Hyun Woo Kwon

Prediction of Tumor Recurrence by 18F-FDG PET in Liver Transplantation for Hepatocellular Carcinoma

Although several prognostic factors are used to predict recurrence and to select adequate candidates for liver transplantation for hepatocellular carcinoma (HCC), these prognostic factors have some clinical limitations. The purpose of this study was to evaluate 18F-FDG PET as a prognostic factor and to optimize its ability to predict tumor recurrence in liver transplantation for HCC. Methods: The study included a total of 59 HCC patients (45 men and 15 women; mean age ± SD, 56 ± 8 y) who underwent 18F-FDG PET and subsequent orthotopic liver transplantation. All patients were followed up for more than 1 y (mean, 29 ± 17 mo), and recurrence of tumor was monitored. Three PET parameters—maximal standardized uptake value (SUVmax), ratio of tumor SUVmax to normal-liver SUVmax (TSUVmax/LSUVmax), and ratio of tumor SUVmax to normal-liver mean SUV (TSUVmax/LSUVmean)—were tested as prognostic factors and compared with conventional prognostic factors. Results: Among the 3 parameters tested, TSUVmax/LSUVmax was the most significant in the prediction of tumor recurrence, with a cutoff value of 1.15. In a multivariate analysis of various prognostic factors including TSUVmax/LSUVmax, serum α-fetoprotein, T stage, size of tumor, and vascular invasion of tumor, TSUVmax/LSUVmax was the most significant, and only vascular invasion of tumor had additional significance. According to TSUVmax/LSUVmax, the 1-y recurrence-free survival rate above the cutoff was markedly different from the rate below the cutoff (97% vs. 57%, P < 0.001). Conclusion: In this study, 18F-FDG PET was an independent and significant predictor of tumor recurrence. In liver transplantation for HCC, 18F-FDG PET can provide effective information on the prognosis for tumor recurrence and the selection of adequate candidates for liver transplantation.

Preoperative [18F]FDG PET/CT predicts recurrence in patients with epithelial ovarian cancer

Objective To determine whether [18F]FDG uptake on PET/CT imaging before surgical staging has prognostic significance in patients with epithelial ovarian cancer (EOC). Methods Patients with EOC were imaged with integrated PET/CT before surgical staging. Hypermetabolic lesions were measured as the standardized uptake value (SUV) in primary and metastatic tumors. SUV distribution was divided into two regions at the level of umbilicus, and the impact of the ratio between above and below umbilicus (SUVlocation ratio) on progression-free survival (PFS) was examined using Cox proportional hazards regression. Results Between January 2004 and December 2009, 55 patients with EOC underwent preoperative PET/CT. The median duration of PFS was 11 months (range, 3 to 43 months), and twenty (36.4%) patients experienced recurrence. In univariate analysis, high SUVlocation ratio (p=0.002; hazard ratio [HR], 1.974; 95% confidence interval [CI], 1.286 to 3.031) was significantly associated with recurrence. Malignant mixed mullerian tumor compared with endometrioid histology was also shown to have significance. In multivariate analysis, high SUVlocation ratio (p=0.005; HR, 2.418; 95% CI, 1.1315 to 4.447) and histology (serous, mucinous, and malignant mixed mullerian tumor compared with endometrioid type) were significantly associated with recurrence. Patients were categorized into two groups according to SUVlocation ratio (<0.3934 vs. ≥0.3934), and the Kaplan-Meier survival graph showed a significant difference in PFS between the groups (p=0.0021; HR, 9.47, log-rank test). Conclusion SUV distribution showed a significant association with recurrence in patients with EOC, and may be a useful predictor of recurrence.

Association between coffee intake and gastroesophageal reflux disease: a meta-analysis

Gastroesophageal reflux disease (GERD) is one of the most common diseases affecting patients worldwide, but its risk factors and causes are not clearly known. The aim of this study was to investigate the effect of coffee intake on GERD by a meta-analysis. We searched online published research databases such as PubMed, EMBASE, and Cochrane Library for studies that were published up to December 2012. These publications were reviewed by two independent authors, and studies that fulfilled the criteria were selected. Whenever there was a disagreement between the authors, a consensus was reached by discussion. Fifteen case-control studies were included in the final analysis. A meta-analysis showed that there was no significant association between coffee intake and GERD. The odds ratio was 1.06 (95% confidence interval, 0.94-1.19). In subgroup analyses in which the groups were subdivided based on the definition of GERD (diagnosed by endoscopy or by symptoms alone), only the endoscopy group showed a significantly higher odds ratio. In subgroup analyses in which the groups were subdivided based on the amount of coffee intake, quality of study, and assessment of exposure, there was no significant association between coffee intake and GERD.

Incidental finding of an 11C-acetate PET-positive multiple myeloma

Multiple myeloma is a malignancy of plasma cells. The 18F-FDG PET findings of multiple myeloma have been reported previously. However, the 11C-acetate PET findings have not been clarified. Here, we report a case of multiple myeloma detected with 11C-acetate PET in a 51-year-old male patient with known hepatocellular carcinoma. The patient was admitted for management of a pathologic fracture of the right tibia. Imaging workup including X-ray, magnetic resonance image, bone scintigraphy; 18F-FDG led to a suspicion of metastatic bony lesions. Further, these lesions showed increased uptake on 11C-acetate PET. Wide excision of the right tibia was performed, and histopathological examination of the lesion confirmed multiple myeloma. This case illustrates the characteristic 11C-acetate PET findings of multiple myeloma.

Diagnostic Performance of Three-Phase Bone Scan for Complex Regional Pain Syndrome Type 1 with Optimally Modified Image Criteria

PurposeAlthough the three-phase bone scan (TBPS) is one of the widely used imaging studies for diagnosing complex regional pain syndrome type I (CRPS-1), there is some controversy regarding the TPBS image criteria for CRPS-1. In this study, we modified the image criteria using image pattern and quantitative analysis in the patients diagnosed using the most recent consensus clinical diagnostic criteria.Materials and MethodsThe study included 140 patients with suspected CRPS-1 (CRPS-1, n = 79; non-CRPS, n = 61; mean age 39 ± 15 years) who underwent TPBS. The clinical diagnostic criteria for CRPS-1 revised by the Budapest consensus group were used for confirmative diagnosis. Patients were classified according to flow/pool and delayed uptake (DU) image patterns, and the time interval between the initiating event and TPBS (TIevent-scan). Quantitative analysis for lesion-to-contralateral ratio (LCR) was performed. Modified TPBS image criteria were created and evaluated for optimal diagnostic performance.ResultsBoth increased and decreased periarticular DU were significant image findings for CRPS-1 (CRPS-1 positive-rate = 73% in the increased DU group, 75% in the decreased DU group). The TIevent-scan did not differ significantly between the different image pattern groups. Quantitative analysis revealed an LCR of 1.43 was the optimal cutoff value for CRPS-1 and diagnostic performance was significantly improved in the increased DU group (area under the curve = 0.732). Given the modified image criteria, the sensitivity and specificity of TPBS for diagnosing CRPS-1 were 80% and 72%, respectively.ConclusionsOptimally modified TPBS image criteria for CRPS-1 were suggested using image pattern and quantitative analysis. With the criteria, TPBS is an effective imaging study for CRPS-1 even with the most recent consensus clinical diagnostic criteria.

[11C]-(R)-PK11195 positron emission tomography in patients with complex regional pain syndrome: A pilot study.

Abstract Complex regional pain syndrome (CRPS) is characterized by severe and chronic pain, but the pathophysiology of this disease are not clearly understood. The primary aim of our case–control study was to explore neuroinflammation in patients with CRPS using positron emission tomography (PET), with an 18-kDa translocator protein specific radioligand [11C]-(R)-PK11195. [11C]-(R)-PK11195 PET scans were acquired for 11 patients with CRPS (30–55 years) and 12 control subjects (30–52 years). Parametric image of distribution volume ratio (DVR) for each participant was generated by applying a relative equilibrium-based graphical analysis. The DVR of [11C]-(R)-PK11195 in the caudate nucleus (t(21) = −3.209, P = 0.004), putamen (t(21) = −2.492, P = 0.022), nucleus accumbens (t(21) = −2.218, P = 0.040), and thalamus (t(21) = −2.395, P = 0.026) were significantly higher in CRPS patients than in healthy controls. Those of globus pallidus (t(21) = −2.045, P = 0.054) tended to be higher in CRPS patients than in healthy controls. In patients with CRPS, there was a positive correlation between the DVR of [11C]-(R)-PK11195 in the caudate nucleus and the pain score, the visual analog scale (r = 0.661, P = 0.026, R2 = 0.408) and affective subscales of McGill Pain Questionnaire (r = 0.604, P = 0.049, R2 = 0.364). We demonstrated that neuroinflammation of CRPS patients in basal ganglia. Our results suggest that microglial pathology can be an important pathophysiology of CRPS. Association between the level of caudate nucleus and pain severity indicated that neuroinflammation in this region might play a key role. These results may be essential for developing effective medical treatments.

Association between volume and glucose metabolism of abdominal adipose tissue in healthy population

OBJECTIVE We investigated the association of adipose tissue volume and metabolic activity with cardiometabolic risk factors. METHODS 232 healthy subjects (43.23±4.09y) having 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) results were included. Clinical information, anthropometry and laboratory results were obtained. Volume and metabolic activity of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) was obtained from FDG PET/CT. Metabolic activity was presented as mean standardised uptake value (SUV). Adipose tissue parameters were compared with clinical and biochemical factors. Independent factors affecting adipose tissue volume were assessed. RESULTS Both SAT and VAT volume showed strong positive correlation with most of cardiometabolic risk factors. Among them, lipid profiles, insulin and C-reactive protein (CRP) had more significant relationship with SUV of SAT than that of VAT. On the contrary, glucose, glycated hemoglobin, and degree of fatty liver showed more significant correlation with SUV of VAT. BMI, age, sex and CRP were independent predictors of SAT volume. BMI, age, triglyceride, CRP and fatty liver were independent variables predicting VAT volume. Adding SUV of adipose tissue improved the model performance. CONCLUSION This study demonstrated that metabolic activities of SAT and VAT were differently correlated with risk factors, suggesting different biologic mechanism for obesity.

Diagnostic performance of 18F-FDG-labeled white blood cell PET/CT for cyst infection in patients with autosomal dominant polycystic kidney disease: a prospective study.

ObjectivesCyst infection (CI) is a common problem in patients with autosomal dominant polycystic kidney disease (ADPKD) and the accurate detection of infected cysts is very important. We evaluated the diagnostic performance of fluorine-18 fluorodeoxyglucose-labeled white blood cell (WBC) PET/computed tomography (CT) for detection of infected cysts in patients with ADPKD. Patients and methodsSeventeen patients with ADPKD (male : female, 6 : 11; age, 53±9 years) and suspected CI were enrolled in this prospective study. Patients were classified as having definite/probable/possible CI. All patients underwent WBC PET/CT within 2 days of starting antibiotic treatment. The degree of WBC accumulation was evaluated qualitatively by nuclear medicine physicians. The diagnostic performance of WBC PET/CT was evaluated by sensitivity, specificity, positive predictive values, and negative predictive values. These values were compared with those generated from CT scans and MRI. ResultsSeven patients were classified as having renal CI (definite 6, probable 1). In this group, WBC PET/CT showed six positive findings and one equivocal finding. Seven patients were diagnosed with possible infection. In this group, WBC PET/CT showed six negative findings and one indeterminate finding. The diagnostic performance of WBC PET/CT showed advantages over CT or MRI scans (sensitivity 85.7%, specificity 87.5%, positive predictive value 85.7%, negative predictive value 87.5%). ConclusionThis prospective study shows that WBC PET/CT can provide an accurate diagnosis of CI in patients with ADPKD.

Prospective evaluation of changes in tumor size and tumor metabolism in advanced gastric cancer undergoing chemotherapy: association and clinical implication

A change in tumor size is a well-validated and commonly used value for evaluating response to chemotherapy in cancer. Metabolic changes induced by chemotherapy are related to prognosis in several tumor types. However, the clinical implication of metabolic changes in patients with advanced gastric cancer (AGC) undergoing chemotherapy remains unclear. We aimed to evaluate response of tumor size and metabolism in AGC during chemotherapy and to reveal the relationship between them in view of their impact on patient survival. Methods: We prospectively enrolled patients with AGC before the initiation of first-line palliative chemotherapy. Using baseline and follow-up contrast-enhanced CT and 18F-FDG PET, we assessed the tumor diameter, SUVmax, and total lesion glycolysis in each lesion and their changes during chemotherapy at the same time. We included all lesions with the maximal longest diameters over 1 cm on CT, and each lesion was evaluated by matched 18F-FDG PET. We analyzed the association between changes in tumor metabolism and tumor size and performed outcome analysis on overall survival (OS) and progression-free survival (PFS). Results: Seventy-four patients were enrolled, and the number of all lesions included in this study was 620. Compared with adenocarcinomas, poorly cohesive carcinomas demonstrated lower SUVmax irrespective of tumor size (P < 0.001). Human epidermal growth factor receptor 2 (HER2)–positive tumors showed higher SUVmax than HER2-negative tumors (P = 0.002). The changes in SUVmax due to chemotherapy had a linear correlation with the changes in tumor size of each lesion, and a 30% tumor size reduction was associated with a 50% SUVmax reduction (P < 0.001). Total lesion glycolysis changes also correlated with tumor size changes (P < 0.001). Better OS and PFS were obtained in patients with both tumor size and SUVmax reduction than in patients with either size or SUVmax reduction only (OS, P = 0.003; PFS, P = 0.038). Conclusion: Changes in tumor metabolism induced by chemotherapy correlated with changes in tumor size in AGC. Considering both changes in metabolism and size could help predict a more accurate prognosis for AGC patients undergoing chemotherapy.Background: A change in tumor size is well-validated and commonly used value for evaluating response to chemotherapy in cancer. Metabolic changes induced by chemotherapy are related to prognosis in several tumor types. However, the clinical implication of metabolic changes in patients with advanced gastric cancer (AGC) undergoing chemotherapy remains unclear. We aimed to evaluate response of tumor size and metabolism in AGC during chemotherapy and to reveal the relationship between them in view of their impact on patient survival. Methods: We prospectively enrolled patients with AGC before the initiation of first-line palliative chemotherapy. Using baseline and follow-up contrast-enhanced computed tomography (CT) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), we assessed the tumor diameter, maximum standardized uptake value (SUVmax), and total lesion glycolysis (TLG) in each lesion, and their changes during chemotherapy at the same time. We included all lesions with the maximal longest diameters over 1 cm on CT, and each lesion was evaluated by matched 18F-FDG PET. We analyzed the association between changes in tumor metabolism and tumor size, and performed outcome analysis on overall survival (OS) and progression-free survival (PFS). Results: Seventy-four patients were enrolled, and the number of all lesions included in this study was 620. Compared to adenocarcinomas, poorly cohesive carcinomas demonstrated lower SUVmax irrespective of tumor size (p<0.001). Human epidermal growth factor receptor 2 (HER2)-positive tumors showed higher SUVmax than HER2-negative tumors (P = 0.002). Changes in SUVmax due to chemotherapy had a linear correlation with changes in tumor size of each lesion, and a 30% tumor size reduction was associated with a 50% SUVmax reduction (p<0.001). TLG changes also correlated with tumor size changes (p<0.001). Better OS and PFS were obtained in patients with both tumor size and SUVmax reduction than in patients with either size or SUVmax reduction only (OS, P = 0.003; PFS, P = 0.038). Conclusion: Changes in tumor metabolism induced by chemotherapy correlated with changes in tumor size in AGC. Considering both changes in metabolism and size could help predict a more accurate prognosis for AGC patients undergoing chemotherapy.

Use of granulocyte colony-stimulating factor for fluorine-18-fluorodeoxyglucose labeling in human leukocytes.

ObjectiveInsufficient labeling efficiency and poor retention of radioactivity are the considerable shortcomings of fluorine-18-fluorodeoxyglucose (18F-FDG) labeling in human leukocytes. This study was conducted toevaluate the feasibility of using granulocyte colony-stimulating factor (G-CSF) to improve 18F-FDG labeling in human leukocytes. MethodsLeukocyte separation was performed using methods reported earlier. Separated leukocytes were preincubated with G-CSF or insulin at 37°C for 1 h. Afterpreincubation, labeling was performed with 18F-FDG (37–74 MBq) at 37°C for 30 min. Retained radioactivity was assessed at 1–4 h after labeling by the same method described in earlier reports. The viability of labeled leukocytes was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. ResultsLabeling efficiency of leukocytes preincubated withG-CSF, G-CSF with insulin, insulin, and control leukocytes was 52.1±8.9%, 49.9±10.5%, 40.3±7.7%, and 40.3±6.0%, respectively. G-CSF significantly increased the labeling efficiency compared with insulin (P=0.005) and control (P=0.004). In leukocytes preincubated with G-CSF, 77.0±1.2%, and 59.0±1.8% of radioactivity was retained at 1 and 3 h after labeling. There was no significant difference in retained radioactivity compared with that of leukocytes with different treatment at all time points. Furthermore, no significant difference in viabilities among leukocytes with different treatments was observed. ConclusionUse of G-CSF significantly improved 18F-FDG labeling efficiency without a significant effect on cell viability and retention of radioactivity.