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PET scan is feasible for medical prognosis in patients with inoperable lung cancer that have most aggressive tumors: a study report

 

(Courtesy: Mitch Machtay, MD, of the Seidman Cancer Center at University Hospitals)

Physicians can now easily determine patients that require specific cancer treatment, to manage their medical condition. Lung cancer is one of the prime cause of deaths in the United States.

Unlike other imaging methods (computed tomography etc.) for detailed body structure, a PET scan brings out physiologic processes in organs; chemical activity and metabolic changes in cancer cells can be observed through PET scan; regions of greater intensity through scan let care providers find/locate the disease easily.

Through the technology, care providers can customize treatment for patients with advanced lung cancers, in a better way; the study encompassed patients with stage III lung cancer that had PET scans, before, and after combined treatment course of radiotherapy and chemotherapy.

In comparison to normal cells, cancerous cells absorb sugar molecules at a higher rate, and show up clearly on PET scans; researchers evaluated FDG (radioactive sugar molecule) uptake in cancer, i.e. how swiftly the tumors absorb radioactive sugar molecules.

Researchers found that patients with higher level of FDG uptake in post treatment scan had more aggressive tumors with likelihood of recurrence. The recurrence rate of cancer was estimated to be more in patients with higher FDG uptake rates than the standard uptake value; such patients usually have lower survival rate than others.

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In vivo and phantom experiments show the possibility of concurrent 3D FOT and PET imaging.

 

The medical research study was contributed by Changqing Li, Yongfeng Yang, Gregory S. Mitchell and Simon R. Cherry from Department of Biomedical Engineering, University of California, Davis, California. (Courtesy: The Journal of Nuclear Medicine)

3-dimensional fluorescence optical tomography (FOT) and incorporated PET are feasible for in vivo molecular imaging applications; the team devised and assessed concurrent 3D FOT system and PET; the design of FOT system is consistent with many available small-animal PET scanners.

3-dimensional FOT system encompasses conical mirror for whole-body surface visualization of mouse, with charge-coupled device (CCD) camera, when a parallel beam is focused on the mouse to incite fluorescence.

The diffusion equation was utilized to model extension of optical photons inside the body of mouse; 3-dimensional fluorescence images were re-formed recurrently from the fluorescence intensity measurements, estimated from the surface of the mouse; introduction of conical mirror into the framework of small-animal PET scanner enabled concurrent 3D FOT and PET imaging.

Reciprocal interaction amid 3D FOT and PET were assessed experimentally. PET has insignificant effects on performance of 3D FOT; the inserted conical mirror enhances the scatter fraction, of the PET system.

An in vivo experiment through both PET and FOT, and PET–FOT phantom experiments were executed.

Conclusion: In vivo and phantom experiments show the possibility of concurrent 3D FOT and PET imaging.

18F-FDG PET scores are acceptable biomarker for progression of mild cognitive impairment to Alzheimer disorder

 

The medical research was contributed by Karl Herholz, Sarah Westwood, Cathleen Haense and Graham Dunn from Wolfson Molecular Imaging Centre, School of Cancer and Enabling Sciences, University of Manchester, Manchester, United Kingdom; and School of Community Based Medicine, University of Manchester, Manchester, United Kingdom. (Courtesy: The Journal of Nuclear Medicine)

Clinical trials are being devised, progressively in patients with mild cognitive impairment, to defer and prohibit the outset of dementia in Alzheimer disorder, by disease-modifying mediation.

Involvement of imaging methods as bio-markers for patient assortment and evaluation of outcomes is anticipated to increase trial effectiveness.

With proper standardization, PET using 18F-FDG measure up as bio-marker; it facilitates purposed information about disablement of synaptic function.

The team assessed PET score, obtained in a reflex manner from 18F-FDG PET scans through a sample of controls, patients with mild cognitive impairment, and patients with mild Alzheimer disorder, from neuro-imaging initiative; subjects encompassed in the study had four scans, and clinical evaluation over 2-year period.

In contrast to standard neuropsychologic examination scores and superior signal strength for progression, PET scores furnish higher test-retest dependability, during examination; simultaneously they are linearly connected to ADAS-cog scores, for valid measurement of cognitive impairment.

More to that, PET scores (MCI patients) considerably forecast clinical advancement to dementia with high precision than ADAS-cog and mini-mental state examination.

Conclusion: 18F-FDG PET scores are acceptable biomarker for progression of mild cognitive impairment to Alzheimer disorder; superior signal strength and test-retest dependability facilitate for abridging study duration, to a great extent.

The utility of imaging the cardiac sympathetic nervous system is progressively sustained by potential clinical studies.

 

Success of molecular imaging depends on cautious design of additional trials; pre-and-clinical utility requires comprehensive knowledge of fundamental biology that determines the connection amid neuronal tracer kinetics, disease mechanisms, and relevant study explanation.

SPECT tracer 123I-MIBG is often utilized for imaging the cardiac sympathetic nervous system. PET is feasible for cardiac neuronal biology, as it enables complete measurements of catecholamine retention.

Each myocardial region can be quantitatively evaluated; this facilitates to elucidate significance of globally afflicted innervation against regional heterogeneity.

Multiple tracers can be used in PET; in comparison to single tracer neuronal imaging, combination of tracers aid in deeper understanding of nerve biology.

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11C-4DST PET is feasible for brain tumor imaging; pharmacological safety and dosimetry are reasonable at the dose necessary for suitable PET images.

 

The medical research study was contributed by Jun Toyohara (Positron Medical Center, Tokyo Metropolitan Institute of Gerontology) and associates. (Courtesy: The Journal of Nuclear Medicine)

Lately, the team developed [methyl-11C]4′-thiothymidine (11C-4DST) as an in vivo cell propagation marker; the research study was to decide radiation dosimetry, security, allocation/distribution and primary brain tumor imaging of 11C-4DST in humans.

Radiation dosimetry and multi-organ biodistribution of 11C-4DST were evaluated in 3 subjects that passed through 2-h whole-body PET imaging.

OLINDA program was utilized for radiation dosimetry; about 6 patients (brain tumor) passed through dynamic 11C-4DST scans with arterial blood sampling; the patients were even assessed with 11C-methionine PET; plasma substance and urine samples were construed through liquid chromatography.

Gadolinium-enhanced T1-weighted MRI was utilized for perturbation of blood-brain obstruction in tumor tissue.

No adverse events were reported during study phase with any of subjects; 11C-4DST PET showed selective consumption in the bone marrow; high-level uptake was observed in liver.

Urinary bladder wall has had highest absorbed dose; the appraised effective dose for 11C-4DST was 4.2 μSv/MBq.

11C-4DST demonstrated slight uptake in normal tissues (brain), ensuing in low background activity for tumor imaging.

In comparison, 11C-4DST PET showed swift uptake in truculent tumor masses; no sign of 11C-4DST was found in clinically fixed disorder in which 11C-methionine uptake was high.

The allocation pattern of 11C-methionine in tumor sections was not always similar to that of 11C-4DST; examination of plasma samples through liquid chromatography showed that more than 60% of radioactivity was present as unaltered 11C-4DST at 20 min.

Conclusion: small group patient study – primary findings show that 11C-4DST PET is plausible for brain tumor imaging; pharmacological safety and dosimetry were reasonable at the dose necessary for suitable PET images.

Fine localization of 124I-huA33 in colorectal cancer, with no considerable toxicity has been found;

PET-deduced 124I concentrations demonstrated good agreement with other samples, and confirmed quantitative precision of 124I-huA33 PET.

 

The medical research was contributed by Jorge A. Carrasquillo and associates from various departments of Memorial Sloan-Kettering Cancer Center, New York. (Courtesy: The Journal of Nuclear Medicine)

Humanized A33 (huA33) is a monoclonal antibody that is present in normal bowel and above 95% of colorectal cancers. The research team tried PET to assess 124I huA33 focusing bio-distribution, and security in patients with colorectal cancer. They even decided the bio-distribution of 124I-huA33, when higher dose of human intravenous IgG (IVIG) was administered to control the Fc receptor, or when 124I-huA33 was administered through hepatic arterial infusion (HAI).

About 25 patients with primary/metastatic colorectal cancer encompassed the study; 19 had resection. Patients received a median of 343 MBq and 10 mg of 124I-humanized A33.

19 had intravenous antibody administration, 6 through hepatic arterial infusion; 5 received human intravenous IgG.

About 11 patients showed up with 10 primary tumors (vide: Oncology); median concentration (primary colon tumors) was 0.016% instilled dose/gram, in comparison with normal colon that had 0.004%.

Notable uptake in bowel hampered tumor recognition in some patients; patients receiving human intravenous IgG had a considerably shorter serum half-time (corroborated through, Pharmacokinetics).

No deviation could be established in clearance rates amid following groups – IVIG, HAI, intravenous; same was that for maximum serum concentration/volume of distribution, serum region under the curve.

Weak concentration of human–antihuman antibodies were found in 6 patients; no considerable toxicities/side effects were related with huA33.

Conclusion: Good determination/localization of 124I-huA33 in colorectal cancer, with no considerable perniciousness has been found. PET-deduced 124I concentrations showed good agreement with other samples, and confirmed quantitative precision of 124I-huA33 PET; no clinically vital changes in blood clearance were brought about by human intravenous IgG.

Imaging probe lets for precise diagnosis of grave infection of the heart valves; radiolabeled protein gives away existence of Staphylococcus aureus in mouse prototype.

 

Massachusetts General Hospital (MGH) has come up with new imaging probe to precisely diagnose grave infection of the heart valves; the existence of Staphylococcus aureus-related endocarditis in a mouse model was brought out by PET imaging, through with radiolabeled variant of protein.

The research was contributed by: Matthias Nahrendorf, MD, PhD (MGH Center for Systems Biology); Peter Panizzi, PhD, (Harrison School of Pharmacy, Auburn University); Ralph Weissleder, MD, PhD (Director, MGH Center for Systems Biology) and associates.

The probe was feasible for existence of Staphylococcus aureus in irregular growth, which hamper regular function of heart valves; to recognize bacteria involved in  endocarditis is difficult, but accurate diagnosis is vital for well-balanced antibiotic therapy.

Endocarditis is distinguished by vegetations (of clotting components); endocarditis due to Staphylococcus aureus is grave, and has high mortality rate – about 25-50%.

Diagnosis is difficult, due to vague symptoms (heart murmur, fever etc.); blood tests may not recognize the involved bacteria. Without relevant antibiotic therapy, Staphylococcus aureus can advance swiftly, causing harm to heart valves.

Staphylococcus aureus aids in growth of vegetations through secretion of staphylocoagulase; the process involves prothrombin, prime constituent of blood clots; clotting process expands the vegetation, hooks it to heart valve, and cover up the bacteria from immune cells, in the blood-stream.

To diagnose, through with image-based approach, MGH team examined molecular mechanism by which staphylocoagulase start out the clotting cascade; as prothrombin is vital in fibrin/staphylocoagulase interaction, the team examined if labeled versions of prothrombin could precisely reveal S. aureus endocarditis in mice.

After primary attempts, FMT-CT (optical imaging technology) confirmed out feasible for fluorescence-labeled variant of prothrombin deposited into Staphylococcus aureus-prompted vegetations; radiolabeled version of prothrombin allowed for discovery of Staphylococcus aureu with PET/CT imaging, which could be utilized for humans after further development and FDA commendation.

The approach is plausible for clinicians, for existence of endocarditis – for severity, causes (if due to Staphylococcus aureus), and effectiveness of antibiotics/other treatments; the team is improving PET reporter probe, for possible testing in patients.

Serial PET scans, through peculiar estrogen-containing isotope found viable for relative effectiveness of estrogen-blocking/depleting therapy in metastatic breast cancer cases, substantiates Seattle Cancer Care Alliance.

 

The study was contributed by: Hannah Linden, M.D.; David Mankoff, M.D.; Jeanne Link, M.D., and Kenneth Krohn, M.D., at the SCCA, and UW; and Brenda Kurland (Statistician, Fred Hutchinson Cancer Research Center).

PET scans – prior, on and after hormonal therapy affirmed the potency of estrogen-receptor-blocking drugs over estrogen-depleting therapies to withhold estrogen receptor in cancer cells; tamoxifen has even been substantiated over fulvestrant in to block estrogen.

Researchers (Linden & the team) evaluated territorial estrogen-receptor blocking/binding through PET scans with 18F-Fluoroestradiol (FES), before, and on discourse with aromatase inhibitors, fulvestrant, and tamoxifen in about 30 patients with breast cancer (vide: oncology) spread to the bones.

Tumor FES uptake waned in patients that took estrogen-receptor blockers, in comparison to others that had taken estrogen-depleting aromatase inhibitors; of both the studies, the rate of all over tumor blockade was highest sticking to use of fulvestrant, in contrast to tamoxifen.

Results suggest FES PET for effective visualization of in vivo activity of endocrine therapy; the technology can be utilized in drug development to gauge effectiveness at purposeful therapeutic targets, and to improve dosing/selection for agents. Moreover, pharmacodynamic imaging is feasible for therapeutic selection, and to evaluate/predict response to estrogen-receptor directed therapy.

(Courtesy: Journal of American Association for Cancer Research)

Multimodality imaging approach is useful in complex/ambiguous cases; cognition of pertinent radiologic features and prime clinical information is vital for convinced lesion delineation and discrimination.

 

The CME paper in Radiology has been contributed by Gavin Low, MBChB, MRCS, FRCR; Anukul Panu, MD; Noam Millo, MD and Edward Leen, MD, FRCR from the Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, Edmonton, AB, Canada; and Department of Imaging Science, Imperial College London, Hammersmith Hospital, London, England. (Courtesy: RSNA Journal)

Cystic pancreatic lesions depict miscellaneous group of entities, which can be widely categorized as either non-neoplastic or neoplastic.

Neoplastic lesions comprise subsequent: pancreatic neuroendocrine tumor, solid pseudopapillary tumor, pancreatic adenocarcinoma, pancreatic lymphoma, pancreatoblastoma, metastases to the pancreas, and uncommon sundry neoplasms.

On the other, Non-neoplastic lesions embody: fatty infiltration-replacement, focal pancreatitis, intrapancreatic accessory spleen, congenital anomalies and infrequent sundry lesions.

These solid lesions can be assessed through following modalities: computed tomography, MRI, ultrasonography, endoscopic ultrasound, SPECT/CT, and PET/CT – all have own capability and restraints.

Precise diagnosis can be difficult, and utilization of multimodality imaging pattern is a great deal beneficial in complex/ambiguous cases.

Facts about pertinent clinical data and prime radiologic attributes is vital for sure-footed lesion distinction and delineation.

It is all about HEART that matters, here!

 

We already know that heart pumps blood through circulatory system by rhythmic contraction and dilation; cardiology is a medical specialty that deals with syndromes and disorders of the heart; medical practitioners specialized in function, structure and diseases of the heart are known as Cardiologists; patients with following conditions are treated by cardiologists: valvular heart disease, congenital heart disease/defects, coronary artery disease/atherosclerosis, congestive heart failure, to name a few.

In case of angiography, after instilling the patient with radio-opaque substance (instilled in) through a catheter, blood vessels are portrayed through an x-ray device for irregularities; about cardiac tumors, primary tumors of heart and membrane enclosing (pericardium) it are uncommon – most are benign; metastatic tumors rise from other nearby organ locality, in the body; in case of intravascular ultrasound, catheter with tiny ultrasound probe/equipment is used for visualization of lipid plaques, and related in coronary arteries.

On the other, electrocardiography (ECG/EKG) is extensively used for to graphically record cardiac cycle, of patients; here, the electrical activities of the heart is captured through electrodes positioned on the skin, of the patient, viz. legs, arms, chest etc., for ECG readings and interpretation. The process facilitates the care provider to measure how regular and frequent, the heart beats in a person.

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