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OBJECTIVE Vascular calcification is known to be associated with cardiovascular risk factors. Recently, F-NaF PET has been reported to be effective for detecting early and active vascular calcification. In this study, correlations between F-NaF PET/computed tomography (CT) findings and cardiovascular risk factors were investigated in patients with suspected coronary artery disease. PATIENTS AND METHODS Forty patients with suspected coronary artery disease underwent F-NaF PET/CT. The maximum and overall burden of calcifying activity, and the overall burden of calcium deposition in the descending thoracic aorta (DTA) were measured on F-NaF PET/CT and they were compared with cardiovascular risk factors, particularly, with those related to metabolic syndrome. RESULTS The maximum and overall burden of calcifying activity in DTA measured on F-NaF PET were significantly correlated with diabetes mellitus (P = 0.030 and 0.049, respectively) and serum HbA1c level (ρ = 0.433 and 0.344, respectively). In contrast, the overall burden of calcium deposition measured on CT was significantly correlated with hypertension (P

OBJECTIVE Typical clinical dosimetry models for trans-arterial radioembolization (TARE) assume uniform dose distribution in each tissue compartment. We performed simple voxel-based dosimetry using post-treatment 90Y PET following TARE with 90Y-resin microspheres and investigated its prognostic value in a pilot cohort. METHOD Ten patients with 14 hepatocellular carcinoma lesions who underwent TARE with 90Y-resin microspheres were retrospectively included. The partition model-based expected target tumor dose (TDp) was calculated using a pretreatment 99mTc-macroaggregated albumin scan. From post-treatment 90Y-microsphere PET and voxel-wise S-value kernels, voxel-based dose maps were produced and the absorbed dose of each lesion (TDv) was calculated. Heterogeneity of intratumoral absorbed doses was assessed using the SD and coefficient of variation of voxel doses. The response of each lesion was determined based on contrast-enhanced MRI or CT, or both. Lesion responses were classified as local control success or failure. Prognostic values of dosimetry parameters and clinicopathological factors were evaluated in terms of progression-free survival (PFS) of each lesion. RESULTS TDv was significantly different between local control success and failure groups, whereas tumor size, TDp and intratumoral dose heterogeneity were not. Univariate survival analysis identified serum aspartate transaminase level ≥40 IU/L, tumor size ≥66 mm and TDv

OBJECTIVE Phase analysis using gated myocardial perfusion single-photon emission computed tomography (GMPS) is a tool used to assess left ventricular (LV) dyssynchrony. We attempted to investigate the role of LV dyssynchrony assessed by GMPS using phase analysis for the late LV function after coronary artery bypass graft surgery (CABG) in patients with patent grafts. METHODS A total of 45 patients who received off-pump CABG with patent graft 1 year after CABG and preserved perfusion reserve were enrolled retrospectively. All patients underwent GMPS before and 3 months and 1 year after CABG. Using the Emory Cardiac Toolbox, both phase histogram bandwidth (PBW) and phase SD derived by phase analysis were used for the analysis, in addition to the conventional perfusion parameters. For the evaluation of LV function, transthoracic echocardiography was also performed. RESULTS All of the patients showed perfusion improvement (paired t-test, P

Background Quantification of volume and inflammatory activity in the fat tissue is important because these are closely related to type 2 diabetes mellitus and cardiovascular disease. Fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) has been utilized to measure the metabolic activity of fat tissue. In this study, we assessed the feasibility of simultaneous PET/magnetic resonance (MR) in metabolic and volumetric measurements of fat tissue and the potential advantage over PET/CT. Methods Twenty-four healthy individuals were enrolled, who underwent simultaneous F-FDG PET/MRI. Twenty-five F-FDG PET/CT scans were selected. Isocontour volumes of interest (VOIs) were used to segment and separate visceral fat (VF) and abdominal subcutaneous fat (SF) in using the MR image (T1 DIXON VIBE sequence) of PET/MR and the CT image of PET/CT. Volume, mean standardized uptake value of VF, and SF VOIs were calculated. Results Overlap between F-FDG PET and VF VOI was better in F-FDG PET/MR than PET/CT. The mean standardized uptake value of VF was associated with the degree of intestinal uptake on F-FDG PET/CT, but not on F-FDG PET/MR. Volumetric and metabolic measurements using F-FDG PET/MR showed an excellent reproducibility, with a high intraclass correlation coefficient between different observers (0.951-0.997). The measured metabolic activity was higher in VF than SF. Conclusion We established a method for the quantitative measurement of volume and metabolic status of abdominal VF and SF using simultaneous F-FDG PET/MR. F-FDG PET/MR has an advantage over F-FDG PET/CT in terms of being less confounded by intestinal uptake. This method could be used to assess the inflammatory activity of fat tissue, which is a major risk factor for type 2 diabetes mellitus and cardiovascular disease.

The purpose of this study was to compare quantitative indexes for fluorine-18 fluorodeoxyglucose uptake and metabolic volume between PET/MRI and PET/CT.Sixty-six patients with solid tumors (32 with lung cancer and 34 with pancreatic cancer) who underwent sequential fluorine-18 fluorodeoxyglucose PET/MRI and PET/CT were retrospectively enrolled. On PET images, maximum and peak standardized uptake values (SUVmax and SUVpeak, respectively), and maximum tumor-to-liver ratio (TLRmax) were measured. Metabolic tumor volume (MTV) and total-lesion glycolysis (TLG) with margin thresholds of 50% SUVmax and SUV 2.5 (MTV50%, MTV2.5; TLG50%, TLG2.5, respectively) were compared between PET/MRI and PET/CT, with patients classified into two groups using imaging protocol (the PET/MRI-first and PET/CT-first groups).There were significant correlations of all tested indexes between PET/MRI and PET/CT (r=0.867-0.987, P0.001). SUVmax and SUVpeak were lower on PET/MRI regardless of imaging protocol (P0.001 in the PET/MRI-first group). In contrast, TLRmax exhibited reverse results between the PET/MRI-first and PET/CT-first groups. MTV50% and TLG values varied between PET/MRI and PET/CT, as well as between the PET/MRI-first and PET/CT-first groups. However, MTV2.5 was relatively robust against imaging protocol and modality.There are significant correlations of the quantitative indexes between PET/MRI and PET/CT. However, uptake indexes of SUVmax and SUVpeak are lower on PET/MRI than on PET/CT, and volumetric indexes of MTV50% and TLG values also exhibited significant differences. It may be suggested that TLRmax and MTV2.5 are relatively more appropriate indexes than others when PET/MRI and PET/CT are used interchangeably.

Objectives The prevalence and risk of malignancy in thyroid incidentalomas has been investigated in previous studies; however, these studies have not looked at the characteristics of incidental thyroid cancer (ITC) detected by fluorine-18 fluorodeoxyglucose PET. Therefore, we aimed to assess the clinicopathologic features of ITC. Methods From March 2008 to December 2011, a total of 2892 patients underwent total thyroidectomy for papillary thyroid cancer. Among them, patients belonging to the ITC group were defined as those in whom focal thyroid uptake was reported as an incidental finding on PET imaging and further evaluation revealed the presence of malignancy. In addition, two control groups with non-PET incidental thyroid cancer (NITC) were selected: NITC-A patients (n=48) who underwent a total thyroidectomy in March 2008 and NITC-B patients (n=48) who underwent a total thyroidectomy for papillary thyroid cancer and were matched for the confounding effects of age and sex. Results There were no significant differences in clinicopathologic features, except for age and tumour node metastasis (TNM) staging, between ITC and NITC-A patients. More ITC than NITC-A patients were aged 45 years or older. Although T, N, or M staging was not different between ITC and NITC-A, there were more ITC patients with stage III/IV tumours. After matching for age and sex, none of the clinicopathologic features showed significant differences between ITC and NITC-B patients. Conclusion No significant differences were observed between ITC and NITC patients except for age and TNM staging. More ITC patients had advanced TNM stage most likely due to patient age.

OBJECTIVES Metabolic volumetry and heterogeneity indexes are increasingly being used in fluorine-18 fluorodeoxyglucose (F-FDG) PET, mostly using isocontour methods. However, there is no standard method to determine optimal margin thresholds for isocontour volume of interest (VOIiso). Here, VOIiso with various margin thresholds were compared with exact anatomical tumor volumes in sarcoma using a hybrid PET/MRI scanner. PATIENTS AND METHODS F-FDG PET/MRI images were retrospectively analyzed for 36 lesions of soft tissue or bone sarcoma. VOIiso of tumors was drawn with varying margin thresholds; standardized uptake value (SUV) 1.0-4.0 with an increment of 0.5 and 30-70% of maximal SUV (SUVmax) with an increment of 10%. Exact anatomical tumor volumes (VOIMRI) were drawn manually on the basis of MRI. In each VOI, metabolic tumor volume, SUVmean, total lesion glycolysis, and SD were measured and compared between VOIiso and VOIMRI. RESULTS Significant correlations were observed between the indexes from VOIiso and VOIMRI. For metabolic tumor volume, no significant difference existed between VOIiso and VOIMRI with margin thresholds of 30 and 40% of SUVmax, and SUV 1.5. For SUVmean, no significant difference existed with 30% of SUVmax, and SUV 1.5. For total lesion glycolysis, no significant difference existed with 40% of SUVmax, SUV 1.5, and 2.0. For SD, no significant difference existed with 30% of SUVmax, SUV 1.5, and 2.0. CONCLUSION Margin thresholds of 30 or 40% of SUVmax and SUV 1.5 or 2.0 may be used for the VOIiso method in F-FDG PET images of sarcoma. VOIiso with these margin thresholds are expected to produce reliable metabolic, volumetric, and heterogeneity indexes on F-FDG PET images.

OBJECTIVE Insufficient labeling efficiency and poor retention of radioactivity are the considerable shortcomings of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) labeling in human leukocytes. This study was conducted to evaluate the feasibility of using granulocyte colony-stimulating factor (G-CSF) to improve ¹⁸F-FDG labeling in human leukocytes. METHODS Leukocyte separation was performed using methods reported earlier. Separated leukocytes were preincubated with G-CSF or insulin at 37°C for 1 h. After preincubation, labeling was performed with ¹⁸F-FDG (37-74 MBq) at 37°C for 30 min. Retained radioactivity was assessed at 1-4 h after labeling by the same method described in earlier reports. The viability of labeled leukocytes was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. RESULTS Labeling efficiency of leukocytes preincubated with G-CSF, G-CSF with insulin, insulin, and control leukocytes was 52.1±8.9%, 49.9±10.5%, 40.3±7.7%, and 40.3±6.0%, respectively. G-CSF significantly increased the labeling efficiency compared with insulin (P=0.005) and control (P=0.004). In leukocytes preincubated with G-CSF, 77.0±1.2%, and 59.0±1.8% of radioactivity was retained at 1 and 3 h after labeling. There was no significant difference in retained radioactivity compared with that of leukocytes with different treatment at all time points. Furthermore, no significant difference in viabilities among leukocytes with different treatments was observed. CONCLUSION Use of G-CSF significantly improved ¹⁸F-FDG labeling efficiency without a significant effect on cell viability and retention of radioactivity.

Background Oestrogen receptors are ligand-dependent transcription factors whose activity is modulated either by oestrogens or by an alternative signalling pathway. Oestrogen receptors interact via a specific DNA-binding domain, the oestrogen responsive element (ERE), in the promoter region of sensitive genes. This binding leads to an initiation of gene expression and hormonal effects. Objective To determine the transcriptional activity of the oestrogen receptor, we developed a molecular imaging system using sodium iodide symporter (NIS) as a reporter gene. Methods The NIS reporter gene was placed under the control of an artificial ERE derived from pERE-TA-SEAP and named as pERE-NIS. pERE-NIS was transferred to MCF-7, human breast cancer cells, which highly expressed oestrogen receptor-alpha with lipofectamine. Stably expressing cells were generated by selection with G418 for 14 days. After treatment of 17beta-oestradiol and tamoxifen with serial doses, the (125)I uptake was measured for the determination of NIS expression. The inhibition of NIS activity was performed with 50 micromol x l(-1) potassium perchlorate. Results The MCF7/pERE-NIS treated with 17beta-oestradiol accumulated (125)I up to 70-80% higher than did non-treated cells. NIS expression was increased according to increasing doses of 17beta-oestradiol. MCF7/pERE-NIS treated with tamoxifen also accumulated (125)I up to 50% higher than did non-treated cells. Potassium perchlorate completely inhibited (125)I uptake. When MDA-MB231 cells, the oestrogen receptor-negative breast cancer cells, were transfected with pERE-NIS, (125)I uptake of MDA-MB-231/pERE-NIS did not increase. Conclusion This pERE-NIS reporter system is sufficiently sensitive for monitoring transcriptional activity of the oestrogen receptor. Therefore, cis-enhancer reporter systems with ERE will be applicable to the development of a novel selective oestrogen receptor modulator with low toxicity and high efficacy.

The aim of this study was to determine whether quantitative information obtained from [(18)F]fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) has a prognostic significance for patients with non-small cell lung cancer (NSCLC). We investigated (18)F-FDG PET imaging of 73 patients with NSCLC. The maximum standardized uptake value (SUV(max)) was significantly different between the histopathological types of tumour (squamous cell carcinoma (n=37, 12.4+/-5.1), adenocarcinoma (n=30, 8.2+/-5.8), bronchioloalveolar carcinoma (n=4, 2.6+/-1.7),0.01). In the univariate analysis of all patients, staging (P=0.0001), tumour cell type (P=0.013), and a SUV(max) greater than 7 (P=0.0011) was correlated with survival. However, a multivariate analysis identified staging and SUV(max) greater than 7 were affected survival adversely. The mortality rate of patients with group I disease (stage I to stage IIIA) was 5.8 times lower than that of patients with group II disease (stage IIIB to stage IV). Patients with a high SUV(max) (or =7) had a 6.3 times higher mortality than those with a low SUV(max)(7). By multivariate analysis of patients with squamous cell carcinoma, only grouping affected survival (P=0.008, relative risk=4.3). In the case of adenocarcinoma, the SUV(max) (10) correlated exclusively with poorer survival (P=0.031, relative risk=11.152). (18)F-FDG uptake correlated with survival in NSCLC. Especially in adenocarcinomas, the SUV(max) was complementary to other known prognostic factors.

Methylation status of the methyl-guanine methyltransferase (MGMT) promoter is associated with a favorable response to a DNA alkylating agent in high-grade gliomas. We analyzed PET scans of patients with high-grade gliomas to determine whether the MGMT methylation status affects the tumor metabolic characteristics.Twenty-three patients with high-grade glioma, who were initially examined with 11C-methionine (MET) and 18F-fluorodeoxyglucose (FDG) PET, were retrospectively enrolled. MET and FDG PET images were coregistered to each other and quantitative uptake of MET or FDG was assessed using tumor-to-normal uptake ratio of the cortex (TNR). TNRs for MET and FDG PET were compared between the two groups classified by MGMT promoter methylation status.Maximum TNR(FDG) of the MGMT methylated group was significantly higher than that of the MGMT unmethylated group (1.80±0.90 vs. 1.29±0.19; P=0.02). The MGMT methylated group also showed a trend for increased mean TNRFDG compared with the unmethylated group (0.85±0.21 vs. 0.72±0.11; P=0.10). There was no significant difference in TNR(MET) between the groups. In subgroup analyses with WHO grade 3 and 4, a trend for higher maximum TNR(FDG) was found in the MGMT methylated group compared with the unmethylated group.The MGMT methylated group showed higher glucose metabolism compared with the unmethylated group, whereas MET uptake did not show a significant difference. This suggests that MGMT methylation in high-grade gliomas could affect the tumor glucose metabolism. Thus, MGMT methylation status can cause a discrepancy in the prognostic prediction of high-grade gliomas by FDG PET, especially in patients scheduled for DNA alkylating chemotherapeutics.

INTRODUCTION 11C-Methionine (MET) PET and diffusion-weighted (DW) MRI are commonly used for evaluation of gliomas. We assessed the correlation between MET uptake and diffusion restriction measured on DW MRI in glioma. MATERIALS AND METHODS Thirty-one patients with gliomas, who were initially examined with MET PET and DW MRI, were enrolled retrospectively. MET PET and apparent diffusion coefficient (ADC) images were coregistered to each other, using rigid-body transformation. Tumor-to-normal count density ratio of the cortex (TNR) and normalized apparent diffusion coefficient (nADC) value were measured for each voxel on the MET PET and ADC map. The maximum TNR (TNRmax) and minimum nADC (nADCmin) were obtained for each tumor. Correlations between those parameters were evaluated. RESULTS The TNRmax and nADCmin values of a glioma were significantly correlated (r=-0.42). TNRmax and nADCmin were significantly correlated with glioma grades. Furthermore, TNRmax and nADCmin showed a trend for correlation with the Ki-67 index. We analyzed the correlation between voxel-based TNR and ADC within a tumor and observed no correlation between them. Regions with high MET uptake did not correspond with regions with low nADC. CONCLUSION We found a negative correlation between TNRmax and nADCmin for each glioma; however, MET uptake and ADC within a tumor were independent of each other and were heterogeneous. The two parameters represent different biological features; thus, as a comprehensive approach, MET PET and DW MRI might have a complementary role in the characterization of gliomas.

In parathyroid adenoma, uptake of technetium-99m-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been suggested to have a correlation with functional markers. The purpose of this study was to evaluate the feasibility of (99m)Tc-MIBI parathyroid single photon emission computed tomography/computed tomography (SPECT/CT) in evaluating the function and disease severity of parathyroid adenoma.Twenty-three patients with surgically confirmed parathyroid adenoma were retrospectively enrolled. A parathyroid planar scan and SPECT/CT were performed before parathyroidectomy. Functional and clinical makers reflecting the disease severity of parathyroid adenoma were also evaluated, including serum intact parathyroid hormone, calcium, bone mineral density, and creatinine clearance. The pathologic volume (V(P)) of the adenoma was measured after parathyroidectomy. On parathyroid SPECT/CT, metabolic volume (V(M)) was measured using an isocontour method. Maximum uptakes of parathyroid adenoma and mean uptakes of contralateral thyroid tissue were measured to calculate the parathyroid adenoma-to-background ratio on parathyroid SPECT/CT (PBR(SCT)) and planar scan (PBR(PL)).V(M) significantly correlated with V(P) (r=0.669, P=0.0005). Serum intact parathyroid hormone level significantly correlated with PBR(PL), PBR(SCT), V(M), and V(P) (P=0.0004, 0.005, 0.003, and 0.025, respectively). However, serum calcium level correlated only with V(M) (P=0.012). Regarding the surgical indication criteria, PBR(SCT) and PBR(PL) were significantly higher in the young-aged group (P=0.0004 and 0.024, respectively) and V(M) was significantly higher in the high calcium level group (P=0.049), whereas V(P) was not different between groups on the basis of any criteria.Quantitative indices of parathyroid SPECT/CT closely correlate with laboratory functional markers and disease severity of parathyroid adenoma. Thus, parathyroid SPECT/CT could be used for evaluation of the underlying functional state and disease severity of parathyroid adenoma, particularly for decision pertaining to surgical treatment.

Characterization of intermediate-high risk adrenal incidentaloma (AI) is important because biopsy or surgery should be performed to confirm the malignancy. We investigated which parameters of F-fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (CT) had an additive role in distinguishing malignancies in patients with incidental adrenal masses of intermediate-high risk.From January 2008 to July 2013, 52 patients with a pathologically proven diagnosis of AI were retrospectively enrolled (age=56.4±12.7 years, M : F=34 : 18; benign : malignant=14 : 38). Volumetric parameters were size and volume according to combined CT, and metabolic parameters were peak standardized uptake value (SUV(peak)), maximum SUV (SUV(max)), mean SUV (SUV(mean)), and tumor-to-background ratio (SUV(max) of adrenal mass/SUV(mean) of liver). Metabolovolumetric parameters of metabolic tumor volume and total lesion glycolysis (TLG, SUV(mean)×metabolic tumor volume) were also included and compared with the diagnostic value. In addition, the highest diagnostic parameters among volumetric and metabolic parameters were combined and compared in terms of diagnostic accuracy.Compared with benign adrenal adenoma, malignant lesions showed significantly higher values of all (18)F-FDG PET/CT volumetric, metabolic, and metabolovolumetric parameters. Size showed the highest area under the curve (AUC) of 0.759 among the volumetric parameters, and SUV(peak) showed the highest AUC of 0.853 among the metabolic parameters. Among all the PET/CT parameters, TLG showed the highest AUC of 0.900, with a sensitivity of 92.1% and specificity of 78.6% at a cutoff of 12.0. The combined value of size and SUV(peak) showed lower diagnostic value than TLG.We found that TLG showed the best result in distinguishing intermediate-high risk AI among PET/CT parameters. TLG can be a useful PET/CT parameter for differential diagnosis of AI.

Technetium-99m antimony sulfide colloid lymphoscintigraphy conveniently demonstrates intestinal leakage of lymph in patients with intestinal lymphangiectasia. However, we found no intestinal radioactivity in some patients. We evaluated lymphoscintigraphic findings and compared them with clinical data. Technetium-99m antimony colloid lymphoscintigraphy was performed in 12 patients (age, 8.9+/-6.4 years; male:female=8:4) with histologically proven intestinal lymphangiectasia. After subcutaneous injection of 103.6 MBq of technetium-99m antimony colloid into the webs of both feet, sequential abdominal images were obtained up to 24 h post-injection. Four patients underwent technetium-99m methylene diphosphonate bone scintigraphy. Patients were divided into two groups according to the presence or absence of intestinal radioactivity. Five showed intestinal activity (Group 1), but seven did not (Group 2). No Group 1 patient had a history of ascites, while all Group 2 patients had ascites as the initial manifestation. Serum total protein and albumin levels were significantly lower in Group 1 patients than in Group 2 patients. In three Group 1 patients, technetium-99m methylene diphosphonate bone scintigraphy revealed intestinal radioactivity, while in one Group 2 patient this was not found. We observed two types of lymphoscintigraphic pattern in patients with intestinal lymphangiectasia. To clarify the exact pathophysiology, further study is required.

We investigated the reproducibility of the quantification of left ventricular volumes and ejection fraction, and grading of myocardial wall motion and systolic thickening with gated myocardial single-photon emission computed tomography (SPECT) and Cedars quantification software.We performed post-stress gated myocardial SPECT in 33 consecutive patients twice sequentially in situ. Sixteen frames per cycle were used for gating. Using Cedars quantitative gated SPECT software ventricular volumes and ejection fraction (EF) were calculated. Wall motion and thickening was graded using 5- and 4-point scores, respectively. Coefficients of variation for re-examination of volumes and EF were calculated. Kappa values for assessing reproducibility of wall motion or wall thickening were calculated.Root mean square of errors was 5.0 ml for end-diastolic volume, 3.9 ml for end-systolic volume and 1.9% for EF. No bias or difference was found between the first and second acquisition by Bland-Altman analysis. Kappa values for wall motion and thickening of repeated acquisition was 0.76 and 0.87, respectively. The value of 2 SD from Bland-Altman analysis was 14.4 ml for EDV, 11.2 ml for ESV and 5.3% for EF.We conclude that quantification of functional indices and assessment of wall motion or thickening using gated 99Tc(m)-sestamibi (MIBI) SPECT was reproducible and we found that their ranges of physiological fluctuation were narrow enough.

Various mannose receptor-binding agents, for example 99mTc-diethylenetriaminepentaacetic acid (DTPA)-mannosyl-polymer, have been developed for sentinel lymph node (SLN) imaging. In order to simplify the synthesis and labelling procedure and to improve the biological properties, we developed a novel mannose receptor-binding agent, 99mTc-neomannosyl human serum albumin (99mTc-MSA), for SLN imaging.MSA was synthesized by conjugating mannopyranosylphenylisothiocyanate to human serum albumin (HSA). After reducing MSA with beta-mercaptoethanol and PD-10 column purification, a medronate solution containing stannous fluoride was added, divided into aliquots and freeze-dried. Reduced MSA was labelled with 99mTc-pertechnetate solution. The stability was checked for 24 h at 37 degrees C in human serum. The biodistribution of 99mTc-MSA in mice was investigated by intravenous injection through the tail vein and subcutaneous injection into the foot pad. The biodistributions of 99mTc-HSA and 99mTc-antimony sulphur colloid (99mTc-ASC) were also investigated for comparison. Dynamic whole-body images were obtained for 30 min after subcutaneous injection into the rats' foot pads.The number of mannose molecules conjugated per MSA was 15.9. The number of thiol groups produced was 19.4 per MSA after reduction with beta-mercaptoethanol. Labelling yields were always higher than 97%. 99mTc-MSA was stable for 24 h at 37 degrees C in human serum. The biodistribution in mice after intravenous injection showed high liver uptake (50.7+/-5.5% and 42.7+/-3.7% injected dose per gram at 10 and 60 min, respectively). 99mTc-MSA and 99mTc-ASC showed high accumulation in the lymph nodes after subcutaneous injection, whereas 99mTc-HSA and Tc-tin colloid did not, in both biodistribution and imaging studies.We have successfully developed a novel 99mTc-MSA for lymphoscintigraphy. The results of animal studies show that 99mTc-MSA has promising properties for SLN imaging.

To clarify the biological significance of [18F]fluorodeoxyglucose (18F-FDG) accumulation in patients with cancer, we assessed the relationships between 18F-FDG uptake and glucose transporter-1 (GLUT-1) expression and proliferation rate in human glioma and lung cancer. We obtained FDG PET images and measured standardized uptake values (SUVs) of primary tumours in 13 patients with brain glioma and 25 patients with non-small-cell lung cancer. After surgery, portions of respected tumours were obtained, and the proliferation rate was measured as proliferation index (per cent of (S+G2+M)/(G0+G1+S+G2+M)) using DNA flow cytometry. The expression of GLUT-1 in a tumour was evaluated by using immunostaining. We classified GLUT-1 expression as grade 0 (no positive cell), grade 1 (10% cells positive), grade 2 (11-50% cells positive) and grade 3 (51-100% cells positive). Based on the expression of GLUT-1, cases with grades 0, 1, 2 and 3 showed SUVs of 6.1 +/- 2.8, 5.0 +/- 3.2, 8.3 +/- 3.3 and 10.4 +/- 6.6, respectively (P0.05). Non-small-cell lung cancer showed higher FDG uptake (SUV, 8.5 +/- 5.1) and higher GLUT-1 expression (grade, 2.0 +/- 1.0) than did brain glioma (SUV, 4.7 +/- 2.5; grade, 0.8 +/- 0.8). Based on the total number of cases, SUVs did not relate to proliferation index (r = 0.19). In non-small-cell lung cancer, SUVs did not correlate with proliferation index, whereas in glioma, SUVs were strongly related to proliferation index (r = 0.79, P0.01). In conclusion, FDG uptake generally correlated with GLUT-1 expression in non-small-cell lung cancer and glioma. In the case of glioma, FDG uptake also indicated increased cellular proliferation, which was not demonstrated in non-small-cell lung cancer.

The aim of this study was to ascertain whether knee SPET can localize lesion sites in patients with internal derangements of the knee. We performed knee SPET as a pre-arthroscopic examination in 63 consecutive patients. SPET imaging was performed with a triple-headed SPET camera 4 h after the injection of 99Tcm-methylene diphosphonate. Arthroscopic diagnoses were as follows: 28 medial meniscus injuries, 24 lateral meniscus injuries, 31 anterior cruciate ligament (ACL) injuries, three posterior cruciate ligament injuries and one medial collateral ligament injury. Of 30 patients with crescent-shaped increased activity at the medial tibial plateau, 22 had medial meniscus injuries (positive predictive value: PPV 73%); of 17 patients with crescent-shaped activity at the lateral tibial plateau, 13 had lateral meniscus injuries (PPV 76%). Of 18 patients with increased activity at ACL attachment sites (primary sign), 17 had ACL injuries (PPV 94%). Of 27 patients with increased activity at bone impaction sites of ACL injury (secondary sign), 22 had ACL injuries (PPV 81%). Of 32 patients who had either a primary or secondary sign, 26 had ACL injuries (PPV 81%). We conclude that knee SPET is very useful in the management of internal derangements of the knee, particularly in determining the need for arthroscopy by localizing lesion sites.