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

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

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

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

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

Fluorodeoxyglucose (FDG) hepatic superscan refers to the diffuse intense uptake of 18F-FDG in the liver on positron emission tomography (PET), with reduced physiological activity in the brain and heart. The common causes include lymphoma and metastasis. In this case report, we describe the imaging features of tuberculosis as a rare cause of FDG hepatic superscan. PET imaging may be the only clue to a diagnosis of hepatic tuberculosis, as other imaging modalities may demonstrate only nonspecific hepatomegaly. It is important to consider this entity in the differential diagnosis of patients presenting with FDG hepatic superscan and proceed with liver biopsy for a definitive diagnosis.
Brain ; diagnostic imaging ; Fluorodeoxyglucose F18 ; pharmacokinetics ; Heart ; diagnostic imaging ; Hepatomegaly ; chemically induced ; Humans ; Liver ; drug effects ; Lymphoma ; diagnostic imaging ; Male ; Middle Aged ; Positron-Emission Tomography ; Tuberculosis, Hepatic ; diagnosis ; Whole Body Imaging

OBJECTIVETo investigate the correlation between ¹⁸F-FDG uptake in positron emission tomography/computed tomography imaging and tumor-proliferating antigen Ki-67 expression in aggressive lymphoma.

METHODSData of ¹⁸F-FDG PET-CT imaging and immunohistochemical detection of Ki-67 expression of seventy-seven cases with initially diagnosed aggressive lymphoma were retrospectively analyzed. The intensity of ¹⁸F-FDG accumulation was determined by calculating the maximum standardized uptake value (SUVmax) and average standardized uptake value (SUVave). The average SUV at biopsy site (BxSUVave), SUVmax at biopsy site (BxSUVmax) and SUVmax at the highest tumor activity site of the body (BmSUVmax) were collected.

RESULTSThe BmSUVmax, BxSUVmax, and BxSUVave were 13.4 ± 6.8, 11.9 ± 6.8 and 7.3 ± 4.4, respectively,and Ki-67 was (61.2 ± 20.4)% in the 77 aggressive lymphomas. The BmSUVmax was significantly higher than the BxSUVmax or BxSUVave (P < 0.05). The BmSUVmax, BxSUVmax and BxSUVave were positively correlated with the Ki-67 expression in aggressive lymphoma (P < 0.05). A positive correlation was revealed between the BxSUVmax and BmSUVmax (P < 0.05), and between the BxSUVmax and BxSUVave (P < 0.05). No significant correlation was found between the BmSUVmax or BxSUVmax and the Ki-67 in DLBCL (P > 0.05). A positive correlation was observed between the BmSUVmax or BxSUVmax and the Ki-67 expression in NK/T cell lymphoma (P < 0.05).

CONCLUSIONThe increasing trend of ¹⁸F-FDG uptake is correlated with the Ki-67 expression in aggressive lymphoma. The results of this study suggest that the metabolic information obtained by using BmSUVmax may help to compensate the limited sampling of histological examination at the biopsy site. Significant correlation in NK/T cell lymphoma suggests that the metabolic information from positron emission tomography-computed tomography may offer a useful parameter in the prognosis and management of this disease.

Adult ; Aged ; Female ; Fluorodeoxyglucose F18 ; pharmacokinetics ; Humans ; Ki-67 Antigen ; metabolism ; Lymphoma, Extranodal NK-T-Cell ; diagnostic imaging ; metabolism ; Lymphoma, Follicular ; diagnostic imaging ; metabolism ; Lymphoma, Large B-Cell, Diffuse ; diagnostic imaging ; metabolism ; Lymphoma, T-Cell, Peripheral ; diagnostic imaging ; metabolism ; Male ; Middle Aged ; Positron-Emission Tomography ; Prognosis ; Retrospective Studies

OBJECTIVE: Suspicious incidental gastrointestinal FDG uptake during positron-emission tomography/computed tomography (PET/CT) examinations can be caused by different diseases, including malignancies. However, differentiation with PET alone is difficult. The aim of this study was to investigate the potential of PET alone, contrast-enhanced CT (ceCT), and low-dose CT (ldCT) in routine PET/CT protocols for differentiation of incidental gastrointestinal lesions. MATERIALS AND METHODS: Sixty patients with incidental gastrointestinal lesions who underwent a routine PET/CT protocol with ldCT and ceCT were retrospectively analysed. The PET lesions were evaluated regarding their FDG uptake patterns and the standard uptake value. The anatomical correlates in both CT protocols were compared in regard to the correct lesion classification with the reference standard endoscopy. RESULTS: Sixty-two lesions were found in 60 patients (17 malignant, 10 premalignant, 5 benign, 13 inflammatory, 17 physiological). The differentiation of the FDG uptake patterns did not enable reliable lesion classification. The positive predictive value for pathology was 0.81 for ceCT in PET/CT and 0.70 for ldCT. Malignancies were detected in 100% of the patients by ceCT vs. 29.4% by ldCT. The false negative rate of ceCT for all pathologies was 31.1%, vs. 68.9% for ldCT. False positive results (17/62) could not be excluded sufficiently by either CT protocol. CONCLUSION: PET/ceCT protocols provide additional benefit especially in detecting gastrointestinal malignancies as a cause of suspicious incidental gastrointestinal FDG uptake. However, since follow-up endoscopy cannot be forgone due to the considerable false negative rate even with ceCT, the addition of ceCT to a routine PET/ldCT protocol cannot be recommended for this purpose.
Adult ; Aged ; Aged, 80 and over ; Contrast Media/diagnostic use/pharmacokinetics ; Female ; Fluorodeoxyglucose F18/*diagnostic use/pharmacokinetics ; Follow-Up Studies ; Gastrointestinal Diseases/*diagnosis/metabolism ; Gastrointestinal Tract/*metabolism/radiography/radionuclide imaging ; Humans ; Male ; Middle Aged ; Positron-Emission Tomography/*methods ; Reproducibility of Results ; Retrospective Studies ; Tomography, X-Ray Computed/*methods

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

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