Comparison of Positron Emission Tomography, Computed Tomography, and Endoscopic Ultrasound in the Initial Staging of Patients with Esophageal Cancer

Introduction Improvement in esophageal cancer staging is needed. Positron emission tomography (PET), computed tomography (CT), and endoscopic ultrasound (EUS) in the staging of esophageal carcinoma were compared. Methods PET, CT, and EUS were performed and interpreted prospectively in 75 patients with newly diagnosed esophageal cancer. Either tissue confirmation or fine needle aspiration (FNA) was used as the gold standard of disease. Sensitivity and specificity for tumor, nodal, and metastatic (TNM) disease for each test were determined. TNM categorizations from each test were used to assign patients to subgroups corresponding to the three treatment plans that patients could theoretically receive, and these were then compared. Results Local tumor staging (T) was done correctly by CT and PET in 42% and by EUS in 71% of patients (P value > 0.14). The sensitivity and specificity for nodal involvement (N) by modality were 84% and 67% for CT, 86% and 67% for EUS, and 82% and 60% for PET (P value > 0.38). The sensitivity and specificity for distant metastasis were 81% and 82% for CT, 73% and 86% for EUS, and 81% and 91% for PET (P value > 0.25). Treatment assignment was done correctly by CT in 65%, by EUS in 75%, and by PET in 70% of patients (P value > 0.34). Conclusions EUS had superior T staging ability over PET and CT in our study group. The tests showed similar performance in nodal staging and there was a trend toward improved distant disease staging with CT or PET over EUS. Assignment to treatment groups in relation to TNM staging tended to be better by EUS. Each test contributed unique patient staging information on an individual basis. This work was presented in part at The Society of Nuclear Medicine Annual Meeting, Los Angeles, CA June 15–19, 2002.     

Best Practices in PET/CT: Consensus on Performance of Positron Emission Tomography–Computed Tomography

Positron emission tomography-computed tomography (PET-CT) using the glucose metabolism tracer 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) has become a widespread and preferred imaging modality for evaluating most cancers. Since commercial PET-CT scanners became available in 2001, there has been rapid dissemination of this hybrid imaging modality and PET-CT scanners have largely replaced stand-alone PET scanners. How PET-CT scans are performed and applied to cancer management has varied considerably, in part reflecting the varied background of the practice settings and training experience of the physicians performing and interpreting the PET-CT studies. Combined PET/CT with FDG has become the gold standard in oncologic imaging by accurately defining anatomy and function of many tumors. From April 2-4, 2008, a focus group composed of physicians and technologists from different practice settings and training backgrounds entitled "Best Practices in PET/CT Symposium" was held in Sonoma, California. The symposium focused on optimization of PET-CT protocols but also included other pertinent topics related to PET-CT imaging in oncology. This article summarizes areas of consensus reached by the group regarding many of the discussion topics. The summary consensus covered in this article is meant to provide direction for future discussions on how to improve the application of this hybrid modality to patient care.     

Imaging dopamine release with Positron Emission Tomography (PET) and (11)C-raclopride in freely moving animals

We investigated an imaging strategy that provides simultaneous measurements of radiotracer binding and behavior in awake, freely moving animals. In this strategy, animals are injected intravenously (i.v.) through a catheterized line and permitted to move freely for 30 min during uptake of the imaging agent, in this case 11C-raclopride. After this Awake Uptake period, animals are anesthetized and scanned for 25 min. We tested the utility of this strategy for measuring changes in striatal 11C-raclopride binding under control conditions (awake and freely moving in the home cage) and with several drug challenges: a loading dose of unlabeled raclopride, pretreatment with methamphetamine (METH) or pretreatment with gamma-vinyl-GABA [S+-GVG] followed by METH. An additional group of animals underwent a stress paradigm that we have previously shown increases brain dopamine. For drug challenge experiments, the change in 11C-raclopride binding was compared to data from animals that were anesthetized for the uptake period ("Anesthetized Uptake") and full time activity curves were used to calculate 11C-raclopride binding. Regardless of the drug treatment protocol, there was no difference in 11C-raclopride striatum to cerebellum ratio between the Awake versus the Anesthetized Uptake conditions. Awake and Anesthetized groups demonstrated over 90% occupancy of dopamine receptors with a loading dose of cold raclopride, both groups demonstrated approximately 30% reduction in 11C-raclopride binding from METH pretreatment and this effect was modulated to the same degree by GVG under both uptake conditions. Restraint during Awake Uptake decreased 11C-raclopride binding by 29%. These studies support a unique molecular imaging strategy in which radiotracer uptake occurs in freely moving animals, after which they are anesthetized and scanned. This imaging strategy extends the applicability of small animal PET to include functional neurotransmitter imaging and the neurochemical correlates of behavioral tasks.     

Clinical Utility of Positron Emission Tomography/Computed Tomography in Inflammatory Bowel Disease

Purpose  

The clinical utility of positron emission tomography/computed tomography (PET/CT) in comparison to standard workup in patients with known or suspected inflammatory bowel disease (IBD) is unknown.     

Positron Emission Tomography for Pretreatment Staging and Posttreatment Evaluation in Cancer of the Anal Canal

Purpose In recent years, combined modality therapy (CMT) with chemotherapy and radiation has replaced surgery as the preferred treatment for cancer of the anal canal. Clinical staging with computed tomography (CT) scan alone may underestimate the extent of disease. We investigated the utility of positron emission tomography (PET) with 2-deoxy-2[F-18]fluoro-d-glucose (FDG) in the staging and determination of response to CMT. Patients and Methods From September 1999 to August 2002, 21 patients with cancer of the anal canal were studied prospectively. All patients underwent pretreatment PET, in addition to standard clinical evaluation that included CT scanning. Follow-up PET studies were ordered one month after completion of CMT. Results Sites of metastases not observed on CT scan were identified in five of 21 patients (24%). These sites included pelvic lymph nodes (four patients) and distant omental metastasis (one patient). In another patient, PET confirmed the presence of suspected M₁ disease in the liver. Posttreatment PET imaging was less useful. Nine patients had minimal residual PET activity at the primary site on the one-month follow-up PET study, but only three of these subsequently developed local recurrence. In addition, recurrences occurred in three patients (two local, one distant) of the six who had negative posttreatment PET studies. Conclusions FDG-PET, in conjunction with CT scanning, provides additional staging information in cancer of the anal canal. This information may have implications for prognosis and radiotherapy planning. Posttreatment PET scans appear to be of little value in predicting durability of response.     

正电子发射计算机断层显像在脑梗死治疗中的应用进展

脑梗死系由各种原因所致的局部脑组织血液供应障碍,导致脑组织缺血缺氧性病变坏死,进而产生临床上对应的神经功能缺失表现。本文对正电子发射计算机断层显像在脑梗死治疗中的应用进行总结。     

PET与伽玛PET在癫痫灶定位中的应用

就正电子发射断层成像 (PET)与伽玛PET在癫痫灶定位中的应用作一介绍     

2-Deoxy-2-[18F]fluoro-d-glucose-Positron Emission Tomography and Positron Emission Tomography/Computed Tomography Diagnosis of Patients with Recurrent Papillary Thyroid Cancer

Objective 2-Deoxy-2-[F-18]fluoro-d-glucose positron emission tomography (FDG-PET) has an established role in restaging of various cancers, including papillary and undifferentiated thyroid carcinoma, but detection rates are variable in the published literature. We were therefore prompted to review our experience with FDG-PET in detection of recurrent papillary thyroid cancer (PTC).Methods This is a retrospective study (April 1, 1995–March 31, 2005) of 21 patients with histologic diagnosis of PTC who had PET examinations. The group included seven men and 14 women, with age range of 26–75 years (average 50 ± 16). The PET scan request was triggered by rising levels of thyroglobulin (Tg) in the presence of a negative iodine-131 scan.Results Recurrent/metastatic disease was identified by PET in 16 (76%) of the 21 patients with PTC. The sensitivity and specificity of FDG-PET for disease detection in this cohort were 88.2% [95% confidence interval (CI), 65.7–96.7] and 75% (95% CI, 30.1–95.4), respectively. The Tg levels were 1.0–10.4 ng/ml (average, 4.52 ng/ml) in the patients with negative PET scans and 1.0–38 ng/ml (average, 16.8 ng/ml) in patients with positive scans. The lesions were located in the cervical lymph nodes (8), thyroid bed (4), lungs (4), and mediastinal lymph nodes (2).Conclusion Our study confirms the feasibility of PET in detection of residual/recurrence of PTC, with sensitivity of 88.2% (95% CI, 65.7–96.7) and specificity of 75% (95% CI, 30.1–95.4). Detectable levels of Tg, even in the presence of negative I-131 scan or anatomic imaging, should prompt restaging with FDG-PET.     

11C-乙酸盐PET/CT显像在肿瘤诊断中的显像原理与临床应用

近年来许多研究认为11C-乙酸盐作为氨基酸及甾醇合成的前体,可用于肿瘤的诊断,它与目前用于肿瘤显像的主要示踪剂--反应细胞内乏氧糖代谢的氟代脱氧葡萄糖(11F-fluorodeoxygluose,18F-FDG)不同.     

Cost-Effectiveness of Positron Emission Tomography in Breast Cancer

PURPOSE: In this study, we used quantitative decision tree modeling to assess the cost-effectiveness of a positron emission tomography (PET)-based management scenario for breast cancer in Canada. PROCEDURES: Two patient management scenarios were compared (with and without PET). A metaanalysis of studies for the accuracy of PET in staging breast cancer was conducted. Life expectancies were calculated. Management costs were determined from previous cost-effective analyses, management costs from our institutions, and recently published Canadian cost estimates of various procedures. RESULTS: A cost savings of $695 per person is expected for the PET strategy, with an increase in life expectancy (7.4 days), when compared with the non-PET strategy. This cost savings remained in favor of the PET strategy when subjected to a sensitivity analysis. CONCLUSIONS: The use of a PET management strategy for the staging of breast cancer is expected to remain economically viable in Canada under various economic conditions.     

胰高血糖素样肽-1受体PET/CT定位诊断胰岛素瘤的技术规范

胰岛素瘤的诊断和手术治疗依赖于准确的影像学检查定位。以胰腺β细胞为靶点的胰高血糖素样肽-1受体(glucagon-like peptide-1 receptor, GLP-1R)是近年来胰岛素瘤影像研究中的亮点, 推荐临床推广使用⁶⁸Ga-exendin-4进行GLP-1R正电子发射断层显像/计算机体层成像(positron emission tomography/computed tomography, PET/CT)来定位诊断胰岛素瘤。本文介绍GLP-1R显像在胰岛素瘤中的应用概况, 并以⁶⁸Ga-exendin-4 GLP-1R PET/CT显像为例, 介绍该技术的操作规范, 以期为临床提供借鉴。     

Utility of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Patients with Fever of Unknown Origin Diagnosed as Lymphoma

Objective

To assess the efficacy of fluorine-18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET)/computed tomography (CT) in the diagnosis of patients with fever of unknown origin (FUO), who were finally diagnosed as lymphoma.

Subjects and Methods

A retrospective study was performed in the First Affiliated Hospital, School of Medicine of Zhejiang University, China, from March 2009 to March 2012. The PET/CT images of consecutive patients with FUO were analyzed. Within 1 week of PET/CT scanning, additional histological tests were also performed if clinically needed.

Results

A total of 73 consecutive patients were included. Of these, 34 (47s%) had a PET/CT finding suggestive of the presence of lymphoma and 29 (85s%) had a diagnosis of confirmed lymphoma; 39 (53s%) had a PET/CT result revealing the absence of lymphoma and 4 (10s%) were diagnosed by biopsy as having lymphoma. The most frequent lymphoma diagnosis was peripheral T cell lymphoma (n = 16; 55s%), followed by diffuse large B cell lymphoma (n = 9; 31s%). The accuracy of PET/CT was 88s%.

Conclusion

In this study, PET/CT had high diagnostic accuracy in patients with FUO resulting from lymphoma, which indicated that PET/CT scanning was a valuable diagnostic tool for these groups of patients with FUO.Key Words: Fever of unknown origin, Positron emission tomography, Computed tomography, Diagnosis, Lymphoma     

2-Deoxy-2-[F-18]Fluoro-d-Glucose–Positron Emission Tomography/Computed Tomography Imaging Evaluation of Esophageal Cancer

We evaluated the clinical utility of 2-deoxy-2-[F-18]fluoro-d-glucose (FDG)–positron emission tomography (PET)/computed tomography (CT) on the precise localization of pathologic foci and exclusion of normal variants in the imaging evaluation of patients with esophageal carcinoma. Combined PET/CT scans were performed in 60 patients (50 males, 10 females, age range 47–84 years) with history of esophageal carcinoma either at the time of initial diagnosis (group I, n = 14) or for surveillance and/or detection of recurrent and metastatic disease (group II, n = 46). Prior treatments included esophagectomy with gastric pull-up (n = 23), surgery and chemotherapy (n = 3), surgery and chemoradiation therapy (n = 10), chemotherapy alone (n = 5), radiation therapy alone (n = 2), and chemoradiation without surgery (n = 3). Diagnostic validation was by tissue sampling in three patients and clinical/radiological follow-up for up to 1.5 years in the remaining patients. In group I, discordant abnormalities were noted in seven patients. PET demonstrated hypermetabolism in normal-size lymph nodes on CT in three patients that were considered likely true positive in view of concurrent existence of other adjacent enlarged hypermetabolic lymph nodes in the same nodal basin. Hypometabolic incidental CT abnormalities of up to 1-cm lung nodules were noted in three patients and pleural effusion in one patient, which were considered true negative in view of no change on follow-up PET/CT studies. In group II, both PET and CT showed concordant abnormalities in 23 patients. The precise image fusion of hypermetabolism in a liver lesion allowed a diagnostic CT-guided biopsy in one patient. PET demonstrated true positive hypermetabolic abnormalities in four patients that localized to structures, which were normal by noncontrast CT criteria, and true negative in one patient with hepatic fatty deposits. PET showed decline in metabolic activity of the primary lesion in one patient after chemotherapy, while the corresponding CT abnormality remained unchanged. PET/CT image fusion provided relevant complementary diagnostic information in 14 patients with discordant findings (23% of total) that resulted in biopsy in three cases, institution of chemotherapy in four cases, and a wait-and-watch strategy in seven cases. In conclusion, our findings add to the current body of literature that suggests that FDG-PET/CT scanning may improve the imaging evaluation of patients with esophageal cancer by providing complementary structural-metabolic information. In particular, our findings support the notion that PET/CT may be the most appropriate imaging modality in the evaluation of patients of esophageal cancer that may impact patient management.     

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Following Chimeric Antigen Receptor T-cell Therapy in Large B-cell Lymphoma

Molecular Imaging and Biology - 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a well-established imaging modality to assess responses in patients with...     

(18)F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings in Mucosa-associated Lymphoid Tissue Lymphoma of the Larynx: a Case Report and Literature Review

Laryngeal mucosa-associated lymphoid tissue (MALT) lymphoma is rare, with only 25 cases reported in the literature. This report presents a case of laryngeal MALT lymphoma in a 35-year-old female with a 6-year history of progressively worsening hoarseness. MALT lymphoma was diagnosed based on biopsy and immunohistochemical analysis. The patient received two cycles of cyclophosphamide + epirubicin + vincristine + prednisone (CHOP) chemo therapy, which was ineffective. (18)F-fluoro deoxy glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) showed (18)F-FDG accumulation in the larynx only and identified stage IE lymphoma. CHOP chemotherapy was terminated and the patient was treated with radiotherapy. After 3 months (total radiation dose 27 Gy), (18)F-FDG PET/CT scan showed that the laryngeal lesion was in complete remission. A review of the literature on the MEDLINE(?)/PubMed(?) databases regarding laryngeal MALT lymphoma and the use of PET/CT found that radiotherapy is the firstline treatment for stage I and II MALT lymphoma.     

Positron Emission Tomography/Computed Tomography with F-18-fluorocholine for Restaging of Prostate Cancer Patients: Meaningful at PSA < 5 ng/ml?

According to reports, re-staging of patients suffering from prostate cancer by positron emission tomography (PET) using C-11-choline has failed to produce positive findings at a PSA level of < 5 ng/ml. Hence, the purpose of our study has been to determine whether this is true also for PET/CT using F-18-fluorocholine (FCH PET/CT) or whether it is possible to obtain true positive results by FCH PET/CT even at lower PSA levels. Methods In 34 patients with prostate cancer who had undergone initial therapy (radical prostatectomy n = 31, radiotherapy n = 3), a PET/CT scan was performed using F-18-fluorocholine (FCH) during follow-up in case of demonstrable or rising PSA levels. Current PSA levels were determined in all patients at the time of examination. Results Median PSA in FCH positive patients was 6.1 ng/ml (mean PSA 17.1 ng/ml), median PSA in FCH negative patients was 2.3 ng/ml (mean PSA 3.4 ng/ml), respectively (p < 0.05). In eight of 17 examinations (47%) with PSA < 5 ng/ml, at least one FCH-positive focus was detected. So far the findings could be confirmed by correlating imaging methods (CT and/or MR), biopsy/histology and the course of the disease, respectively, in seven of the eight FCH-positive cases with PSA < 5 ng/ml, so that a true positive FCH PET/CT finding was obtained all in all in seven of 17 (41%) examinations with PSA < 5 ng/ml. In four of these seven FCH PET-positive patients with PSA < 5 ng/ml, adjuvant hormonal therapy was administered at the time of the examination or prior to the examination. Conclusion In re-staging patients with prostate cancer, FCH PET/CT is able to yield true positive findings even at PSA < 5 ng/ml. Therefore, FCH PET/CT should not be restricted to patients with PSA > 5 ng/ml.     

A Review of Prostate-Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) in Renal Cell Carcinoma (RCC)

Molecular Imaging and Biology - Metastatic renal cell carcinoma (mRCC) is a disease that portends poor prognosis despite an increasing number of novel systemic treatment options including new...     

[68Ga]PSMA PET/CT Improves Initial Staging and Management Plan of Patients with High-Risk Prostate Cancer

Molecular Imaging and Biology - In this retrospective study, we compared the diagnostic value of 68Gallium prostate-specific membrane antigen positron emission tomography computed tomography...