Adult ; Female ; Humans ; Hyperthyroidism ; drug therapy ; metabolism ; Iodine Radioisotopes ; pharmacokinetics ; therapeutic use ; urine ; Male ; Middle Aged ; Models, Biological ; Radiation Dosage ; Radiation Monitoring ; Radiopharmaceuticals ; pharmacokinetics ; therapeutic use ; urine ; Radiotherapy Dosage ; Young Adult

PURPOSE: Both 18F-fluorodeoxyglucose (18F-FDG) uptake and epidermal growth factor receptor (EGFR) status are prognostic variables of colorectal cancer (CRC). The aim of this study was to investigate a possible association between 18F-FDG uptake on preoperative positron emission tomography/computed tomography (PET/CT) and EGFR status in primary CRC. MATERIALS AND METHODS: Records of 132 patients (66 men and 66 women; mean age=67.1+/-11.1 years) who underwent 18F-FDG PET/CT for CRC staging and subsequent bowel resection were reviewed. In primary lesions, 18F-FDG uptake was semiquantitatively evaluated in terms of maximum standardized uptake value (SUVmax), and EGFR status was determined by immunohistochemistry. Associations of clinicopathological parameters and EGFR status were analyzed by Pearson's chi-square test, multiple logistic regression, and receiver operating characteristic curves. RESULTS: Eighty-six patients (65.2%) showed EGFR expression. SUVmax was significantly lower in EGFR-negative tumors than in EGFR-expressing tumors (10.0+/-4.2 vs. 12.1+/-2.1; p=0.012). It was the only significant parameter correlated with EGFR expression (odds ratio=2.457; relative risk=2.013; p=0.038). At the SUVmax threshold of 7.5, the sensitivity and specificity for predicting EGFR expression were 84.9% and 40.4%, respectively (area under the curve=0.624; p=0.019). CONCLUSION: Preoperative 18F-FDG uptake is slightly correlated with EGFR status in primary CRC. Preoperative SUVmax of 18F-FDG may have a limited role in predicting EGFR expression in such tumors because of its poor specificity.
Adult ; Aged ; Aged, 80 and over ; Colorectal Neoplasms/metabolism/pathology/*radiography/*radionuclide imaging ; Female ; Fluorodeoxyglucose F18/*pharmacokinetics ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Multimodal Imaging/*methods ; Neoplasm Staging ; Positron-Emission Tomography/*methods ; Predictive Value of Tests ; Prognosis ; ROC Curve ; Radiopharmaceuticals/*pharmacokinetics ; Receptor, Epidermal Growth Factor/*metabolism ; Sensitivity and Specificity

OBJECTIVE: We investigated the prognostic value of intratumoral [18F]fluorodeoxyglucose (FDG) uptake heterogeneity (IFH) derived from positron emission tomography/computed tomography (PET/CT) in patients with cervical cancer. METHODS: Patients with uterine cervical cancer of the International Federation of Obstetrics and Gynecology (FIGO) stage IB to IIA were imaged with [18F]FDG PET/CT before radical surgery. PET/CT parameters such as maximum and average standardized uptake values (SUV(max) and SUV(avg)), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and IFH were assessed. Regression analyses were used to identify clinicopathological and imaging variables associated with progression-free survival (PFS). RESULTS: We retrospectively reviewed clinical data of 85 eligible patients. Median PFS was 32 months (range, 6 to 83 months), with recurrence observed in 14 patients (16.5%). IFH at an SUV of 2.0 was correlated with primary tumor size (p<0.001), SUV(tumor) (p<0.001), MTV(tumor) (p<0.001), TLG(tumor) (p<0.001), depth of cervical invasion (p<0.001), and negatively correlated with age (p=0.036). Tumor recurrence was significantly associated with TLG(tumor) (p<0.001), MTV(tumor) (p=0.001), SUV(LN) (p=0.004), IFH (p=0.005), SUV(tumor) (p=0.015), and FIGO stage (p=0.015). Multivariate analysis identified that IFH (p=0.028; hazard ratio, 756.997; 95% CI, 2.047 to 279,923.191) was the only independent risk factor for recurrence. The Kaplan-Meier survival graphs showed that PFS significantly differed in groups categorized based on IFH (p=0.013, log-rank test). CONCLUSION: Preoperative IFH was significantly associated with cervical cancer recurrence. [18F]FDG based heterogeneity may be a useful and potential predicator of patient recurrence before treatment.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Squamous Cell/metabolism/*radionuclide imaging/secondary ; Disease-Free Survival ; Female ; Fluorodeoxyglucose F18/*pharmacokinetics ; Glycolysis ; Humans ; Middle Aged ; Multimodal Imaging ; Neoplasm Invasiveness ; Neoplasm Recurrence, Local/metabolism/radionuclide imaging ; Neoplasm Staging ; *Positron-Emission Tomography ; Predictive Value of Tests ; Radiopharmaceuticals/*pharmacokinetics ; Retrospective Studies ; Tomography, X-Ray Computed ; Tumor Burden ; Uterine Cervical Neoplasms/metabolism/pathology/*radionuclide imaging

Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) may be a promising modality for treating medial temporal lobe epilepsy. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a noninvasive method for monitoring in vivo glucose metabolism. We evaluated the efficacy of hUCB-MSCs transplantation in chronic epileptic rats using FDG-PET. Rats with recurrent seizures were randomly assigned into three groups: the stem cell treatment (SCT) group received hUCB-MSCs transplantation into the right hippocampus, the sham control (ShC) group received same procedure with saline, and the positive control (PC) group consisted of treatment-negative epileptic rats. Normal rats received hUCB-MSCs transplantation acted as the negative control (NC). FDG-PET was performed at pre-treatment baseline and 1- and 8-week posttreatment. Hippocampal volume was evaluated and histological examination was done. In the SCT group, bilateral hippocampi at 8-week after transplantation showed significantly higher glucose metabolism (0.990 +/- 0.032) than the ShC (0.873 +/- 0.087; P < 0.001) and PC groups (0.858 +/- 0.093; P < 0.001). Histological examination resulted that the transplanted hUCB-MSCs survived in the ipsilateral hippocampus and migrated to the contralateral hippocampus but did not differentiate. In spite of successful engraftment, seizure frequency among the groups was not significantly different. Transplanted hUCB-MSCs can engraft and migrate, thereby partially restoring bilateral hippocampal glucose metabolism. The results suggest encouraging effect of hUCB-MSCs on restoring epileptic networks.
Animals ; Chronic Disease ; Cord Blood Stem Cell Transplantation/*methods ; Epilepsy, Temporal Lobe/*metabolism/pathology/*therapy ; Fluorodeoxyglucose F18/*pharmacokinetics ; Hippocampus/*metabolism/*pathology/surgery ; Male ; Mesenchymal Stem Cell Transplantation/methods ; Radiopharmaceuticals/pharmacokinetics ; Rats ; Rats, Sprague-Dawley ; Reproducibility of Results ; Sensitivity and Specificity ; Tissue Distribution ; Treatment Outcome

PURPOSE: To investigate the prevalence and clinical significance of incidental prostate fluoro-2-deoxyglucose (FDG) uptake and to evaluate its impact on patient management. MATERIALS AND METHODS: Of 47,109 men who underwent FDG positron emission tomography between 2004 and 2014, 1,335 (2.83%) demonstrated incidental FDG uptake in the prostate, with 99 of the latter undergoing prostate biopsy. The primary end point was the histological presence of prostate adenocarcinoma in the biopsy specimen. Outcomes, including treatment methods, survival, and causes of death, were also assessed. Factors associated with the diagnosis of prostate cancer were evaluated by using logistic regression analysis. RESULTS: Patients with prostate cancer were more likely to have higher serum prostate-specific antigen (PSA) (p=0.001) and focal FDG uptake (p=0.036) than were those without. Prostate cancer occurred in 1 of 26 patients (3.8%) with serum PSA<2.5 ng/mL, compared with 40 of 67 patients (59.7%) with serum PSA> or =2.5 ng/mL. Multivariable analysis showed that focal lesions (odds ratio [OR], 5.50; p=0.038), age (OR, 1.06; p=0.031), and serum PSA (OR, 1.28; p=0.001) were independent predictors of prostate cancer diagnosis. Most patients with prostate cancer had organ-confined tumors. Of these, 12 (29.3%) underwent radical prostatectomy and 25 (60.9%) received hormone therapy. Of the 11 patients who died, 9 died of primary cancer progression, with only 1 patient dying from prostate cancer. CONCLUSIONS: The prevalence of incidental FDG uptake in the prostate was not high, although patients with elevated serum PSA had a higher incidence of prostate cancer. Patients with FDG uptake in the prostate should be secondarily evaluated by measuring serum PSA, with those having high serum PSA undergoing prostate biopsy.
*Adenocarcinoma/epidemiology/pathology/surgery ; Aged ; Biopsy ; Fluorodeoxyglucose F18/*pharmacokinetics ; Humans ; Incidental Findings ; Male ; Middle Aged ; Organ Specificity ; Positron-Emission Tomography/*adverse effects ; Prevalence ; *Prostate/drug effects/pathology ; Prostatectomy/methods/statistics & numerical data ; *Prostatic Neoplasms/epidemiology/pathology/surgery ; Radiopharmaceuticals/pharmacokinetics ; Republic of Korea/epidemiology ; Retrospective Studies ; Tissue Distribution

OBJECTIVETo establish a labeling method for a specific lung cancer-targeting small molecule peptide cNGQGEQc with ¹³¹I and observe the radioactivity distribution of the labeled peptide in rabbits using single-photon emission computed tomography (SPECT).

METHODSChloramine-T method was used for ¹³¹I labeling of the tyrosine amino group on cNGQGEQc, and the labeling efficiency and radiochemical purity of ¹³¹I-cNGQGEQc were determined with paper chromatography. The stability of ¹³¹I-cNGQGEQc in saline and human serum was assessed after incubation in water bath at 37 degrees celsius; for 24 h. The octanol-water partition coefficient lg P (the radioactivity counting ratio of ¹³¹I-cNGQGEQc dissolved in 100 µl octanol or in 100 µl saline) was calculated. SPECT was performed in 3 male New Zealand white rabbits after intravenous injection of ¹³¹I-cNGQGEQc to observe the dynamic distribution of the peptide with the time-radioactivity curve (T-A curve) of the region of interest (ROI).

RESULTSWith a labeling efficiency of 90%, ¹³¹I-cNGQGEQc showed a radiochemical purity of was 95% after purification with HPLC. The radiochemical purity of ¹³¹I-cNGQGEQc was (93.12 ± 1.18)% and (88.34 ± 5.43)% after intubation in saline and human serum for 24 h, respectively. The octanol-water partition coefficient lg P of ¹³¹I-cNGQGEQc was -1.75, suggesting its hydrosolubility. In rabbits with intravenous injection of ¹³¹I-cNGQGEQc, SPECT visualized the kidneys at 1 min after the injection; the imaging of the heart and liver became attenuated at 5 min when the bladder was visualized with an increasing radioactivity. The radioactivity of the soft tissues began to fade at 30 min. No gallbladder visualization was detected, and the radioactivity of the abdomen remained low. No obvious radioactivity concentration was observed in the thyroid and stomach. The T-A curves of the ROI of all the tissues and organs descended over time.

CONCLUSIONRadiolabeling of cNGQGEQc with ¹³¹I is simple and highly efficient. ¹³¹I-cNGQGEQc has good stability in vitro and good distribution characteristics for in vivo imaging, and is cleared mainly by renal excretion due to its hydrosolubility. These results provide experimental basis for further studies of diagnosis and therapy of lung cancer with targeting polypeptide.

Animals ; Antineoplastic Agents ; pharmacokinetics ; Chloramines ; Humans ; Iodine Radioisotopes ; chemistry ; Lung Neoplasms ; Male ; Peptides ; pharmacokinetics ; Rabbits ; Radiopharmaceuticals ; pharmacokinetics ; Tissue Distribution ; Tomography, Emission-Computed, Single-Photon ; Tosyl Compounds

F-18-fluorodeoxyglucose (FDG) positron emission tomography/CT is an important whole-body imaging tool in the oncology and widely utilized to stage and restage various malignancies. The findings of significant focal accumulation of FDG in the lung parenchyma in the absence of corresponding CT abnormalities are related to the lung microembolism and known as hot-clot artifacts. Herein we present two cases with focal FDG uptake in the lung parenchyma with no structural lesions on the CT scan and discuss the possible mechanisms.
*Artifacts ; False Positive Reactions ; Female ; Fluorodeoxyglucose F18/*administration & dosage/diagnostic use/pharmacokinetics ; Humans ; Lung/metabolism/radiography/*radionuclide imaging ; Male ; Middle Aged ; Multimodal Imaging/methods ; Positron-Emission Tomography/*methods ; Pulmonary Embolism/radiography/*radionuclide imaging ; Radiopharmaceuticals/*administration & dosage/diagnostic use/pharmacokinetics ; Tomography, X-Ray Computed/methods ; Young Adult

The radiologic appearance of multiple discrete pulmonary nodules in immunocompetent patients, with cryptococcal infection, has been rarely described. We describe a case of pulmonary cryptococcosis, presenting with bilaterally and randomly distributed nodules on a computed tomography, mimicking hematogeneous metastases. Positron emission tomography does not demonstrate 18F-fluorodeoxyglucose (FDG) uptake, suggesting a low probability for malignancy, which is a crucial piece of information for clinicians when making a management decision. We find the absence of FDG uptake correlates with the pathologic finding of an infectious nodule, composed of fibrosis and necrosis.
Cryptococcosis/metabolism/*radionuclide imaging ; Fluorodeoxyglucose F18/*diagnostic use/pharmacokinetics ; Humans ; Immunocompetence ; Lung Diseases, Fungal/metabolism/*radionuclide imaging ; Lung Neoplasms/radionuclide imaging ; Male ; Middle Aged ; Multimodal Imaging/*methods ; Multiple Pulmonary Nodules/radionuclide imaging ; Positron-Emission Tomography/*methods ; Radiopharmaceuticals/*diagnostic use/pharmacokinetics ; Tomography, X-Ray Computed/*methods

OBJECTIVE: We investigated the clinical significance of incidental diffuse thyroid uptake (DTU) on 18F-FDG PET in subjects without a history of cancer. MATERIALS AND METHODS: This study included 2062 studies from adults who underwent 18F-FDG PET as a cancer screening program. Subjects were divided into the following two groups: with (group I) or without (group II) DTU. The presence of DTU and the thyroid visual grading score were compared with thyroid function tests, serum anti-microsomal antibody (AMA) levels, and the presence of diffuse parenchymal change (DPC) on ultrasonography (USG). RESULTS: DTU was found in 6.6% of the scans (137/2062). Serum thyroid stimulating hormone (TSH) and AMA levels were significantly higher in group I than in group II. Increased AMA level (55.1%) and DPC (48.7%) were more frequently found in group I (p < 0.001). The proportion of subjects with any abnormal results in serum free thyroxine, triiodothyronine, TSH, or AMA levels or DPC on USG was significantly higher in group I than in group II (71.5% vs. 10.6%, p < 0.001), and was significantly and gradually increased according to the visual grading score group (0 vs. 1-2 vs. 3-4 = 10.6% vs. 58.5% vs. 90.9%, p < 0.001). TSH and is AMA levels were significantly increased according to the visual grading score. CONCLUSION: The presence or degree of incidental DTU on 18F-FDG PET is closely correlated with increased serum AMA and TSH levels, and the presence of DPC on USG. Therefore, the most plausible pathological cause of DTU may be cell damage by an autoimmune mechanism.
Adult ; Aged ; Aged, 80 and over ; Antibodies/blood ; Female ; Fluorodeoxyglucose F18/*diagnostic use/pharmacokinetics ; Humans ; *Incidental Findings ; Male ; Microsomes/immunology ; Middle Aged ; Neoplasms ; Positron-Emission Tomography/methods ; Radiopharmaceuticals/*diagnostic use/pharmacokinetics ; Retrospective Studies ; Thyroid Gland/metabolism/*radionuclide imaging/ultrasonography ; Thyrotropin/blood ; Young Adult

We present an interesting case of incidental diffuse fluorodeoxyglucose (FDG) uptake at PET in her left breast, related to atypical breastfeeding practice. Clinically, differential diagnoses of diffuse intense FDG uptake in unilateral breast include advanced breast cancer, breast lymphoma and inflammatory condition. However, normal physiologic lactation may also show increased FDG uptake in the breasts. Therefore, if we encounter that finding in daily practice, we should question the patient regarding unilateral breastfeeding. In addition, mammography and ultrasound would be helpful to confirm the diagnosis.
Adult ; Breast/*metabolism/radionuclide imaging ; Breast Feeding/*methods ; Breast Neoplasms/radionuclide imaging ; Diagnosis, Differential ; Female ; Fluorodeoxyglucose F18/diagnostic use/*pharmacokinetics ; Humans ; Lactation/metabolism ; Lymphoma/radionuclide imaging ; Mammography ; Positron-Emission Tomography ; Radiopharmaceuticals/diagnostic use/*pharmacokinetics ; Ultrasonography, Mammary