scholarly journals Usefulness of carbon-11-labeled methionine positron-emission tomography for assessing the treatment response of primary central nervous system lymphoma

2020 ◽  
Vol 50 (5) ◽  
pp. 512-518
Author(s):  
Yasuji Miyakita ◽  
Makoto Ohno ◽  
Masamichi Takahashi ◽  
Hiroaki Kurihara ◽  
Hitoshi Katai ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Area Under The Curve ◽  
Central Nervous System Lymphoma ◽  
Complete Response ◽  
Resonance Imaging ◽  
Tumor Mass ◽  
Positron Emission ◽  
Unconfirmed Complete Response ◽  
Response Group ◽  
Met Pet

Abstract Background Primary central nervous system lymphoma (PCNSL) responds relatively quickly to chemotherapy or radiotherapy. However, determination of a complete response after treatment is often difficult because of extremely light residual contrast enhancement on magnetic resonance images due to the effects of microhemorrhages and scar tissue formation. These small enhancing lesions define an unconfirmed complete response. The aim of this study was to investigate the usefulness of carbon-11-labeled methionine (11C-Met) positron-emission tomography (PET) for determining the treatment response of PCNSL. Methods Data for 36 patients who were treated for PCNSL between 2011 and 2015 and underwent magnetic resonance imaging and 11C-Met PET were reviewed. Magnetic resonance imaging findings were classified as complete response, unconfirmed complete response, and tumor mass (a composite of partial response, stable disease and progressive disease). PET images were evaluated, standardized uptake values were quantified, and the tumor-to-normal tissue count ratio (TNR) was calculated. Receiver operating characteristic curves were generated to determine the optimal cutoff TNRs. Results The optimal TNRs for differentiating complete response and unconfirmed complete response from tumor mass were 1.83 (area under the curve, 0.951) and 1.80 (area under the curve, 0.932), respectively. The corresponding sensitivity and specificity values for the diagnosis of tumor mass were 82.4 and 100%, respectively, in the complete response group and 85.3 and 85%, respectively, in the unconfirmed complete response group. Conclusions A TNR of ≥1.80 can aid in the detection of active PCNSL using 11C-Met PET. Thus, 11C-Met-PET may be a useful tool for accurate evaluation of the treatment efficacy in PCNSL.

Integration of [11C]Methionine-Positron Emission Tomographic and Magnetic Resonance Imaging for Image-guided Surgical Resection of Infiltrative Low-grade Brain Tumors in Children

2005 ◽  
Vol 57 (suppl_1) ◽  
pp. 128-139 ◽  
Author(s):  
Benoit Pirotte ◽  
Serge Goldman ◽  
Patrick Van Bogaert ◽  
Philippe David ◽  
David Wikler ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Brain Tumors ◽  
Tumor Resection ◽  
Low Grade ◽  
Resonance Imaging ◽  
Image Guided ◽  
Positron Emission ◽  
Mri Scans ◽  
Met Pet

Abstract OBJECTIVE: To evaluate the interest of integrating positron emission tomography (PET) images with the radiolabeled tracer [11C]methionine (Met) into the image-guided navigation planning of infiltrative low-grade brain tumors (LGBTs) in children. METHODS: Twenty-two children underwent combined Met-PET with magnetic resonance imaging (MRI) scans in the planning of a navigation procedure. These children presented an LGBT (astrocytomas, 10; oligodendrogliomas, 4; ependymomas, 4; gangliogliomas, 4) located close to functional areas. Tumor boundaries were ill-defined on MRI (including T2-weighted and fluid-attenuated inversion-recovery scans) and could not be clearly identified for allowing a complete, or at least a large, image-guided resection. The PET tracer Met was chosen because of its higher sensitivity and specificity than MRI to detect tumor tissue. The level and extension of MET uptake were analyzed to define the PET contour, subsequently projected onto MRI scans to define a final target contour for volumetric resection. The quality of tumor resection was assessed by an early postoperative MRI and Met-PET workup. RESULTS: In 20 of the 22 children with ill-defined LGBTs, PET improved tumor delineation and contributed to define a final target contour different from that obtained with MRI alone. Met-PET guidance allowed a total resection of Met uptake in 17 cases that were considered total tumor resections because the operative margin left in place contained nontumor tissue. CONCLUSION: These data suggested that Met-PET guidance could help to improve the number of total resections and the amount of tumor removed in infiltrative LGBTs in children.

scholarly journals Observation of magnetic susceptibility changes within the thalamus: a comparative study between healthy and Parkinson’s disease afflicted cynomolgus monkeys using 7 T MRI

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sangwoo Kim ◽  
Youngjeon Lee ◽  
Chang-Yeop Jeon ◽  
Yeung Bae Jin ◽  
Sukhoon Oh ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Parkinson’S Disease ◽  
Positron Emission Tomography ◽  
Parkinson's Disease ◽  
Magnetic Resonance ◽  
Disease Model ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Cynomolgus Monkeys ◽  
Positron Emission

Abstract Background Although the thalamus is known to modulate basal ganglia function related to motor control activity, the abnormal changes within the thalamus during distinct medical complications have been scarcely investigated. In order to explore the feasibility of assessing iron accumulation in the thalamus as an informative biomarker for Parkinson’s disease (PD), this study was designed to employ quantitative susceptibility mapping using a 7 T magnetic resonance imaging system in cynomolgus monkeys. A 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-injected cynomolgus monkey and a healthy control (HC) were examined by 7 T magnetic resonance imaging. Positron emission tomography with 18F-N-(3-fluoro propyl)-2ß-carboxymethoxy-3ß-(4-iodophenyl) nortropane was also employed to identify the relationship between iron deposits and dopamine depletion. All acquired values were averaged within the volume of interest of the nigrostriatal pathway. Findings Compared with the HC, the overall elevation of iron deposition within the thalamus in the Parkinson’s disease model (about 53.81% increase) was similar to that in the substantia nigra (54.81%) region. Substantial susceptibility changes were observed in the intralaminar part of the thalamus (about 70.78% increase). Additionally, we observed that in the Parkinson’s disease model, binding potential values obtained from positron emission tomography were considerably decreased in the thalamus (97.51%) and substantia nigra (92.48%). Conclusions The increased iron deposition in the thalamus showed negative correlation with dopaminergic activity in PD, supporting the idea that iron accumulation affects glutaminergic inputs and dopaminergic neurons. This investigation indicates that the remarkable susceptibility changes in the thalamus could be an initial major diagnostic biomarker for Parkinson’s disease-related motor symptoms.

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