69 research outputs found
Revisiting the prognostic value of preoperative 18F-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET) in early-stage (I & II) non-small cell lung cancers (NSCLC)
Impact of staging with 18F-FDG-PET on outcome of patients with stage III non-small cell lung cancer: PET identifies potential survivors
Early Detection of Erlotinib Treatment Response in NSCLC by 3β²-Deoxy-3β²-[18F]-Fluoro-L-Thymidine ([18F]FLT) Positron Emission Tomography (PET)
Background: Inhibition of the epidermal growth factor receptor (EGFR) has shown clinical success in patients with advanced non-small cell lung cancer (NSCLC). Somatic mutations of EGFR were found in lung adenocarcinoma that lead to exquisite dependency on EGFR signaling; thus patients with EGFR-mutant tumors are at high chance of response to EGFR inhibitors. However, imaging approaches affording early identification of tumor response in EGFR-dependent carcinomas have so far been lacking. Methodology/Principal Findings: We performed a systematic comparison of 3β²-Deoxy-3β²-[]-fluoro-L-thymidine ([]FLT) and 2-[]-fluoro-2-deoxy-D-glucose ([]FDG) positron emission tomography (PET) for their potential to identify response to EGFR inhibitors in a model of EGFR-dependent lung cancer early after treatment initiation. While erlotinib-sensitive tumors exhibited a striking and reproducible decrease in []FLT uptake after only two days of treatment, []FDG PET based imaging revealed no consistent reduction in tumor glucose uptake. In sensitive tumors, a decrease in []FLT PET but not []FDG PET uptake correlated with cell cycle arrest and induction of apoptosis. The reduction in []FLT PET signal at day 2 translated into dramatic tumor shrinkage four days later. Furthermore, the specificity of our results is confirmed by the complete lack of []FLT PET response of tumors expressing the T790M erlotinib resistance mutation of EGFR. Conclusions: []FLT PET enables robust identification of erlotinib response in EGFR-dependent tumors at a very early stage. []FLT PET imaging may represent an appropriate method for early prediction of response to EGFR TKI treatment in patients with NSCLC
Concurrent gemcitabine and 3D radiotherapy in patients with stage III unresectable non-small cell lung cancer
Diagnostic Value of EBUS-TBNA for Lung Cancer with Non-Enlarged Lymph Nodes: A Study in a Tuberculosis-Endemic Country
BACKGROUND: In tuberculosis (TB)-endemic areas, contrast-enhanced computed tomography (CT) and positron emission tomography (PET) findings of lung cancer patients with non-enlarged lymph nodes are frequently discrepant. Endobronchial ultrasound-guided transbronchial aspiration (EBUS-TBNA) enables real-time nodal sampling, and thereby improves nodal diagnosis accuracy. This study aimed to compare the accuracy of nodal diagnosis by using EBUS-TBNA, and PET. METHODS: We studied 43 lung cancer patients with CT-defined non-enlarged mediastinal and hilar lymph nodes and examined 78 lymph nodes using EBUS-TBNA. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of EBUS-TBNA were 80.6%, 100%, 100%, and 85.7%, respectively. PET had low specificity (18.9%) and a low positive predictive value (44.4%). The diagnostic accuracy of EBUS-TBNA was higher than that of PET (91% vs. 47.4%; p<0.001). Compared to CT-based nodal assessment, PET yielded a positive diagnostic impact in 36.9% nodes, a negative diagnostic impact in 46.2% nodes, and no diagnostic impact in 16.9% nodes. Patients with lymph nodes showing negative PET diagnostic impact had a high incidence of previous pulmonary TB. Multivariate analysis indicated that detection of hilar nodes on PET was an independent predictor of negative diagnostic impact of PET. CONCLUSION: In a TB-endemic area with a condition of CT-defined non-enlarged lymph node, the negative diagnostic impact of PET limits its clinical usefulness for nodal staging; therefore, EBUS-TBNA, which facilitates direct diagnosis, is preferred
A systematic review of PET and PET/CT in oncology: A way to personalize cancer treatment in a cost-effective manner?
Quantifying drug-related 5-HT1A receptor occupancy with [F-18]MPPF
Rationale: There is an increased interest in measuring the interaction of new or established drugs with their targets, in order to gain a better understanding of their mechanisms of action. PET can provide this information if an appropriate radioligand is available. [F-18]MPPF (4-(2'-methoxyphenyl)-1-[2'-(N-2"-pyridinyl)-p-[F-18]fluorobenzamido]ethylpiperazine) is a selective radioligand for serotonin 5-HT1A receptors. We have established that the binding potential (BP=B-max/K-D) of [F-18]MPPF for cerebral 5-HT1A receptors can be assessed in human brain without arterial sampling. Objectives: The aim of this study was to assess if 5-HT1A receptor occupancy can be measured through calculation of a drug-related decrease in BP with [F-18]MPPF and PET. Methods: Six volunteers were scanned twice using a Siemens Exact HR+ camera following injection of 70+/-18 MBq [F-18]MPPF (baseline and medicated conditions). Before the second scan, volunteers orally received either 3x10 mg pindolol at T=-15.5 h, T=-6.5 h, and T=-1.5 h (n=3) or 10 mg buspirone in a single dose at T=-1.5 h (n=3). Binding potentials were calculated using the simplified reference tissue model with the cerebellum as reference. Results: Administration of 30 mg pindolol led to a significant reduction in [F-18]MPPF binding potential of 42+/-17%. In contrast, no significant reduction of [F-18]MPPF binding potential was observed following administration of buspirone (5+/-17%). Conclusions: These results show that [F-18]MPPF can be used for measurement of drug-related 5-HT1A receptor occupancy and may be of particular interest in determining the 5-HT1A receptor interaction of new or established drugs in phase 1 and early phase 2 drug trials. Apparently, the 5-HT1A partial agonist buspirone is already clinically effective at low levels of 5-HT1A receptor occupancy
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