The value of ~(18)F-FDG PET/CT on the detection and staging of natural killer/T cell lymphomas / 中华核医学杂志

Objective To investigate the value of ~(18)F-fluorodeoxyglucose (FDG) PET/CT on the detection and staging of natural killer (NK)/T cell lymphomas.Methods Thirteen new and 2 recurrent csses of NK/T cell lymphoma were inchded in this study and they all underwent wllole-body ~(18)F-FDG PET/CT scans.A lesion with intense ~(18)F-FDG uptake was taken as positive for disease involvement and semiquantitative metabolic assessment was performed with the maximum standardized uptake value(SUV_(max)).All patients were followed for more than 6 months.The t-test was used to analyze the semi-quantitative data statistics.Results (1) ~(18)F-FDG PET/CT had 100%positive detection rate for NK/T cell lymphom.Of 11 cases with disease involvement of the nasal region.PET/CT detected 10.either in the nasal cavity or in the nasopharynx,6 with extra-nasal infiltration,and 7 with regional nodal metastasis.There were 4 non-nasal cases and PET/CT detected one or multiple extra-nasal lymphoma lesions.The SUV_(max) of nasal and extra-nasal lesions was 12.42±9.25,9.54±7.12,respectively,with no significant difference(t=1.120,P＞0.05).(2)Two cases(2/15)diagnosed of this disease by PET/CT were initially referred as investigation of fever of unknown origin.For the remaining 13/15 known cases,PET/CT detected more "unsuspected" lymphoma lesions in 7 cases and affected the staging in 6 patients.The ~(18)F-FDG uptake (SUV_(max))of Ⅰ-Ⅱ stage patients was mildly lower than that of Ⅲ-Ⅳ stage patients,but no significant difference was observed (t=0.757,P＞0.05).Conclusions NK/T cell lymphoma is an intensely ~(18)F-FDG-avid tumor.~(18)F-FDG PET/CT is an effective imaging tool for detection and staging of this disease.

Application of 11C-choline PET/CT for the hepatic space-occupying lesions with an indeterminate diagnosis by 18F-FDG PET/CT / 中华核医学杂志

Objective To explore the value of 11C-choline PET/CT in patients with hepatic spaceoccupying lesions that have an indeterminate diagnosis by 18F-fluorodeoxyglucose (FDG) PET/CT. Methods A total of 25 liver masses in 20 patients with an indeterminate diagnosis based on 18F-FDG PET/CT were enrolled. Regional 11C-choline PET/CT scan was performed in all of the patients. Lesions with intense 11C-choline uptake were considered as positive. The semiquantitative maximum standardized uptake value(SUVmax) was measured and the tumor-to-liver (T/L) radioactivity ratio was calculated. The Mann-Whitney test,Kruskal-Wallis test and crosstabs x2-test were performed by using SPSS version 11.5. Results Of the 25 lesions,21 were proven to be hepatocellular carcinomas (HCC),3 hemangiomas,and 1 parasitic granuloma. The sensitivity of 11C-choline PET/CT for the detection of HCC was 66.7% (14/21). 11C-choline PET/CT had a higher sensitivity for well differentiated HCC than moderately and poorly differentiated HCC on a patient basis (8/9 vs 2/5,respectively). There were significant differences of 11C-choline T/L ratios between the HCC positive group,HCC negative group and benign lesion group ( 1.70 ± 0.35,0.86 ± 0.15,and 0.36 ± 0.18,x2 = 19.00,P ＜0.01 ). The lesion size and alphafetoprotein (AFP) level between the HCC positive and negative groups had no significant difference respectively ( Mann Whitney U = 39.00,P ＞0.05,and U=16.00,P＞0.05,respectively). Conclusions 11C-choline is complementary to 18F-FDG PET/CT for the detection of HCC,especially for well differentiated HCC.

Risk factor analysis of 167 patients with high myopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To analyse the risk factors of age, sex, course, best corrected visual acuity(BCVA),diopter and fundus features of high myopes with progressive high myopia. METHODS: A total of 167 patients with high myopes were categorized into four groups: group 1,age of 29 years or younger; group 2,between the age of 30 to 49 years; group 3,between the age of 50 to 69 years and group 4,age of 70 years or older. The refractive errors of all patients were measured without cycloplegia with an autorefractometer. Data of the spherical equivalent(SE) of the refractive errors in diopters (D)and fundus examed by direct ophthalmoscope were used in statistical analyses.RESULTS: The number of female was statistically larger than that of male(P＜0.01),also the disease course was correlated to the age. The visual acuity of high myopes significantly decreased as they grew older including the higher incidence of lacquer cracker, submacular hemorrhage, Fuchs spots, chorioretinal atrophy . CONCLUSION: Female maybe a risk factor of high myopia, advanced age is an important factor of visual acuity decrease. High myopes ought to be treated early to delay the progress of myopia and development of macular degeneration.

Radiosynthesis of peripheral benzodiazepine receptor radioligand N-methyl-(11)CPK 11195 as an imaging agent for positron emission tomography / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a protocol of automated synthesis of 1-(2-chlorophenyl)-N-[(11)C]methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide ((11)C-PK11195) as the positron-emitter-labeled ligand for peripheral benzodiazepine receptor (PBR) using a commercial synthesizer and explore the quality control methods for the resulting product.</p><p><b>METHODS</b>(11)C-methyl iodide ((11)C-CH(3)I) was synthesized via liquid-phase distillation approach using a (11)C-iodomethane synthesizer. (11)C-PK11195 was prepared by (11)C-methylation of 1-(2-chlorophenyl)-N-(1-methylpropyl)-3-isoquinoline carboxamide (N-demethyl-PK 11195) as the precursor with (11)C-CH(3)I and purified by semi-preparative reversed phase high performance liquid chromatography (HPLC). The radiochemical purity, chemical purity and stability of the product were evaluated by HPLC, and the toxicity was assessed in normal mice. The factors that affected (11)C-PK11195 synthesis were also studied.</p><p><b>RESULTS</b>(11)C-PK11195 was successfully synthesized using the TracerLab FX(F-N) synthesizer. The synthesis time was about 35 min from the end of (11)C-carbon dioxide production by cyclotron to the end of (11)C-PK11195 synthesis (EOS), with a (11)C-methylation reaction time of 3-4 min. The uncorrected radiochemical yield for (11)C-methylation was (33-/+5)%. Analysis with radio-analytical HPLC showed a radiochemical purity and chemical purity of the product both exceeding 99%, with a specific radioactivity of 30-65 GBq/micromol at EOS (from the end of radionuclide production). The (11)C-PK11195 synthesized was radiochemically stable at room temperature and showed low toxicity in normal mice.</p><p><b>CONCLUSION</b>The (11)C-PK11195 injection can be conveniently prepared using an automated synthesizer for clinical use in positron emission tomography.</p>

Biodistribution of (18)F-NaF as an imaging agent in osteoporotic rats for position emission tomography / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the biodistribution of (18)-NaF as an imaging agent for position emission tomography (PET) in rat models of osteoporosis.</p><p><b>METHODS</b>Osteoporosis was induced in 10 rats via injection with an excess of dexamethasone phosphate sodium, and the biodistribution of (18)-NaF in the rats was studied, with another 10 normal rats as the control group. (18)-NaF PET was also performed in 8 healthy volunteers, and the uptakes of (18)-F- in the bone tissues were measured.</p><p><b>RESULTS</b>Compared with the control rats, the osteoporotic rats showed significantly decreased (18)-F- uptake, especially in the femoral neck, lumbar vertebrae, the 7th rib and the tibia (P<0.05). Dynamic chest PET scanning in the volunteers revealed obvious (18)-F- uptake in the spine, ribs and humerus 20 s after injection of the imaging agent. (18)-F- uptake significantly increased with time in the bones, reaching the peak level 60 min after the injection, and whole-body PET at this point demonstrated obvious skeletal (18)-F- uptake, with high skeletal-to-muscle (STM) ratio that averaged 8.12.</p><p><b>CONCLUSION</b>(18)-NaF is an excellent skeletal imaging agent for clinical skeletal blood flow and metabolism measurements. The uptake of (18)-NaF has significant difference between normal and osteoporotic bone tissues, indicating the value of (18)-NaF PET for study of osteoporosis.</p>

Synthesis and radiopharmacology of S-(2-18F-fluoroethyl)-L-methionine for tumor imaging / 药学学报

<p><b>AIM</b>To develop S-(2-18F-fluoroethyl)-L-methionine (18FEMET) as an amino acid positron emission tomography (PET) tracer for tumors, and to evaluate the value of 18FEMET in the differentiation of experimental tumor and experimental inflammation.</p><p><b>METHODS</b>18FEMET was prepared by nucleophilic fluorination reaction via a two-step procedure. Biodistribution of 18FEMET in normal mice, carcinoma-bearing mice and inflammatory mice, and 18FEMET PET imaging for carcinoma-bearing mice and inflammatory mice were performed compared with 2-[18F] fluoro-2-deoxy-D-glucose (FDG) and O-(2-[18F] fluoroethyl)-L-tyrosine (FET).</p><p><b>RESULTS</b>The overall radiochemical yield with no decay correction was 15%-25%, the whole synthesis time was about 70 min by manual operation, and the radiochemical purity was above 95%. High uptake and long retention of 18FEMET in pancreas, kidney, colon, liver and heart were observed. But low uptakes in brain and blood were found. Furthermore, high uptake of 18FEMET, FDG and FET in tumor, high uptake of FDG in inflammatory tissue, and almost no uptake of 18FEMET and FET in inflammatory tissue were also observed.</p><p><b>CONCLUSION</b>18FEMET is easy to prepare and can be used to differentiate between tumor and inflammatory tissue. It seems to be a potential amino acid tracer for tumors with PET imaging.</p>