Evaluation of Fluorodeoxyglucose Positron Emission Tomography in the Detection of Axillary Lymph Node Metastases in Patients With Early-Stage Breast Cancer

Background: The aim of this study was to assess the capacity of positron emission tomography (PET) with fluorodeoxyglucose (FDG) to determine axillary lymph node status in patients with breast cancer undergoing sentinel node (SN) biopsy.Methods: Thirty-two patients with breast cancer and clinically negative axillary nodes were recruited. All patients underwent FDG-PET before SN biopsy. After SN biopsy, all patients underwent complete axillary lymph node (ALN) dissection.Results: The SNs were identified in all patients. Fourteen patients (43.8%) had metastatic SNs (macrometastatic in seven, micrometastatic in six, and isolated tumor cells in one). The false-negative rate of SN biopsy was 6.6% (1 in 15). FDG-PET identified lymph node metastases in 3 of the 14 patients with positive SNs. The overall sensitivity, specificity, and positive and negative predictive values of FDG-PET in the diagnosis of axillary metastasis were 20%, 100%, 100%, and 58.6%, respectively. No false-positive findings were obtained with FDG-PET.Conclusions: This study demonstrates the limitations of FDG-PET in the detection of ALN metastases in patients with early breast cancer. In contrast, FDG-PET seems to be a specific method for staging the axilla in breast cancer. SN biopsy can be avoided in patients with positive FDG-PET, in whom complete ALN dissection should be the primary procedure.     

What is the best way to diagnose and stage malignant pleural mesothelioma?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was which diagnostic modality [computed tomography (CT), positron emission tomography (PET), combination PET/CT and magnetic resonance imaging (MRI)] provides the best diagnostic and staging information in patients with malignant pleural mesothelioma (MPM). Overall, 61 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results are tabulated. We conclude that fluorodeoxyglucose (FDG)-PET is superior to MRI and CT but inferior to PET-CT, in terms of diagnostic specificity, sensitivity and staging of MPM. Four studies reported outcomes using FDG-PET to diagnose MPM. PET diagnosed MPM with high sensitivity (92%) and specificity (87.9%). Mean standardised uptake value (SUV) was higher in malignant than benign disease (4.91 vs. 1.41, P<0.0001). Lymph node metastases were detected with higher accuracy (80% vs. 66.7%) compared to extrathoracic disease. Three studies assessed the utility of PET-CT to diagnose MPM. Mean SUV was higher in malignant than benign disease (6.5 vs. 0.8, P<0.001). MPM was diagnosed with high sensitivity (88.2%), specificity (92.9%) and accuracy (88.9%). PET-CT had low sensitivity for stage N2 (38%) and T4 (67%) disease. CT-guided needle biopsy definitively diagnosed MPM after just one biopsy (100% vs. 9%) much more often than a 'blind' approach. CT had a lower success rate (92% vs. 100%) than thoracoscopic pleural biopsy but was equivalent to MRI in terms of detection of lymph node metastases (P=0.85) and visceral pleural tumour (P=0.64). CT had a lower specificity for stage II (77% vs. 100%, P<0.01) and stage III (75% vs. 100%, P<0.01) disease compared to PET-CT. Overall, the high specificity and sensitivity rates seen with open pleural biopsy make it a superior diagnostic modality to CT, MRI or PET for diagnosing patients with MPM.     

Prognostic significance of preoperative [18-F] fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging in patients with resectable soft tissue sarcomas

OBJECTIVE: The objective of this study was to evaluate the prognostic significance of preoperative positron emission tomography (PET) using 2-fluoro-2-deoxy-D-glucose (FDG) by calculating the mean standardized uptake values (SUV) in patients with resectable soft tissue sarcomas (STS). SUMMARY AND BACKGROUND DATA: FDG-PET might be used as an adjunctive tool (in addition to biopsy and radiologic tomography) in the preoperative prognostic assessment of resectable STS. METHODS: A total of 74 adult patients with STS underwent preoperative FDG-PET imaging with calculation of the SUV. Clinicopathologic data and the SUV were analyzed for an association with the clinical outcome. The first and the third quartiles of the SUV distribution function were used as cutoff values (1.59 and 3.6). Survival was estimated by the Kaplan-Meier method. Univariate and multivariate analyses were performed using log-rank test and the Cox proportional hazards regression model. RESULTS: In 55 cases, STS were completely resected (follow up 40 months): 5-year recurrence-free survival rates in patients with SUV <1.59, 1.59 to <3.6, and > or =3.6 were 66%, 24%, and 11%, respectively (P = 0.0034). SUV was a predictor for overall survival (5-year rates: 84% [SUV <1.59], 45% [SUV 1.59 to <3.6], and 38% [SUV > or =3.6]; P = 0.057) and local tumor control (5-year rates: 93% [SUV <1.59], 43% [SUV 1.59 to <3.6], and 15% [SUV > or =3.6]; P = 0.0017). By multivariate analysis, SUV was found to be predictive for recurrence-free survival. The prognostic differences with respect to the SUV were associated with tumor grade (P = 0.002). CONCLUSION: The semiquantitative FDG uptake, as measured by the mean SUV on preoperative PET images in patients with resectable STS, is a useful prognostic parameter. SUV with cutoff values at the first and the third quartiles of the SUV distribution predicted overall survival, recurrence-free survival, and local tumor control. Therefore, FDG-PET can be used to improve the preoperative prognostic assessment in patients with resectable STS.     

Determinants of diagnostic performance of [F-18]fluorodeoxyglucose positron emission tomography for axillary staging in breast cancer

OBJECTIVE: To prospectively investigate determinants of the accuracy of staging axillary lymph nodes in breast cancer using [F-18]fluorodeoxyglucose positron emission tomography (FDG PET). METHODS: Patients with primary operable breast cancer underwent FDG PET of the chest followed by sentinel node biopsy (SNB, n = 47) and/or complete axillary lymph node dissection (ALND, n = 23). PET scans were independently interpreted by three observers in a blinded fashion with respect to the FDG avidity of the primary tumor and the axillary status. The results were compared to histopathological analyses of the axillary lymph nodes. Clinicians were blinded to the PET results. RESULTS: Axillary lymph node specimens and FDG PET scans were evaluated in 70 patients (59% cT1). Overall, 32 (46%) had lymph node metastases as established by SNB (18/47) or ALND (14/23), 20 of which were confined to a single node. The overall sensitivity of FDG PET was 25%, with a specificity of 97%. PET results were false-negative in all 18 positive SNBs and true-positive in 8/14 in the ALND group. The performance of FDG PET depended on the axillary tumor load and the FDG avidity of the primary tumor. Intense uptake in the primary tumor was found in only 57% of the patients, and this was independent of the size. There was excellent interobserver agreement of visual assessment of FDG uptake in primary tumor and axillary lymph nodes. CONCLUSIONS: The sensitivity of FDG PET to detect occult axillary metastases in operable breast cancer was low, and it was a function of axillary tumor load and FDG avidity of the primary tumor. Even though the clinical relevance of occult disease detected by SNB needs to be confirmed, it is suggested that FDG PET in these patients should be focused on exploiting its nearly perfect specificity and the potential prognostic relevance of variable FDG uptake.     

Evaluation of 18F-2-deoxy-2-fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose Positron Emission Tomography for Gastric Cancer

Positron emission tomography (PET) with ¹⁸F-2-deoxy-2-fluoro-d-glucose (FDG) has been investigated as a means of detecting certain primary tumors and their metastatic disease in recent years. The aim of this study was to compare the performance of FDG-PET and operative assessment with formal pathologic staging. Altogether, 85 patients had undergone surgical treatment for gastric cancer with curative intent, with FDG-PET preoperatively. The results using FDG-PET were compared with those using computed tomography (CT); they were also correlated with the pathologic findings. For quantitative analysis, the regional tumor uptake was measured by the standard uptake value (SUV) using a region of interest technique. Using FDG-PET, the primary tumor was visualized in 75.2% of patients. A comparison of the FDG uptake and the clinicopathologic findings showed that there was a significant association between FDG uptake and the depth of invasion, the size of the tumor, and lymph node metastasis. FDG-PET scans had less accuracy for diagnosing locoregional lymph nodes than CT because of a significant lack of sensitivity (23.3% vs. 65.0%). The survival rate for patients with high FDG uptake (SUV > 4) was significantly lower than that for those with low FDG uptake (SUV < 4) (p < 0.05). FDG-PET was successful in detecting the primary gastric cancer lesion but not for finding early-stage gastric cancers. Detection of nodal metastasis also was not possible by FDG-PET. However, FDG-PET appears to provide important additional information concerning the aggressiveness of the tumor and the prognosis in patients with gastric cancer.     

18氟脱氧葡萄糖-正电子发射体层显像在贲门癌定性诊断中的价值

目的　探讨18氟脱氧葡萄糖 (FDG) 正电子发射体层显像 (PET)检查在贲门癌定性诊断中的价值。方法　对 1998年 12月至 2 0 0 2年 4月我院收治的 2 7例全身FDG PET检查时贲门部有异常FDG高摄取区域患者的临床资料进行回顾性分析 ,PET结果采用目测法与半定量分析方法进行判断 ,同病理诊断以及随访结果对照。结果　 16例贲门癌患者显影与 11例非特异性显影均被目测法判断为恶性肿瘤 ;半定量分析中 16例贲门癌的最大与平均标准摄取值 (SUVmax与SUVmean)分别为 6 71± 2 75与 5 4 6± 2 31,11例胃底贲门非特异性显影的SUVmax与SUVmean分别为2 99± 0 6 7与 2 38± 0 5 1,贲门癌高于胃底贲门非特异性显影 (Z =- 4 171,Z =- 4 195 ,P均 <0 0 1)。结论　FDG PET检查目测法对于贲门癌肿瘤的定性价值有限 ,半定量分析方法区分良恶性的阈值有待于病例数的积累     

Fluorodeoxyglucose positron emission tomography with sentinel lymph node biopsy for evaluation of axillary involvement in breast cancer

BACKGROUND: This study analysed the value of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting axillary lymph node involvement in women with breast cancer. METHODS: In the first 150 women in this prospective study, axillary lymph node dissection (ALND) was performed regardless of the PET results. In a second group (125 women) FDG-PET was complemented with sentinel lymph node biopsy (SLNB) only in those who did not have pathological axillary uptake. RESULTS: The sensitivity and specificity of FDG-PET in detecting axillary involvement was 84.5 and 98.5 per cent respectively in the whole series of 275 patients, with two false-positive and 22 false-negative results. False-negative results were associated with some intrinsic tumour characteristics. In 21 women, PET revealed pathological uptake, suggesting involvement of the internal mammary lymph node chain. Whole-body PET identified a second synchronous tumour in five asymptomatic patients and haematogenous metastases in two patients. CONCLUSION: The high positive predictive value of PET (98.4 per cent) suggests that FDG uptake in the axilla could be an indication for full ALND without previous SLNB.     

18-Fluorodeoxyglucose-Positron Emission Tomography <Emphasis Type="Bold">in Inflammatory Breast Cancer</Emphasis>

Inflammatory breast cancer (IBC) is the most aggressive form of locally advanced breast cancer. It can be diagnosed based on a clinical or pathologic basis. We evaluated the usefulness of ¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scans for diagnosing and staging IBC. We retrospectively reviewed the medical records of seven consecutive patients with IBC who underwent FDG-PET scanning for the initial staging. Four patients had follow-up PET scans after chemotherapy. All seven patients presented with diffuse breast enlargement, redness, and peau dorange for 1 to 5 months duration. In addition, four patients had a palpable breast mass, and three had axillary lymph node enlargement. Mammography showed diffuse, increased parenchymal density and skin thickening in 85% and parenchymal distortion in 43%. There was no evidence of distant metastasis on computed tomography of the chest or abdomen. Pathologic examination of breast biopsy specimens showed infiltrating ductal carcinoma in six patients, and one had lobular carcinoma. All patients had prechemotherapy whole-body PET scans that showed diffuse FDG uptake in the breast with superimposed intense foci in the primary tumor. Furthermore, there was skin enhancement in 100%, axillary lymph node in 85%, and skeletal metastases in 14% of the patients, confirmed by bone scintigraphy. Postchemotherapy FDG-PET scans performed in four patients showed response in the primary tumor, axillary lymph nodes, and skeletal metastases. The FDG-PET scan is thus useful for displaying the pattern of FDG breast uptake that reflects the extent of the pathologic involvement in IBC (i.e., diffuse breast involvement and dermal lymphatic spread). It can also detect the presence of lymph node and skeletal metastases, demarcating the extent of the disease locally as well as distally.     

肺部良性结节性病变18F-脱氧葡萄糖正电子发射体层摄影术检查

目的探讨肺部良性结节性病变18F-脱氧葡萄糖(FDG)正电子发射体层摄影术(PET)检查的显像特点.方法回顾分析1998年10月-2004年7月间的47例肺部良性结节性病变患者的FDG-PET检查资料,PET结果采用目测法判读,半定量分析法测量显影病灶的最大与平均标准摄取值(SUVmax与SUVmean)、正常肺组织的标准摄取值(SUVlung).所有患者的病变均手术切除明确诊断,其中17例结核性干酪样坏死、17例钙化及纤维化结节、6例炎性假瘤、3例新型隐球菌性肉芽肿、2例硬化性血管瘤、2例错构瘤.结果 21例病变FDG-PET检查未显影,包括钙化及纤维化结节、错构瘤以及硬化性血管瘤.26例病变或浓或淡显影,半定量分析病变组织的FDG摄取高于相应的正常肺组织(P＜0.001),SUVmax、SUVmean和SUVlung分别为3.04±1.65,2.48±1.35和0.40±0.07,其中9例(35%)患者的SUVmean与11例患者的SUVmax高于2.5;SUV与病变大小无相关性(P＞0.05).结论肺部良性结节性病变中一部分炎性结节表现为高代谢.     

Abdominal positron-emission tomography lesions with increased standardized uptake values correlate with intraoperative findings

BACKGROUND: The reporting of standardized uptake value (SUV) on fluoro-2-deoxy-D-glucose positron-emission tomography (FDG-PET) in colorectal cancer is becoming common practice, but its clinical utility remains to be determined. This study was designed to compare FDG-PET uptake as measured by SUV with operative findings. METHODS: A colorectal cancer database was queried to identify patients who underwent FDG-PET scans with reported SUVs followed by exploratory laparotomy within 3 months and compare these results to determine FDG-PET sensitivity. RESULTS: Of 46 patients, 16 (34.8%) were found to be have increased extent of disease intraoperatively than seen on FDG-PET scan. This patient population had a statistically significant decreased mean maximal SUV than the patients whose FDG-PET scan equaled intraoperative findings (P < .025). CONCLUSIONS: This initial study indicates patients with potentially resectable disease by PET scan but decreased FDG uptake should undergo laparoscopic evaluation before performing laparotomy.     

三种类型肺癌18氟脱氧葡萄糖摄取量的初步研究

目的探讨肺鳞癌、腺癌、细支气管肺泡癌对18氟脱氧葡萄糖(fluorine -18 fluorode～oxyglucose,FDG)摄取的差异以及影响肺癌摄取FDG的常见因素. 方法对82例肺癌患者行全身或肺部正电子发射体层显像(positron emission tomography,PET)检查,测定肿瘤组织FDG的标准摄取值(standard uptake value,SUV)、最大与平均标准摄取值(SUVmax、SUVmean)、正常肺组织的SUV(SUVlung). 结果 82例患者中,肿瘤组织对FDG的摄取能力均高于相应的正常肺组织(P＜0.01).肺鳞癌、腺癌、细支气管肺泡癌的SUVmax分别为8.42±4.05,5.91±3.91和 2.97±1.10;SUVmean 分别为6.12±2.90,4.35±3.10和 2.25±0.99,三者差异有显著性意义(P＜0.01).SUV与肿瘤的大小呈正相关(P＜0.01).血糖水平与正常肺组织的SUV对肿瘤的SUV有影响(P＜0.05).结论 (1)肺癌组织对FDG的摄取能力高于正常肺组织,而且不同组织类型的肺癌之间SUV值差异有显著性意义.(2)肿瘤的大小与FDG摄取量存在着正相关性.(3)临床上解释肺癌患者PET检查结果时应考虑到血糖等因素的影响.     

Visualization of prostate cancer with 11C-choline positron emission tomography

BACKGROUND AND OBJECTIVE: Visualization of prostate cancer with positron emission tomography (PET) using 2-[18F]-2-deoxy-D-glucose (FDG) as radiopharmaceutical is limited by the low uptake of FDG in the tumor and by radioactivity excreted into the bladder. More specific PET radiopharmaceuticals would be welcome. Carbon-11 labeled choline (CHOL) is a new radiopharmaceutical potentially useful for tumor imaging as it is incorporated in the cell membranes as phosphatidylcholine. We prospectively studied the visualization of prostate cancer using CHOL PET. METHODS: A total of 25 consecutive patients with histologically proven prostate cancer and five patients with a benign prostate were included. PET images were performed with an ECAT HR(+) using 400MBq CHOL. Data acquisition was started at 5 minutes post-injection. Attenuation-corrected images were evaluated visually. Standardized uptake values (SUV) were calculated of the normal prostate gland and of the prostate tumor tissue. RESULTS: The normal prostate was visualized with a mean SUV of 2.3 (range 1.3-3.2). The primary tumor could be visualized with a mean SUV of 5.0 (range 2.4-9.5). Lymph node metastases >5mm could be identified. Non-specific uptake of CHOL was noticed in the intestines. Little to no radioactivity in the bladder was observed. CONCLUSION: Carbon-11-choline is avidly taken up in prostate cancer, both primary tumor and lymph node metastases, in the virtual absence of urinary radioactivity. These results confirm the early results obtained by others and permit further clinical research on the value of CHOL PET as a metabolic imaging technique in areas where conventional imaging have a limited sensitivity.     

Preoperative Positron Emission Tomography with Fluorine-18-Fluorodeoxyglucose is Predictive of Prognosis in Patients with Hepatocellular Carcinoma after Resection

Background: Hepatocellular carcinomas (HCCs) accumulate fluorine-18 fluorodeoxyglucose (FDG) to various degrees. The standardized uptake values (SUVs) of FDG-positron emission tomography (PET) in high-grade HCCs are significantly higher than those in low-grade HCCs. Aim: The aim of this study was to evaluate the possible usefulness of FDG-PET in predicting the prognosis of HCC patients after resection. We analyzed the relationship between the tumor to non-tumor SUV ratios (SUV ratio) and surgical outcome in 31 patients. Results: Of the 31 cases of HCC studied, seven (23%) exhibited SUV ratios greater than 2, as the cutoff value. The percentage of patients with poorly differentiated HCC was greater in the higher SUV ratio group (SUV ratio >2) than in the lower SUV ratio group (SUV ratio <2) (57 vs. 32%). The overall survival was significantly longer in the lower SUV ratio group than in the higher SUV ratio group (5-year-survival rate: 63 vs. 29% P = 0.006) (median survival time: 2310 vs.182 days). Conclusion: The SUV ratio was related significantly to disease-related death as well as other predictive factors, including the number of tumors, the size, stage, and involvement of vessels, and the involvement of the capsule. Consequently, we conclude that the SUV ratio provides information of prognostic relevance in patients with HCC before surgery.     

The utility of F-18 fluorodeoxyglucose whole body PET imaging for determining malignancy in cystic lesions of the pancreas

Previous studies have suggested that whole body positron-emission tomography (PET) can distinguish between benign and malignant cysts of the pancreas. Patients were identified (n=68) who had undergone whole body PET imaging for a cystic lesion of the pancreas between Jan. 1997 and May 2005. Cross-sectional imaging studies were reviewed by a single blinded radiologist, and positive PET studies were reviewed by a blinded nuclear medicine physician. Operative resection was performed in 21 patients (31%), and 47 patients were managed with radiographic follow-up. F-18 Fluorodeoxyglucose (FDG)-avid lesions were identified in eight of the 68 patients (12%). Within the resected group of patients (n=21), four of the seven patients (57%) with either in situ or invasive malignancy (adenocarcinoma: 3 of 5, papillary mucinous carcinoma: 1 of 2) had positive PET imaging (mean SUV, 5.9; range 2.5-8.0), and 2 of the 14 patients (14%) with benign lesions had positive PET imaging (serous cystadenoma, n=1, SUV=3.3; pseudocyst n=1, SUV=2.7). All lesions proven to be malignant with increased FDG uptake had highly suspicious findings on cross-sectional imaging. Within the group of resected patients, the sensitivity of PET for identifying malignant pathology was 57%, and the specificity was 85%. The sensitivity and specificity of PET for malignancy in this study was lower than previously reported, and PET findings did not identify otherwise occult malignant cysts. We do not believe whole body FDG-PET to be essential in the evaluation of cystic lesions of the pancreas.     

Evaluation of prostate cancer using FDG-PET

The clinical usefulness of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was examined in 54 patients with prostate cancer. FDG accumulation was positive in 38 of 54 the prostates (70%), 3 of 8 the lymph node metastases (38%) and 10 of 16 the bone metastases (63%), which suggested that FDG-PET is not superior to other conventional imaging methods as a tool for tumor detection. On the other hand, a quantitative value for FDG uptake in the prostate, expressed as a standardized uptake value (SUV), significantly correlated to the histological grade, clinical stage and serum PSA of the patients. A decrease of SUV was observed in all the patients who responded to endocrine treatment, and the patients with high pre-treatment SUV were shown to be at the risk for disease progression after initial treatment. The present results indicated that FDG-PET could provide us with useful prognostic information for the patients with prostate cancer by evaluating the malignant potential of the tumor.     

Does positron emission tomography offer prognostic information in malignant pleural mesothelioma?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether positron emission tomography is useful in the diagnosis and prognosis of malignant pleural mesothelioma (MPM). Altogether 136 papers were found using the reported search, of which 15 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that fluorodeoxyglucose-positron emission tomography (FDG-PET) accurately differentiates benign from malignant pleural disease, helps detect recurrence and provides prognostic information in terms of staging, survival and mortality. Eleven studies evaluated the role of FDG-PET in the diagnosis and prognosis of MPM. Malignant disease had a higher standardised uptake value (SUV) (6.5 ± 3.4 vs. 0.8 ± 0.6; P < 0.001) than benign pleural disease. Shorter median survival (9.7 vs. 21 months; P = 0.02) was associated with high SUV (>10) than low SUV (<10). PET accurately upstaged 13% and downstaged 27% of cases initially staged with computed tomography (CT). In patients undergoing chemotherapy, higher total glycolytic volume led to a lower median survival (4.9 vs. 11.5 months; P = 0.09), while a decline in FDG uptake was associated with a longer time to tumour progression (14 vs. 7 months; P = 0.02). Four studies observed the role of FDG-PET-CT in the diagnosis and prognosis of MPM. SUV was found to be higher in MPM compared to benign pleural disease (6.5 vs. 0.8; P < 0.001). A higher SUV(max) was observed in primary pleural lesions of metastatic (7.1 vs. 4.7; P = 0.003) compared to non-metastatic disease. Patients who underwent surgery had equivalent survival to those excluded based on scan results (20 vs. 12 months; P = 0.3813). One study compared the utility of PET and PET-CT in the diagnosis and prognosis of mesothelioma. PET-CT was found to be more accurate than PET in terms of staging (P < 0.05) disease. Overall, PET accurately diagnoses MPM, predicts survival and disease recurrence. It can guide further management by predicting the response to chemotherapy and excluding surgery in patients with extrathoracic disease. Combined PET-CT has additional benefits in accurately staging disease.     

Positron emission tomography for preoperative lymph node diagnosis in esophageal carcinoma]

BACKGROUND: Exact preoperative staging is a prerequisite for the indication and the choice of appropriate operative technique for patients with esophageal carcinoma. The objective of this prospective study was to assess whether positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) increases the accuracy of preoperative lymph node staging with standard computed tomography (CT) and thus leads to a different surgical approach. PATIENTS AND METHODS: Fifty-eight patients with carcinoma of the esophagus (46 men and 12 women) with a median age of 61 years underwent FDG-PET imaging of the neck, chest, and abdomen as well as CT of the chest and abdomen. Sensitivity, specificity, and accuracy were calculated for both imaging techniques to evaluate the detection of histologically verified lymph node metastases. RESULTS: The FDG-PET showed higher specificity, whereas CT proved to be more accurate for detecting lymph node metastases not only of the abdomen (73% vs 59%) but also of the thorax (73% vs 63%). Resections were transhiatal in 23 patients and transthoracal in 16. As a supplement to conventional CT diagnostic procedure, FDG-PET was not decisive for the surgical approach. CONCLUSIONS: Altogether, pretherapeutical PET imaging did not increase the accuracy of lymph node staging for our patients with esophageal carcinoma, which had already been defined through CT. Therefore, no new consequences resulted for the surgical procedure. Due to the high costs involved with PET investigation, lymph node staging with it is momentarily indicated mainly for clinical studies and when CT does not offer unequivocal results. Increased sensitivity of the already advantageous whole-body FDG-PET imaging by means of tumor-affinitive radiopharmaceuticals and optimized apparatus resolution could lead to new indications for this staging procedure.     

Detecting metastatic pelvic lymph nodes by 18F-2-deoxyglucose positron emission tomography in patients with prostate-specific antigen relapse after treatment for localized prostate cancer

AIM: To evaluate whether positron emission tomography (PET) with (18)F-2-deoxyglucose (FDG) can detect pelvic lymph node metastases in prostate cancer patients who had elevated serum prostate-specific antigen (PSA) levels after treatment. METHODS: Twenty-four patients with a rising serum PSA level after treatment for localized prostate cancer were examined with FDG-PET before pelvic lymph node dissection. All patients had negative findings on whole body bone scan and equivocal pelvic computed tomography (CT) results. The results of FDG-PET were then compared to the histology of the pelvic lymph nodes obtained at surgery. RESULTS: Lymph node metastases were detected by histopathological examination in 16/24 (66.7%) patients. At the sites with histopathologically proven metastases, increased FDG uptake was found in 12/16 (75.0%) patients. In addition, there were 4 patients with false-negative results, but no patient with a false-positive result on FDG-PET images. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG-PET in detecting metastatic pelvic lymph nodes were 75.0, 100.0, 83.3, 100.0, and 67.7%, respectively. CONCLUSIONS: These results suggest that FDG-PET may be a valuable diagnostic tool in the staging of pelvic lymph nodes in patients with PSA relapse after treatment of localized prostate cancer when the whole body bone scan is negative and pelvic CT findings are equivocal.     

Preoperative evaluation of patients with primary head and neck cancer using dual-head 18fluorodeoxyglucose positron emission tomography

OBJECTIVE: To evaluate the value of 18fluorodeoxyglucose (FDG) positron emission tomography (PET) in primary head and neck cancer. BACKGROUND DATA: Head and neck carcinomas tend to metastasize to regional lymph nodes rather than to spread hematogenously. With nodal metastases, cure rates decrease by approximately 50%. Moreover, in approximately 3% of the patients, a second primary tumor is found at initial presentation. METHODS: Fifty-four consecutive patients (31 men and 23 women; mean age 60 years, range 34-81 years) with previously untreated squamous cell carcinomas of the oral cavity or oropharynx were studied. Before surgery and within a period of 3 weeks, clinical examination, chest x-ray, computed tomography (CT), ultrasonography with fine-needle aspiration cytology (US/ FNAC), and FDG-PET were performed. All study results were scored per neck side and were also classified as 0 (no metastases), 1 (single metastasis), or 2 (multiple metastases). RESULTS: The sensitivity for the detection of lymph node metastases per neck side was 96%, 85%, and 64% for FDG-PET, CT, and US/FNAC, respectively. The specificity was 90%, 86%, and 100% for FDG-PET, CT, and US/FNAC, respectively. In terms of the classification, FDG-PET showed the best correlation with the histologic data. Finally, in nine patients (17%), a second primary tumor was detected by FDG-PET and confirmed by histologic evaluation. CONCLUSION: Because of the high prevalence of second primary tumors detected by FDG-PET and the decreased error rate in the assessment of lymph node involvement compared with CT and US, FDG-PET should be routinely performed in patients with primary head and neck cancer.     

Axillary staging using positron emission tomography in breast cancer patients qualifying for sentinel lymph node biopsy

Axillary lymph node dissection (ALND) is the standard of care for nodal staging of patients with invasive breast cancer. Due to significant somatic and psychological side effects, replacement of ALND with less invasive techniques is desirable. The goal of this study was to evaluate the clinical usefulness of axillary lymph node (ALN) staging by means of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in breast cancer patients qualifying for sentinel lymph node biopsy (SLNB). FDG-PET was performed within 1 week before surgery in 24 clinically node-negative breast cancer patients with tumors smaller than 3 cm. Sentinel lymph nodes (SLNs) were identified by preoperative lymphoscintigraphy following peritumoral technetium 99m-labeled colloid albumin injection, and by intraoperative gamma detector and blue dye localization. Following SLNB, a standard ALND was performed. Serial sectioning and immunohistochemistry of the SLN as well as standard histologic examination of the non-SLN was performed. FDG-PET detected all primary breast cancers. Staging of ALNs by PET was accurate in 15 of 24 patients (62.5%), whereas PET staging was false negative in 8 of 10 node-positive patients and false-positive in 1 patient. The sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET for nodal status was 20%, 93%, 67%, and 62%, respectively. The mean diameter of false-negative ALN metastases was 7.5 mm (range 1-15 mm). Lymph node staging using FDG-PET is not accurate enough in clinically node-negative patients with breast cancer qualifying for SLNB and should not be used for this purpose.