A glass of CABERNET or MERLOT for a leaky case of AMD

Posted on June 16, 2011 by admin

By Ajay Malik, PhD

Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness in adults over 50 years age. While 90% of AMD patients have the dry-type AMD (atrophic), it is the wet AMD (exudative), driven by choroidal neovascularization (CNV), which is responsible for severe and acute vision loss in over 90% of the patients. Famous people, like the artist Georgia O’Keefe, entertainer Bob Hope and the author Henry Grunwald have coped with AMD. There are over 1.6 million people with AMD in the United States and about 200,000 people are diagnosed with wet AMD every year.

One promising approach in late-stage clinical development is the use of beta-radiation to selectively target the proliferating cells in the macular lesion. A small company 40-miles south of San Francisco called NeoVista in Newark, Calif., is at the forefront of testing an epimacular brachytherapy device in the pivotal CABERNET (CNV Secondary AMD Treated with BEta RadiatioN Epiretinal Therapy) Study. The results of this trial are expected in October 2011 (read here). The CABERNET trial is a multicenter randomized controlled study with two arms in which 495 treatment-naive patients will be randomized into a control group who will receive a regular schedule of ranibizumab (anti-VEGF Fab; Lucentis; Genentech, South San Francisco) injections (the standard of care); the patients in the second arm will receive strontium-90 beta radiation and Lucentis as needed.

Continue reading →

Posted in Industry Updates | Tagged , , , , , , , , | Leave a comment

F18 FLT: Imaging cell proliferation in contrast to cell metabolism in PET tumor imaging

Posted on June 12, 2011 by Jennifer Lilly Gutiérrez

Investigational radioisotope, F-18 FLT (fluorothymidine), is showing promise in clinical trials in it’s ability to assess response to cancer treatment. Research into the clinical applications of the FLT radiotracer has been underway for over 10 years. After FDA approval for the use in clinical trials, the molecular imaging community is holding much promise in the use of this tracer for the assessment of cancer treatments.

While the most widely used PET tracer, F-18 FDG, exhibits glucose metabolism in cellular tissue, F-18 FLT is retained only in proliferating tissues. This difference in uptake can mean quite a lot when examining some applications of tumor assessment, such as brain imaging. Due to the high glucose metabolism in the brain, some lesions of the brain can be hard to assess using F-18 FDG imaging.

When using FLT imaging to assess chemotherapy response, serial imaging is indicated. Cell proliferation is expected to decrease after the first course of treatment. A baseline FLT study would be performed, and then a post-treatment study after the first course of treatment. The amount of uptake, and more importantly, the differences in the amount of uptake, will determine the effectiveness and response of the treatment.

Method of Uptake: How and why does F18 FLT incorporate itself into proliferating cells?

In order to understand the method of uptake of F18 FLT, it is important to understand a few simple biochemical aspects:

1) Fluorothymidine is a thymidine (also called deoxythymidine) analogue

2) Thymidine is the nucleoside ‘T’ of DNA (composed of thymine and deoxyribose)

3) Every time a cell divides it synthesizes its DNA to create a new cell: thymidine is used to create new DNA

4) This is why the thymidine analogue exhibits itself in proliferating cells and is retained: the radiolabeled thymidine analogue incorporates itself in the DNA of the newly created cells and remains there

In contrast to using F18 FDG, where we see the metabolic state of the cells, we are able to use this application to see if the cells are growing (or if growth is being slowed down due to therapy).

 

By Jennifer Lilly Gutiérrez, CNMT, RT(N)(CT)

 

Also read: Can a New PET Imaging Technique More Quickly Predict Response to Ongoing Cancer? : Newswise

Posted in Nuclear Medicine, radiotracers | Tagged , , , , , , , , , , , , | Leave a comment

Taking the bite out of second cancer risk attributable to radiotherapy of primary first cancer

Posted on May 12, 2011 by admin

By Ajay K Malik, PhD

Over the last forty years, we have made great strides in the diagnosis and treatment of cancer. According to the Centre for Disease Control and Prevention (CDC), the number of cancer survivors have steadily increased from three million in 1971 to over eleven million today; one in twenty Americans is a cancer survivor.  The increasing ranks of cancer survivors have brought new concerns into focus—second primary cancers now account for 18% of all cancer diagnosis and are the third most common cancer diagnosis in US.  Similar data is also emerging from other countries.  Second primary cancers (a.k.a. second cancers) are new cancers that arise after the first incidence of any cancer.  Second cancer may be in the same, surrounding or distant organs, and differ from metastatic cancer which is a result of primary first cancer cells disseminating to a distant organs (see a definition here).

Genetics and lifestyle behaviors, for instance, smoking, alcohol or poor diet, are partly responsible for second cancer, the treatment modalities during first cancer may also have a role.  Both chemotherapy and radiotherapy can increase predisposition of other cells to cancer.  Radiotherapy, while a highly effective cancer treatment option, has long been considered to increase the risk of subsequent cancers, but convincing data had been lacking.  Now, an epidemiological study published by the National Cancer Institute in the April 2011 issue of Lancet Oncology journal shows that 92% of all second cancers are due to causes other than the radiation treatment of previous cancer.

Continue reading →

Posted in Industry Updates, Nuclear Medicine | Tagged , , | Leave a comment

Could Positron Emission Mammography (PEM) replace Breast MRI?

Posted on May 11, 2011 by Jennifer Lilly Gutiérrez

In January of 2011, Radiology magazine released results of an NIH study indicating a new technique, Positron Emission Mammography (PEM) as being more accurate in identifying cancerous and benign breast lesions than breast imaging using MRI. PEM’s 13% higher PPV (Positive Predictive Value) results in a possible reduction in unnecessary breast biopsies.1 Not only can this mean a reduction in patient trauma, but could significantly lower costs associated with breast cancer detection and staging.

PEM Effective Dose (2)

PEM uses dedicated scanners (manufactured by Naviscan since 2007) and F18 labeled FDG to determine the metabolic activity of suspicious lesions in the breast. PEM scanners are similar in size to an ultrasound machine, with 16cm x 24cm FOV and spatial resolution of 2mm. Using a 10mCi dose, Whole Body Radiation Dose has been calculated at 6.2 to 7.1 mSv (effective dose)2 which is comparable to that of a chest, abdomen, or pelvic CT, and is 23 times higher than the effective dose of an Xray mammogram (0.44 to 0.56 mSv).3 This could be the primary reason that PEM is currently being used for staging and assessment after a breast cancer diagnosis, and is not being used as a screening tool.

Continue reading →

Posted in Industry Updates, Nuclear Medicine | Tagged , , | 2 Comments

Fearing a professional rut?

Posted on May 10, 2011 by Paul Dow

By Paul Dow, BS, RT(R)(CT)

These days many people are planning their career paths out of fear. It is almost unavoidable with the constant reporting of economic upheaval and uncertainty. With that fear, people are looking for job security and healthcare is proving to be an attractive field for people who have been forced out of other professions. What does an influx of technologists mean for people who have been lifelong healthcare providers? First, it means that competition for positions will be more intense than ever. For each open position, there can be as many as 100 or more applicants. Second, it means that you will need to challenge yourself, personally and professionally, to keep up with the changing employment market. The real question is this: How can you make yourself more desirable to employers, while staying true to your goals and  professional aspirations?

Continue reading →

Posted in Career, Technologists | Tagged , , , , , , | 2 Comments

Gamma Imaging Makes Waves in Women’s Health: Molecular Breast Imaging Improves Breast Cancer Detection

Posted on April 21, 2011 by admin

Maggie E. Mason

from article: MBI casts wider net for improved breast cancer diagnosis: A 45-year-old woman with elevated risk for breast cancer due to breast density underwent digital screening mammogram (left) and screening MBI (right) as part of a clinical trial. A biopsy from the area of suspicious technetium-99m (Tc-99m) sestamibi uptake (arrow) indicated the presence of a large lobular carcinoma. All images courtesy of Carrie Hruska, PhD.

While scintigraphy has been in use for decades, over the last several years gamma imaging has begun to make waves again, not only within the nuclear medicine community, but also in the field of women’s health.  Molecular Breast Imaging (MBI) is garnering much of this enthusiasm by way of the December 2010 TED talks presentation given by MBI co-creator, Dr. Deborah Rhodes, an internal medicine physician at Mayo Clinic.[i] During the extremely heartfelt discussion, Dr. Rhodes not only describes the incredible story behind MBI and its development, but she also presents research findings that show MBI to detect “3 times as many cancers as mammography with equivalent specificity and a higher positive predictive value.”[ii]

MBI is a breast imaging modality, which has been shown to be a powerful adjunct to mammography, particularly when applied to screening women with an increased risk of breast cancer and women with dense breast tissue.  Following an injection of Tc-99m Sestamibi, MBI uses a dual-head cadmium-zinc-telluride (CZT) gamma camera to image the breast.[iii] In a study of 940 women with dense breast tissue, conducted by researchers at Mayo Clinic, MBI was shown to find 83 percent of tumors, while mammography found only 25 percent of tumors. [iv]

Continue reading →

Posted in Industry Updates, Nuclear Medicine | Tagged , , , | Leave a comment

Career advice for Technologists in a shrinking job market

Posted on April 19, 2011 by Jennifer Lilly Gutiérrez

The job market for radiology techs has been pretty bleak across the country over the past few years, and many technologists are looking for ways to move into other areas of the industry, either for more opportunities, or just a change of pace. The hard thing we find as radiology professionals, holding degrees with titles like “BS in Radiological Sciences,” is many medical and science related fields view our experience as too narrow to take on positions in writing or marketing, or maybe our patient care and imaging experience doesn’t seem to fit with their management or communications positions. As we all know, the experience we gain working in a hospital department on biomedical equipment supplies us with experience in a plethora of areas, but nothing tangible to present at a job interview. Job listings require experience in certain fields, but with no companies offering entry level positions in communications, writing, marketing, and management, how will you gain the experience?

If you’re serious about changing gears in your career, here is some advice on how to gain “real” experience and give you an edge when searching for a promotion, or your next job.

Continue reading →

Posted in Technologists | Tagged , , , , , , | 2 Comments

DaTscan: New SPECT agent for detecting Parkinson’s disease

Posted on April 4, 2011 by admin

By Dr. Kirandeep Kaur

DaTscan (Ioflupane I 123 or phenyltropane) (GE Healthcare) is a radiopharmaceutical contrast agent recently approved by US FDA for use with single-photon emission computed tomography (SPECT) for detecting dopamine transporters (DaT) in suspected Parkinsonian syndromes.

In January 2011, FDA approved DaTscan for non-invasive visualization of striatal DaT while differentiating between essential tremors and tremors due to Parkinsonian Syndrome (which includes idiopathic Parkinson’s disease, multiple system atrophy and progressive supranuclear palsy). DaTscan cannot help in differentiating among the different manifestations of Parkinsonian syndrome. DaTscan is an adjunct to other diagnostic evaluations.

Dopamine is one of the main monoamine neurotransmitters in the brain and is involved in the regulation of important brain functions such as locomotor activity, reward, and cognition. DaT is a plasma membrane protein expressed exclusively in dopamine neurons, where it acts by rapidly clearing dopamine released into the extracellular space, thus regulating the amplitude and duration of dopamine signaling.

DaTScan binds to the dopamine transporters in the brain and thus helps in their visualization. The pathology of Parkinson’s disease consists of the loss of dopamine neurons in the substantia nigra and the reduction of dopamine projections to the striatum. The DaTScan image of Essential Tremor shows normal distribution of DaT whereas there is asymmetric loss of DaT in Parkinsons Disease.

Continue reading →

Posted in radiotracers | Tagged , , , | Leave a comment

Turf-war no more in Maryland: state upholds self-referral ban

Posted on April 4, 2011 by admin

by Maggie E. Mason

On January 24, the Maryland Special Court of Appeals ruled that the Maryland Self-Referral Law, strictly prohibits Orthopedic Surgeons, as well as other non-radiologist practitioners, from offering “in-office ancillary services,” specifically Magnetic Resonance Imaging (MRI), Radiation Therapy, or Computer Tomography Scan (CT Scan) Services. Moreover, the Self-Referral Law prohibits the referral of a patient for such services to another physician in his or her group practice.

This decision upholds an earlier ruling made by the Circuit Court of MontgomeryCounty, which affirmed the Maryland State Board of Physicians’ interpretation of the Maryland Self-Referral Law, which the Board issued in its 2006 Declaratory Ruling.

Physician Self-Referral

Physician self-referral occurs when a physician orders tests for a patient, and the physician either performs those tests himself or refers the patient to have the test administered at a facility, in which the physician has a financial investment. The Maryland Self-Referral Law, enacted in 1993, was intended to parallel the restrictions put in place at the federal level in the Stark Law, part of the federal Ethics in Patient Referrals Act of 1989.

In an opinion offered to the House of Delegates by J. Joseph Curran, Jr. State Attorney General, “[The Self-Referral Law] was a response to growing concern about over-utilization of services and increased costs resulting from the action of physicians in referring patients to medical facilities in which the physicians haveinvestments.” (1)

While the Maryland State Legislature enacted the Self Referral Law in 1993, theBoard did not take action to enforce the law, until 2006, when CareFirst BlueCross BlueShield and The Injured Workers’ Insurance Fund filed petitions to the Board to determine whether physicians could legally refer patients for MRI “when the physician has a financial interest in the performance of that scan,” in accordance with Maryland’s Self-Referral Law. (2)

Continue reading →

Posted in Industry Updates, Legal Issues | Tagged , , | Leave a comment

Amyvid for the imaging of Alzheimer’s disease: an update

Posted on April 4, 2011 by admin

By Charlene Supnet, Ph.D.

Among the limited tools available for the detection and diagnosis of Alzheimer’s disease (AD), molecular imaging for early detection of AD is an appealing one because it could allow for patient treatment prior to significant cognitive decline and extensive neurodegeneration. In addition, the ability to accurately detect and diagnose AD would be invaluable in clinical trials for the evaluation of potentially disease-modifying therapeutics.

What is Amyvid?

Amyvid (florbetapir F18/18F-AV-45) is a molecular imaging tool that is under investigation for use in the detection of beta-amyloid plaques in living brain. Based on the original technology using the 11C-labeled Pittsburgh Compound B (PIB) to bind amyloid plaques, the F18 radioligand is used in conjunction with positron emission tomography (PET) to visualize and quantify the amyloid burden in brain. With a radioactive half-life of 110 min, thereby increasing its ability to be transported significant distances away from manufacturing sites, F18 can be widely used by physicians and researchers.

Continue reading →

Posted in radiotracers | Tagged , | Leave a comment