model should be undertaken to correlate clinical with neurometabolic change.

Pilot study of efficacy of tongue and body acupuncture in children with visual impairment.

We studied the efficacy of tongue and body acupuncture in affecting visual recovery in children with central and peripheral visual disorders. Twelve children (five boys, seven girls) (age range 18 months to 14.5 years) with visual disorder with static functional visual ability for at least 12 months were recruited for the study. The causes of cortical visual impairment (10) included severe perinatal asphyxia (4), postencephalitis (1), traumatic brain injury (1), hydrocephalus (1), and increased intracranial pressure (3). Peripheral causes (2) were due to congenital optic atrophy. We used the following assessment tools: clinical visual improvement, defined as improvement of vision by one grade in one or both eyes with measurement of visual acuity; the functional visual outcome scale of 0 to 5, with positive outcome defined as improvement in one level on a functional scale; visual evoked potential, with positive improvement defined as 10% improvement in P100 latency of one or both eyes; [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) of the brain, with positive improvement defined as a 10% increase in glucose metabolism in one or both occipital lobes; and the Clinical Global Impression Scale (parental report). Tongue and body acupuncture consisted of 60 sessions, with 5 sessions per week. Four children showed clinical or functional improvement (33%). Of nine children with abnormal visual evoked potentials, five had improvement (56%). Of seven children who underwent PET, six had improvement in glucose metabolism in the visual cortex (86%). Seven parents (58%) reported improvement (three children had 75% improvement; four children had 25% improvement). There was a significant correlation between the interval of onset of visual impairment and starting treatment with clinical or functional outcome, with a longer interval resulting in a better outcome (P = .0282). However, there was no correlation between cause, severity, or clinical or functional visual outcome with improvement in the visual evoked potential or PET. We demonstrated that tongue and body acupuncture can improve the visual status of children with visual disorders, both peripheral and central in origin. As children with chronic visual impairment also showed some visual recovery, more studies should be done to assess the full potential of acupuncture as an adjunct to Western medicine in neuroplasticity.

11C-acetate PET imaging in hepatocellular carcinoma and other liver masses.

UNLABELLED: It is well known that (18)F-FDG PET has a high average false-negative rate of 40%-50% in the detection of hepatocellular carcinoma (HCC). This is not an acceptable accuracy, particularly in countries where this tumor is prevalent. In this study, we evaluated prospectively the characteristics of (11)C-acetate and (18)F-FDG metabolism in HCC and other liver masses. METHODS: Fifty-seven patients were recruited into this study, with masses consisting of 39 HCC; 3 cholangiocarcinomas; 10 hepatic metastases from lung, breast, colon, and carcinoid primary malignancies; and 5 benign pathologies, including focal nodular hyperplasia (FNH), adenoma, and hemangioma. All patients, except 2 with typical findings of hemangioma and 3 clinically obvious metastases, were confirmed histopathologically by liver biopsy or resection. All patients fasted for at least 6 h and blood glucose concentration was measured before they underwent dual PET radiopharmaceutical evaluation of the upper abdomen with (11)C-acetate and (18)F-FDG. RESULTS: In the subgroup of HCC patients with the number of lesions < or = 3 (32 patients; 55 lesions; mean size +/- SD, 3.5 +/- 1.9 cm), the sensitivity of detection by (11)C-acetate is 87.3% ((11)C-acetate maximum SUV [SUV(max)] = 7.32 +/- 2.02, with a lesion-to-normal liver ratio of 1.96 +/- 0.63), whereas the sensitivity of detection by (18)F-FDG is only 47.3%, and 34% lesions show uptake of both tracers. None of the lesions was negative for both tracers (100% sensitivity using both tracers). In some lesions and in the subgroup of HCC patients (n = 7) with multifocal or diffuse disease, dual-tracer uptake by different parts of the tumor is demonstrated. Histopathologic correlation suggests that the well-differentiated HCC tumors are detected by (11)C-acetate and the poorly differentiated types are detected by (18)F-FDG. All 16 non-HCC malignant (cholangiocarcinoma and metastatic) liver lesions do not show abnormal (11)C-acetate metabolism. Of the benign liver lesions, only FNH shows mildly increased (11)C-acetate activities ((11)C-acetate SUV(max) = 3.59, with a lesion-to-normal liver ratio of 1.25). CONCLUSION: (11)C-Acetate has a high sensitivity and specificity as a radiotracer complementary to (18)F-FDG in PET imaging of HCC and evaluation of other liver masses.