-
Koichiro Abe,
Masayuki Sasaki,
Yasuo Kuwabara,
Hirofumi Koga,
Shingo Baba,
Koichiro Kaneko, Kazutaka Hayashi,
Yoshiyuki Shioyama,
Tatsuro Tajiri,
Sachiyo Suita,
Hiroshi Honda
[show abstract]
[hide abstract]
ABSTRACT: Objective: The aim of this study is to clarify the period of extraosseous accumulation of99mTc-hydroxymethylenediphosphonate (HMDP) to radiation nephropathy mimicking recurrent or remnant neuroblastoma in the pararenal
region.Methods: We reviewed five neuroblastoma and one ganglioneuroblastoma patients (2 boys and 4 girls aged 1–9 years) who underwent99mTc-HMDP bone scintigraphies periodically before and after radiation therapy.Results: Increased renal uptake coincident with the radiation port appeared in 5 of 6 patients from 0 to 3 months (mean 1.7 months),
and persisted up to 7 months after the completion of radiotherapy. Renal uptake of99mTc-HMDP was gradually decreased, and eventually became accumulation defects in 5 of 6 patients from 6 to 17 months (mean 8.9
months) after radiotherapy.Conclusion: When extraosseous accumulation is found after radiation therapy in neuroblastoma patients, radiation nephropathy would be
a candidate in the differential diagnosis besides recurrent or remnant tumor.
Annals of Nuclear Medicine 04/2012; 19(1):35-40. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: ObjectivesCarbon-11-l-methyl-methionine (11C-methionine) has been reported to be useful for evaluating brain tumors, but several other brain disorders have also shown
signs of high methionine uptake. We retrospectively evaluated the significance of11C-methionine uptake in cerebrovascular diseases, and also compared our results with those for18F-FDG PET and99mTc-HMPAO SPECT.
MethodsSeven patients, including 3 patients with a cerebral hematoma and 4 patients with a cerebral infarction, were examined. All
7 patients underwent both11C-methionine PET and99mTc-HMPAO SPECT, and 6 of them underwent18F-FDG PET.Results: A high11C-methionine uptake was observed in all 3 patients with cerebral hematoma. Increased99mTc-HMPAO uptake was observed in 2 out of 3 patients, and all 3 patients had decreased18F-FDG uptake. Of 4 patients with a cerebral infarction, high11C-methionine uptake was observed in 3. Increased99mTc-HMPAO uptake was also observed in one patient, whereas 3 patients had decreased18F-FDG uptake.
ConclusionsWe should keep in mind that high11C-methionine uptake is frequently observed in cerebrovascular diseases. CVD should therefore be included in the differential
diagnosis when encounting patients with a high11C-methionine uptake.
Annals of Nuclear Medicine 04/2012; 16(3):207-211. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The aim of this study was to develop an efficient fully automated synthesis method to achieve a high radiochemical yield of [(18)F]FAZA with a small amount of precursor. A small cartridge containing 25mg of the QMA resin was prepared and evaluated to obtain [(18)F]F(-) in a small quantity of base (K(2)CO(3)), which might allow the use of a small amount of precursor. The labeling and hydrolyzing conditions for [(18)F]FAZA synthesis were also investigated manually. No-carrier-added [(18)F]F(-) was trapped on the small QMA cartridge and eluted with a mixture of Krytofix 222 (2.26 mg, 6.0 μmol) and K(2)CO(3) (0.69 mg, 5.0 μmol) in 70% MeCN (0.4 mL). The automated synthesis of [(18)F]FAZA was optimally performed with a modified NIRS original synthesis system for clinical use, by labeling 2.5mg (5.2 μmol) of the precursor in DMSO (0.4 mL) at 120°C for 10 min, and then by hydrolyzing the (18)F-labeled intermediate with 0.1M NaOH (0.5 mL) at room temperature for 3 min. Using the above condition, the [(18)F]FAZA injection was obtained with a high radiochemical yield of 52.4±5.3% (decay-corrected, n=8) within 50.5±1.5 min.
Applied radiation and isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine 02/2011; 69(7):1007-13. · 1.09 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An ultrafast and efficient high-performance liquid chromatographic (LC) method was developed to purify positron emission tomography (PET) radiopharmaceuticals as well as for metabolite analysis of the plasma sample. Chromatographic separation was achieved on a short (60 mm length) semipreparative (10 mm I.D.) column packed with 2.5-mum particles using a mixture of acetonitrile and sodium phosphate buffer as the mobile phase at a flow rate of 8-10 ml/min. Under the optimum conditions, excellent separation of the target PET probe was obtained from chemical/radiochemical impurities or radioactive metabolites with a very short run time of 2 min. This characteristic enabled significant shortening of the purification and evaporation processes in the production of short-lived radiopharmaceuticals and highly sensitive radiometric analysis with good temporal resolution during the metabolism study.
Nuclear Medicine and Biology 01/2010; 37(1):67-72. · 3.02 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A rapid and efficient preparative high-performance liquid chromatographic procedure was established to purify short-lived positron emission tomography radio-probes. This method is based on hydrophilic interaction chromatography utilizing a semi-preparative silica column (10 mm I.D.) and a high volatile organic mobile phase (>90% acetonitrile). In nine different radiopharmaceuticals studied, six compounds could be separated from the unlabeled precursor with good resolution and faster elution than its precursor. These characteristics enabled significant shortening of the separation and evaporation processes in the manufacture of short-lived radiopharmaceuticals. Several (11)C-radiopharmaceuticals could be prepared within one half-life of carbon-11 (20.4 min), including radiosynthesis, purification and formulation steps with sufficient radiochemical/chemical purity and high levels of radioactivity/specific radioactivity.
Journal of chromatography. A 06/2009; 1216(18):3933-40. · 4.19 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An ultra-fast, sensitive and versatile radio-liquid chromatographic (LC) procedure was developed and validated for quality control (QC) tests of PET radiopharmaceuticals. For a wide variety of radio-probes, the usual LC conditions were used: (1) column: Waters XBridge RP(18) (50 mm x 3.0 mm ID, 2.5 microm), (2) mobile phase: a mixture of three modifiers (90% CH3CN, ammonium phosphate at pH 2.1 and pH 9.3), and (3) detection: UV absorption and NaI(Tl) scintillation. The introduction of a short column packed with small particles of 2.5 microm allowed excellent separation of target analytes within a very short run time of 1 min; only a 3% decline of radioactivity was observed during QC analysis of (11)C-labelled pharmaceuticals. Combining ammonium-phosphate buffer as the mobile-phase component and low-wavelength UV detection led to an improvement in the applicability and sensitivity. All 34 pharmaceuticals investigated could be successfully applied to determine the specific radioactivity, radiochemical and chemical purity with 10-times better sensitivity than traditional LC. We could analyze different pharmaceuticals in a short period since this system utilized a common column and mobile phase. The proposed procedure fulfils the requirements for routine QC tests in terms of rapidity, sensitivity, simplicity and applicability.
Journal of pharmaceutical and biomedical analysis 05/2009; 50(2):245-51. · 2.45 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Bone is one of the most common sites of metastasis in breast cancer patients. Although bone scintigraphy is widely used to detect metastatic breast cancer, the usefulness of 18FDG-PET for detecting bone metastasis has not been clearly evaluated. The purpose of this study was to compare the diagnostic accuracy of 18FDG-PET with bone scintigraphy in detecting bone metastasis in breast cancer patients.
Forty-four women aged 35 to 81 years (mean, 56 years) with breast cancer were examined in this study. Both 18FDG-PET and bone scintigraphy were performed for each patient with 0-69 day intervals (mean, 11.5 days). The results of each image interpretation were compared retrospectively. Whole-body bones were classified into 9 anatomical regions. Metastases were confirmed at 45/187 regions in 14 patients by bone biopsy or clinical follow-up including other imaging techniques for a period of at least 6 months afterwards.
On a region basis, the sensitivity, specificity, and accuracy of 18FDG-PET were 84%, 99% and 95%, respectively. Although these results were comparable to those of bone scintigraphy, the combination of 18FDG-PET and bone scintigraphy improved the sensitivity (98%) and accuracy (97%) of detection. False negative lesions of bone scintigraphy were mostly bone marrow metastases and those of 18FDG-PET were mostly osteoblastic metastases. 18FDG-PET was superior to bone scintigraphy in the detection of osteolytic lesions (92% vs. 73%), but inferior in the detection of osteoblastic lesions (74% vs. 95%).
This study shows that 18FDG-PET tends to be superior to bone scintigraphy in the detection of osteolytic lesions, but inferior in the detection of osteoblastic lesions. 18FDG-PET should play a complementary role in detecting bone metastasis with bone scintigraphy.
Annals of Nuclear Medicine 11/2005; 19(7):573-9. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: ObjectiveBone is one of the most common sites of metastasis in breast cancer patients. Although bone scintigraphy is widely used to
detect metastatic breast cancer, the usefulness of18FDG-PET for detecting bone metastasis has not been clearly evaluated. The purpose of this study was to compare the diagnostic
accuracy of18FDG-PET with bone scintigraphy in detecting bone metastasis in breast cancer patients.
MethodsForty-four women aged 35 to 81 years (mean, 56 years) with breast cancer were examined in this study. Both18FDG-PET and bone scintigraphy were performed for each patient with 0-69 day intervals (mean, 11.5 days). The results of each
image interpretation were compared retrospectively. Whole-body bones were classified into 9 anatomical regions. Metastases
were confirmed at 45/187 regions in 14 patients by bone biopsy or clinical follow-up including other imaging techniques for
a period of at least 6 months afterwards.
ResultsOn a region basis, the sensitivity, specificity, and accuracy of18FDG-PET were 84%, 99% and 95%, respectively. Although these results were comparable to those of bone scintigraphy, the combination
of18FDG-PET and bone scintigraphy improved the sensitivity (98%) and accuracy (97%) of detection. False negative lesions of bone
scintigraphy were mostly bone marrow metastases and those of18FDG-PET were mostly osteoblastic metastases.18FDG-PET was superior to bone scintigraphy in the detection of osteolytic lesions (92% vs. 73%), but inferior in the detection
of osteoblastic lesions (74% vs. 95%).
ConclusionsThis study shows that18FDG-PET tends to be superior to bone scintigraphy in the detection of osteolytic lesions, but inferior in the detection of
osteoblastic lesions.18FDG-PET should play a complementary role in detecting bone metastasis with bone scintigraphy.
Annals of Nuclear Medicine 09/2005; 19(7):573-579. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To clarify the relationship between D2 receptor binding and the cerebral metabolic rate for glucose (CMRGlu) in patients with parkinsonism, we simultaneously measured both of these factors, and then compared the results.
The subjects consisted of 24 patients: 9 with Parkinson's disease (PD), 3 with Juvenile Parkinson's disease (JPD), 9 with multiple system atrophy (MSA), and 3 with progressive supranuclear palsy (PSP). The striatal D2 receptor binding was measured by the C-11 raclopride transient equilibrium method. CMRGlu was investigated by the F-18 fluorodeoxyglucose autoradiographic method.
The D2 receptor binding in both the caudate nucleus and putamen showed a positive correlation with the CMRGlu in the PD-JPD group, but the two parameters demonstrated no correlation in the MSA-PSP group. The left/right (L/R) ratio of D2 receptor binding in the putamen showed a positive correlation with that of CMRGlu in the MSA-PSP group, while the two demonsrated no correlation in the PD-JPD group.
Our PET study showed striatal D2 receptor binding and the CMRGlu to be closely related in patients with parkinsonism, even though the results obtained using the L/R ratios tended to differ substantially from those obtained using absolute values. The reason for this difference is not clear, but this finding may reflect the pathophysiology of these disease entities.
Annals of Nuclear Medicine 07/2005; 19(4):267-75. · 1.50 Impact Factor
-
Koichiro Abe,
Masayuki Sasaki,
Yasuo Kuwabara,
Hirofumi Koga,
Shingo Baba,
Koichiro Kaneko, Kazutaka Hayashi,
Yoshiyuki Shioyama,
Tatsuro Tajiri,
Sachiyo Suita,
Hiroshi Honda
[show abstract]
[hide abstract]
ABSTRACT: The aim of this study is to clarify the period of extraosseous accumulation of (99m)Tc-hydroxymethylenediphosphonate (HMDP) to radiation nephropathy mimicking recurrent or remnant neuroblastoma in the pararenal region.
We reviewed five neuroblastoma and one ganglioneuroblastoma patients (2 boys and 4 girls aged 1-9 years) who underwent (99m)Tc-HMDP bone scintigraphies periodically before and after radiation therapy.
Increased renal uptake coincident with the radiation port appeared in 5 of 6 patients from 0 to 3 months (mean 1.7 months), and persisted up to 7 months after the completion of radiotherapy. Renal uptake of (99m)Tc-HMDP was gradually decreased, and eventually became accumulation defects in 5 of 6 patients from 6 to 17 months (mean 8.9 months) after radiotherapy.
When extraosseous accumulation is found after radiation therapy in neuroblastoma patients, radiation nephropathy would be a candidate in the differential diagnosis besides recurrent or remnant tumor.
Annals of Nuclear Medicine 03/2005; 19(1):35-40. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We evaluated the quantitative accuracy of the post-injection transmission-based segmented attenuation correction (SAC) technique and transmissionless calculated attenuation correction (CAC) technique in both 2D and 3D scanning for the brain, and compared the results with those obtained using the pre-injection transmission-based measured attenuation correction (MAC) technique, which is generally accepted as the 'gold standard'.
We examined [18F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) on both a cylindrical phantom and in 10 patients with epilepsy. The statistical analyses were performed using both the region of interest (ROI) method and statistical parametric mapping (SPM).
In the ROI analysis, [18F] activity concentration values obtained by the SAC technique were well correlated with those obtained by the MAC technique (2D, R2=0.94; 3D, R2=0.98; P<0.001), although these values were underestimated over the entire brain. The CAC technique was also found to have significant correlation with the MAC technique (2D, R2=0.84; 3D, R2=0.86; P<0.001), but this technique showed apparent overestimation or underestimation in several parts of the brain. In the SPM analysis, there were no significant differences between the SAC and MAC technique, while those values obtained by the CAC technique were significantly lower in the parieto-occipital region and higher in the lower frontal region (P<0.001, uncorrected).
The SAC technique was superior to the CAC technique in both 2D and 3D scanning, although we found that both the SAC and CAC techniques had some problems in quantitative evaluation. We considered that the SAC technique may yield adequate qualitative measurements of the [18F] activity concentration value after global normalization.
Nuclear Medicine Communications 12/2004; 25(11):1095-102. · 1.40 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Hypoperfusion in the posterior cingulate cortex is thought to be useful for the early diagnosis of dementia of Alzheimer type (DAT). In the present study, we compared the incidence of posterior cingulate hypoperfusion in patients with Alzheimer's disease (AD), patients with senile dementia of Alzheimer type (SDAT), and patients with other types of dementia, as evaluated by three-dimensional stereotactic surface projection (3D-SSP) imaging. The subjects were 20 AD patients, 20 SDAT patients, 13 frontotemporal dementia patients, and 3 other types of dementia patients. A SPECT study was performed 5 minutes after the injection of 740 MBq technetium-99m hexamethylpropylene amine oxime. 3D-SSP images were obtained with global normalization to perform the statistical analysis. The normal database of 3D-SSP consisted of 15 healthy volunteers. Hypoperfusion was considered to be significant when the Z-score was over 2.5. Posterior cingulate hypoperfusion was observed in 13 of 20 AD patients (65%), in 5 of 20 SDAT patients (25%), but in none of other type of dementia patients. Posterior cingulate hypoperfusion was considered to be a finding specific to DAT, and this finding was thought to be useful to diagnose DAT patients, especially for AD patients. However, it was considered to be difficult to diagnose early-stage SDAT patients.
Clinical Nuclear Medicine 07/2004; 29(6):362-6. · 3.67 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the reliability of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) values obtained by deconvolution algorithm perfusion-weighted MR imaging (D-PWI), we compared these values with those obtained by first-moment algorithm perfusion-weighted MR imaging (F-PWI) and 15O-PET.
Six healthy volunteers and eleven patients with chronic occlusive cerebrovascular disease were studied with both perfusion-weighted MR imaging and 15O-PET, and region-of-interest analyses were performed. Normalization factors for CBF and CBV values obtained by D-PWI were determined as the mean values of 15O-PET divided by those of D-PWI in healthy volunteers. Then these values were used in analyzing the data of the patients.
The MTT value obtained by D-PWI was 6.1 +/- 0.5 seconds on the non-occluded side, 6.4 +/- 0.7 seconds on the minimally to moderately stenosed side, and 6.7 +/- 1.2 seconds on the severely stenosed to occluded side. These values were significantly correlated with those obtained by F-PWI (r = 0.83; P < .001), and with those obtained by 15O-PET (r = 0.78; P < .05). However, the CBF and CBV values obtained by D-PWI did not correlate with those obtained by 15O-PET.
MTT values obtained by D-PWI were reliable parameters of cerebral hemodynamics, but the CBF and CBV values obtained by D-PWI were not always reliable.
Academic Radiology 05/2004; 11(5):489-97. · 1.69 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The aim of this study was to investigate the lesion detectability of a gamma camera based coincidence detector system (c-PET system) in comparison to the dedicated PET system (d-PET system), and thereby clarify the feasibility of the clinical application of this system and also describe any factors influencing the lesion detectability of the c-PET system.
We examined 74 patients including 19 with malignant lymphoma, 16 with lung cancer, 9 with primary malignant bone tumor, 7 with esophageal cancer, 6 with malignant melanoma, 3 with hepatocellular carcinoma, 3 with primary unknown cancer, 2 with breast cancer, 2 with colon cancer, and 7 with others. d-PET images were obtained using ECAT EXACT HR+ at 60 min, followed by c-PET imaging using ECAM at 120 min after the injection of 185 MBq of FDG. Each image was reconstructed without any attenuation correction. In the image interpretation, the whole body was classified into 16 regions (5 superficial regions and 11 deep regions). The FDG accumulation of the lesions was evaluated by visual grading based on the consensus of three nuclear medicine physicians, and the findings were classified into three grades; (++), (+), and (-). The lesions were also classified into 3 groups according to their size: large group (> or =2 cm), middle group (1 < or = <2 cm) and small group (<1 cm).
In 627 regions, the abnormal FDG uptake was detected in 109 regions by the d-PET system. Out of 109 regions, the c-PET system could detect the lesions in 91 regions and was false positive in 1 region. Therefore, the sensitivity, specificity, and accuracy of the c-PET system were 83.5%, 99.8% and 97.0%, respectively. Lesion detectability of the small group (54.5%) was significantly lower than that of the large group (97.9%) (p < 0.001) and that of the middle group (93.1%) (p < 0.001); however, the difference in lesion detectability between the large and middle groups was not significant. Neither the degree of FDG accumulation nor the location of the lesion markedly influenced the lesion detectability of the c-PET system. However, when we focused on the large and middle size lesions, the detectability of deep lesions tended to be lower than that of superficial lesions.
In conclusion, the lesion detectability of the c-PET system was inferior to that of the d-PET system, especially in the case of small lesions. Further examination is required to assess the clinical usefulness of the c-PET system.
Annals of Nuclear Medicine 04/2004; 18(2):131-6. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The purpose of this study was to clarify the normal gastric FDG uptake pattern to provide basic information to make an accurate diagnosis of gastric lesions by FDG PET. We examined 22 cases, including 9 of malignant lymphoma, 8 of lung cancer, 2 of esophageal cancer, and 3 of other malignancies. No gastric lesions were observed in any of the 22 cases on upper gastrointestinal examinations using either barium meal or endoscopic techniques. The intervals between FDG PET and the gastrointestinal examination were within one week in all cases. The stomach regions were classified into the following three areas: U (upper)-area, M (middle)-area, and L (lower)-area. The degree of FDG uptake in these three gastric regions was qualitatively evaluated by visual grading into 4 degrees, and then a semiquantitative evaluation was carried out using the standardized uptake value (SUV). Based on a visual grading evaluation, the mean FDG uptake score in the U-, M-, and L-areas was 1.14 +/- 0.96, 0.82 +/- 0.96, and 0.36 +/- 0.49 (mean +/- S.D.), respectively. The FDG uptake scores obtained in the three areas were significantly different (Friedman test, p < 0.05). Furthermore, the rank order of the FDG uptake score in each case (U > or = M > or = L) was found to be statistically significant (Cochran-Armitage trend test, p < 0.05). The mean SUVs of 11 cases in the three areas were 2.38 +/- 1.03, 1.91 +/- 0.71, and 1.34 +/- 0.44 (mean +/- S.D.), respectively. The SUV in the U-area was significantly higher than that in the L-area (Friedman test, p < 0.05). A significant difference in FDG uptake was observed among the three gastric areas, and the FDG uptake extent in all cases was U > M > L. In conclusion, the physiological gastric FDG uptake was significantly higher at the oral end. A stronger gastric FDG uptake at the anal end may therefore be suggestive of a pathological uptake.
Annals of Nuclear Medicine 12/2003; 17(8):733-8. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We herein report a case of malignant lymphoma that showed differential FDG accumulation associated with the degree of glucose transporter 1 (GLUT-1) expression. For clinical staging purpose, FDG-PET was performed on a 47-year-old male who had been diagnosed to have malignant lymphoma, diffuse medium B-cell type. Although an X-ray CT showed multiple and bulky lymphadenopathy including bilateral submandibular, deep cervical, supraclavicular, axillar, hilar, mesenteric and paraaortic regions, FDG-PET showed a high accumulation only in the bilateral submandibular and deep cervical region. An immunohistochemical analysis demonstrated a high GLUT-1 expression in the right cervical lymph node, which showed a high FDG uptake. On the other hand, a bone marrow specimen with diffuse lymphoma cell involvement indicated showed no FDG accumulation and also revealed a negative GLUT-1 expression. This case suggests that the differential FDG accumulation shown by lesions is associated with the degree of GLUT-1 expression in patients with lymphoma.
Annals of Nuclear Medicine 07/2003; 17(4):327-31. · 1.50 Impact Factor
-
Masayuki Sasaki,
Kenji Sugio,
Yasuo Kuwabara,
Hirofumi Koga,
Makoto Nakagawa,
Tao Chen,
Koichiro Kaneko, Kazutaka Hayashi,
Yoshiyuki Shioyama,
Shuji Sakai,
Hiroshi Honda
[show abstract]
[hide abstract]
ABSTRACT: The FDG uptake in lung cancer is considered to reflect the degree of malignancy, while alterations of some tumor suppressor genes are considered to be related to the malignant biological behavior of tumors. The aim of this study is to examine the relationship between FDG-PET and alterations in the tumor suppression genes of lung cancer.
We examined 28 patients with primary lung cancer who underwent FDG-PET before surgery consisting of 17 patients with adenocarcinoma, 10 with squamous cell carcinoma and 1 with large cell carcinoma. The FDG-PET findings were evaluated based on the standardized uptake value (SUV). Alterations in the tumor suppressor genes, Rb, p16, p27 and p53, were evaluated immunohistochemically.
The FDG uptake in lung cancer with alteration in each tumor suppressor gene tended to be higher than in those genes without alterations, although the differences were not significant. In 15 tumors with alterations in either tumor suppressor genes, the FDG uptake was 6.83 +/- 3.21. On the other hand, the mean FDG uptake was 1.95 in 2 tumors without alterations in any genes. The difference in the FDG uptake between the 2 groups was statistically significant (p < 0.001).
In conclusion, the presence of abnormalities in the tumor suppressor genes, which results in an accelerated cell proliferation, is thus considered to increase the FDG uptake in lung cancer.
Annals of Nuclear Medicine 06/2003; 17(3):189-96. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The aims of this study were to examine the enhancing effects of aloe-emodin anthrone (AEA) on the colonic membrane permeability of water-soluble and poorly permeable compounds and to clarify the mechanism of the permeation-enhancing activity of AEA. The permeation-enhancing activity of AEA was estimated from changes in the permeability coefficient of 5(6)-carboxyfluorescein (CF) in rat colonic mucosa using a Ussing-type chamber. Various inhibitors were used to investigate the mechanism of action of AEA. The structural change in the membrane and the cytotoxicity of AEA in the intestinal mucosa were evaluated by measuring the electrical resistance of the membrane (R(m)) and lactate dehydrogenase (LDH) activity, respectively. AEA significantly increased the permeation of CF in a dose-dependent manner. The enhanced permeability was significantly suppressed by a histamine H(1) receptor antagonist, pyrilamine, and a mast cell stabilizer, ketotifen, but not by a histamine H(2) receptor antagonist, cimetidine. The enhancing effect was also inhibited by an inhibitor of protein kinase C (PKC). Potential difference and short-circuit current values decreased, while R(m) values remained constant throughout the experiment. The addition of AEA to the mucosal solution decreased R(m) to 30%, but then remained constant. LDH activity with AEA was not significantly different from that of the control. In conclusion, AEA is a candidate for effective absorption enhancers without damage of the membrane and cytotoxicity. We propose that AEA stimulates mast cells within the colonic mucosa to release histamine, which probably bind to the H(1) receptor. The intracellular PKC route activated by H(1) receptor activation enhances the permeability of water-soluble and poorly permeable drugs via opening of tight junctions in rat colonic membrane.
Biological & Pharmaceutical Bulletin 01/2003; 25(12):1608-13. · 1.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The aim of this study is to evaluate the clinical impact of whole-body FDG-PET for the pre-therapeutic evaluation of malignant lymphoma and compared to that of 67Ga-scintigraphy when added to non-RI examinations.
We examined 46 patients with malignant lymphoma including 42 newly diagnosed cases and 4 relapsed cases. Whole-body FDG-PET was started 63 minutes after the administration of FDG with ECAT EXACT HR+. The clinical stage of each patient was determined based on the results of a non-RI examination (consisting of physical examination, CT, gastrointestinal studies and bone marrow aspiration), 67Ga planar images and FDG-PET. Discrepant findings were verified based on the response to treatment and the findings of a follow-up examination more than 6 months after treatment. Finally, 152 nodal regions and 19 extranodal tissues were found to be involved by disease.
In the 152 nodal lesions, FDG-PET detected 54 nodal lesions in addition to 98 lesions detected by non-RI examinations, whereas 67Ga-scintigraphy detected 14 additional lesions. The sensitivity of non-RI, non-RI + 67Ga and non-RI + FDG was 64.5%, 73.7% and 100.0%, respectively. In 19 extranodal lesions, FDG-PET detected 5 extranodal lesions in addition to 13 lesions detected by non-RI examinations, whereas 67Ga-scintigraphy detected 1 additional lesion. The sensitivity of non-RI, non-RI + 67Ga and non-RI + FDG was 68.4%, 73.7% and 94.7%, respectively. When combining the FDG-PET findings with the non-RI findings, the improvement of the detectability was much higher than that when 67Ga findings were combined to the non-RI findings. For the staging of lymphoma, the non-RI and non-RI + 67Ga findings accurately diagnosed 76.1% and 80.4%, respectively, whereas the non-RI + FDG findings accurately diagnosed 82.6%. Finally, FDG-PET resulted in changes in the clinical management of 8 patients (17.4%).
FDG-PET offers more information in addition to the findings of conventional diagnostic methods than 67Ga-scintigraphy in order to accurately detect malignant lymphoma. FDG-PET can therefore play an important role in therapeutic decision making on lymphoma.
Annals of Nuclear Medicine 08/2002; 16(5):337-45. · 1.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Carbon-11-L-methyl-methionine (11C-methionine) has been reported to be useful for evaluating brain tumors, but several other brain disorders have also shown signs of high methionine uptake. We retrospectively evaluated the significance of 11C-methionine uptake in cerebrovascular diseases, and also compared our results with those for 18F-FDG PET and 99mTc-HMPAO SPECT.
Seven patients, including 3 patients with a cerebral hematoma and 4 patients with a cerebral infarction, were examined. All 7 patients underwent both 11C-methionine PET and 99mTc-HMPAO SPECT, and 6 of them underwent 18F-FDG PET.
A high 11C-methionine uptake was observed in all 3 patients with cerebral hematoma. Increased 99mTc-HMPAO uptake was observed in 2 out of 3 patients, and all 3 patients had decreased 18F-FDG uptake. Of 4 patients with a cerebral infarction, high 11C-methionine uptake was observed in 3. Increased 99mTc-HMPAO uptake was also observed in one patient, whereas 3 patients had decreased 18F-FDG uptake.
We should keep in mind that high 11C-methionine uptake is frequently observed in cerebrovascular diseases. CVD should therefore be included in the differential diagnosis when encounting patients with a high 11C-methionine uptake.
Annals of Nuclear Medicine 06/2002; 16(3):207-11. · 1.50 Impact Factor
