Animals ; Carbon Radioisotopes ; Diabetes Mellitus, Experimental ; genetics ; metabolism ; Diabetes Mellitus, Type 1 ; genetics ; metabolism ; Gene Expression Regulation ; Glucose ; administration & dosage ; metabolism ; Lipid Metabolism ; Liver ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Transcriptome

OBJECTIVEThe objective of this study was to compare the biodistribution and PET imaging of (11)C-PDT and (18)F-FDG in a mouse model of lung adenocarcinoma, and to evaluate the value of (11)C-PDT as a new tracer for PET imaging of lung cancer.

METHODSTwenty four lung adenocarcinoma-bearing mice were randomly divided into two groups, 12 each. The mice received (11)C-PDT or (18)F-FDG injection i.v. respectively. The biodistribution of (11)C-PDT or (18)F-FDG in the mice was measured with a well-gamma detector at 60 min after injection. The PET imagings of mice were performed using either of the two tracers.

RESULTSConsiderable uptake of the both radioactive tracers in the tumors was observed. The tumor uptake of (11)C-PDT [(0.65 +/- 0.20)%ID/g] was significantly lower than that of (18)F-FDG [(7.44 +/- 1.56)%ID/g, P < 0.01]. In the (11)C-PDT group, the highest uptake was observed in the liver, kidney and blood in a successively declining order, while the highest uptake of (18)F-FDG was seen in a order of heart, tumor and kidneys. The tumor/muscle ratio of (11)C-PDT uptake was relatively high (2.02 +/- 0.56), but still lower than that of (18)F-FDG (2.95 +/- 0.49, P < 0.01). All values of other tumor/organ ratios (T/NT) of (11)C-PDT uptake were < 2. High radioactive uptake was showed in the tumor and abdominal organs on PET images in the tumor-bearing mice injected with (11)C-PDT, and (18)F-FDG uptake was showed in the heart, tumor and abdominal organs. The tumor PET images with (11)C-PDT and (18)F-FDG were all clear.

CONCLUSIONThe uptake of (11)C-PDT in lung cancer is higher than that in muscle tissues, and pulmonary cancers can be detected by PET imaging. (11)C-PDT may be a promising PET tracer for lung cancers.

Adenocarcinoma ; diagnostic imaging ; metabolism ; pathology ; Animals ; Carbon Radioisotopes ; pharmacokinetics ; Cell Line, Tumor ; Fluorodeoxyglucose F18 ; pharmacokinetics ; Kidney ; diagnostic imaging ; metabolism ; Liver ; diagnostic imaging ; metabolism ; Lung Neoplasms ; diagnostic imaging ; metabolism ; pathology ; Mice ; Myocardium ; metabolism ; Podophyllotoxin ; pharmacokinetics ; Positron-Emission Tomography ; Tissue Distribution

OBJECTIVETo 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.

METHODS(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.

RESULTS(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.

CONCLUSIONThe (11)C-PK11195 injection can be conveniently prepared using an automated synthesizer for clinical use in positron emission tomography.

Animals ; Carbon Radioisotopes ; Contrast Media ; chemical synthesis ; Isoquinolines ; adverse effects ; chemical synthesis ; Mice ; Positron-Emission Tomography ; Radioligand Assay ; Radiopharmaceuticals ; adverse effects ; chemical synthesis ; Receptors, GABA-A ; metabolism

OBJECTIVETo evaluate the value of (18)F-FDG and (11)C-MET PET-CT scan in differentiation of brain ringlike-enhanced lesions on MRI imaging.

METHODSForty-one brain ringlike-enhanced lesions on MRI imaging including 30 brain tumors and 11 non-neoplastic lesions confirmed pathologically or clinically underwent (18)F-FDG and (11)C-MET PET-CT brain scan. Among them, 15 patients who were suspected to have brain metastasis received body scan by (18)F-FDG PET-CT. Both images were analyzed visually and semi-quantitatively.

RESULTSVisual analysis: for brain tumors the diagnostic sensitivity, specificity and accuracy of (18)F-FDG PET-CT was 53.3%, 72.7%, 58.5%, versus 96.7%, 90.9%, 95.1% of (11)C-MET PET-CT, respectively. All the primary foci in 9 patients with brain metastases were detected by body (18)F-FDG PET-CT scan. Semiquantitative analysis: There was a significant difference in the uptake between highly differentiated malignant and poorly differentiated tumors as well as non-neoplastic lesions for both tracers (P < 0.01), while between low-grade malignant tumors and non-neoplasm lesions, there was a difference in uptake only by (11)C-MET (P < 0.01). No significant difference between the uptakes in brain metastasis and glioblastomas was found by both tracers (P > 0.05).

CONCLUSIONBoth (18)F-FDG and (11)C-MET PET-CT are useful in differentiation of brain ringlike-enhanced lesions on MRI imaging. (11)C-MET PET-CT is more helpful than (18)F-FDG PET-CT in differential diagnosis of low-grade neoplastic from non-neoplastic lesions. Combination of (18)F-FDG and (11)C-MET PET-CT scans can improve the accuracy of differential diagnosis for brain ringlike-enhanced lesions on MRI imaging.

Acetates ; Adolescent ; Adult ; Aged ; Brain Abscess ; diagnosis ; Brain Neoplasms ; diagnosis ; pathology ; secondary ; Carbon ; Carbon Radioisotopes ; Child ; Craniopharyngioma ; diagnosis ; pathology ; secondary ; Diagnosis, Differential ; Female ; Fluorodeoxyglucose F18 ; Glioblastoma ; diagnosis ; pathology ; secondary ; Humans ; Lung Neoplasms ; diagnosis ; pathology ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Pituitary Neoplasms ; diagnosis ; pathology ; secondary ; Positron-Emission Tomography ; methods ; Radiopharmaceuticals ; Sensitivity and Specificity ; Young Adult

OBJECTIVETo investigate the value of 11C-PD153035 as an EGFR imaging agent in C6 tumor-bearing rat.

METHODSThe tumor-bearing rats were generated by subcutaneous injection of glioma C6 cells. Positron emission tomography/computer tomography (PET/CT) scans started as soon as intravenous injection of 11C-PD153035 (15-20 MBq/0.3 ml) was completed, images were collected continuously. The region of interest (ROI) was used to study the percentage of radioactivity in major organs and implanted tumors in the rats. The accumulation and blocking study in vitro was completed.

RESULTSThere were significant differences in 11C-PD153035 uptake among major organs. The maximum uptake in the organs ranked in the following order: liver > gastrointestinal tract > kidney > lung > brain > muscle. Radioactivity could be also observed in the tumors. The radioactivity ratio (T/NT, target/non-target) peaked (4.15) at 40 - 50 min post injection. The in vitro blocking study showed that 11C-PD153035 uptaken by C6 cells could be blocked by PD153035.

CONCLUSIONThe results of this study show that 11C-PD153035 can be uptaken by EGFR-expressing tumors. 11C-PD153035 has a potential as a bioprobe to yield useful information for both diagnosis and therapy of tumors. However, the high concentration of 11C-PD153035 in the gastrointestinal tract is unfavorably affecting the tumor detection in these organs.

Animals ; Brain Neoplasms ; diagnostic imaging ; metabolism ; pathology ; Carbon Radioisotopes ; Cell Line, Tumor ; Gastrointestinal Tract ; metabolism ; Glioma ; diagnostic imaging ; metabolism ; pathology ; Liver ; metabolism ; Male ; Neoplasm Transplantation ; Positron-Emission Tomography ; Quinazolines ; pharmacokinetics ; Rats ; Rats, Wistar ; Receptor, Epidermal Growth Factor ; metabolism ; Tissue Distribution ; Tomography, X-Ray Computed

OBJECTIVETo study the biodistribution of L-[S-methyl-(11)C]-methioine ((11)C-MET) and explore its clinical application in positron emission tomography (PET) for brain tumor detection.

METHODSTwenty-four Wistar rats and divided into 6 equal groups and injected with (11)C-MET through the tail vein and killed by decollation at 5, 10, 20, 30 and 40 min after injection, respectively. The liver, brain, blood, heart, lung, kidney, and spleen were harvested to measure the radioactivity and calculate the biodistribution of (11)C-MET. PET imaging with (11)C-MET was performed in 6 normal volunteers and 30 patients with pathologically confirmed brain gliomas.

RESULTS AND CONCLUSION(11)C-MET showed high blood uptake and a long retention in the tumor mass, therefore can be a valuable tracer for PET imaging of brain tumor and the hypophysis.

Adult ; Aged ; Animals ; Brain ; diagnostic imaging ; metabolism ; pathology ; Brain Neoplasms ; diagnosis ; diagnostic imaging ; metabolism ; Carbon Radioisotopes ; Female ; Glioma ; diagnosis ; diagnostic imaging ; metabolism ; Humans ; Injections, Intravenous ; Male ; Middle Aged ; Positron-Emission Tomography ; methods ; Radiopharmaceuticals ; administration & dosage ; pharmacokinetics ; Rats ; Rats, Wistar ; Sensitivity and Specificity ; Tissue Distribution ; Vitamin U ; administration & dosage ; pharmacokinetics

BACKGROUND(11)C-4-N-(3-bromoanilino)-6,7-dimethoxyquinazoline ((11)C-PD153035) has been reported as a tracer for imaging human tumors that overexpress epidermal growth factor receptor (EGFR). However it is still unclear whether (11)C-PD153035 uptake correlates with EGFR expression levels. The objective of this study was to investigate the relationship between (11)C-PD153035 accumulation and EGFR expression levels.

METHODSSynthesis of (11)C-PD153035 was performed in the Tracerlab FXc system. Accumulation of (11)C-PD153035 by MDA-MB-468, A549 and MDA-MB-231 cells was measured in vitro. There were six tumor-bearing mice in each group. (11)C-PD153035 uptake in tumors was determined by positron emission tomography/computed tomography (PET/CT). Tumor/normal muscle tissue (T/NT) analysis in PET images was applied to quantify the PET data. Sixty minutes after PET/CT scanning, the nude mice were sacrificed and the tumors were excised. The (11)C-PD153035 accumulation in different tumors was determined by a gamma counter.

RESULTSClose correlation existed between the uptake and the level of EGFR expression both in vitro and ex vivo (r(2) = 0.72, P < 0.001; r(2) = 0.63, P = 0.003). When the static T/NT analysis method was applied to analyze the PET data, the observed correlation was again excellent (r(2) = 0.70, P = 0.001).

CONCLUSIONSThe uptake of PET tracer (11)C-PD153035 closely correlates with the EGFR expression levels in tumor cells. (11)C-PD153035 has the potential to yield useful information for both cancer diagnosis and therapy.

Animals ; Carbon Radioisotopes ; Cell Line, Tumor ; Female ; Humans ; Ligands ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Positron-Emission Tomography ; Quinazolines ; metabolism ; Receptor, Epidermal Growth Factor ; analysis ; metabolism

OBJECTIVETo evaluate the potential benefit of carbon ion radiotherapy (C-ion RT) through comparison with photon intensity-modulated radiotherapy (IMRT) in dose distribution for prostatic adenocarcinoma.

METHODSIn randomly selected 5 patients, treatment planning of C-ion RT (4 coplanar beams) and IMRT (7 coplanar fields) were worked out by computer working station. In order to make a meaningful comparison, it was defined that the 95% isodose surface had to cover 100% of the PTV in each plan; all dose was given as normalized dose with the definition of the minimum dose of the PTV being equal to 95% of prescribed dose. Dose-volume histograms (DVHs) of the tumor and organ-at-risks (OARs) were calculated. Volume irradiated more than or equal to some specified doses, conformity index ( CI) , and inhomogeneity coefficient (IC) of each treatment plan was compared, respectively.

RESULTSWith C-ion RT, the mean irradiated volumes (in %) of the rectum were significantly smaller than that with IMRT except for 95% dose level, and C-ion RT could provide complete protection to the posterior rectal wall. In addition, C-ion RT could also remarkably reduce the dose to the bladder, femoral heads and non-target normal tissues at each dose level. Dose conformation and homogeneity in the target volume of C-ion RT were better than that in IMRT (mean CI50%, 3.36 vs. 5.04, mean CI95%, 1.20 vs. 1.46, mean IC, 0.03 vs. 0.12).

CONCLUSIONCompared with IMRT, C-ion RT can obtain better dose distribution, and may reduce tumor recurrence and radiation-induced complications in prostatic adenocarcinoma.

Adenocarcinoma ; pathology ; radiotherapy ; Aged ; Carbon Radioisotopes ; therapeutic use ; Femur Head ; radiation effects ; Humans ; Male ; Prostatic Neoplasms ; pathology ; radiotherapy ; Radiotherapy Dosage ; Radiotherapy, Intensity-Modulated ; methods ; Rectum ; radiation effects ; Urinary Bladder ; radiation effects

OBJECTIVETo assess the value of carbon-11 choline (CH) positron emission tomography (PET) in patients with pulmonary nodules.

METHODSFrom September 2002 to December 2004, 39 patients with pulmonary nodules were imaged with CH-PET. CH-PET data was analyzed by visual method and semiquantitative method. When pulmonary nodules with abnormal CH uptake appeared in PET scans confirmed by visual method, their maximum and mean standard uptake value (SUVmax and SUVmean) were measured using semiquantitative method. Diagnoses were confirmed by surgery or biopsy and follow-up survey.

RESULTSTwenty-four cancerous and 3 inflammatory nodules and 1 bronchogenic cyst were detected by CH-PET and were diagnosed malignant with visual method. Three bronchial alveolar carcinoma, 2 metastatic tumor from kidney and colon, 3 fibrous nodules, 1 cryptococcosis, 1 hamartoma and 1 sclerosing hemangioma showed nothing abnormal in PET scans. For identification of pulmonary nodules with CH-PET, the sensitivity was 89% (24/29), the specificity was 60% (6/10), and the accuracy was 77% (30/39). There were differences in SUV between 8 squamous cell carcinomas and 9 adenocarcinomas (Z = -2.937, -2.887, P < 0.01). In diagnosing 70 resected enlarged lymph nodes beyond 1 cm in 17 lung cancer patients, CH-PET had the sensitivity of 86% (25/29), the specificity of 90% (37/41), and the accuracy of 89% (62/70). CH-PET confirmed 7 distant metastases in 25 lung cancer patients. In 5 cases suspected brain metastases CH-PET identified 2 cases positive correctly.

CONCLUSIONSCH-PET can confirm malignant pulmonary nodules, but still there were false positive and false negative cases. CH-PET can evaluate N stage effectively in patients with lung cancer. CH-PET can depict brain metastases accurately.

Adult ; Aged ; Aged, 80 and over ; Carbon Radioisotopes ; Choline ; Female ; Humans ; Lung ; diagnostic imaging ; pathology ; Lung Diseases ; diagnosis ; Lung Neoplasms ; diagnosis ; Male ; Middle Aged ; Positron-Emission Tomography ; methods ; Retrospective Studies ; Sensitivity and Specificity

BACKGROUNDMiddle mediastinal masses comprise a wide variety of tumors but may also reflect lymphadenopathy, and thus remain an interesting diagnostic challenge. We performed positron emission tomography (PET) of mediastinal masses in order to evaluate the ability of PET to predict the malignancy of these tumors. We compared histologic findings, videomediastinoscopy, computed tomography (CT), and PET-CT in patients with mediastinal disease.

METHODSThirty-two patients were evaluated with CT, PET-CT and videomediastionoscopy, and all studies were performed within four weeks in each patient. (11)C-choline as a PET tracer was used to visualize masses. PET data were evaluated using the standardized uptake value (SUV) and were compared with pathologic data.

RESULTSThere were 13 men and 19 women aged from 21 to 74 (mean 45.2) years. Among the patients with mediastinal diseases, sarcoidosis was diagnosed in 12 patients, tuberculosis in 5 patients, lymphoma in 5 patients, and noncaseating granulomata without classical "sarcoid" finding in 3 patients. N2 or N3 nodal metastasis was revealed in 6 of 7 patients who had non-small cell lung cancer or suspected lung cancer, and one was negative (the pathological diagnosis was reactive hyperplasia). The accuracies for correctly diagnosing mediastinal masses for CT, PET-CT and videomediastinoscopy were 38% (12/32), 63% (20/32), and 91% (29/32) respectively. The diagnostic accuracy of videomediastinoscopy was superior to that of PET-CT (chi(2) = 11.130, P < 0.001). The SUVs were similar among these diseases. On the other hand, if the diagnostic classification was benign vs malignancy, the accuracies for CT, PET-CT and videomediastinoscopy were 53% (17/32), 75% (24/32), 100% (32/32) respectively. The diagnostic accuracy of videomediastinoscopy was superior to that of PET-CT (chi(2) = 22.042, P < 0.001). The SUV of malignant lesions (6.9, 3.2 - 9.8; n = 11) appeared to be higher than that of benign lesions (4.9, 2.9 - 8.3; n = 21), however, this difference was not statistically significant (P = 0.054).

CONCLUSIONSTo diagnose lesions located in the middle mediastinum, videomediastinoscopy possesses the highest diagnostic accuracy, and therefore remains the gold standard. PET-CT is valuable for differential diagnosis of benign vs malignant lesions, CT alone or PET alone (SUV) may provide misdiagnosis in a substantial proportion of patients with mediastinal masses.

Adult ; Aged ; Carbon Radioisotopes ; Female ; Humans ; Male ; Mediastinal Diseases ; diagnosis ; Mediastinoscopy ; methods ; Middle Aged ; Positron-Emission Tomography ; Tomography, X-Ray Computed ; Video Recording