Biomedical subjects

Tzu-Chen Yen

Publications and source records attributed to Tzu-Chen Yen.

At least 37 records · Page 2Linked to original sources

PubMed2005

Utility of 2-fluoro-2-deoxy-D-glucose positron emission tomography in managing patients of colorectal cancer with unexplained carcinoembryonic antigen elevation at different levels.

PURPOSE: Serum carcinoembryonic antigen elevation without detectable relapse during colorectal cancer follow-up presents a challenge. This study was designed to evaluate the utility of fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose positron emission tomography in colorectal cancer patients with unexplained carcinoembryonic antigen elevation at different levels. METHODS: Thirty-seven colorectal cancer patients referred for positron emission tomography after primary surgery who had serum carcinoembryonic antigen levels >5 ng/ml and negative or equivocal conventional imaging studies were analyzed. Patient status was determined by histopathology and/or clinical follow-up. Grouping as disease-free, potentially resectable, or advanced disease was performed. The management impact was defined as the percentage of patients with a true-positive positron emission tomography result. RESULTS: The sensitivity, specificity, and accuracy of positron emission tomography for relapse detection were 89, 89, and 89 percent, respectively. The management impact was 68 percent. In 24 patients with carcinoembryonic antigen levels <25 ng/ml, positron emission tomography helped correct patient grouping in 20 patients (83 percent), including 8 in the disease-free group, 5 in the potentially resectable group, and 7 in the advanced-disease group. In 13 patients with carcinoembryonic antigen levels >25 ng/ml, positron emission tomography identified 8 patients in the advanced-disease group and 1 patient in the potentially resectable group but missed 2 patients with relapse and undergrouped 2 patients in the advanced-disease group as potentially resectable. CONCLUSIONS: 2-fluoro-2-deoxy-D-glucose positron emission tomography can help triage patients for appropriate management with unexplained carcinoembryonic antigen elevation <25 ng/ml. For patients with unexplained elevation of carcinoembryonic antigen >25 ng/ml, the utility of positron emission tomography is mainly to confirm the presence of advanced disease and occasionally to identify potentially resectable lesions.

Adenocarcinoma↗

PubMed2005

The value of 18F-FDG PET in the detection of stage M0 carcinoma of the nasopharynx.

UNLABELLED: Distant metastasis is an important issue for nasopharyngeal carcinoma (NPC). The potential value of PET using 18F-FDG has not been well defined. This prospective study investigated the impact of 18F-FDG PET in NPC patients with stage M0 disease. METHODS: From April 2001 to June 2003, 140 NPC patients (118 primary and 22 primary recurrent) with stage M0 (negative results from chest radiography, liver sonography, and whole-body bone scanning) underwent 18F-FDG PET to check for distant metastases. Confirmatory MRI or CT was performed if any abnormal 18F-FDG uptake was found at distant sites. The distant lesion was confirmed pathologically, if feasible, and was followed up clinically and with imaging for at least 6 mo. RESULTS: 18F-FDG PET detected 26 true-positive metastatic sites in 18 (12.9%) of the 140 patients, among whom 14 had primary and 4 had recurrent tumors. The patient-based sensitivity and specificity of 18F-FDG PET for distant metastases were 100% and 86.9%, respectively. Mediastinal lymph nodes (n = 8) were the most common sites, followed by lung, liver, and bone (n = 5 each) and by other lymph nodes (n = 3). In patients with primary tumors, advanced nodal status (N2-3) was a statistically significant variable associated with development of distant metastases (P = 0.044). For recurrent NPC, neither age, sex, initial tumor stage, grade of differentiation, nor nodal stage showed a statistically significant difference between patients with and patients without distant metastases. CONCLUSION: 18F-FDG PET is valuable in avoiding aggressive locoregional radiotherapy in some NPC patients by the revelation of occult distant metastases, especially in patients with primary disease at a nodal stage of N2-3.

Adolescent↗

PubMed2005

Staging of untreated squamous cell carcinoma of buccal mucosa with 18F-FDG PET: comparison with head and neck CT/MRI and histopathology.

UNLABELLED: This prospective, nonrandomized, case-control study evaluated the impact of (18)F-FDG PET in staging untreated squamous cell carcinoma of the buccal mucosa (BSCC) and compared the results with CT/MRI and histopathology. METHODS: Between January 2002 and April 2004, 102 untreated BSCC patients with cM0 (no evidence of distant metastatic focus on chest radiograph, liver ultrasonograph, and bone scan) were enrolled with either conventional work-up (CWU, n = 51) or PET (CWU+PET, n = 51). All were monitored for at least 6 mo. The comparative diagnostic efficacies of PET and CT/MRI were evaluated using the area under the receiver-operating-characteristic curve (AUC). The primary endpoint was the percentage reduction in futile surgery (preoperative detection of distant metastatic lesions). The secondary endpoint was the 2-y cumulative recurrence rate among study participants (with PET) compared with that of comparable control subjects (without PET). RESULTS: Significant benefits of PET compared with those of CT/MRI for BSCC patients were in the detection of locoregional (AUC, 0.973 vs. 0.928; P = 0.026), regional (AUC, 0.939 vs. 0.837; P = 0.026), and level II (AUC, 0.974 vs. 0.717; P = 0.02) lymph nodes. Two percent (1/51) of the patients experienced a reduction in futile surgery in the CWU+PET group compared with 0% (0/51) in the CWU group. However, no statistical difference was found in the 2-y locoregional control rate between the CWU and the CWU+PET groups. CONCLUSION: The role of (18)F-FDG PET for BSCC with cM0 is limited. Although PET is superior to CT/MRI in identifying cervical nodal metastases, it does not improve locoregional recurrence.

Adult↗

PubMed2005

18F-FDG PET and CT/MRI in oral cavity squamous cell carcinoma: a prospective study of 124 patients with histologic correlation.

UNLABELLED: Accurate evaluation of primary tumors and cervical lymph node status of squamous cell carcinoma (SCC) of the oral cavity is important to treatment planning and prognosis prediction. In this prospective study, we evaluated the use of 18F-FDG PET, CT/MRI, and their visual correlation for the identification of primary tumors and cervical nodal metastases of SCC of the oral cavity with histologic correlation. METHODS: One hundred twenty-four patients with pathologically proven diagnoses of oral cavity SCC underwent 18F-FDG PET and CT/MRI within 2 wk before surgery. We interpreted 18F-FDG PET, CT/MRI, and visually correlated 18F-FDG PET and CT/MRI separately to assess the primary tumors and their regional lymph node status. We recorded lymph node metastases according to the neck level system of imaging-based nodal classification. Histopathologic analysis was used as the gold standard for assessment of the primary tumors and lymph node involvement. We analyzed differences in sensitivity and specificity among the imaging modalities using the McNemar test. The receiver-operating-characteristic (ROC) curve and calculation of the area under the curve were used to evaluate their discriminative power. RESULTS: The accuracy of 18F-FDG PET, CT/MRI, and their visual correlation for the identification of primary tumors was 98.4%, 87.1%, and 99.2%, respectively. The sensitivity of 18F-FDG PET for the identification of nodal metastases on a level-by-level basis was 22.1% higher than that of CT/MRI (74.7% vs. 52.6%, P < 0.001), whereas the specificity of 18F-FDG PET was 1.5% lower than that of CT/MRI (93.0% vs. 94.5%, P = 0.345). The sensitivity and specificity of the visual correlation of 18F-FDG PET and CT/MRI were 3.2% and 1.5% higher than those of 18F-FDG PET alone (77.9% vs. 74.7%, P = 0.25; 94.5% vs. 93.0%, P = 0.18, respectively). The area under the curve obtained from the ROC curve showed that 18F-FDG PET was significantly superior to CT/MRI for total nodal detection (0.896 vs. 0.801, P = 0.002), whereas the visual correlation of 18F-FDG PET and CT/MRI was modestly superior to 18F-FDG PET alone (0.913 vs. 0.896, P = 0.28). CONCLUSION: 18F-FDG PET is superior to CT/MRI in the detection of cervical status of oral cavity SCC. The sensitivity of 18F-FDG PET for the detection of cervical nodal metastasis on a level-by-level basis was significantly higher than that of CT/MRI, whereas their specificities appeared to be similar. Visual correlation of 18F-FDG PET and CT/MRI showed a trend of increased diagnostic accuracy over 18F-FDG PET alone but without a statistically significant difference, and its sensitivity was still not high enough to replace pathologic lymph node staging based on neck dissection.

Adult↗

PubMed2004

Are dual-phase 18F-FDG PET scans necessary in nasopharyngeal carcinoma to assess the primary tumour and loco-regional nodes?

PURPOSE: This prospective study aimed to investigate the efficacy of dual-phase positron emission tomography (PET) in evaluating the loco-regional status of nasopharyngeal carcinoma (NPC). METHODS: Eighty-four patients with newly diagnosed NPC and a fasting serum glucose level of <200 mg/dl were enrolled. [18F]fluoro-2-deoxy-D-glucose (18F-FDG) PET studies (at 40 min and 3 h after injection of 370 MBq 18F-FDG) and head and neck magnetic resonance imaging (MRI) were performed within 1 week. Diagnostic criteria for NPC comprised the histopathological findings, the joint judgments of the research team and the post-treatment outcome. Each lesion's maximum standardised uptake value (SUV) and retention index were obtained. SUV data were evaluated using a paired t test. Receiver operating characteristic curves and calculation of the area under the curve (AUC) determined the discriminative power. RESULTS: 18F-FDG PET was significantly superior to MRI in identifying lower neck NPC nodal metastasis (AUC: 1 vs 0. 972, P=0.046) and overall loco-regional metastases (AUC: 0.985 vs 0.958, P=0.036). However, 18F-FDG PET was similar to MRI in detecting primary tumour, as well as retropharyngeal, upper neck and supraclavicular nodal metastases. There was no significant difference between early phase (40 min) and delayed phase (3 h) 18F-FDG PET in the detection of primary tumours (accuracy: 100% vs 100%) or loco-regional nodal metastasis (AUC: 0.984 vs 0.985, P=0.834). CONCLUSION: 18F-FDG PET is superior to MRI in identifying lower neck nodal metastasis of NPC. Additional 3-h 18F-FDG PET contributes no further information in the detection of primary tumours or loco-regional metastatic nodes in untreated NPC patients.

Adolescent↗

PubMed2004

Positron emission tomography for unexplained elevation of serum squamous cell carcinoma antigen levels during follow-up for patients with cervical malignancies: a phase II study.

BACKGROUND: During follow-up for patients with cervical carcinoma, elevation of serum squamous cell carcinoma antigen (SCC-Ag) levels in the absence of detectable recurrent lesions presents a diagnostic and therapeutic challenge. In the current prospective study, the authors evaluated the use of fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) to detect disease recurrence in this setting. METHODS: Women with cervical carcinoma who experienced complete responses to primary treatment or salvage therapy and who had no evidence of recurrent disease as detected by conventional methods but had serum SCC-Ag levels > or = 2.0 ng/mL on 2 consecutive occasions were eligible for the study. PET was performed within 2 weeks after the completion of conventional studies for the assessment of recurrence. RESULTS: Twenty-seven consecutive patients were registered for the current study. PET findings were positive for 19 patients: 14 who had a distant lesion or lesions, 2 who had a local lesion or lesions, and 3 who had both local and distant lesions. Of these 19 patients, 17 were confirmed to have recurrent disease; the remaining two were found to be free of disease but had severe anthracosis in the PET-positive mediastinal lymph nodes. Seven of the eight patients with negative PET findings were not found to have recurrent disease on follow-up. Overall, PET detected FDG-avid lesions in 17 (94%; P < 0.001) of the 18 patients with recurrent disease. Seven of these 18 patients received therapy with curative intent; complete control was achieved in 6, four of whom currently are alive and free of disease. The addition of PET in the current setting curbed the use of futile curative therapy and significantly increased overall survival for patients in the current cohort compared with a historical group of 30 consecutive patients who had elevated SCC-Ag levels as a first sign of recurrence. CONCLUSIONS: PET expedited the detection of recurrent cervical carcinoma in patients with unexplained elevation of SCC-Ag levels. Such expedited detection may have positive effects on patient survival.

Antigens, Neoplasm↗

PubMed2004

Preliminary report of using FDG-PET to detect extrapelvic lesions in cervical cancer patients with enlarged pelvic lymph nodes on MRI/CT.

PURPOSE: To evaluate, in a prospective study, the effects of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) on the detection of extrapelvic lesions, the design of whole pelvis or extended field radiotherapy, and subsequent failure patterns for patients with cervical cancer and enlarged pelvic lymph nodes (LNs) shown on MRI or CT. METHODS AND MATERIALS: Between April and December 2001, 19 consecutive patients underwent an additional FDG-PET examination before concurrent chemoradiotherapy. The inclusion criteria for the study were at least one enlarged pelvic LN > or =10 mm in its maximal dimension as shown on radiologic images and no extrapelvic tumors detected by conventional examination. The PET findings of the primary tumor, pelvic LNs, and extrapelvic lesions were investigated and compared with the MRI/CT findings. Tumor FDG uptake was quantitated with the maximal pixel standardized uptake value. RESULTS: Except for 1 patient with diabetes mellitus who was excluded from analysis, 18 cervical tumors had significant FDG uptake (maximal pixel standardized uptake value >8). A total of 39 pelvic LNs were reported, and the agreement of positive pelvic LNs between MRI/CT and PET was 79.5%. Five patients (28%) had positive paraaortic LNs on FDG-PET, and their treatment fields were extended to include the paraaortic region. In addition to the paraaortic LNs, 1 patient also had metastasis at the left supraclavicular node. After a minimum follow-up of 12 months (median 15.9), 4 patients (22.2%) developed new extrapelvic metastases. The disease-free survival rate was 78% at 12 months. CONCLUSION: FDG-PET is a useful tool to detect paraaortic LN metastasis and determine the appropriate treatment field for cervical cancer with enlarged pelvic LNs on MRI/CT. The preliminary data suggest that pretreatment FDG-PET can supplement conventional imaging studies, but still has limitations in the detection of microscopic disease.

Adult↗

PubMed2004

Nodal metastases of nasopharyngeal carcinoma: patterns of disease on MRI and FDG PET.

The patterns of nodal spread of nasopharyngeal carcinoma (NPC) have an important influence on treatment planning, but have not yet been fully addressed. We prospectively used MRI and FDG PET to document the patterns of nodal spread in NPC. One hundred and one patients with newly diagnosed NPC were studied with MRI and FDG PET. On MRI, nodes were considered as metastatic according to criteria regarding size, the presence of nodal necrosis, and extracapsular spread. FDG PET images were interpreted visually, and nodes were considered metastatic if they showed prominent FDG uptake against the background. Nodal metastases were found in 89 of our 101 patients. Analysis of the distributions of nodal metastases in these 89 patients showed that retropharyngeal nodes were less frequently involved than cervical nodes (82.0% vs 95.5%). The vast majority of cervical nodal metastases were to the internal jugular chain, including nodes at levels II, III, and IV, with decreasing incidences of 95.5%, 60.7%, and 34.8%, respectively. Level V nodal involvement was found in 27% of patients. Supraclavicular fossa nodal metastases were not uncommon and occurred in 22.5% of patients. Skip metastases in the lower-level nodes or supraclavicular fossa nodes occurred in 7.9% of patients. Mediastinal and abdominal metastatic adenopathy was present in 4.5% and 3.4% of patients, respectively, and was associated with advanced nodal metastasis in the supraclavicular fossa. Level VI (2.2%), level VII (1.1%), submandibular (2.2%), and parotid (3.4%) nodal metastases were uncommon and were always associated with advanced ipsilateral nodal metastases of the neck. We conclude that the combined use of FDG PET and MRI can comprehensively depict the pattern of nodal metastasis in NPC patients. Nodal metastases principally affected level II nodes, from which lymphatic spread extended down in an orderly manner to involve level III, level IV, and the supraclavicular fossa nodes, or extended posteriorly to involve level V nodes. The frequency of skip metastases was 7.9%. Distant spread to mediastinal or abdominal nodes was found in 3-5% of patients, usually in association with supraclavicular nodal metastases.

Adolescent↗

PubMed2004

Restaging of recurrent cervical carcinoma with dual-phase [18F]fluoro-2-deoxy-D-glucose positron emission tomography.

BACKGROUND: The clinical value of positron emission tomography (PET) with [18F]fluoro-2-deoxy-D-glucose (FDG) for primary staging in cervical carcinoma appears to be promising. The authors sought to evaluate the diagnostic efficacy and benefit of PET in restaging cervical carcinoma at the time of first recurrence. METHODS: Forty patients with cervical carcinoma who experienced confirmed treatment failure but who were feasible candidates for curative salvage therapy were enrolled prospectively in the current study. Restaging was performed with PET and with computed tomography and/or magnetic resonance imaging (CT/MRI). Dual-phase PET was performed by adding 3-hour-delayed images to the 40-minute scans. The results of the PET and CT/MRI scans were compared. Lesion status was determined by pathologic findings or by clinical follow-up. The receiver operating characteristic curve method with calculation of area under the curve (AUC) was used to evaluate diagnostic efficacy. The primary endpoint was percent improvement in restaging (with improvement indicated by treatment modification) after PET. The secondary endpoint was 2-year overall survival among study participants compared with comparable previously treated patients who did not undergo disease restaging with PET. RESULTS: Twenty-two patients (55%) had their treatment modified due to PET findings. PET was significantly superior to CT/MRI (sensitivity: 92% vs. 60%; AUC: 0.962 vs. 0.771; P<0.0001) in identifying metastatic lesions. For individuals receiving primary surgery, a significantly better 2-year overall survival rate was observed among study participants compared with patients who underwent disease restaging without PET (HR, 0.21 [95% confidence interval, 0.05-0.83]; P=0.020). CONCLUSIONS: Dual-phase FDG-PET is superior to CT/MRI in the restaging of recurrent cervical carcinoma. Restaging with PET provides benefit by allowing the physician to offer optimal management of recurrent cervical carcinoma.

Adult↗

PubMed2004

The parkinsonian phenotype of spinocerebellar ataxia type 3 in a Taiwanese family.

We report a parkinsonian phenotype of spinocerebellar ataxia type 3 (SCA3) in three female sibs from one Taiwanese family, found in a genetic analysis of 60 patients from 49 families with familial parkinsonism. Initially, all three patients presented with early onset resting tremor, rigidity, bradykinesia, and good response to levodopa. In the later stages, peripheral neuropathy developed in one sib and mild ataxia in another one. Decreased concentration of dopamine transporter in the striatum was demonstrated by (99m)Tc-TRODAT-1 SPECT imaging in the two sibs studied. Therefore, SCA3 should be considered as an important etiology of familial parkinsonism.

Adult↗

PubMed2004

Dopamine transporter binding study in differentiating carbon disulfide induced parkinsonism from idiopathic parkinsonism.

Long-term exposure to carbon disulfide (CS(2)) may induce parkinsonian features. There may be confusion in distinguishing between CS(2) parkinsonism and idiopathic parkinsonism, especially for workers who developed parkinsonian features in viscose rayon plants. We performed clinical examinations, and laboratory studies including magnetic resonance imaging (MRI) and dopamine transporter (DAT) studies with (99m)Tc-TRODAT-1 brain single photon emission computed tomography (SPECT) in three workers who had long-term exposure to CS(2). Patient 1 had polyneuropathy, and encephalopathy with tremor; patient 2 had polyneuropathy, and encephalopathy with parkinsonian features; and patient 3 had pure parkinsonian features without polyneuropathy or cerebellar signs. The treatment with l-dopa was effective in patient 3, but non-effective in patient 2. Brain MRI revealed multiple high signal intensities over the subcortical white matter, basal ganglia, and/or even the brainstem in patients 1 and 2, but normal in patient 3. In DAT studies, the bindings were normal in patients 1 and 2 and was decreased in patient 3. We conclude that CS(2) exposure may induce polyneuropathy, and cerebellar dysfunction in addition to parkinsonian features and that brain MRI may show multiple lesions in the cerebral white matter and basal ganglia. In addition, DAT with (99m)Tc-TRODAT-1 brain SPECT may provide a useful information in differential diagnosis between CS(2) parkinsonism and idiopathic parkinsonism.

Brain↗

PubMed2004

Imaging early-stage corticobasal degeneration with [99mTc]TRODAT-1 SPET.

AIM: The aim of this study was to investigate the nigrostriatal dopaminergic function in patients with corticobasal degeneration (CBD) using [2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino]ethanethiolato(3-)-N2,N2',S2,S2']oxo-[1R-(exo-exo)]-[99mTc]technetium ([99mTc]TRODAT-1) brain single-photon emission tomography (SPET). METHODS: Five patients with probable CBD, 10 age- and duration-matched patients with idiopathic Parkinson's disease (IPD) and 10 age-matched healthy volunteers completed the SPET study. The images were obtained 4 h after intravenous injection of 925 MBq of [99mTc]TRODAT-1. Using a magnetic resonance imaging atlas of the striatum, the ratios of specific striatal binding to non-specific occipital binding were calculated. RESULTS: Clinical analysis showed that the CBD patients obtained significantly higher scores on the Unified Parkinson's Disease Rating Scale and a significantly worse score for activities of daily living. In the CBD and IPD groups, striatum-occipital/occipital, caudate nucleus-occipital/occipital and putamen-occipital/occipital ratios decreased significantly relative to those of healthy subjects. No statistical difference could be found between the CBD and IPD groups for these ratios, although relatively even, decreased uptakes in the caudate nucleus and putamen were found in the CBD group. On further analysis of the index of binding reduction, the differences between the caudate nucleus and putamen were significantly lower in the CBD group than in the IPD group. The striatal uptake of [99mTc]TRODAT-1 showed a distinct asymmetry in both the CBD and IPD patients. CONCLUSION: From this study, it can be concluded that early-stage CBD patients have a worse performance and more difficulties with daily activities than IPD patients. CBD patients demonstrated essentially similar patterns of [99mTc]TRODAT-1 binding as those with IPD. However, there was relatively more homogeneous involvement of the caudate nucleus and putamen in the CBD patients. This provides information about the differences between these patients in the early stages.

Adult↗

PubMed2004

18F-FDG uptake in squamous cell carcinoma of the cervix is correlated with glucose transporter 1 expression.

UNLABELLED: This prospective study investigates the relationship between glucose transporter-1 (Glut-1) expression and PET images using (18)F-FDG and its uptake and compares them with the tumor status (primary vs. recurrent or persistent), initial grade of histologic differentiation, and International Federation of Gynecologic Obstetrics (FIGO) staging for cervical cancer patients. METHODS: A dual-phase (18)F-FDG PET scan was performed on 51 participants within the 2 wk before surgery or biopsy. (18)F-FDG uptake was quantified by calculating standardized uptake values (SUVs). After (18)F-FDG PET scanning, 51 histologically proven squamous cell carcinoma specimens were examined to determine their degree of differentiation, using hematoxylin and eosin staining, and the expression of Glut-1 by an immunohistochemical stain. Twenty normal cervical and 20 cervical intraepithelial neoplasia (CIN) sets of tissue were also used to compare the results of Glut-1 expression in these tissues. The expression of Glut-1 was the product of (the intensity [with grades 0-3, defined qualitatively]) with (percentages of the lesion area that were positive). The results of Glut-1 expression were analyzed in combination with the SUVs (SUV1 was that at 40 min and SUV2 was that at 3 h), tumor status, initial cell differentiation, and FIGO staging. RESULTS: Significant overexpression of Glut-1 was noted in 48 of the 51 (94.1%) cancer specimens. None or only minimal expression of Glut-1 was observed in basal layers of normal and CIN tissues. Significant positive correlation was observed between Glut-1 expression and the SUVs in cervical cancer specimens (r = 0.74, P < 0.000 for SUV1 and r = 0.65, P < 0.000 for SUV2). In recurrent or persistent tumor, tumor size was significantly associated with both Glut-1 expression (r = 0.508, P = 0.011) and SUV1 (r = 0. 456, P = 0.025). For recurrent or persistent tumor, only SUV1 reached statistical significance when compared with lymph node metastasis (P = 0.0226). CONCLUSION: Glut-1 expression was related to (18)F-FDG uptake in cervical cancer patients. Recurrent or persistent cervical cancer tumor had significantly higher Glut-1 expression than metastatic lymph nodes. The values of SUV and the expression of Glut-1 did not correlate with the initial grade of histologic differentiation and FIGO staging.

Adult↗

PubMed2004

99mTc-TRODAT-1 imaging of multiple system atrophy.

UNLABELLED: Using (99m)Tc-TRODAT-1 ((99m)Tc-[2[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]-oct-2-yl]-methyl](2-mercaptoethyl) amino]ethyl]amino]ethane-thiolato(3-)-N2,N2',S2,S2]oxo-[1R-(exo-exo)])) brain SPECT imaging, we measured striatal dopamine transporters (DATs) activity in multiple system atrophy (MSA) to investigate the possibility of differentiating it from Parkinson's disease (PD) and to correlate the findings with the parkinsonian (MSA-P) and cerebellar (MSA-C) subtypes of MSA. METHODS: Forty-nine patients with probable MSA (30 MSA-P, 19 MSA-C), a disease control group of 36 age- and disease duration-matched patients with probable PD, and a healthy control group of 33 age-matched healthy volunteers participated in a SPECT study. The ratios of specific striatal binding-to-nonspecific occipital binding, including the striatum-to-occipital ratio (S/O), putamen-to-occipital ratio (P/O), caudate nucleus-to-occipital ratio (C/O), and putamen-to-caudate nucleus ratio (P/C), were calculated. The statistical analyses of uptakes among 4 groups used ANOVA followed by Games-Howell's multiple comparisons. The Spearman correlation coefficient between the motor scores of Unified Parkinson's Disease Rating Scale (UPDRS-III) and those binding ratios of the MSA-P and MSA-C groups and the PD group was also performed. RESULTS: The striatal binding was more symmetrically reduced in the MSA-P (asymmetric index, 14.2) and MSA-C (asymmetric index, 8.1) groups, in contrast to the greater asymmetric reduction in the PD group (asymmetric index, 28.6). Overall striatal binding was significantly reduced in the MSA-P (-59.8%), MSA-C (-29.9%), and PD (-58.0%) groups with no overlap between these values and those of the control group. Like the PD group, bilateral P/O, C/O, and S/O ratio values were significantly reduced in the MSA-P and MSA-C groups. Nevertheless, the reduction of bilateral P/O and S/O ratios was more for the MSA-P group than for the MSA-C group. P/C ratios showed that the MSA-P and PD groups had similar patterns of nigral impairment, but the MSA-C group had a different pattern. No correlation between the UPDRS-III scores and (99m)Tc-TRODAT-1 bindings was found in both MSA-P and MSA-C groups; in contrast, a significant negative correlation was noted in the PD group. CONCLUSION: (99m)Tc-TRODAT-1 brain SPECT is capable of scientifically differentiating between the MSA-P and MSA-C subtypes, and MSA-P has more symmetric nigrostriatal damage than that in PD. (99m)Tc-TRODAT-1 brain SPECT imaging probably could provide important information to differentiate MSA from PD.

Corpus Striatum↗

PubMed2004

Sensitivity and specificity of 99mTc-TRODAT-1 SPECT imaging in differentiating patients with idiopathic Parkinson's disease from healthy subjects.

UNLABELLED: The imaging of dopamine transporter (DAT) with (99m)Tc-TRODAT-1 ([2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino]ethanethiolato(3-)-N2,N2',S2,S2']oxo-[1R-(exo-exo)]-(99m)Tc-technetium) and SPECT has been recently proposed to be a valuable and feasible means of assessment of the integrity of dopamine neurons. The purpose of this study was to further investigate the clinical correlations and the age-specific sensitivity and specificity of this new approach in the diagnosis of patients with idiopathic Parkinson's disease (PD) that manifests in patients >50 y of age. METHODS: SPECT imaging with (99m)Tc-TRODAT-1 was conducted in 78 consecutive PD patients and in 40 age-matched healthy subjects. The images were obtained 4 h after the intravenous injection of the tracer. The ratios of specific striatal binding to nonspecific occipital binding were calculated. S/O represents the ratio for whole striatal binding, whereas P/O and C/O represent the putamen and caudate nucleus, respectively. Statistical analyses of the sensitivity and specificity of these ratios in different age-specific subgroups were performed. The correlations between these ratios and clinical assessments were also analyzed. The age-related declines in the striatal binding in both patients and controls were given particular focus. RESULTS: The S/O, C/O, and P/O ratios decreased significantly both contralaterally and ipsilaterally to the dominant symptomatic side in the PD group (P < 0.0001). The mean reduction of binding was found in the order of putamen (contralateral side, -81%; ipsilateral side, -67%) and caudate nucleus (contralateral side, -46%; ipsilateral side, -40%). The sensitivity and specificity of both P/O and S/O ratios were 100% in discriminating PD patients from healthy subjects in the age-specific groups. The binding ratios correlated negatively with the Unified Parkinson's Rating Scale and Hoehn and Yahr (H-Y) staging. Of particular interest, the binding of the striatum contralateral to the asymptomatic side in H-Y stage I patients also decreased significantly. The age-related decline of these ratios was significant in the control group. CONCLUSION: We have demonstrated that (99m)Tc-TRODAT-1 SPECT has a high sensitivity and specificity for measuring the decrement of DAT in PD patients. In addition to its wide availability, we suggest that this new approach may serve as a diagnostic marker for PD.

Age Factors↗

PubMed2004

Characterization of the binding sites for 123I-ADAM and the relationship to the serotonin transporter in rat and mouse brains using quantitative autoradiography.

UNLABELLED: Imaging of serotonin transporter (SERT) in the central nervous system may provide an important tool to evaluate some psychiatric disorders. Recently, a novel (123)I-labeled radiotracer, 2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine ((123)I-ADAM), has been developed that exhibited a high selectivity for SERT. The aim of this study was to characterize the biodistribution and specificity of (123)I-ADAM to SERT using quantitative autoradiography in both control and neurotoxin-treated animals. METHODS: (123)I-ADAM (74 MBq) was injected intravenously into the mice to access its biodistribution in the brain via quantitative autoradiography. Further, rats with serotonin depleted by intraperitoneal injection of p-chloroamphetamine (PCA) were used to evaluate the specificity of (123)I-ADAM to SERT. The levels of biogenic amines were then measured and correlated with quantitative (123)I-ADAM labeling in control and PCA-treated rat brains. RESULTS: The autoradiographic results showed that (123)I-ADAM accumulated in SERT-rich brain areas after systemic injection, including the globus pallidus, thalamus, hypothalamus, substantia nigra, interpeduncular nucleus, amygdala, and raphe nucleus. The dorsal raphe nucleus had the highest initial uptake with a peak specific binding ratio (i.e., [target - cerebellum]/cerebellum) at 120 min after injection. (123)I-ADAM uptake was dramatically decreased in the hippocampus, thalamus, amygdala, geniculate nuclei, hypothalamus, raphe nucleus, and substantia nigra in PCA-lesioned rats. The decrement in radioactivity was more prominent at higher dosages of PCA and was in parallel with the changes in amounts of serotonin and 5-hydroxyindoleacetic acid in the prefrontal cortex. CONCLUSION: This study demonstrates that regional distribution of (123)I-ADAM radioactivity is similar to the SERT localization in both rat and mouse brains. We also validated that destruction on central serotonergic neurons after PCA treatment inhibits the uptake of (123)I-ADAM in serotonin-rich brain regions. High specific binding to SERT in vivo makes (123)I-ADAM an appropriate radiotracer for solitary studies of serotonin functions in living humans.

Animals↗

PubMed2004

Defining the priority of using 18F-FDG PET for recurrent cervical cancer.

UNLABELLED: PET with 18F-FDG has shown its potential in cervical cancer. For maximizing the benefits of this new imaging technology, we aimed to define the prognostic features of recurrent cervical cancer patients for selecting appropriate candidates using 18F-FDG PET. METHODS: Patients enrolled were from 2 independent prospective studies investigating the role of 18F-FDG PET in cervical cancer patients after definitive treatment with documented failure (CTRP-018) or unexplained elevated tumor marker serum levels (CTRP-016) and proven relapse after PET. A total of 55 eligible patients received PET and CT or MRI. Lesion status was determined from pathologic results or clinical follow-up. The benefits calculated were based on treatment that was modified because of the PET findings. The Cox proportional hazards ratio (HR) was used to select independent prognostic covariates. RESULTS: Thirty-six (65.5%) patients had treatment that was modified due to PET. Primary radiation (HR = 14.62; 95% confidence interval [CI] = 2.74-77.92), squamous cell carcinoma antigen (SCC-Ag) > or = 4 ng/mL (HR = 5.82; 95% CI = 1.53-22.04), and presence of symptoms (HR = 6.24; 95% CI = 1.99-19.61) at recurrence were significant factors associated with poor survival. A scoring system using these covariates defined 3 distinct prognostic groups: score < or = 1 (HR = 1.00); score = 2 (HR = 6.91; 95% CI = 1.49-32.14); and score = 3 (HR = 60.46; 95% CI = 9.68-378.09) (P < 0.0001). CONCLUSION: Using this risk score, 18F-FDG PET may offer maximal benefits by selecting appropriate recurrent cervical cancer patients for salvage therapy with precise restaging information.

Adult↗

PubMed2004

Clinical usefulness of 18F-FDG PET in nasopharyngeal carcinoma patients with questionable MRI findings for recurrence.

UNLABELLED: It has been reported that 18F-FDG PET is highly sensitive for the detection of recurrent head-and-neck cancer. The objective of our prospective study was to validate the ability of this technique to detect the presence of tumors in primary, nodal, and distant sites as well as to assess its overall clinical usefulness in patients with questionable MRI findings for residual or recurrent nasopharyngeal carcinoma (NPC). METHODS: From January 2002 to October 2003, a group of 37 NPC patients whose postradiation follow-up MRI examination showed questionable residual or recurrent disease was assessed with 18F-FDG PET. 18F-FDG PET was interpreted visually. Disease at primary, nodal, and distant sites was assessed. The final diagnosis was confirmed histopathologically or with clinical and imaging follow-up of at least 6 mo. RESULTS: Our results showed that the sensitivity and specificity of 18F-FDG PET for the detection of recurrent NPC were 91.6% and 76.0%, respectively, at the primary site; 90.0% and 88.9%, respectively, at nodal sites; and 100% and 90.6%, respectively, at distant sites. The overall sensitivity and specificity were 89.5% and 55.6%, respectively. Among the 37 patients, 18F-FDG PET added significant information to the MRI findings in 18, including offering true-negative findings in 10, revealing unexpected small metastatic adenopathy in 3, and disclosing distant metastatic foci in 5. CONCLUSION: 18F-FDG PET is highly sensitive and moderately specific for the detection of recurrent NPC in patients with questionable MRI findings. Overall, 18F-FDG PET appears to add significant information to MRI findings in about half of the NPC patients whose MRI examination shows questionable tumor recurrence.

Adolescent↗