FDG PET imaging in the staging and management of gastric cancer

Gastric cancer is a leading cause of cancer death worldwide. Complete resection offers the only chance for permanent control, and accurate staging and evaluation of treatment response are crucial for appropriate management. Positron Emission Tomography (PET) is increasingly used to complement anatomic imaging in cancer management. PET use in gastric cancer has been limited by 1) some gastric histologies are not PET avid, 2) spatial resolution limits the ability to distinguish between primary tumor and compartment I or II lymph nodes, and 3) the lack of a unified criteria in how to interpret PET for management decisions. New criteria have been proposed establishing response metrics in the utilization of PET. More study is needed to support these criteria in routine practice and establish the place of PET in the staging and management of gastric cancer.     

18^F-FDG PET及PET/CT在食管癌评估中的应用价值

食管癌是我国常见的消化道肿瘤,预后较差。进一步提高诊断的准确性可以有效提高治疗效果。目前,18^F-FDG PET或PET/CT在食管癌评估中的应用越来越多,主要用来探查远处转移情况及评估治疗反应。半定量分析的诊断方法可提供患者的预后信息,也可用于制定患者的个体化治疗。本篇综述将讨论图像方法尤其是18^F-FDG PET及PET/CT在食管癌评估中的作用。     

The utility of PET/CT in staging and assessment of treatment response of nasopharyngeal cancer

Introduction: The aim of this study was to evaluate the impact of positron emission tomography/computerised tomography (PET/CT) as an adjunct to conventional imaging (CI) in the management of nasopharyngeal cancer (NPC) both for initial staging and assessment of post‐treatment response. Methods: All NPC cases referred to the Peter MacCallum Centre for Metabolic Imaging between January 2002 and December 2007 were identified. In patients undergoing initial staging, any differences between the pre‐PET/CT management plan based on CI and that following performance of the PET/CT scan were noted. Clinical impact was scored using the Centre's published criteria: 'high' if PET/CT changed the primary treatment modality or intent, ‘medium’ if treatment modality was unchanged but the radiotherapy technique or dose was altered, and ‘low’ if there was no change in treatment modality or intent. Patients undergoing PET/CT following definitive treatment were scored according to whether or not they achieved a complete metabolic response. Results: Forty‐eight patients underwent a staging PET/CT. The clinical impact was high in 8%, medium in 25% and low in 66% of patients. Twenty‐one patients were scanned for post‐treatment response. PET/CT was less frequently equivocal than MRI (3 vs 8/21). A complete metabolic response on PET/CT was associated with a 93% negative predictive value for subsequent recurrence. Conclusion: PET/CT is a valuable staging tool for the detection of occult metastatic disease and defining the extent of neck nodal disease. Post‐treatment, a complete metabolic response on PET/CT has a very high negative predictive value with fewer equivocal results than MRI.     

The additional value of integrated PET/CT over PET in initial lymph node staging of esophageal cancer

The purpose of the present study was to assess the contribution of simultaneous functional/anatomical imaging using integrated 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT), compared with PET alone for the evaluation of initial lymph node staging in esophageal cancer. We studied 167 consecutive patients with thoracic esophageal squamous cell carcinoma (SCC) who had radical esophagectomy performed between January 1999 and April 2007. For individual nodal group evaluation, PET/CT showed 46.0% sensitivity (p<0.05 vs. PET), 99.4% specificity, 95.1% accuracy (p<0.05 vs. PET), 87.0% positive and 95.5% negative predictive values. PET showed 32.9% sensitivity, 98.9% specificity, 93.1% accuracy, 74.7% positive predictive value and 93.9% negative predictive value. Thus, the sensitivity and accuracy of PET/CT were significantly higher than those of PET. Comparisons between CT, PET and PET/CT in detecting lymph node metastasis by each region showed that PET/CT had a higher sensitivity in lower thoracic regions than PET and CT (p<0.05 vs. CT and PET). Lymph node staging (N0 vs. N1) was not significantly different, but staging per lymph nodal group was significantly better with PET/CT. Integrated PET/CT imaging with co-registration of anatomic and functional imaging data is useful in the initial lymph node staging of patients with operable esophageal cancer compared with PET alone.     

Screening diagnosis and staging of esophageal cancer

In geographic areas where there is a high risk of esophageal cancer, analysis of cells obtained from the esophagus has been used effectively to detect early lesions. This has been demonstrated on a large scale in studies from China. Using abrasive balloon cytology techniques, 75% of the cancers detected were early lesions, where the 5-year survival after resection was in the range of 90%. Endoscopic followup studies indicate that dysplastic changes in the esophageal mucosa are a common precursor to malignancy. In many cases, the time course from dysplasia to carcinoma in situ to early invasive cancer may take place over many years, allowing a reasonable amount of time for screening. In low-incidence areas, such as the United States, most esophageal cancers are related to the excessive use of tobacco and alcohol. These factors are too common and the incidence of the disease too low, however, to justify screening on this basis. There are smaller groups at higher risk where selective screening by endoscopy with cytology and biopsy is recommended, usually every 1 to 3 years. These include patients with longstanding achalasia, lye strictures, and Plummer- Vinson syndrome. Patients with cancers of the head and neck region and patients with celiac disease may also be considered to be at increased risk. Tylosis is a rare inherited disease with a very high risk of esophageal cancer. There is an increased incidence of adenocarcinoma of the esophagus with Barrett's epithelium, and once identified such patients should be kept under endoscopic surveillance. The finding of severe dysplasia in any of these groups would indicate a shorter screening interval. Most patients with symptoms referable to the esophagus are first tested by barium esophagram. If negative, with persistent symptoms or if a suspicious lesion is identified, endoscopy with cytology and biopsy is recommended. Staging of the cancer is based on the size of the cancer both longitudinally and circumferentially and the presence of extraesophageal spread. At the present time, CT is the best noninvasive method for judging the extent of the cancer. Performance and nutritional status are also determinants of prognosis and should be considered in planning treatment.     

~(18)F-FDG PET及PET/CT在食管癌评估中的应用价值

食管癌是我国常见的消化道肿瘤,预后较差.进一步提高诊断的准确性可以有效提高治疗效果.目前,18F-FDG PET 或PET/CT在食管癌评估中的应用越来越多,主要用来探查远处转移情况及评估治疗反应.半定量分析的诊断方法可提供患者的预后信息,也可用于制定患者的个体化治疗.本篇综述将讨论图像方法尤其是18F-FDG PET及 PET/CT在食管癌评估中的作用.     

18F-FDG PET/CT显像在食管癌分期中的应用

目的:探讨18F-FDG PET/CT显像在食管癌分期中的应用价值.方法:对23例病理学确诊的食管癌患者,术前1周行全身PET/CT显像,根据病理结果评价PET/CT显像在食管癌分期中的应用价值.结果:19例患者进行了食管癌切除和淋巴结清除术,PET/CT显像发现50处病灶,与病理结果相比较,假阳性5处,假阴性3处,PET/CT诊断灵敏性为94%,特异性为76%;另4例患者因PET/CT发现多发转移而改变了治疗方案.结论:应用18F-FDG PET/CT进行食管癌检查能显著提高分期的敏感性和准确性,具有较好的临床应用前景.     

The utility of body FDG PET in staging primary central nervous system lymphoma

(18)F-Fluorodeoxyglucose (FDG) PET has become an important tool in the management of non-Hodgkin's lymphoma (NHL), but its role in the evaluation of primary CNS lymphoma (PCNSL) has not been established. We investigated the ability of body FDG PET to detect systemic disease in the staging and restaging of PCNSL. The records of 166 PCNSL patients seen at Memorial Sloan-Kettering Cancer Center were examined. Forty-nine patients who underwent body FDG PET for staging of PCNSL were identified. Clinical data were reviewed to determine FDG PET results and their influence on therapy. Body FDG PET disclosed a systemic site of malignancy in 15% of patients. NHL was found in 11% of all patients, 7% of patients at diagnosis, and 27% of patients at CNS relapse. Four percent had a second systemic neoplasm. Workup with conventional staging did not reveal systemic disease, and in 8% of patients, body FDG PET was the only abnormal diagnostic exam suggestive of lymphoma. FDG PET findings altered patient treatment and resulted in additional chemotherapy, surgery, or radiotherapy. Our findings suggest that FDG PET may be more sensitive than conventional body staging and may disclose higher rates of concomitant systemic disease at PCNSL diagnosis. Body FDG PET may be an important noninvasive adjunct to conventional PCNSL staging, and its utility should be evaluated prospectively.     

The role of PET scan in diagnosis, staging, and management of non-small cell lung cancer

Positron emission tomography (PET) is now an important cancer imaging tool, both for diagnosis and staging, as well as offering prognostic information based on response. This report attempts to comprehensively review the value of PET in the locoregional and distant staging of non-small cell lung cancer (NSCLC), illustrate the potential effects on patient management, and give a short overview of newer applications. PET sets the gold standard in the evaluation of an indeterminate solitary pulmonary nodule or mass, where PET has proven to be significantly more accurate than computed tomography (CT) in the distinction between benign and malignant lesions. In the evaluation of metastatic spread to locoregional lymph nodes, PET is significantly more accurate than CT, so that invasive surgical staging may be omitted in many patients with negative mediastinal PET images. In patients with positive mediastinal PET images, invasive surgical staging remains mandatory because of the possibility of false-positive findings due to inflammatory nodes or granulomatous disorders. In the search for metastatic spread, PET is a useful adjunct to conventional imaging. This may be due to the finding of unexpected metastatic lesions or due to exclusion of malignancy in lesions that are equivocal on standard imaging. However, at this time, PET does not replace conventional imaging. Large-scale randomized studies are currently examining whether PET staging will actually improve the appearance of lung cancer outcome.     

^18F-FDG PET/CT显像在食管癌分期中的应用

目的：探讨^18F-FDG PET/CT显像在食管癌分期中的应用价值。方法：对23例病理学确诊的食管癌患者,术前1周行全身PET/CT显像,根据病理结果评价PET/CT显像在食管癌分期中的应用价值。结果：19例患者进行了食管癌切除和淋巴结清除术,PET/CT显像发现50处病灶,与病理结果相比较,假阳性5处,假阴性3处,PET/CT诊断灵敏性为94%,特异性为76%;另4例患者因PET/CT发现多发转移而改变了治疗方案。结论：应用^18F-FDG PET/CT进行食管癌检查能显著提高分期的敏感性和准确性,具有较好的临床应用前景。     

Positron emission tomography in the staging of esophageal cancer

Accurate staging of patients with esophageal cancer (EC) is essential for selection of appropriate treatment and to predict prognosis. In recent years, positron emission tomography using the positron emitting glucose analogue 18F- fluorodeoxyglucose (FDG-PET) has emerged as a particularly useful adjunct to anatomical imaging modalities as computed tomography (CT) and endoscopic ultrasonography (EUS). In the initial staging of EC the additional value of FDG-PET is its ability to identify distant metastases (stage IV disease), excluding patients from unnecessary surgery. The combination of FDG-PET and endoscopic ultrasonography with fine-needle aspiration (EUS-FNA) has been suggested as the most effective strategy for preoperative EC staging.     

Positron-emission tomography in imaging and staging prostate cancer

With increasing application of positron-emission tomography (PET) imaging, familiarity with the applications of PET in genitourinary oncology, especially prostate-cancer (PCa) imaging, becomes important. PET studies provide functional information using radiolabeled tracers, with fluoro-dexoxy-glucose (FDG) being the most commonly used. Nevertheless FDG has limitations for evaluation of PCa patients and therefore alternative tracers are being investigated. To date, the best results have been obtained with 11C-choline and 11C-acetate PET, which seem to demonstrate similar values in this field. We review the current role of PET in PCa patients based on data published in the literature as well as our own experience. Most studies of PET imaging of PCa address three goals: a) detecting primary PCa; b) staging PCa; and c) assessing PCa recurrence. From available results, routine clinical use of 11C-choline PET cannot be recommended for detecting and staging primary PCa. At present, the only clinical indication for imaging PCa with 11C-choline-PET is evaluation of suspected recurrence after treatment.     

影像手段对食管癌治疗前分期的价值

准确的分期是选择合理治疗方案、预后评价、不同治疗方法疗效比较及诊治信息交流的基本工具.CT、MRI、EUS、PET和PET/CT等作为目前食管癌治疗前的分期手段,不同的手段因其成像原理不同,对不同区域、不同器官检测的敏感性、特异性和准确性不同.综合应用不同手段是提高食管癌分期准确性的有效方法.其中EUS联合CT检查似乎是一种比较经济且准确率高的组合方法.     

Role of endoscopy in the staging of esophageal and gastric cancer

Progress in instrumentation and clinical research continues to expand the potential utility of endoscopic ultrasound (EUS) in the treatment of esophageal and gastric cancer. This review focuses on the role of EUS in the staging and treatment planning of patients with esophageal and gastric cancer.     

PET scan in the staging of non-small cell lung cancer

Imaging techniques play an essential role in the diagnosis, staging, and follow-up of patients with lung cancer. Positron emission tomography (PET) has become an important innovation in lung cancer imaging. In this report, a comprehensive overview is given of the important number of prospective performance studies, looking at the value of PET in locoregional and distant staging of NSCLC, and at its potential impact on patient management. In the assessment of locoregional lymph node spread, PET has a high negative predictive value in the exclusion of N2 or N3 disease, so that mediastinoscopy can be omitted in most patients with negative mediastinal PET-images. False negative mediastinal PET findings may occur in patients with minimal N2 disease. Because of possible false positive findings in patients with inflammatory nodes or granulomatous disorders, confirmation and lymph node mapping by mediastinoscopy remains mandatory in these situations. In the extrathoracic staging, PET is a useful adjunct to conventional imaging, because it is able to detect unexpected metastatic lesions. An isolated positive finding that determines the possibility for radical treatment requires pathological verification, because of the possibility of a false positive result. PET is also able to exclude malignancy in equivocal lesions, but caution is needed in case of small lesions. There are currently insufficient data to state that PET could replace standard imaging. The use of PET as described in the performance studies, now undergoes further validation in large-scale randomised patient outcome studies. In the meanwhile, a current recommendation for the use of PET in contemporary lung cancer staging is provided.     

Molecular staging individualizing cancer management

Although the most important prognostic and predictive marker in colorectal cancer is tumor cells in lymph nodes, approximately 30% of patients who are node-negative die from occult metastases. Molecular staging employing specific markers and sensitive detection technologies has emerged as a powerful platform to assess prognosis in node-negative colon cancer. Integrating molecular staging into algorithms that individualize patient management will require validation and the definition of relationships between occult tumor cells, prognosis, and responses to chemotherapy.     

食管癌治疗前分期的意义和方法

准确的术前分期对于选择合适的治疗方案非常重要,可以避免一些不当的治疗方式.确诊为食管癌后,增强CT仍是首选的检查方法,可以排除一些无法切除和远处转移的病例.近年来,随着多排CT的出现,通过使用薄层CT和三维重建,使得食管癌术前分期更准确.超声内镜(endoscopic ultrasonography,EUS)被认为是判断肿瘤浸润深度和淋巴结转移最可靠的检查方式,结合细针穿刺活检可以提高淋巴结转移诊断的准确度.正电子发射断层扫描(positron emission tomography,PET)对于判断远处转移和新辅助治疗后反应相当敏感,但对于判断肿瘤浸润深度作用不大.每种术前分期检查方法都有各自的优缺点,因此各种检查方法应该互补,综合使用,这样才能提高术前分期的准确度.     

食管癌临床分期与病理分期分布合理性和预后判断价值比较

目的 通过与术后病理分期标准的比较,探讨《非手术治疗食管癌的临床分期标准(草案)》的分布合理性及判断预后的价值。方法 回顾分析2009—2012年间本院根治手术或术后辅助治疗的 162例食管癌患者临床资料,对其进行术前临床分期及术后病理分期,并采用Kappa法分析两种分期间各期病例分布一致性。Kaplan-Meier法计算OS率并Logrank法检验差异和单因素分析。结果 T、N、TNM分期总符合率分别为67.9%、57.4%、67.9%,一致性程度分别为中等、较差、中等(Kappa=0.544、0.302、0.509)。随访率为93.2%,1、2、3年样本数分别为127、66、27例。全组1、2、3年OS率分别为82.6%、56.2%、37.7%。术前除了T₁与T₂期、N₀与N₁期OS相近外(P=0.086、0.101),T、N、TNM分期各期间OS均不同(P=0.000~0.028),与术后病理分期对预后判断的预示作用一致。结论 《非手术治疗食管癌的临床分期标准(草案)》的分布合理性一般,预后判断价值较好,但仍需进一步细化和完善。