Search results for "Positron-emission tomography"
showing 10 items of 228 documents
Simulated one-pass list-mode: an approach to on-the-fly system matrix calculation.
2013
In the development of prototype systems for positron emission tomography a valid and robust image reconstruction algorithm is required. However, prototypes often employ novel detector and system geometries which may change rapidly under optimization. In addition, developing systems generally produce highly granular, or possibly continuous detection domains which require some level of on-the-fly calculation for retention of measurement precision. In this investigation a new method of on-the-fly system matrix calculation is proposed that provides advantages in application to such list-mode systems in terms of flexibility in system modeling. The new method is easily adaptable to complicated sy…
Measurement of cerebral ABCC1 transport activity in wild-type and APP/PS1-21 mice with positron emission tomography
2020
Previous data suggest a possible link between multidrug resistance-associated protein 1 (ABCC1) and brain clearance of beta-amyloid (Aβ). We used PET with 6-bromo-7-[11C]methylpurine ([11C]BMP) to measure cerebral ABCC1 transport activity in a beta-amyloidosis mouse model (APP/PS1-21) and in wild-type mice aged 50 and 170 days, without and with pretreatment with the ABCC1 inhibitor MK571. One hundred seventy days-old-animals additionally underwent [11C]PiB PET scans to measure Aβ load. While baseline [11C]BMP PET scans detected no differences in the elimination slope of radioactivity washout from the brain (kelim) between APP/PS1-21 and wild-type mice of both age groups, PET scans after MK…
Past, present and future of 68Ge/68Ga generators.
2013
(68)Ga represents one of the very early radionuclides applied to positron emission tomography (PET) imaging at a time when even the wording PET itself was not established. Today it faces a renaissance in terms of new (68)Ge/(68)Ga radionuclide generators, sophisticated (68)Ga radiopharmaceuticals, and state-of-the-art clincial diagnoses via positron emission tomography/computed tomography (PET/CT). Thanks to the pioneering achievement of radiochemists in Obninsk, Russia, a new type of (68)Ge/(68)Ga generators became commercially available in the first years of the 21st century. Generator eluates based on hydrochloric acid provided "cationic" (68)Ga instead of "inert" (68)Ga-complexes, openi…
Design of Bimodal Ligands of Neurotensin Receptor 1 for Positron Emission Tomography Imaging and Fluorescence-Guided Surgery of Pancreatic Cancer
2020
International audience; Neurotensin receptor 1 (NTSR1) is overexpressed in most human pancreatic ductal adenocarcinomas. It makes it an attractive target for the development of pancreatic cancer imaging agents. In this study, we sought to develop a bimodal PET-fluorescent imaging agent capable of specifically targeting these receptors. Starting from the structure of a known NTSR1 agonist, a series of tracers was synthesized, radiometalated with gallium-68 and evaluated in vitro and in vivo, in mice bearing an AsPC-1 xenograft. PET imaging allowed us to identify the compound [ 68 Ga]Ga-NODAGA-Lys(Cy5**)-AEEAc-[Me-Arg 8 , Tle 12 ]-NT(7-13) as the one with the most promising biodistribution pr…
Minimally invasive secondary cytoreduction plus HIPEC for recurrent ovarian cancer: a case series.
2014
Objective To analyze the feasibility of laparoscopic/robotic secondary cytoreductive surgery and hyperthermic intraperitoneal intra-operative chemotherapy (SCS + HIPEC) in a retrospective series of isolated platinum sensitive recurrent ovarian cancer. Methods We retrospectively evaluated a consecutive series of ovarian cancer patients with isolated platinum sensitive relapse. Isolated relapse was defined as the presence of a single nodule, in a single anatomic site. In all cases the presence of isolated relapse was assessed at pre-operative FDG-PET/CT scan, and confirmed with staging laparoscopy performed immediately before SCS + HIPEC. Results 84 women with platinum sensitive relapse recei…
Identification of Biomarkers Including 18FDG-PET/CT for Early Prediction of Response to Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer.
2015
Abstract Purpose: To investigate the value of the metabolic tumor response assessed with 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), compared with clinicobiologic markers to predict pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) in women with triple-negative breast cancer (TNBC). Experimental Design: Fifty consecutive women with TNBC and an indication for NAC were prospectively included. Different pretreatment clinical, biologic, and pathologic biomarkers, including SBR grade, the Ki-67 proliferation index, androgen receptor expression, EGF receptor (EGFR), and cytokeratin 5/6 staining, were assessed. Tumor glucose metabolism at baseline and its chan…
Role of Positron Emission Tomography for the Monitoring of Response to Therapy in Breast Cancer
2015
Abstract This review considers the potential utility of positron emission tomography (PET) tracers in the setting of response monitoring in breast cancer, with a special emphasis on glucose metabolic changes assessed with 18F-fluorodeoxyglucose (FDG). In the neoadjuvant setting of breast cancer, the metabolic response can predict the final complete pathologic response after the first cycles of chemotherapy. Because tumor metabolic behavior highly depends on cancer subtype, studies are ongoing to define the optimal metabolic criteria of tumor response in each subtype. The recent multicentric randomized AVATAXHER trial has suggested, in the human epidermal growth factor 2-positive subtype, a …
Genotyping analysis and 18FDG uptake in breast cancer patients: a preliminary research
2013
Background: Diagnostic imaging plays a relevant role in the care of patients with breast cancer (BC). Positron Emission Tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (FDG) has been widely proven to be a clinical tool suitable for BC detection and staging in which the glucose analog supplies metabolic information about the tumor. A limited number of studies, sometimes controversial, describe possible associations between FDG uptake and single nucleotide polymorphisms (SNPs). For this reason this field has to be explored and clarified. We investigated the association of SNPs in GLUT1, HIF-1a, EPAS1, APEX1, VEGFA and MTHFR genes with the FDG uptake in BC. Methods: In 26 caucasian individu…
Positron emission tomography and neoadjuvant therapy of breast cancer
2011
The increasing use of neoadjuvant therapy for breast cancer has led to the development of early surrogate markers of response. Positron emission tomography (PET) allows noninvasive study of fundamental biologic processes in the tumor; furthermore, PET provides various markers to assess tumor response early in the course of therapy. Numerous studies have shown that changes in tumor glucose metabolism during therapy are significantly correlated with final response and patient outcome. Moreover, new PET tracers that are currently being developed or under evaluation, providing specific information on tumor characteristics or receptor expression, will assist the development of new targeted antic…
[11C]choline-PET-guided helical tomotherapy and estramustine in a patient with pelvic-recurrent prostate cancer: local control and toxicity profile a…
2010
[11C]choline positron emission tomograhy can be useful to detect metastatic disease and to localize isolated lymph node relapse after primary treatment in case of prostate-specific antigen failure. In case of lymph node failure in prostate cancer patients, surgery or radiotherapy can be proposed with a curative intent. Some reports have suggested that radiotherapy could have a role in local control of oligometastatic lymph node disease. This is the first reported case of [11C]choline positron emission tomography-guided helical tomotherapy concomitant with estramustine for the treatment of pelvic-recurrent prostate cancer. At 24 months after the end of helical tomotherapy, prostate-specific…