18F-FDG PET/CT纳入肝细胞癌肝移植标准的趋势与价值

肝移植是治疗肝细胞癌(HCC)的有效方法,为降低HCC肝移植术后可能出现较高肿瘤复发率,有学者率先提出著名的Milan标准。但该标准过于严格,部分患者因其肿瘤病变较大或多个结节,虽其生物行为相对“温良”,也被排除在等待肝移植名单之外,随之世界各地出现了众多的“扩大Milan版标准”。HCC组织病理学的微血管侵犯(MVI)、肿瘤组织低分化与HCC肝移植术后较高复发率有显著相关性。复习总结了近年来国内外18氟-脱氧葡萄糖(18F-FDG)PET/CT在HCC肝移植方面的应用文献,发现18F-FDG在HCC病变部位不同的摄取程度,反映了肿瘤组织生物学行为特征即侵袭性的差异;18F-FDG高摄取与HCC病变的MVI、低分化呈正相关;18F-FDG还能敏感、准确地发现HCC肝外转移灶。认为术前18F-FDG PET/CT结果对HCC肝移植预后评估有巨大价值,将其结果纳入HCC肝移植标准是趋势所归,也有望统一“扩大Milan版标准”。建议新的肝移植标准可定义为,原则上遵循Milan标准;对超出Milan标准者,满足HCC病变18F-FDG PET/CT阴性,且排除大血管侵犯和肝外转移。     

Metabolic restaging of hepatocellular carcinoma using whole-body 18F-FDG PET/CT

AIM: To evaluate the ability of ¹⁸F-fluorodeoxyglucose positron emission and computed tomography (¹⁸F-FDG PET/CT) in restaging of hepatocellular carcinoma (HCC) after treatment.METHODS: We reviewed a database of the diagnostic performance of ¹⁸F-FDG PET/CT scan for patients with HCC following local or regional treatment. The database consisted of ¹⁸F-FDG PET/CT information of 21 male and 4 female (age range, 27-81 years; mean age, 51.6 years) patients who had received surgical resection and/or interventional treatments and then underwent ¹⁸F-FDG PET/CT scan. All patients had received enhanced CT scan of the liver two weeks before or after the ¹⁸F-FDG PET/CT scan. Intrahepatic recurrence and/or extrahepatic metastases were confirmed by histological analysis or clinical and imaging follow-up. The accuracy of ¹⁸F-FDG PET/CT study was determined by histopathological results or by clinical and imaging follow-up.RESULTS: ¹⁸F-FDG PET/CT was abnormal in 19 of the 25 (76.0%) patients. In detecting HCC recurrence, ¹⁸F-FDG PET/CT scored 17 true positives, 5 true negatives, 2 false positives and 1 false negative. The sensitivity, specificity and accuracy of ¹⁸F-FDG PET/CT in detecting HCC recurrence was 89.5%, 83.3% and 88%, respectively. ¹⁸F-FDG PET/CT had an impact on management of these patients by settling the problem of an unexplained increase in alpha-fetoprotein after treatment (14 patients), by monitoring response to the treatment and guiding additional regional therapy (12 patients), by identifying extrahepatic metastases (10 patients), by identifying tumor growth or thrombosis in the portal vein (6 patients), or by guiding surgical resection of extrahepatic metastases (2 patients).CONCLUSION: Our results suggest that whole body ¹⁸F-FDG PET/CT may be useful in the early evaluation of residual, intrahepatic recurrent or extrahepatic metastatic lesions and able to provide valuable information for the management of HCC recurrence.     

Diagnostic value for extrahepatic metastases of hepatocellular carcinoma in positron emission tomography/computed tomography scan

AIM: To evaluated the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan in diagnosis of hepatocellular carcinoma (HCC) and extrahepatic metastases.METHODS: A total of 138 patients with HCC who had both conventional imaging modalities and ¹⁸F-FDG PET/CT scan done between November 2006 and March 2011 were enrolled. Diagnostic value of each imaging modality for detection of extrahepatic metastases was evaluated. Clinical factors and tumor characteristics including PET imaging were analyzed as indicative factors for metastases by univariate and multivariate methods.RESULTS: The accuracy of chest CT was significantly superior compared with the accuracy of PET imaging for detecting lung metastases. The detection rate of metastatic pulmonary nodule ≥ 1 cm was 12/13 (92.3%), when < 1 cm was 2/10 (20%) in PET imaging. The accuracy of PET imaging was significantly superior compared with the accuracy of bone scan for detecting bone metastases. In multivariate analysis, increased tumor size (≥ 5 cm) (P = 0.042) and increased average standardized uptake value (SUV) uptake (P = 0.028) were predictive factors for extrahepatic metastases. Isometabolic HCC in PET imaging was inversely correlated in multivariate analysis (P = 0.035). According to the receiver operating characteristic curve, the optimal cutoff of average SUV to predict extrahepatic metastases was 3.4.CONCLUSION: ¹⁸F-FDG PET/CT scan is invaluable for detection of lung metastases larger than 1 cm and bone metastases. Primary HCC having larger than 5 cm and increased average SUV uptake more than 3.4 should be considered for extrahepatic metastases.     

Positron emission tomography scanning in the evaluation of hepatocellular carcinoma

BACKGROUND/AIMS: 18F-fluorodeoxyglucose uptake allows estimation of glucose metabolism by tumor cells using positron emission tomography (PET). We evaluated the role of PET imaging in the diagnosis of hepatocellular carcinoma. METHODS: PET images were collected after intravenous injection of 8-12 mCi of 18F-FDG in 20 patients with hepatocellular carcinoma (HCC). PET tumor activity level was assessed on a scale of 1 to 4 compared to normal liver tissue. The PET score was compared with abdominal computerized tomography (CT) scan results and between tumors of different grades and differentiation. RESULTS: Of the 20 patients studied, 11 (55%) had positive PET scans (PET score: 3 or 4) while nine (45%) were negative (PET score: 1 or 2). CT scan was positive in 18 patients (90%) and negative in two (10%). PET, however, revealed metastases in three patients that were not seen on CT. On pathological review, well-differentiated and low-grade tumors had lower PET scores. Comparison of the well-differentiated with the moderately- and poorly-differentiated tumors revealed a statistically significant difference. No statistical significance was observed between the moderately- and poorly-differentiated tumors or between different tumor grades and PET scores. CONCLUSIONS: The sensitivity of PET in diagnosis of HCC was 55% compared to 90% for CT scanning, although only PET detected some tumors (including distant metastases). Well-differentiated and low tumor grades had lower activity on PET and correspondingly lower PET scores. PET imaging may help assess tumor differentiation and may be useful in the diagnosis and staging and prognostication of HCC as an adjunct to CT.     

Fluorine-18 FDG imaging in hepatocellular carcinoma using positron coincidence detection and single photon emission computed tomography

BACKGROUND/AIMS: We prospectively evaluated whether fluorine-18 deoxyglucose (FDG) positron coincidence detection (PCD) or FDG single-photon emission computed tomography (SPECT) provides additional benefits to our conventional preoperative evaluation of lesion detection in patients suspected to have hepatocellular carcinoma (HCC). METHODS: Thirteen consecutive patients with a suspected HCC underwent conventional preoperative evaluation with ultrasonography (US), triple-phase helical computed tomography (CT), superparamagnetic iron oxides (SPIO) enhanced magnetic resonance imaging (MRI) and serum alpha-fetoprotein (AFP) level. All 13 patients had an FDG-PCD and SPECT. These results were evaluated to assess the value of FDG-PCD and SPECT in addition to US, SPIO-enhanced MRI and triple-phase helical CT. RESULTS: Ten of the 13 (77%) patients had at least one histologically confirmed HCC without extrahepatic abdominal spread. The tumors ranged in size from 1 to 8 cm and the serum AFP ranged from 3 to 30 000 microg/l. Of these 10 patients, two patients had an increased tumor F-FDG uptake (sensitivity of 20%); one patient with an AFP of 5 microg/l and a tumor size of maximum 4.5 cm and one patient with an AFP of 249 microg/l and a tumor size of maximum 2 cm. In three patients with a benign liver mass, FDG imaging with either PCD or SPECT was negative. There was no false positive finding. CONCLUSIONS: We found poor sensitivity of FDG-PCD and FDG-SPECT for the detection of HCC. There were no clear relations between AFP or tumor size and FDG uptake. Therefore, we conclude that FDG imaging with PCD or SPECT has no value in the preoperative work-up for HCC in patients with cirrhosis.     

Clinical application of 18F-fluorodeoxyglucose positron emission tomography for assessment and evaluation after therapy for malignant hepatic tumor

Positron emission tomography (PET) is widely available and its application with 2-[¹⁸F] fluoro-2-deoxy-d-glucose (¹⁸F-FDG) in oncology has become one of the standard imaging modalities in diagnosing and staging of tumors, and monitoring the therapeutic efficacy in hepatic malignancies. Recently, investigators have measured glucose utilization in liver tumors using ¹⁸F-FDG and positron emission tomography/computer tomography (PET/CT) in order to establish a diagnosis of tumors, assess their biologic characteristics and predict therapeutic effects on hepatic malignancies. The PET/CT with ¹⁸F-FDG may further enhance the hepatic malignancy diagnostic algorithm by accurate diagnosis, staging, restaging and evaluating its biological characteristics, which can benefit the patients suffering from primary and metastatic hepatic tumors such as hepatocellular carcinoma (HCC), cholangiocarcinoma (CCC), and metastatic liver tumor.     

Clinical applications of positron emission tomography in hepatic tumors

Fluorodeoxyglucose (FDG), which allows the evaluation of glucose metabolism, is widely used for tumor diagnosis using positron emission tomography (PET). FDG‐PET, which is used for the diagnosis of intrahepatic tumor lesions, shows high FDG accumulation in cholangiocellular carcinoma (CCC) and metastatic liver cancer. FDG‐PET shows high FDG accumulation in moderately or poorly differentiated hepatocellular carcinoma (HCC) and is useful for the diagnosis of extrahepatic HCC metastases and recurrences. However, because the imaging method frequently shows low FDG accumulation in well‐differentiated HCC, it is not very useful for that diagnosis. For the diagnosis of well‐differentiated HCC, F‐18 fluorocholine for evaluation of phospholipid metabolism and C‐11 acetate for evaluation of free fatty acid metabolism are useful in the diagnosis of that HCC. It is expected that the combination of these PET agents will enhance the diagnostic performance of FDG‐PET for HCC in the future. The problem of a lack of anatomical information is being resolved with the development of the use of PET in combination with computed tomography or magnetic resonance imaging. For the problem of low resolution, PET devices using semiconductors have been developed.     

<Superscript>18</Superscript>F-FDG PET in the detection of extrahepatic metastases from hepatocellular carcinoma

Background Positron emission tomography (PET) with ¹⁸F-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) is useful in detecting distant metastases from a variety of malignancies. However, its efficiency in detecting distant metastases from hepatocellular carcinoma (HCC) has not been investigated. The aim of this study was to evaluate the usefulness of ¹⁸F-FDG PET for the detection of extrahepatic metastases from HCC.Methods Nineteen patients suspected of having extrahepatic HCC underwent ¹⁸F-FDG PET. Fourteen patients (group A) had extrahepatic lesions, which were detected by conventional studies. In five patients (group B), conventional imaging showed no extra- or intrahepatic lesions, but the tumor marker levels were elevated. The PET results were compared with those obtained by histopathology or by clinical follow-up.Results The detection rate of ¹⁸F-FDG PET was 83% (24 of 29 metastases) for extrahepatic metastases larger than 1cm in greatest diameter and 13% (1 of 8 metastases) for lesions less than or equal to 1cm. PET revealed two bone metastases not depicted by bone scan, and detected the nodal metastasis and intestinal metastases inconclusive on computed tomography. Extrahepatic lesions were resected in 5 patients of group A on the basis of PET findings. In all patients of group B, PET results were true negative for extrahepatic metastases, but HCCs were detected in the liver within 4 months in 4 patients. These were no false-positive lesions in either group.Conclusions This preliminary study suggested that ¹⁸F-FDG PET could provide additional information and contribute to the management of HCC patients suspected of having extrahepatic metastases.     

Whole-body positron emission tomography using 18F-fluorodeoxyglucose compared to standard procedures for staging patients with Hodgkin's disease

BACKGROUND AND OBJECTIVES: Accurate staging is essential in order to determine appropriate treatment in Hodgkin's disease (HD). (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) offers the advantage of metabolic imaging that is largely independent of morphologic criteria. In the present study we evaluated the role of (18)F-FDG PET compared to routine procedures for the staging of patients with HD. DESIGN AND METHODS: Thirty-three patients with HD underwent standard staging procedures (clinical examination, laboratory screening, chest X-ray, computed tomography (CT) of the chest and abdomen and bilateral bone marrow biopsies) and a whole-body (18)F-FDG PET study. In clinical examination, an isolated lymph node > 1 cm or multiple lymph nodes > or = 1 cm in size were considered abnormal. Positive findings at both clinical examination or CT and (18)F-FDG PET were regarded as actual locations of disease. Negative findings with both methods were regarded as true negative (no involvement by HD). In cases of discrepancy, response to treatment and follow-up data were used to assess the overall accuracy of the patient's original evaluation. RESULTS: Completely concordant results in lymph node staging were observed in 20 patients. The two staging procedures indicated complementary information in 1 patient. Conventional staging indicated more pathologic lymph node areas in 6 patients (at least 1 false positive). (18)F-FDG PET showed more sites in 6 patients. The sensitivity of (18)F-FDG PET in detecting all known pathologic lymph nodes was 83% for peripheral lymph nodes, 91% for thoracic lymph nodes and 75% for abdominal and pelvic lymph nodes. Conventional staging procedures and (18)F-FDG PET indicated the same tumor stage in 26 patients. Based on (18)F-FDG PET, downstaging was suggested in 4 patients, including a biopsy-proven case. However in 1 of these cases this was incorrect. (18)F-FDG PET suggested upstaging in 3 patients. Based on conventional staging or (18)F-FDG PET the same treatment strategy was defined in 32 patients. In one patient (18)F-FDG PET downstaged disease extension (stage IIIA-->IIA) that would have suggested radiotherapy as a possible treatment option. INTERPRETATION AND CONCLUSIONS: (18)F-FDG PET provides an easy and efficient whole-body method for the evaluation of patients with HD. (18)F-FDG PET never missed tumor masses >1 cm. (18)F-FDG PET detected additional sites of disease not seen by conventional procedures and identified absence of disease in some sites suspected to be involved. However, in our patients this did not translate into changes in treatment strategy.     

18氟-脱氧葡萄糖正电子发射计算机断层摄影诊断胃恶性肿瘤

目的 探讨18氟-脱氧葡萄糖正电子发射计算机断层摄影(18F-FDG PET/CT)判断胃恶性肿瘤的临床应用价值.方法 2007年5至7月对24例临床疑诊胃恶性肿瘤患者进行18F-FDGPET/CT显像检查,根据初次胃镜及病理活检结果将患者分为确诊组(胃镜和病理检查均提示恶性,9例)和未确诊组(胃镜下疑似恶性但病理检查提示良性,15例).确诊组行PET/CT以助术前评估,之后行手术治疗.未确诊组行PET/CT以判断病灶良恶性,之后再行胃镜和活检病理复查,符合手术指征者行手术治疗,无手术指征者临床随访.最终诊断以手术病理或临床随访结果为准.分析18F-FDG PET/CT对胃恶性肿瘤的诊断灵敏度、特异度、阳性预测值、阴性预测值及对腺癌患者l临床分期的作用.结果 18F-FDG PET/CT检出胃恶性肿瘤患者16例(确诊组9例、未确诊组7例),胃部原发灶16处,腔外增殖性病灶1处侵犯肝脏、胰腺及腹膜,肝转移1处,肺转移1处,空回肠病变3处,累及淋巴结13处,均获术后病理确诊.另有1例未确诊组患者PET/CT疑似恶性病变,术后病理确诊为良性间质瘤;1例未确诊组腺癌患者PET/CT漏诊.PET/CT诊断胃恶性肿瘤的灵敏度为16/17,特异度为6/7,阳性预测值16/17,阴性预测值6/7.对Ⅲ、Ⅳ期胃癌患者的分期正确率为6/6.结论 18F-FDG PET/CT为简单易行、安全、无创及有前景的检查方法,对胃恶性肿瘤的检出及良恶性肿瘤的鉴别有较高的临床应用价值,可作为胃镜检查的补充手段和制定手术方案的辅助工具.     

Positron emission tomography/computer tomography in guidance of extrahepatic hepatocellular carcinoma metastasis management

Hepatocellular carcinoma （HCC） is one of the most common primary cancers in the world. Surgery is the gold standard for treatment of patients with HCC. Recurrence and metastasis are the major obstacles to further improve the prognosis of HCC. Most recurrences are intrahepatic. However, 30% of the recurrences are extrahepatic. The role of resection in intrahepatic recurrences is widely accepted. The role of resection in extrahepatic HCC recurrence and metastasis is not well established. 18F fluorodeoxyglucose （18F-FDG） positron emission tomography/computer tomography （PET/CT） is useful in detecting distant metastasis from a variety of malignancies and shows superior accuracy to conventional imaging modalities in identification of intrahepatic and extrahepatic metastasis. We present one patient with one new isolated omental lymph node metastasis, who had a history of huge HCC resected six years ago. The metastatic focus was identified with 18 F-FDG PET/CT and resected. The follow-up revealed good prognosis with a long-term survival potential after resection of the omental lymphatic metastasis.     

Positron emission tomography/computed tomography with (18)F-fluorodeoxyglucose identifies tumor growth or thrombosis in the portal vein with hepatocellular carcinoma

Patients suffering from hepatocellular carcinoma (HCC) with tumor thrombus in the portal vein generally have a poor prognosis. Portal vein tumor thrombus must be distinguished from portal vein blood thrombus, and this identification plays a very important role in management of HCC. Conventional imaging modalities have limitations in discrimination of portal vein tumor thrombus. The application of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) for discrimination between tumor extension and blood thrombus has been reported in few cases of HCC, while portal tumor thrombosis and portal vein clot identified by 18F-FDG PET/CT in HCC patients has not been reported so far. We present two HCC cases, one with portal vein tumor thrombus and one thrombosis who were identified with 18F-FDG PET/CT. This report illustrates the complimentary value of combining the morphological and functional imaging in achieving a correct diagnosis in such clinical situations.     

Highly metabolic thrombus of the portal vein： ^18F fluorodeoxyglucose positron emission tomography/computer tomography demonstration and clinical significance in hepatocellular carcinoma

AIM： To assess the ability of ^18F-fluorodeoxyglucose positron emission tomography/computer tomography （^18F-FDG PET/CT） to differentiate between benign and malignant portal vein thrombosis in hepatocellular carcinoma （HCC） patients.
METHODS： Five consecutive patients who had HBV cirrhosis, biopsy-proven HCC, and thrombosis of the main portal vein and/or left/right portal vein on ultrasound （US）, computer tomography （CT） or magnetic resonance imaging （MRI） were studied with ^18F-FDG PET/CT. The presence or absence of a highly metabolic thrombus on ^18F-FDG PET/CT was considered diagnostic for malignant or benign portal vein thrombosis, respectively. All patients were followed-up monthly with US, CT or MRI. Shrinkage of the thrombus or recanalization of the vessels on US, CT or MRI during follow-up was considered to be definitive evidence of the benign nature of the thrombosis, whereas enlargement of the thrombus, disruption of the vessel wall, and parenchymal infiltration over follow-up were considered to be consistent with malignancy. ^18SF-FDG PET/CT, and US, CT or MRI results were compared.
RESULTS： Follow-up （1 to 10 mo） showed signs of malignant thrombosis in 4 of the 5 patients. US, CT or MRI produced a true-positive result for malignancy in 4 of the patients, and a false-positive result in 1. ^18F-FDG PET/CT showed a highly metabolic thrombus in 4 of the 5 patients. ^18F-FDG PET/CT achieved a true-positive result in all 4 of these patients, and a true-negative result in the other patient. No false-positive result was observed using ^18F-FDG PET/CT.
CONCLUSION： ^18F-FDG PET/CT may be helpful in discriminating between benign and malignant portal vein thrombi. Patients may benefit from ^18F-FDG PET/CT when portal vein thrombi can not be diagnosed exactly by US, CT or MRI.     

Fluorine‐18 FDG imaging in hepatocellular carcinoma using positron coincidence detection and single photon emission computed tomography

Abstract: Background/aims: We prospectively evaluated whether fluorine‐18 deoxyglucose (FDG) positron coincidence detection (PCD) or FDG single‐photon emission computed tomography (SPECT) provides additional benefits to our conventional preoperative evaluation of lesion detection in patients suspected to have hepatocellular carcinoma (HCC). Methods: Thirteen consecutive patients with a suspected HCC underwent conventional preoperative evaluation with ultrasonography (US), triple‐phase helical computed tomography (CT), superparamagnetic iron oxides (SPIO) enhanced magnetic resonance imaging (MRI) and serum α‐fetoprotein (AFP) level. All 13 patients had an FDG‐PCD and SPECT. These results were evaluated to assess the value of FDG‐PCD and SPECT in addition to US, SPIO‐enhanced MRI and triple‐phase helical CT. Results: Ten of the 13 (77%) patients had at least one histologically confirmed HCC without extrahepatic abdominal spread. The tumors ranged in size from 1 to 8 cm and the serum AFP ranged from 3 to 30 000 µg/l. Of these 10 patients, two patients had an increased tumor F‐FDG uptake (sensitivity of 20%); one patient with an AFP of 5 µg/l and a tumor size of maximum 4.5 cm and one patient with an AFP of 249 µg/l and a tumor size of maximum 2 cm. In three patients with a benign liver mass, FDG imaging with either PCD or SPECT was negative. There was no false positive finding. Conclusions: We found poor sensitivity of FDG‐PCD and FDG‐SPECT for the detection of HCC. There were no clear relations between AFP or tumor size and FDG uptake. Therefore, we conclude that FDG imaging with PCD or SPECT has no value in the preoperative work‐up for HCC in patients with cirrhosis.     

Persistent tumor 18F-FDG uptake after a few cycles of polychemotherapy is predictive of treatment failure in non-Hodgkin's lymphoma

BACKGROUND AND OBJECTIVE: Early recognition of the ineffectiveness of chemotherapy could result in lower cumulative drug toxicity and tumor burden at the start of salvage therapy, which might improve clinical outcome. Therefore, we studied the value of (18)F-FDG PET for early evaluation of response in patients with non-Hodgkin's lymphoma (NHL). DESIGN AND METHODS: We studied 28 patients by (18)F-FDG PET after a median of 3 cycles of polychemotherapy. The presence or absence of abnormal (18)F-FDG uptake was correlated to clinical outcome (median follow-up: 17.5 months, range 4-47 months). RESULTS: Five of 28 patients still had increased (18)F-FDG uptake in one or more sites previously shown to be involved by lymphoma at baseline evaluation. Only one of these five patients entered complete remission (CR), whereas among the 23 patients with negative (18)F-FDG PET studies, two died of toxicity during chemotherapy and all the others entered clinical CR (p<0.00001). All five patients with and 7/21 patients without residual abnormal (18)F-FDG uptake relapsed or reprogressed (positive predictive value for relapse: 100%, negative predictive value: 67%). By Kaplan-Meier analysis, progression-free survival (PFS) at 1 and 2 years was respectively 20+/-18% and 0% for (18)F-FDG PET positive patients and 81+/-9% and 62+/-12% for (18)F-FDG PET negative patients (p=0.0001). Overall survival (OS) at 1 and 2 years was respectively 20+/-18% and 0% for (18)F-FDG PET positive and 87+/-7% and 68+/-11% for (18)F-FDG PET negative patients (p<0.0001). INTERPRETATION AND CONCLUSIONS: Persistent tumoral (18)F-FDG uptake after a few cycles of polychemotherapy is predictive of CR, PFS and OS in NHL. Further studies are warranted to determine whether (18)F-FDG PET has a predictive value independent from conventional prognostic factors. However, the sensitivity of qualitative (18)F-FDG PET imaging in identifying patients with a poor outcome was insufficient. Earlier evaluation after only one cycle of chemotherapy and quantitative analysis might increase the sensitivity of 18F-FDG PET is predicting treatment failure.     

Diagnostic usefulness of fluorine-18-alpha-methyltyrosine positron emission tomography in combination with 18F-fluorodeoxyglucose in sarcoidosis patients

OBJECTIVES: L-[3-(18)F]-alpha-methyltyrosine ((18)F-FMT) is an amino-acid tracer for positron emission tomography (PET) and is used for tumor detection because malignant tumor cells accumulate (18)F-FMT based on the increased expression of an amino-acid transporter. This study was conducted to investigate the usefulness of (18)F-FMT PET in combination with fluorine-18-fluorodeoxyglucose ((18)F-FDG) PET for the diagnosis of sarcoidosis in patients with suspected malignancy. SETTING: Twenty-four sarcoidosis patients with suspected malignancy underwent (18)F-FDG and (18)F-FMT PET. The study included 17 patients with extrapulmonary manifestation mimicking malignant disease (13 patients with systemic lymphadenopathy, 3 of them with concomitant hepatosplenic processes; 3 patients with hepatosplenic processes without concomitant lymphadenopathy; and 1 patient with multiple bone lesions), 3 patients with occurrence of bilateral hilar lymphadenopathy in cancer patients, and 4 patients with multiple nodules mimicking pulmonary metastasis. RESULTS: All patients showed increased uptake of (18)F-FDG and no increase in the accumulation of (18)F-FMT in their lymphadenopathy. Standardized uptake values (SUVs) of (18)F-FDG and (18)F-FMT were 5.01 +/- 2.15 and 0.77 +/- 0.24, respectively (mean +/- SD). All extranodal lesions such as liver, spleen, and bone were visually positive on (18)F-FDG PET and negative on (18)F-FMT PET. No neoplasm was confirmed in all patients. In a control group of patients with lung cancer, SUVs for (18)F-FDG and (18)F-FMT were 6.34 +/- 2.52 and 1.54 +/- 0.82, respectively. CONCLUSION: The uptake of (18)F-FDG was positive in the sarcoid lesions, and therefore (18)F-FDG PET could not differentiate sarcoidosis from malignant disease. Use of (18)F-FMT PET in combination with (18)F-FDG PET may be the effective method to distinguish sarcoidosis from malignancy.     

Value of fusing PET plus CT images in hepatocellular carcinoma and combined hepatocellular and cholangiocarcinoma patients with extrahepatic metastases: preliminary findings.

BACKGROUND/AIMS: This study aimed to evaluate the usefulness of (18)F-fluoro-2-deoxy-d-glucose positron emission tomography (PET) and PET plus computed tomography (CT) fusion images for the detection of extrahepatic metastases of hepatocellular carcinoma (HCC) and combined hepatocellular and cholangiocarcinoma (combined HCC/CC). METHODS: Twenty-one patients with HCC and combined HCC/CC were enrolled in the study from December 2004 to February 2005. In all patients, PET and CT of the chest to pelvis region were performed. The sensitivity of PET plus CT fusion images was compared with the sensitivity of PET, CT, and bone scintigraphy. RESULTS: In 14 patients, a total of 58 extrahepatic metastases were diagnosed. The detection rate of PET plus CT fusion images, PET, CT, and bone scintigraphy was 98.2% (57 of 58 metastases), 89.6% (52 of 58 metastases), 91.2% (52 of 57 metastases), and 68.7% (11 of 16 bone metastases), respectively. No extrahepatic metastases were detected in the other seven patients. The detection rate of PET was 10/18 (55.6%) for intrahepatic lesions of HCC and combined HCC/CC. CONCLUSIONS: The fusion of PET plus CT images is useful in detecting extrahepatic metastases in HCC and combined HCC/CC patients.     

Is combined 18F-fluorodeoxyglucose-positron emission tomography/computed tomography superior to positron emission tomography or computed tomography alone for diagnosis, staging and restaging of pancreatic lesions?

BACKGROUND AND STUDY AIMS: To evaluate whether combined 18F-FDG PET/CT has an additive value over 18F-FDG-PET or CT alone for diagnosis, staging and restaging of pancreatic lesions. PATIENTS AND METHODS: Forty-six consecutive patients (23 women, 23 men; median age 62.5 years) underwent FDG-PET/CT. Analysis of PET, CT and fused PET/CT images was performed by 2 readers. Patients were divided into 2 groups: diagnosis and staging of primary tumours (n=34) and restaging: screening for recurrent or progressive pancreatic cancer (n=12). Accuracy analysis was performed lesion-by-lesion and patient-by-patient. Results were correlated with histopathology or clinical follow-up. RESULTS: Ninety-five foci were identified on PET, 140 lesions on CT and 119 on PET/CT. Thirty-four lesions were defined as 'definitely pathologic' and localised in pancreas, liver, lung or bone by all 3 techniques with equal certainty. In 11 patients malignancy was ruled out with the highest certainty by PET/CT. All 3 modalities made 2 false positive diagnoses of malignancy and missed metastases or vascular ingrowth in 7 patients. The accuracy rate of PET/CT (91.2%) for diagnosis of primary pancreatic lesions is higher compared to CT (88.2%) and PET alone (82.3%). Also for locoregional staging PET/CT has a higher accuracy rate (85.3%) compared to CT (83.8%) and PET (79.4%). When used for restaging, sensitivity (90.0%) and accuracy rate (91.6%) were highest for PET and PET/CT. CT had a lower sensitivity (80.0%). CONCLUSIONS: Topographical assignment of 'spots' with high FDG uptake is superior with PET/CT compared to PET alone. Fused PET/CT has a slightly higher sensitivity and accuracy rate for diagnosis and locoregional staging of primary pancreatic lesions compared to CT alone. PET and PET/CT perform equally well in screening for recurrent or progressive pancreatic cancer, with high accuracy. Due to its unlimited access, lower radiation exposure and cost, multidetector row CT remains the imaging technique of choice for diagnosis, staging and screening for recurrent pancreatic cancer.     

18F-FDG PET/CT对显像阳性原发性肝癌125I粒子植入治疗疗效价值的评估

目的:探讨<'18>F-FDG PET/CT对显像阳性的原发性肝癌行<'125>I粒子植入治疗疗效价值的评价.方法:原发性肝癌患者39例,共55个肿瘤病灶,均于放射性<'125>I粒子植入治疗前确定病灶为<'18>F-FDG PET/CT显像阳性;放射性<'125>I粒子植入治疗后2 mo行PET/CT检查评价疗效,之...     

Cyclooxygenase-2 expression in hepatocellular carcinoma

BACKGROUND/AIMS: Cyclooxygenase-2 (Cox-2) is an isoform of cyclooxygenase, which is the key enzyme converting arachidonic acids to prostaglandins. It has been reported that Cox-2 is overexpressed in colon cancer, and that inhibition of this enzyme activity reduces colon cancer development in humans and animals. However, the significance of Cox-2 in human liver cancer is still unclear. To clarify significance of Cox-2 in liver cancer, we immunohistochemically examined expression of this enzyme in cancerous and non-cancerous tissues of hepatocellular carcinoma (HCC). METHODOLOGY: Twenty-nine patients with HCC were examined; 10 patients had well differentiated HCC, 10 had moderately differentiated HCC, and 9 had poorly differentiated HCC. RESULTS: Twenty-eight of 29 (97%) patients with HCC exhibited a positive staining. More intense staining of Cox-2 in cancer tissue rather than non-cancerous tissue was observed in 7 of 10 (70%) patients with well differentiated HCC, in 3 of 10 (30%) with moderately differentiated HCC, and in 3 of 9 (33%) with poorly differentiated HCC, respectively. Rate of higher expression of Cox-2 in cancer tissue rather than in non-cancerous tissue of well differentiated HCC was increased, compared to that of moderately and poorly differentiated HCC (7/10 vs. 6/19, p < 0.05). CONCLUSIONS: The results of the present study showed that Cox-2 is related to HCC whose histology is well differentiated.