Quantitative bone scan lesion area as an early surrogate outcome measure indicative of overall survival in metastatic prostate cancer.

A clinical validation of the bone scan lesion area (BSLA) as a quantitative imaging biomarker was performed in metastatic castration-resistant prostate cancer (mCRPC). BSLA was computed from whole-body bone scintigraphy at baseline and week 12 posttreatment in a cohort of 198 mCRPC subjects (127 treated and 71 placebo) from a clinical trial involving a different drug from the initial biomarker development. BSLA computation involved automated image normalization, lesion segmentation, and summation of the total area of segmented lesions on bone scan AP and PA views as a measure of tumor burden.

Most of the Intended Management Changes After Ga-DOTATATE PET/CT Are Implemented.

In this prospective referring-physician-based survey, we investigated the definite clinical impact of Ga-DOTATATE PET/CT on managing patients with neuroendocrine tumors (NETs). We prospectively studied 130 patients with Ga-DOTATATE PET/CT referred for initial or subsequent management decisions (NCT02174679). Referring physicians completed one questionnaire before the scan (Q1) to indicate the treatment plan without PET/CT information, one immediately after review of the imaging report to denote intended management changes (Q2), and one 6 mo later (Q3) to verify whether intended changes were in fact implemented.

Human Biodistribution and Radiation Dosimetry of F-Clofarabine, a PET Probe Targeting the Deoxyribonucleoside Salvage Pathway.

F-clofarabine, a nucleotide purine analog, is a substrate for deoxycytidine kinase (dCK), a key enzyme in the deoxyribonucleoside salvage pathway. F-clofarabine might be used to measure dCK expression and thus serve as a predictive biomarker for tumor responses to dCK-dependent prodrugs or small-molecule dCK inhibitors, respectively. As a prerequisite for clinical translation, we determined the human whole-body and organ dosimetry of F-clofarabine.

The incidence of thyroid cancer in focal hypermetabolic thyroid lesions: an 18F-FDG PET/CT study in more than 6000 patients.

Background: The clinical significance of incidental thyroid abnormalities discovered in fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) (FDG PET/CT) studies remains controversial. The aim of this large retrospective study was to (a) determine the prevalence of focal F-FDG thyroid uptake on whole-body F-FDG PET/CT studies carried out for nonthyroid cancers and (b) to test whether intense focal F-FDG thyroid uptake is associated with malignancy.

Materials And Methods: A total of 11 921 F-FDG PET/CT studies in 6216 patients carried out at our institution between January 2012 and December 2014 were analyzed.

Incidence of abnormal positron emission tomography in patients with unexplained cardiomyopathy and ventricular arrhythmias: The potential role of occult inflammation in arrhythmogenesis.

Background: The incidence of myocardial inflammation in patients with unexplained cardiomyopathy referred for ventricular arrhythmias (VAs) is unknown.

Objective: The purpose of this study was to report fasting positron emission tomographic (PET) scan findings in consecutive patients referred with unexplained cardiomyopathy and VA.

Methods: Fluorine-18 fluoro-2-deoxyglucose (18-FDG) PET/computed tomographic (CT) scans with a >16-hour fasting protocol were prospectively ordered for patients referred for VA and unexplained cardiomyopathy (ejection fraction <55%).

Biodistribution and radiation dosimetry for the chemokine receptor CXCR4-targeting probe 68Ga-pentixafor.

Unlabelled: (68)Ga-pentixafor is a promising PET tracer for imaging the expression of the human chemokine receptor 4 (CXCR4) in vivo. The whole-body distribution and radiation dosimetry of (68)Ga-pentixafor were evaluated.

Methods: Five multiple-myeloma patients were injected intravenously with 90-158 MBq of (68)Ga-pentixafor (mean ± SD, 134 ± 25 MBq), and a series of 3 rapid multiple-bed-position whole-body scans were acquired immediately afterward.

Impact of 68Ga-DOTATATE PET/CT on the management of neuroendocrine tumors: the referring physician's perspective.

Unlabelled: Somatostatin receptor imaging with (68)Ga-DOTATATE PET/CT (DOTATATE) is increasingly used for managing patients with neuroendocrine tumors. The objective of this study was to determine referring physicians' perspectives on the impact of DOTATATE on the management of neuroendocrine tumors.

Methods: A set of 2 questionnaires (pre-PET and post-PET) was sent to the referring physicians of 100 consecutive patients with known or suspected neuroendocrine tumors, who were evaluated with DOTATATE.

¹⁸F-FLT and ¹⁸F-FDOPA PET kinetics in recurrent brain tumors.

Purpose: In this study, kinetic parameters of the cellular proliferation tracer (18)F-3'-deoxy-3'-fluoro-L-thymidine (FLT) and the amino acid probe 3,4-dihydroxy-6-(18)F-fluoro-L-phenylalanine (FDOPA) were measured before and early after the start of therapy, and were used to predict the overall survival (OS) of patients with recurrent malignant glioma using multiple linear regression (MLR) analysis.

Methods: High-grade recurrent brain tumors in 21 patients (11 men and 10 women, age range 26 - 76 years) were investigated. Each patient had three dynamic PET studies with each probe: at baseline and after 2 and 6 weeks from the start of treatment.

Brain tumors.

This review addresses the specific contributions of nuclear medicine techniques, and especially positron emission tomography (PET), for diagnosis and management of brain tumors. (18)F-Fluorodeoxyglucose PET has particular strengths in predicting prognosis and differentiating cerebral lymphoma from nonmalignant lesions. Amino acid tracers including (11)C-methionine, (18)F-fluoroethyltyrosine, and (18)F-L-3,4-dihydroxyphenylalanine provide high sensitivity, which is most useful for detecting recurrent or residual gliomas, including most low-grade gliomas.

Clinical utility of (18)F-fluoride PET/CT in benign and malignant bone diseases.

(18)F labeled sodium fluoride is a positron-emitting, bone seeking agent with more favorable skeletal kinetics than conventional phosphate and diphosphonate compounds. With the expanding clinical usage of PET/CT, there is renewed interest in using (18)F-fluoride PET/CT for imaging bone diseases. Growing evidence indicates that (18)F fluoride PET/CT offers increased sensitivity, specificity, and diagnostic accuracy in evaluating metastatic bone disease compared to (99m)Tc based bone scintigraphy.

Discriminant analysis of ¹⁸F-fluorothymidine kinetic parameters to predict survival in patients with recurrent high-grade glioma.

Purpose: The primary objective of this study was to investigate whether changes in 3'-deoxy-3'-[¹⁸F]fluorothymidine (¹⁸F-FLT) kinetic parameters, taken early after the start of therapy, could predict overall survival (OS) and progression-free survival (PFS) in patients with recurrent malignant glioma undergoing treatment with bevacizumab and irinotecan.

Experimental Design: High-grade recurrent brain tumors were investigated in 18 patients (8 male and 10 female), ages 26 to 76 years. Each had 3 dynamic positron emission tomography (PET) studies as follows: at baseline and after 2 and 6 weeks from the start of treatment, ¹⁸F-FLT (2.

Molecular imaging in oncology: the acceptance of PET/CT and the emergence of MR/PET imaging.

In the last decade, PET-only systems have been phased out and replaced with PET-CT systems. This merger of a functional and anatomical imaging modality turned out to be extremely useful in clinical practice. Currently, PET-CT is a major diagnostic tool in oncology.

Human biodistribution and radiation dosimetry of novel PET probes targeting the deoxyribonucleoside salvage pathway.

Purpose: Deoxycytidine kinase (dCK) is a rate-limiting enzyme in deoxyribonucleoside salvage, a metabolic pathway involved in the production and maintenance of a balanced pool of deoxyribonucleoside triphosphates (dNTPs) for DNA synthesis. dCK phosphorylates and therefore activates nucleoside analogs such as cytarabine, gemcitabine, decitabine, cladribine, and clofarabine that are used routinely in cancer therapy. Imaging probes that target dCK might allow stratifying patients into likely responders and nonresponders with dCK-dependent prodrugs.

Molecular mechanisms of bone 18F-NaF deposition.

There is renewed interest in (18)F-NaF bone imaging with PET or PET/CT. The current brief discussion focuses on the molecular mechanisms of (18)F-NaF deposition in bone and presents model-based approaches to quantifying bone perfusion and metabolism in the context of preclinical and clinical applications of bone imaging with PET.

Correlation of 6-18F-fluoro-L-dopa PET uptake with proliferation and tumor grade in newly diagnosed and recurrent gliomas.

Unlabelled: 6-(18)F-fluoro-l-dopa ((18)F-FDOPA) measured with PET as a biomarker of amino acid uptake has been investigated in brain tumor imaging. The aims of the current study were to determine whether the degree of (18)F-FDOPA uptake in brain tumors predicted tumor grade and was associated with tumor proliferative activity in newly diagnosed and recurrent gliomas.

Methods: Fifty-nine patients (40 men, 19 women; mean age ± SD, 44.

Kinetics of 3'-deoxy-3'-18F-fluorothymidine during treatment monitoring of recurrent high-grade glioma.

Unlabelled: 3'-Deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) is used as a biomarker of cell proliferation. We investigated the kinetics of (18)F-FLT during treatment of malignant glioma with bevacizumab and irinotecan.

Methods: Fifteen patients with recurrent high-grade brain tumors (2 grade III, 13 grade IV) were studied at baseline (study 1 [S1]), after 1 course of therapy (2 wk, study 2 [S2]), and at the end of therapy (6 wk, study 3 [S3]).

Development and intra-institutional and inter-institutional validation of a comprehensive new hepatobiliary software: Part 1--Liver and gallbladder function.

Objective: To develop a software tool for quantification of liver and gallbladder function, and to assess the repeatability and reproducibility of measurements made with it.

Materials And Methods: The software tool developed with the JAVA programming language uses the JAVA2 Standard Edition framework. After manual selection of the regions of interest on a 99mTc hepatic iminodiacetic acid study, the program calculates differential hepatic bile flow, basal duodeno-gastric bile reflux (B-DGBR), hepatic extraction fraction (HEF) of both the lobes with deconvolutional analysis and excretion half-time with nonlinear least squares fit.

1-11C-acetate kinetics of prostate cancer.

Unlabelled: (18)F-FDG is in widespread use in cancer imaging but has limited utility in staging and monitoring of prostate cancer. 1-(11)C-Labeled acetate, a substrate for the citric acid cycle, is superior. The kinetics of prostate tumors were investigated.

18F-FDOPA kinetics in brain tumors.

Unlabelled: L-3,4-Dihydroxy-6-(18)F-fluoro-phenyl-alanine ((18)F-FDOPA) is an amino acid analog used to evaluate presynaptic dopaminergic neuronal function. Evaluation of tumor recurrence in neurooncology is another application. Here, the kinetics of (18)F-FDOPA in brain tumors were investigated.

18F-fluorothymidine kinetics of malignant brain tumors.

Purpose: 18F-labeled deoxy-fluorothymidine (FLT), a marker of cellular proliferation, has been used in PET tumor imaging. Here, the FLT kinetics of malignant brain tumors were investigated.

Methods: Seven patients with high-grade tumors and two patients with metastases had 12 studies.

Accuracy of PET/CT in characterization of solitary pulmonary lesions.

Unlabelled: Characterization of a pulmonary lesion is a well-established indication for metabolic imaging with 18F-FDG. There is extensive literature on the use of PET and CT in the characterization of a solitary pulmonary nodule (SPN). The performance of dual-modality imaging with PET/CT for characterizing SPNs was investigated in a clinical referral setting.

18F-FDOPA PET imaging of brain tumors: comparison study with 18F-FDG PET and evaluation of diagnostic accuracy.

Unlabelled: We evaluated the amino acid and glucose metabolism of brain tumors by using PET with 3,4-dihydroxy-6-(18)F-fluoro-l-phenylalanine ((18)F-FDOPA) and (18)F-FDG.

Methods: Eighty-one patients undergoing evaluation for brain tumors were studied. Initially, 30 patients underwent PET with (18)F-FDOPA and (18)F-FDG within the same week.

Evaluation of thoracic tumors with 18F-fluorothymidine and 18F-fluorodeoxyglucose-positron emission tomography.

Study Objectives: 18F-fluorodeoxyglucose (FDG) is the most widely used positron emission tomography (PET) imaging probe used for the diagnosis, staging, restaging, and monitoring therapy response of cancer. However, its specificity is less than ideal. A new molecular imaging probe (18F-deoxyfluorothymidine [FLT]) has been developed that might afford more specific tumor imaging.