Prospective evaluation of pretreatment and intratreatment FDG PET-CT SUV stability in primary head and neck cancer.

Purpose: To evaluate standardized uptake value (SUV) stability on pretreatment and intratreatment 18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in patients undergoing definitive CRT for head and neck cancer (HNC).

Methods: Primary tumor and nodal volumes of interest (VOIs) from HNC patients were contoured on the pretreatment and intratreatment PET-CT by two independent observers. SUV stability was measured with intersection calculations (DICE, overlap fraction, center to center) between the VOIs at threshold levels of 50%, 60%, 70%, 80%, and 90% of the SUV maximum.

Differentiating between visual hallucination-free dementia with Lewy bodies and corticobasal syndrome on the basis of neuropsychology and perfusion single-photon emission computed tomography.

Introduction: Dementia with Lewy bodies (DLB) and Corticobasal Syndrome (CBS) are atypical parkinsonian disorders with fronto-subcortical and posterior cognitive dysfunction as common features. While visual hallucinations are a good predictor of Lewy body pathology and are rare in CBS, they are not exhibited in all cases of DLB. Given the clinical overlap between these disorders, neuropsychological and imaging markers may aid in distinguishing these entities.

Dose equivalent rate constants and barrier transmission data for nuclear medicine facility dose calculations and shielding design.

A primary goal of nuclear medicine facility design is to keep public and worker radiation doses As Low As Reasonably Achievable (ALARA). To estimate dose and shielding requirements, one needs to know both the dose equivalent rate constants for soft tissue and barrier transmission factors (TFs) for all radionuclides of interest. Dose equivalent rate constants are most commonly calculated using published air kerma or exposure rate constants, while transmission factors are most commonly calculated using published tenth-value layers (TVLs).

Phase I trial of intraoperative detection of tumor margins in patients with HER2-positive carcinoma of the breast following administration of 111In-DTPA-trastuzumab Fab fragments.

Introduction: Our aim was to conduct a Phase I clinical trial to determine the feasibility of intraoperative detection of tumor margins in HER2 positive breast carcinoma using a hand-held γ-probe following administration of (111)In-DTPA-trastuzumab Fab fragments. Accurate delineation of tumor margins is important for preventing local recurrence.

Methods: Six patients with HER2-positive in situ or invasive ductal carcinoma were administered 74MBq (0.

Feasibility evaluation of radioimmunoguided surgery of breast cancer.

Breast-conserving surgery involves completely excising the tumour while limiting the amount of normal tissue removed, which is technically challenging to achieve, especially given the limited intraoperative guidance available to the surgeon. This study evaluates the feasibility of radioimmunoguided surgery (RIGS) to guide the detection and delineation of tumours intraoperatively. The 3D point-response function of a commercial gamma-ray-detecting probe (GDP) was determined as a function of radionuclide ((131)I, (111)In,( 99m)Tc), energy-window threshold, and collimator length (0.

Visual attention deficits in Alzheimer's disease: relationship to HMPAO SPECT cortical hypoperfusion.

Patients with Alzheimer's disease (AD) display a multiplicity of cognitive deficits in domains such as memory, language, and attention, all of which can be clearly linked to the underlying neuropathological alterations. The typical degenerative changes occur early on in the disease in the temporal-parietal lobes, with other brain regions, such as the frontal cortex, becoming more affected as the disease progresses. In light of the importance of the parietal cortex in mediating visuospatial attentional processing, in the present study, we investigated a deficit in covert orienting of visual attention and its relationship to cortical hypoperfusion in AD.

Design and construction of a quality control phantom for SPECT and PET imaging.

In this article, the authors present a method for quickly and easily constructing test phantoms for PET and SPECT quality assurance. As a demonstration, they constructed a complex prototype test phantom, showing the strengths of the construction method. Images taken using a PET/CT and a SPECT scanner are presented, along with a qualitative evaluation of PET/CT using the test phantom.

Experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype for partial breast irradiation.

Previously, our team used Monte Carlo simulation to demonstrate that a gamma camera could potentially be used as an online image guidance device to visualize seeds during permanent breast seed implant procedures. This could allow for intraoperative correction if seeds have been misplaced. The objective of this study is to describe an experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype.

Online gamma-camera imaging of 103Pd seeds (OGIPS) for permanent breast seed implantation.

Permanent brachytherapy seed implantation is being investigated as a mode of accelerated partial breast irradiation for early stage breast cancer patients. Currently, the seeds are poorly visualized during the procedure making it difficult to perform a real-time correction of the implantation if required. The objective was to determine if a customized gamma-camera can accurately localize the seeds during implantation.

Comparison of manual and semi-automated delineation of regions of interest for radioligand PET imaging analysis.

Background: As imaging centers produce higher resolution research scans, the number of man-hours required to process regional data has become a major concern. Comparison of automated vs. manual methodology has not been reported for functional imaging.

Medial temporal hypoperfusion and aggression in Alzheimer disease.

Background: It is not understood why some patients with Alzheimer disease (AD) display aggression and others do not.

Objective: To examine the relation between regional brain perfusion and aggression in AD.

Design: Single-photon emission computed tomographic scans were coregistered to a standardized template in Talairach space, generating mean ratios of uptake referenced to the cerebellum.

The influence of sex on limbic volume and perfusion in AD.

The goal of the current study was to determine whether Alzheimer's disease (AD) pathology affects the limbic system of men and women differently as measured by in vivo neuroimaging. Magnetic resonance imaging (MRI) and coregistered single photon emission computed tomography (SPECT) were used to examine the limbic system in 20 men and 20 women with probable AD compared to 40 age- and education-matched normal controls (20 men, 20 women). Limbic volumes and relative perfusion values were obtained from the MR images and coregistered SPECT scans, respectively.

Can PET provide the 3D extent of tumor motion for individualized internal target volumes? A phantom study of the limitations of CT and the promise of PET.

Purpose: To characterize the limitations of fast, spiral computed tomography (CT) when imaging a moving object and to investigate whether positron emission tomography (PET) can predict the internal target volume (ITV) and ultimately improve the planning target volume (PTV) for moving tumors.

Methods And Materials: To mimic tumors, three fillable spheres were imaged while both stationary and during periodic motion using spiral CT and PET. CT- and PET-imaged volumes were defined quantitatively using voxel values.

Multimodality imaging for precise localization of craniofacial osteomyelitis.

Functional imaging identifies areas of abnormal bone turnover, providing a useful adjunct in the treatment of osteomyelitis and bone tumors. The low resolution and lack of anatomical detail limit the application of bone scans in craniofacial surgery, however. Multimodality image registration addresses this problem by fusing functional images (single photon emission computed tomography [SPECT]) to high-resolution structural images (computed tomography [CT]) for precise anatomical delineation of bone activity.

Utility of simultaneous brain, CSF and hyperintensity quantification in dementia.

Improved methods of quantifying MRI are needed to study brain-behavior relationships in dementia. Rating scales are variable; lesion-tracing approaches can be subjective and ignore atrophy; segmentation of MRI hyperintensities is complicated by partial volume effects; and hyperintense lesions in different anatomical areas may have different effects. The goal of this study was to extend existing segmentation approaches to include hyperintensities and to demonstrate the utility of simultaneously assessing atrophy and lesion compartments in dementia.

Limbic system perfusion in Alzheimer's disease measured by MRI-coregistered HMPAO SPET.

The goal of this study was to perform a systematic, semi-quantitative analysis of limbic perfusion in patients with Alzheimer's disease (AD) using coregistered single-photon emission tomography (SPET) images aligned to magnetic resonance (MR) images. Limbic perfusion in 40 patients with mild to moderate AD was compared with that of 17 age-, sex-, and education-matched normal controls (NC). HMPAO SPET scans and 3D T1-weighted MR images were acquired for each subject.

The impact of (18)FDG-PET on target and critical organs in CT-based treatment planning of patients with poorly defined non-small-cell lung carcinoma: a prospective study.

Purpose: To prospectively study the impact of coregistering (18)F-fluoro-deoxy-2-glucose hybrid positron emission tomographic (FDG-PET) images with CT images on the planning target volume (PTV), target coverage, and critical organ dose in radiation therapy planning of non-small-cell lung carcinoma.

Methods And Materials: Thirty patients with poorly defined tumors on CT, referred for radical radiation therapy, underwent both FDG-PET and CT simulation procedures on the same day, in radiation treatment position. Image sets were coregistered using external fiducial markers.