Jeong Won Lee

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.

18F-FDG PET/CT in mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic country: consideration of lymph node calcification and distribution pattern to improve specificity.

PurposeThe aim of the study was to assess the accuracy of 18F-fluorodeoxyglucose (FDG) PET/CT in mediastinal lymph node staging of patients with non-small-cell lung cancer (NSCLC) in a region with a high prevalence of granulomatous disease.MethodsBetween March 2004 and February 2006, all patients with NSCLC underwent FDG PET/CT and contrast-enhanced thoracic CT, and subsequent surgical resection. PET/CT and contrast-enhanced CT images of 182 patients (126 men and 56 women; mean age 60.7xa0years) with NSCLC were acquired. Mediastinal node staging was determined using the American Joint Committee on Cancer (AJCC) staging system. Surgical and histological findings served as the reference standard.ResultsA total of 182 patients with 778 mediastinal node stations were evaluated. Sensitivity and specificity of contrast-enhanced CT were 36% and 80% on a per-patient basis and 23% and 92% on a per-node station basis. Sensitivity and specificity of PET/CT were 81% and 73% on a per-patient basis and 75% and 85% on a per-node station basis. After lymph nodes with calcification and bilateral hilar distribution were considered benign, sensitivity and specificity of PET/CT were 75% and 89% on a per-patient basis and 66% and 96% on a per-node station basis.ConclusionThis prospective study suggests that FDG PET/CT can more accurately stage mediastinal lymph nodes than CT. Considering lymph node calcification and distribution pattern could improve specificity at the cost of a decrease in sensitivity.

Cancer screening using 18F-FDG PET/CT in Korean asymptomatic volunteers: a preliminary report

ObjectiveThis study was performed to evaluate the clinical value of 18F-fluorodeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) for cancer screening in Korean asymptomatic people.MethodsBetween February 2004 and December 2006, 1,587 asymptomatic individuals underwent FDG PET/CT as part of a cancer screening program with some other diagnostic tests at the healthcare center of our hospital. After excluding patients with a history of malignant tumor, 1,336 subjects were enrolled. All PET/CT images were visually analyzed. In subjects showing positive findings for PET/CT or other screening tests, further diagnostic tests and pathological confirmation were performed.ResultsOf the 1,336 subjects, malignant tumors were found in 16 participants (1.2%, thyroid cancer: 9, lung cancer: 2, stomach cancer: 2, and others: 4). There were 47 cases (3.6%) of positive PET/CT findings—11 cases were true positive (thyroid cancer: 8, lung cancer: 1, renal cancer: 1, and invasive thymoma), and 36 false positive, and five cases were false negative. The overall detection rate of PET/CT was 0.8%, and the sensitivity, specificity, positive-predictive value, and negative-predictive value of PET/CT were 68.8, 97.2, 23.4, and 99.6%, respectively.ConclusionsFluorodeoxyglucose positron-emission tomography has the potential to detect various kinds of malignant tumors in cancer screening test, and the overall detection rate of PET/CT was 0.8%. FDG PET/CT can be a useful cancer screening modality with the selection of high-risk group and appropriate combination with other screening modalities.

Prognostic Significance of 18F-FDG Uptake in Hepatocellular Carcinoma Treated with Transarterial Chemoembolization or Concurrent Chemoradiotherapy: A Multicenter Retrospective Cohort Study

This study aimed to assess the prognostic value of 18F-FDG uptake in hepatocellular carcinoma (HCC) patients who had transarterial chemoembolization (TACE) or concurrent intraarterial chemotherapy with external-beam radiotherapy (CCRT) and to compare the prognosis between patients treated with TACE and those with CCRT according to 18F-FDG uptake. Methods: Two hundred fourteen intermediate–to–advanced-stage HCC patients without extrahepatic metastasis who underwent staging 18F-FDG PET/CT before TACE (153 patients) or CCRT (61 patients) were recruited from 7 hospitals. Progression-free survival (PFS) and overall survival (OS) were compared using an optimal cutoff value for tumor-to-normal liver uptake ratio (TLR). Further, PFS and OS were compared according to treatment modalities (TACE vs. CCRT) using the same TLR cutoff value. Results: On multivariate analysis, age and TLR were independent prognostic factors for PFS (P < 0.050). For OS, Child–Pugh classification and TLR were independent prognostic factors (P < 0.050). When the TLR was greater than 2.0, patients treated with CCRT showed significantly better PFS and OS than those treated with TACE after adjusting for tumor size and number (P = 0.014, for all). In contrast, there was no significant difference in PFS and OS between patients treated with TACE or CCRT when the TLR was 2.0 or less. Conclusion: 18F-FDG uptake was an independent prognostic factor for PFS and OS in HCC patients treated with TACE or CCRT. Especially, in HCCs with high 18F-FDG uptake, patients treated with CCRT showed better survival than those treated with TACE. 18F-FDG PET/CT may help determine the treatment modality for intermediate–to–advanced-stage HCCs.

Prognostic value of pretreatment FDG PET in pediatric neuroblastoma

PURPOSEnThis study aimed to evaluate the prognostic value of pretreatment (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in pediatric neuroblastoma patients.nnnMETHODSnThe study included 50 pediatric neuroblastoma patients who underwent diagnostic work-up FDG PET before any treatment. The maximum standardized uptake value (SUV(max)) of the primary tumor lesion (P(max)), the SUV(max) of all the tumor lesions, including the primary tumor lesion and metastatic lesions (T(max)), and the uptake ratio of T(max) to mean SUV of normal liver tissue (T(max)/L(mean)) were calculated and tested as prognostic factors.nnnRESULTSnOf the 50 patients, 15 (30.0%) experienced disease progression and 21 (42.0%) died during the follow-up period. On univariate analysis, the histopathology, tumor stage, bone marrow involvement, serum levels of lactate dehydrogenase (LDH), neuron-specific enolase, and ferritin, primary tumor size, P(max), T(max), and T(max)/L(mean) were significant prognostic factors for disease progression-free survival (PFS), whereas the tumor stage, serum level of LDH, T(max), and T(max)/L(mean) were determined to be significant for predicting overall survival (OS). On multivariate analysis, the histopathology and serum level of LDH were independent prognostic factors for PFS, and only the T(max)/L(mean) was an independent prognostic factor for OS. The 2-year PFS and OS rates were over 80.0% in patients with low FDG uptake, meanwhile, patients with high FDG uptake showed the 2-year PFS of less than 30.0% and OS of less than 55.0%.nnnCONCLUSIONnFDG PET was an independent prognostic factor for OS in neuroblastoma patients. FDG PET can provide effective information on the prognosis for neuroblastoma patients.

The predictive value of metabolic tumor volume on FDG PET/CT for transarterial chemoembolization and transarterial chemotherapy infusion in hepatocellular carcinoma patients without extrahepatic metastasis

ObjectiveThe aim of this study was to evaluate the prognostic value of metabolic tumor volume (MTV) on pre-treatment F-18 fluorodeoxyglucose (FDG) PET/CT in patients with hepatocellular carcinoma (HCC).MethodsA total of 59 HCC patients who underwent FDG PET/CT before transarterial chemoembolization (TACE) or transarterial chemotherapy infusion (TACI) were retrospectively enrolled. The region of interest was drawn in the HCC and normal liver tissue. MTV2SD, defined as the sum of the voxels with higher standardized uptake values (SUV) than the SUV of the 97.5th percentile of voxels of the normal liver for each patient, was calculated using an intensity–volume histogram (IVH). The ratio of the maximum SUV of the tumor to the mean SUV of normal liver (Tmax/Lmean) was also calculated. The prognostic significance of MTV2SD and Tmax/Lmean for progression-free survival (PFS) and overall survival (OS) was evaluated along with other clinical factors.ResultsThe tumor number, Tmax/Lmean, and MTV2SD were significant prognostic factors affecting PFS (pxa0<xa00.05), whereas tumor number, serum alpha-fetoprotein level, tumor stage, portal vein thrombosis, Tmax/Lmean, and MTV2SD were significant prognostic factors for OS (pxa0<xa00.05). In multivariate analysis, the tumor number and MTV2SD were independent prognostic factors for PFS (pxa0<xa00.05), whereas the independent prognostic factors for OS were tumor number, tumor stage, and MTV2SD (pxa0<xa00.05). The mean PFS and OS in patients with low MTV2SD (15.4 and 63.1xa0months, respectively) were significantly longer than those in patients with high MTV2SD (6.0 and 15.2xa0months, respectively; pxa0=xa00.005 and pxa0<xa00.0001, respectively).ConclusionsMetabolic tumor volume was an independent prognostic factor for PFS and OS in patients with HCC. Therefore, FDG PET/CT can provide valuable prognostic information for HCC patients who undergo TACE or TACI.

Prognostic Value of Volumetric Parameters on Staging and Posttreatment FDG PET/CT in Patients With Stage IV Non-Small Cell Lung Cancer.

Purpose This study aimed to evaluate the prognostic value of metabolic tumor burden as measured with metabolic tumor volume (MTV) and total lesion glycolysis (TLG), as well as SUVmax on initial staging and posttreatment 18F-FDG PET/CT in patients with stage IV non–small cell lung cancer (NSCLC). Methods Sixty-three NSCLC patients with stage IV who underwent staging and posttreatment FDG PET/CT after completion of the first-line chemotherapy were retrospectively enrolled. SUVmax, MTV, and TLG of primary cancer and all metastatic lesions (lymph node and distant metastases) on both PET/CT images were measured and their association with progression-free survival (PFS) and overall survival (OS) analyzed. Results Median PFS and OS in the patient population were 5.9 and 23.1 months, respectively. Among the PET/CT parameters, MTV and TLG of primary cancer lesions on initial PET/CT and MTV and TLG of metastatic lesions on posttreatment PET/CT were independent prognostic factors for both PFS and OS (P < 0.05). The median OS in patients who showed low values of those PET/CT parameters was more than 26.0 months, whereas patients with high values of those parameters had a median OS of less than 15.0 months. Conclusions Metabolic tumor burdens of primary cancer lesions on staging PET/CT and metastatic lesions on posttreatment PET/CT were independent prognostic factors in patients with stage IV NSCLC. Volume-based PET parameters could further stratify the prognosis of stage IV NSCLC patients.

Unexpected Small Bowel Intussusception Caused by Lung Cancer Metastasis on 18F-Fluorodeoxyglucose PET-CT

Small bowel metastasis from primary lung cancer is rare. We report the case of an unexpected small bowel intussusception caused by primary non-small cell lung cancer, which was primarily detected by 18 fluorine ((18)F)-fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT). A 74-year-old man underwent FDG PET-CT for the diagnostic workup of a lung mass in the left upper lobe. On FDG PET-CT images, intense FDG uptake was observed in the primary lung mass lesion and mediastinal paraesophageal area. Furthermore, unexpected intense FDG uptake was observed in the jejunum along with the findings of intussusception in the proximal jejunum on the CT images of the PET-CT, which suggested jejunojejunal intussusception caused by lung cancer metastasis. The patient underwent an immediate operation, and the histopathologic results of the resected bowel indicated metastatic lesion from adenocarcinoma of the lung.

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.

Efficient ECH-assisted plasma start-up using trapped particle configuration in the versatile experiment spherical torus

An efficient and robust ECH (electron cyclotron heating)-assisted plasma start-up scheme with a low loop voltage and low volt-second consumption utilizing the trapped particle configuration (TPC) has been developed in the versatile experiment spherical torus (VEST). The TPC is a mirror-like magnetic field configuration providing a vertical magnetic field in the same direction as the equilibrium field. It significantly enhances ECH pre-ionization with enhanced particle confinement due to its mirror effect, and intrinsically provides an equilibrium field with a stable decay index enabling prompt plasma current initiation. Consequently, the formation of TPC before the onset of the loop voltage allows the plasma to start up with a lower loop voltage and lower volt-second consumption as well as a wider operation range in terms of ECH pre-ionization power and H2 filling pressure. The TPC can improve the widely-used field null configuration significantly for more efficient start-up when ECH pre-ionization is used. This can then be utilized in superconducting tokamaks requiring a low loop voltage start-up, such as ITER, or in spherical tori with limited volt-seconds. The TPC can be particularly useful in superconducting tokamaks with a limited current slew-rate of superconducting PF coils, as it can save volt-second consumption before plasma current initiation by providing prompt initiation with an intrinsic stable equilibrium field.