Radioisotopes, also known as radionuclides and radioactive isotopes, are used in both therapeutic and diagnostic applications in the medical field. According to the Nuclear Regulatory Commission, approximately a third of all patients in the U.S. admitted to hospitals will be diagnosed or treated using radioisotopes. A radionuclide is an unstable isotope with excess energy that is released in the form of radioactive decay. Radioisotopes will vary in characteristics such as energy, decay mode, and half-life.

Isotope Production

Radioisotopes used in medicine are created in various ways.  Nuclear reactors, cyclotrons (a particle accelerator), and nuclear generators are all used in the production of radioisotopes. 

Nuclear reactors are responsible for producing radioisotopes such as thallium-201 (Tl- 201), molybdenum-99 (Mb-99), iodine-131 (I-131), strontium-89 (Sr-89), yttrium-90 (Y 90), and xenon-133 (Xe-133). In radioisotope production via nuclear reactors, nuclear transmutation takes place when atoms of elements introduced into the reactor take on additional neutrons, made possible by a high neutron flux in the reactor.

Cyclotrons are responsible for producing radioisotopes such as fluorine-18 (F-18), oxygen-15 (O-15), indium-111 (In-111), iodine-123 (I-123) and rubidium-82 (Rb-82). Tl- 201 can also be produced in a cyclotron. A cyclotron is a type of particle accelerator. In radioisotope production via a cyclotron, atoms are bombarded with protons accelerated via a vacuum chamber, a magnetic target, and the application of alternating voltage across electrodes. Cyclotrons can be found in hospitals and nuclear pharmacies.

Radioisotope generators are most commonly used to produce technetium-99 (Tc- 99m). This radioisotope is the most widely used for nuclear medicine applications. A generator consists of a parent isotope, which naturally decays to a daughter isotope. The parent isotope is usually a long-lived isotope (an isotope having a long half-life) and the daughter isotope is a short-lived isotope (having a short half-life). For Tc-99m, the parent isotope is molybdenum-99 (Mb-99). A generator can be kept at a hospital and chemical elution will extract the Tc-99m from the column to be used for medical purposes.

Uses of radioactive materials in medicine

The characteristic of radioactive decay is what makes radioisotopes useful in their medical applications; however, different applications will take advantage of radioactive emissions in different ways. Radioactive materials are regularly used to treat medical conditions, diagnosis pathology, visualize and measure physiological functions, and localize structures and pathways. The following sections serve as an outline and review of various uses of radiopharmaceuticals in nuclear medicine, but are not intended to be a comprehensive collection of all indications and uses.

Diagnostic Applications

In diagnostic uses, the scintillation caused by the interaction of photons emitted during radioactive decay along with a scintillation material in detectors is used to either measure the amount of radioactivity in a certain area of the human body, or to create an image depicting where radioactivity has localized. Many radioisotopes are tagged to pharmaceuticals that follow specific pathways in the human body. Depending on their properties, different isotopes are attached to various materials, making them useful in imaging many different body parts such as the heart, brain, gallbladder, and bones.

Visualizing physiology

Because of ability to tag various materials to a radioactive element, a variety of physiological pathways can be visualized to assess proper function and determine pathology. Once a radiopharmaceutical enters the patient’s system, images can be taken that follow that pharmaceutical’s pathway through the body, and localization of the pharmaceutical at various time intervals can be assessed. This is the reason why, unlike many other radiological procedures, nuclear medicine imaging can take many hours to complete, and sometimes imaging takes place days after injection. Imaging times are dependent on the body’s physiological processing of the radiopharmaceutical, and not on technology or mechanics of instrumentation.

Blood perfusion: By using radiopharmaceuticals that localize in a specific organ upon delivery via the circulatory system, specific blood perfusion to most body organs can be assessed. Lack of blood flow is assessed by visualization of a lack of radioactivity in particular areas of the organ (“cold” spots in the image). 

Cardiac: One of the most common nuclear medicine procedures evaluating blood perfusion to a specific organ is a myocardial perfusion scan, assessing blood perfusion to the various areas of the heart muscle. By attaching a radioactive element to a pharmaceutical that localizes in the heart muscle, intravenous injection of cardiac imaging tracers can illustrate blood perfusion to the heart at the specific time of injection. This system is what allows rest and stress images to be obtained of the heart muscle. A patient is given one injection of a radiopharmaceutical while under resting conditions, and images can be obtained of the blood flow the heart muscle under those conditions. Decreased blood flow could be indicative of stenosis or scarred muscle tissue. A second set of images can be taken after a patient is injected with a second dose of the radiopharmaceutical under stress conditions (either via exercise or pharmaceutical stress). Although the images of the heart are not taken at the time of stress/exercise, because the pharmaceutical localized in the heart indicative of blood flow at the time of injection, images taken hours after stress/exercise will depict blood flow under those conditions. A cardiac perfusion agent can also be given to a patient at the time of acute chest pain to later assess if a decrease in blood flow to the heart muscle is causing the pain. Some of the radiopharmaceuticals used in perfusion imaging of the heart include: Tl-201, Tc-99m sestamibi, Tc-99m tetrosmin, Tc-99m teboroxime, and the positron emitter Rb-82. Cardiac perfusion tests are often given for risk stratification, assessment of CAD, and assessment of chest pain. 

Pulmonary: Blood perfusion to the lungs is most commonly indicated to assess pulmonary embolism. Tc-99m-labeled macroaggregated albumin (MAA) is injected intravenously, and immediately localizes in the capillaries of the lung where blood has perfused the tissue. MAA consists of particles that are too large to travel further than the capillaries of the lung. If an embolism is blocking blood flow in the lungs, it can be determined by lack of perfusion (lack of tracer activity) visualized on images.

Brain: Studies to assess blood flow to the brain are used to evaluate brain death. Various radiopharmaceuticals are used clinically for this assessment. Preferred agents to assess blood profusion to the brain include brain-specific Tc-99m-labeled ethylcysteinate dimer (ECD) and hexamethylpropylene amine oxime (HMPAO). Because these agents localize in the brain, they can be more reliable for assessment as delayed imaging of the brain can be assessed for perfusion and they are not reliant on a quality bolus injection (as non specific agents following blood flow on a first pass would be). Visualization of the tracer in the brain indicates blood perfusion to the brain, while lack of activity will indicate lack of blood perfusion/brain death. In addition to assessment of global blood perfusion, brain specific agents can identify areas of the brain receiving more perfusion than others. Various patterns and presentation of perfusion in specific areas of the brain can indicate specific neurological or behavioral disorders.

Cell metabolism/tumor detection: Positron Emission Tomography (PET) scans and bone scans are often used in nuclear medicine to detect the presence of tumors and metastatic disease. PET scans for cancer imaging employ the use of radioisotope and positron-emitter F-18 flurodeoxyglucose (FDG). This glucose analogue is injected intravenously and will be taken up by cells metabolizing sugar in the body. Since malignant cells are hypermetabolic, they have a much higher demand for the glucose molecule than normal tissues. Whole-body imaging after injection will show abnormal metabolism of tissues to assess hypermetaoblism in suspected or known areas of cancer. This can be used for detection, staging, or assessment of treatment. A limitation in visualizing disease in this procedure would be in areas of the body already highly metabolic cells, specifically the brain and heart. 

Whole-body bone imaging is done with a similar imaging protocol, and the skeleton is surveyed for areas of increased tracer uptake indicating bone metastasis. The radiotracer used most commonly for bone imaging is a Tc-99m-labeled phosphate that can incorporate itself into the bone matrix. Much like in PET imaging, areas of increased metabolic activity in the bone will take up more of the phosphate necessary for growth. Bone imaging can be used for other indications of bone pathology as well.  

Imaging for specific types of tumors is also carried out, as is the case with somatostatin receptor scintigraphy (SRS) using In-111 labeled pentetreotide. The pentetreotide pharmaceutical is a somatostatin analog and binds to somatostatin receptors on cell surfaces. Somatostatin receptors are present on neuroendocrine tumors, as well as some nonneuroendocrine tumors. Due to their high expression of somatostatin receptors, the most common tumors that appear using SRS are: adrenal medullary tumors, gastroenteropancreatic neuroendocrine tumors, Merkel cell tumors of the dermis, pituitary adenomas and small-cell lung cancer. Visualization of abnormal uptake of the tracer can indicate somatostatin receptor-containing tumors.   

Infection detection: For evaluation of infection, nuclear medicine has the capability to image the distribution of white blood cells a specific area or for whole body assessment. In this procedure, blood is withdrawn from the patient, white blood cells are extracted and labeled with In-111, and the radiolabeled lymphocytes are then reinjected into the patient. Via imaging tracer accumulation, it can be visually detected if there is an area of increased WBC accumulation, which can be indicative of infection. This can help confirm infection in a known area, or detect the presence and location of an infection. Whole body assessment is often used in cases of fever of unknown origin (FUO). 

Neuronal activity: Neuronal activity in the brain can be assessed with the F-18 FDG. The majority of ATP activity required for normal brain function is supplied by glucose, therefor a glucose agent is expected to locate in areas of high glucose metabolism in the body, and a lack of activity will be displayed visually when little or no glucose is being utilized. Certain areas of the brain where neuronal activity has been affected by disease can be visualized by assessing the appearance of radioactivity in specific areas of the brain and comparing appearances with normal visual presentation.

Gastrointestinal bleeding: Suspected gastrointestinal bleeding can be detected by tagging the patient’s red blood cells with Tc-99m, and reinjecting the radiolabeled blood back into the patient’s circulatory system. Imaging of the abdomen takes places over a period of time, assessing images for the presence of accumulated activity (blood pooling) in the gastrointestinal tract. Confirmation of a gastrointestinal bleed, as well as information regarding to the location of the bleed, can both be assessed using Tc-99m RBC imaging of the abdomen. Patients must actively be bleeding at the time of injection for the images to depict a bleed accurately. If bleeding has stopped prior to injection, the radioactive-labeled blood will not be delivered to the site of the previous bleed.   

Thyroid metabolism and function: Visual assessment of the thyroid tissue using radiotracers can determine physiological characteristics of thyroid nodules, as well as visualization of global activity characteristics in patients with suspected thyroid dysfunction. Tc-99m sodium pertechnetate and I-123 can both be used to visualize the function of the thyroid. Increased localization of the tracer on images will indicate hyperfunctioning tissue, while decrease/lack of activity in specific areas will indicate hypofunction. Assessment of the function of nodules can help assess if malignancy is present. Whole-body images can also be taken of patients with known thyroid cancer to indicate if cancerous thyroid tissue has spread/reoccurred after treatment and/or surgery.  

Gallbladder function: Evaluation of acute or chronic cholecystitis can be evaluated in hepatobiliary imaging using Tc-99m labeled disofenin or mebrofenin, which both follow the biliary pathway in the body. After injection, the tracer accumulates in the liver. Normally, the body will excrete bile from the liver into the gallbladder, and then into the intestinal tract. If the gallbladder does not visualize on the images (meaning no tracer has arrived in the gallbladder) acute cholecystitis is suspected. In chronic cholecystitis, the tracer may arrive to the gallbladder, but is inhibited from effectively delivering bile into the intestinal tract from the gallbladder, so the tracer will remain in the gallbladder for a longer period of time than in normal pathology. In the next section, the means of evaluating normal excretion of bile into the intestinal tract is discussed.  

Measuring function

The function of various organs and physiological systems can be measured and quantified using various isotopes and techniques in nuclear medicine.

Thyroid: Thyroid function can be measured by oral administration of radioiodine and subsequent measurement of the patient’s thyroid by the counting of radioactivity present in the patient’s thyroid using an uptake probe. Using the known activity of the dose, time of administration, time of the uptake measurement, value of the uptake measurement, and the appropriate decay factors, the percentage of iodine uptake in the thyroid can be measured. The determination of whether the thyroid is taking up more iodine than normal or less iodine than normal can help diagnosis and evaluate disease.   

Lung: Lung function can be quantified in post-operative patients to assess the ventilation capacity of and the blood perfusion to a transplanted lung. This test can also be carried out pre-operatively, to evaluate a patient’s lung function prior to a pneumonectomy. If a patient’s left lung is diseased and it’s removal is suggested, physicians can assess if the right lung’s function is sufficient to remove the left lung. This method can also be carried out to assess the function of various lobes of the lung when considering lobectomy. 

Ventilation and perfusion in the lungs are assessed using two different radiopharmaceuticals, however the means of quantification are the same. Ventilation studies often use a Tc-99m-labeled aerosol or a Xe-133 gas to image ventilation function in the lungs. When the radiopharmaceutical is inhaled, images are obtained of a breath hold, as well as equilibrium and washout during normal breathing.

Perfusion is measured using a Tc-99m-labeled radiopharmaceutical Tc-99m macroaggregated albumin (MAA). These radiolabeled particles become trapped within the lung capillaries upon the first-pass injection and allow visualization of where blood flow to the lungs is. On both ventilation and perfusion images, areas of interest are drawn using a computer program around separate lungs, or lobes of the lungs. Counts are calculated via the computer program to assess the amount of radioactivity localizing in each area of the lung in each respective scan. These values are used by physicians to assess the function of areas of the lungs prior to and after surgical procedures.  

Heart: Function of the pumping ability and capacity of the heart ventricles can be assessed using planar imaging of the heart. To assess left ventricular function, a first-pass of any Tc-99m-labeled agent can be imaged. By drawing a region of interest around the right ventricle, the amount of radioactive tracer (determined by counts) in the ventricle at systole and diastole can be assessed by a computer program. The resulting data called a Right Ventricular Ejection Fraction (RVEF). During a gated blood pool study, red blood cells can be tagged with Tc-99m, and images of the heart pumping over time are acquired. The resulting images depict the blood pumping in and out of the ventricles of the heart. This study also allows determination of ventricular function, where a region of interest is drawn over the left ventricle and an ejection fraction (LVEF) is calculated. Due to positioning and imaging restrictions, some clinicians may prefer calculating ventricular function using various scanning techniques and protocols, but the ultimate determination of function via imaging blood within the ventricles remains the same. This test is often used to assess a patient’s suitability for chemotherapy, as treatment agents will often cause a decrease in heart function. It may also be used as assessment post-therapy to compare to a pre-therapy baseline and determine the amount of damage done to the heart. Ventricular ejection fractions can also be calculated using cardiac perfusion studies and PET applications in nuclear medicine. 

Kidneys: Renal emptying function can be quantified via time activity curves when using a radiotracer that binds to renal parenchyma, excretes into the urine via tubular secretion, and is processed through glomerular filtration. This protocol most often uses Tc-99m-labeled diethylenetriaminepenta-acetic acid (DTPA) or mercaptoacetyltriglycine (MAG3). Once the radiotracer localizes inside of the kidneys, following urinary excretion pathways, emptying of the kidneys into the bladder is imaged (often after administration of a diuretic). Regions of interest can be drawn over the kidneys and a computer program can generate a time-activity curve to assess the emptying function of the kidneys by gathering count information within the regions.

Gallbladder: In hepatobiliary imaging, function can be measured by obtaining an ejection fraction of the gallbladder. The Tc-99m-labeled radiopharmaceuticals disofenin or mebrofenin are used to visualize the biliary pathway. When acute cholecystitis is not present, the tracer accumulates in the gallbladder. Excretion of the tracer into the intestine follows biliary excretion (often after administration of cholecystokinin to stimulate excretion). A region of interest is drawn around the gallbladder and an ejection fraction and time activity curve can be generated via a computer program to assess biliary function.

Gastric Emptying: Administration of a radiopharmaceutical in a food source will enable measurement of digestive function. Tc-99m-labeled agent sulfur colloid is combined with a small meal (often an egg or oatmeal) and images are obtained of the stomach after ingestion to assess digestion over a time. Sulfur colloid is preferable to use, as it is not absorbed through the stomach into the blood stream, therefor activity remains localized throughout the gastrointestinal tract. A stomach-emptying curve is created after a region of interest is drawn around the stomach and applied to images over a specific time period. Percent emptying is calculated to assess for gastroparesis.

Localization of pathways

Lymphoscintigraphy: Nuclear medicine applications can be used to localize the sentinel nodes where cancerous tissues are draining to prior to mass removal. This assists surgeons in the ability to remove only lymph nodes that could be affected by cancerous tissues. In this procedure, Tc-99m labeled sulfur colloid is administered subcutaneously in the areas immediately surrounding the cancerous tissue. Because sulfur colloid particles will not diffuse into surrounding tissues, the lymphatic flow from the site of the malignancy can be followed via imaging. Radioactive material will then accumulate in the lymph nodes where the malignancy is draining. Technologists can mark the location of these lymph nodes on the patient’s body using a marker prior to them going into surgery to assist the surgeon in localizing possibly affected lymph nodes. Surgeons can also use a gamma probe in the operating room to survey the patient’s body and localize the lymph nodes with the accumulated tracer.

Therapeutic Applications

In therapeutic uses, the deleterious effect of high-energy radiation on human cells is used. Therapeutic radioisotopes are generally longer lived than those in diagnostic use and possess higher energies. A few examples of how radioisotopes are used for therapeutic purposes are summarized below.

Treatment of thyroid disease with Iodine-131

I-131 is therapeutically used for to treat thyroid cancer, hyperthyroidism (including Graves’ disease, toxic multinodular goiter, and toxic autonomously functioning thyroid nodules), and Nontoxic multinodular goiter. Iodine molecules are naturally taken up by the thyroid gland, and used to produce the thyroid hormones triiodothyronine (T3) and thyroxine (T4). By introducing a radioactive form of iodine into the body, the element and radioactivity will localize in the thyroid tissue, causing damage to the thyroid tissue, but no other vital tissues. I-131 has a physical half-life of 8.1 days. It emits beta particles (average energy of 0.192 MeV, maximum energy of 0.61 MeV). Because the beta particle’s range in tissue is 0.8mm, it prevents cellular damage to tissues outside of the thyroid gland. I-131 also emits a gamma ray of 364 KeV, which can be used diagnostically for imaging. I-131 is administered orally in capsule form. When used to treat thyroid cancer, I-131 therapy can be carried out post-thyroidectomy to ablate any remaining tissue, as well as to treat residual thyroid cancer or metastatic thyroid cancer.

Palliative Treatment of bone metastasis

Bone metastases are a common outcome of metastatic cancers. The pain occurring from these metastases is thought to be of a separate origin than neurological or inflammatory, making many conventional methods of pain alleviation ineffective. Pain from bone metastases can be quite severe and highly affect a patient’s quality of life. Radiopharmaceutical therapy is used as a palliative treatment to alleviate pain in the late stages of cancer. Radiopharmaceuticals are used that are naturally taken up by the bones and incorporated into the skeleton. This skeletal incorporation will allow the radioisotope to deliver a specific radiation dose directly to the bone, inhibiting osteoclast-activating compounds, and/or destroying hypertrophic bone matter. This disruption of the malformation of bone in metastatic areas is caused by radiation damage to cellular compounds. Various radioisotopes and pharmaceuticals are used to deliver palliative treatment of bone metastases, including samarium-153 (Sm-153), strontium-89 (Sr-89) chloride, and phosphorus-32 (P-32) sodium phosphate. The two most common side effects occurring from radiopharmaceutical therapy for metastatic bone disease are initial increased bone pain (flare) and a decrease in WBC and platelet counts.  

Samarium-153 EDTMP (lexidronan): The most commonly used radioisotope for this treatment in the United States is Sm-153. Sm-153 has a physical half-life of 1.9 days and emits beta particles with an average energy of 0.23 MeV (maximum energy of 0.81 MeV). Sm-153 has a soft-tissue range of approximately 0.6mm, keeping radioactive damage to tissue localized in bone matter. Sm-153 also has a gamma ray emission of 103 keV, which allows diagnostic imaging of the radioisotope distribution to be performed. Sm-153 will localize specifically in osteoblastic sites (sites of bone proliferation).  Sm-153 is administered intravenously. 

Strontium-89 chloride: Sr-89 incorporates itself into the bone similarly to calcium. Its primary area of localization is in areas of osteoblastic activity. Sr-89 has a physical half-life of 50.5 days and emits beta particles with an average of 0.58 MeV (maximum energy of 1.46MeV). Sr-89 has a soft-tissue range of approximately 2.4mm, keeping radiation damage localized in the bone tissue.

Phosphorous-32 sodium phosphate: P-32 is one of the first radioisotopes used for palliative treatment of bone metastases. It incorporates itself into the cortex of the bone as well as into the nucleic acids of growing bone matter. Its beta particle emission has an average energy of 0.70MeV (maximum energy 1.71MeV) and a soft tissue range of approximately 3.0mm, limiting damage to organs surrounding the skeleton. Its physical half-life is 14.3 days. P-32 can be administered orally or intravenously. 

Non-Hodgkin’s lymphoma therapy

Therapeutic treatments are given using a radioisotope attached to an antibody to deliver radioactivity to specific cells are called radioimmunotherapy (RIT). Radiopharmaceuticals I-131 tositumomab and Y-90 ibritumomab are used in this way to treat Non-Hodgkin’s lymphoma.

I-131 tositumomab: Tositumomab is an anti-tumor monoclonal antibody against the CD20 antigen, and attaches to B-cell lymphocytes, both malignant and normal (over 90% of NHL B-cells). When tositumomab is tagged with I-131, a radioactive dose can be directly delivered to B-lymphocytes carrying the CD20 antigen. I-131, emitting beta particles and gamma rays, allows for therapeutic treatment as well as imaging assessing distribution and delivery of dose. Beta particle emission is responsible for the majority of the damage to cancerous cells while gamma rays allow for imaging. I-131 tositumomab is administered intravenously. Because of the natural uptake of I-131 in the thyroid, an oral thyroid-blocking agent is administered to the patient during treatment to prevent damage to thyroid tissue. The specific patient dose necessary for I-131 tositumomab treatment is calculated based specifically on patient metabolism and elimination of the radiolabeled antibody, determined from imaging procedures.

Y-90 ibritumomab tiuxetan:Ibritumomab tiuxetan is a monoclonal antibody that also targets the CD20 antigen found on mature B-cell lymphocytes to carryout RIT. Ibritumomab tiuxetan is labeled with Y-90, which allows delivery of beta particles directly to B-lymphocytes carrying the CD20 antigen. Prior to administration of the radiolabeled antibody, patients receive a nonradioactive dose of rituximab to clear B cells from circulation and localize cancerous B cells in lymphatic tissues. This allows a higher delivered dose to the cancerous B cells at the time of injection of the radiolabeled antibody. Rituximab is used in non-radioactive therapy treatment to destroy B lymphocytes expressing the CD20 antigen in Non-Hodgkin’s lymphoma patients. When rituximab is administered during Y-90 ibritumomab therapy, it is given at a nontherapeutic dose, and used only to enhance the effects of the following injection of radiolabeled monoclonal antibody. Y-90 ibritumomab tiuxetan is administered via intravenous infusion. The specific patient dose necessary for Y-90 ibritumomab tiuxetan is based on patient weight and platelet count. Because Y-90 is a pure beta-emitter, a biodistribution scan must be performed using a ibritumomab dose labeled with a gamma-emitting isotope. This is performed using In-111 ibritumomab tiuxetan injection after delivery of the therapeutic dose. In-111 has dual energy photopeaks of 172 and 247 keV.

Regulation of radioactive materials in medicine

The licensing and regulation of radioactive materials in the United States is shared between two agencies: the U.S. Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission (NRC). Radiopharmaceuticals specifically must be evaluated and approved by the Food and Drug Administration (FDA) just as any other pharmaceutical. In certain states, designated as “Agreement States,” some regulatory powers and licensing requirements are handed over to the state authorities.

Access the continuing education assessment for 1.5 Category A CE credits here.

References:

Imaging Startups

Imaging companies in the early stages of their business may not have the history of income necessary to secure a loan or lease for imaging equipment; camera rentals are a great alternative to camera leasing, with month-to-month agreements and without many of the qualifications necessary for loan agreements.

Startups are not always sure if they’ll be able to acquire the patient flow to be viable; Camera rentals can limit this risk with not long-term lease to worry about.

Startups can use a camera rental agreement as an opportunity to build equity through regular monthly rental payments.

Existing Sites wanting to expand

Imaging centers with a plan to expand their practices could find renting a camera as opposed to purchasing or leasing one, will allow them to mitigate risk and assess patient volume without making any long-term commitments. Imaging centers may also find a camera rental option better for their expansion plans due to less financial qualifications required as opposed to leases and loans, and still have the opportunity to build equity in their equipment through their monthly payments.

Imaging Centers in need of a temporary camera

Imaging centers in the middle of a move will benefit from a flexible rental agreement and compact camera options if they are confined to a smaller area In the midst of construction. This allows centers to maintain a scanning schedule even when their permanent imaging rooms are unavailable.

Imaging centers waiting for a new camera delivery can utilize a camera rental if when their site and staff are ready, This way centers can begin patient scanning whenever they’re ready, and won’t have to worry about unexpected delays due to delivery and installation of the new equipment.

What are the benefits of renting a camera?

In addition to specific benefits mentioned above, camera rental programs also allow for:

Quick delivery

Personalized rental programs designed to build equity in equipment

Short-term commitment/low-risk

DICOM included for uninterrupted archiving

What additional benefits can MAI Services offer with their camera rental program versus others?

MAI offers a variety of nuclear gamma cameras for rental; ranging from dedicated cardiac cameras to dual-head variable angle cameras that can perform all nuclear imaging procedures. MAI has experienced staff to complete all necessary installation and deinstallatoin procedures for larger cameras, and also offers rentals of portable and small footprint cameras such as the maiCAM180/GVI mSPECT. maiServices has solutions for imaging practices of all specialties and stages of business development.

For more information on maiServices Gamma Camera Rentals, click here.

Personal mobile devices such as smart phones and tablet computers are becoming more popular among clinicians as they look for ways to improve their daily delivery of healthcare. These devices have increasingly powerful processors and larger hard drive capacities which can be an asset when interacting with large image data sets. However, there are risks for organizations and individuals who use these devices if they are lost or stolen and there is protected health information (PHI) stored within the device. A little preparation by an organization before a loss occurs can possibly limit the scope of the damage, or at least provide a starting place for recovering from the initial shock of the event.

The Centers for Medicare and Medicaid Services offers extensive information about how to handle the various types of data losses that are considered reportable. Click here to view an incident handling procedure document which provides definitions and descriptions of each type of data beach. Once the possible situations are understood, organizations can begin preparing accordingly.

Depending on your organization’s IT infrastructure and polices, handling the loss or breach of these devices may already be a part of your emergency plan of action. However, if you are a smaller facility, for example a critical access hospital or an outpatient imaging center, there might not be as much technical support for employees with these types of devices. There are some very good resources freely available from the Center for Internet Security which offers step-by-step guidance for configuring the security settings for a wide variety of devices, including those that run iOS or Android operating systems. The security benchmarks are updated regularly as newer versions of software are released.

Another suggestion to make a data breach more manageable is to create an audit of personal devices that interact with your clinical networks and/or PHI. This should include all device serial numbers, operating software level, and what type of PHI, if any, that permanently resides on your device. Optimally, no patient data should be stored on a device, but rather the device is used to access information based on secure, encrypted servers. Be sure to keep this list in a safe location that can accessed by the staff responsible for the organized response.

There are many steps an organization must take to ensure that the devices that interact with PHI are secure. Any preparation that can precede a data breach occurs will take some of the chaos out of the situational response. Collecting basic data about the devices used at your facility are some early, relatively painless steps that can contribute to a successful resolution of the event.

More about author, Paul Dow, MD, RT(R)(CT)

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Fearing a professional rut? 

According to the latest ASRT survey, the vacancy rates for all imaging modalities have dropped significantly since 2003. The modality seeing the biggest hit is Cardiovascular Intervention, dropping 11.1%, and Nuclear Medicine close behind dropping 9.5%. Our survey participants identified Radiography and Nuclear Medicine as the modalities in the lowest demand (43% and 35% respectively), while 41% felt Sonography was in the highest demand.

The statistic that speaks the loudest to the current job climate for RTs and CNMTs is that 57% of those surveyed knew more than 5 technologists that were either unemployed, or employed with limited/decreased hours, due to the inability to find work. Overall, 94% identified knowing at least 1 technologist (including themselves) that could not find full-time work in their field. While some professionals attribute this to the overall reduction in work due to the economy, others argue that this statistic of unemployment is too high to blame entirely on budget cuts.

Some professionals feel that imaging schools are doing a disservice to the profession by not taking measures to reduce class size, thereby helping the demand for the profession. 81% of or participants thought that accreditation bodies should take action to limit the number of students admitted into imaging schools in response to the current surplus of techs. While the overwhelming majority felt this responsibility lay with the professional oversight in the industry, some participants who disagreed commented that it is the responsibility of students to research the job market before applying. While others agreed that to be true, they noted the students are not the only ones suffering due to the size of graduating classes. Many technologists who have been in the field for years are now unable to find work, being passed up for new grads to decrease salary costs. Many participants also noted they were being told they were “overqualified” for tech positions, so new grads were being hired. Additionally, numerous new-grads have found themselves without jobs, over a year after graduation from the programs. With no employment and experience directly after graduation, many new grads find themselves with a terrible disadvantage in competition for open positions.

So with all this being said, how did Radiologic Technology make it to U.S. News’ Best Careers of 2011? Radiology technologists are proud of their profession, skill set, and the role they play in patient diagnostics and medical advancement; however, most are shocked to see it pop up as a smart career move in this job market. U.S. News identifies an expectation of job growth in the field due to the aging population leading to an increased need for diagnostic imaging. After publishing the article in December of last year, techs were fast to comment on the site about their own experiences in the radiology field, some accusing U.S. News of being irresponsible to publish an article promoting entrance into a field with such a high unemployment rate.

Our 135 survey participants represent 32 states and 7 modalities.

Advice given by techs answering our survey to help in getting and maintaining work includes: multi-modality certification, relocation, networking, searching for work in education, application, sales, and health IT, and patience!

For more career advice for rad techs, read previous posts: Career Advice for Technologists in a Shrinking Job Market & Fearing a Professional Rut.

Articles on the technologist job market and field:

U.S. News, Best Careers of 2011

DOTmed News, Radiologic technologist job market still tight

HealtheCareers, Radiologic Technology Makes it to U.S. News’ 50 Best Careers of 2011 List

Radiology Careers Job Postings:

JobJobHealth

ASRT via Healthecareers

ADVANCE for Healthcare Careers via HealthcareJobs

RSNA Career Connect

Hot Radiology Jobs

Radworking Job Board

Aunt Minnie Career Center

RadiologyJobs.com

The exposure of protected health information is always a cause for concern. There are varying degrees of exposure, and there are varying degrees of response. What separates the quality of the response from good to bad is the level of accountability and responsibility an organization takes for the loss of patient data. The best response I have seen recently from an organization has come from Stanford Hospital and Clinics.

A breach of information for approximately 20,000 emergency room patients of the Stanford Hospital and Clinics website occurred between March and August of 2009, as reported by a recent New York Times article. The breach arose from the actions of a contractor who posted patient information on a publicly accessible web site. The incident was not caused by the hospital and the contractor has assumed responsibility for the event. There will be other steps taken by the hospital as the investigation continues.

What makes this situation response remarkable to me is that Stanford Hospital and Clinics has gone the extra step to provide identity theft protection to each person who had their data exposed. Although the information exposed did not include credit card or social security numbers, Stanford is going a step further to ensure that patients feel their private information will not cause them substantial damage. It also shows that Stanford is taking steps to demonstrate that they take this event seriously and that they realize that patient/customer trust is a fragile thing.

There are choices people can make. If people do not feel their information, clinical or not, is safe, then they might take their business elsewhere. In this case, the proactive choices made by Stanford seem to be the best response an organization could provide.

According to the article, a patient discovered the breach and alerted the facility. As patients become more technologically savvy, what could your organization do to ensure that in the event of a similar situation, it could win back the trust of your valuable patients/customers? Could you convince people that your facility respects their information and treats it as if it was their own?

More on author and clinical informatics educator, Paul Dow

NMAA candidates must first be graduates of an accredited Nuclear Medicine Technology program, and hold a Nuclear Medicine Technologist certification.

In addition to regular technologist duties, NMAAs could be responsible for:

• ordering and administering testing agents
• administering sedation (under supervision of a physician)
• assessing and monitoring patients, monitor exercise and pharmaceutical stress testing procedures
• performing therapeutic procedures (under supervision of a physician)
• assessing patient images
• requesting further imaging and/or ordering additional diagnostic procedures to compliment nuclear medicine findings
• preparing preliminary reports and readings on tests
• communicating report findings to ordering physician

The NMAA program at UAMS is designed as a distance learning program, which makes it accessible to technologists all over the country. Online courses are combined with clinical assignments at local facilities, often times the technologists current place of employment. The program consists of 5 semesters, and is flexible enough that it can be carried out over of a course of up to five years. This means, not only can you study online, you can carryout your clinical practices without leaving your current job. It’s a lot of work, but UAMS and it’s collaborates have designed a program that can help a candidate succeed, by eliminating many of the burdens of advanced studies.

There are three start dates available per year, and the GRE is also required for admission. Two letters of reference (preferably one academic and one professional) are required, a letter of intent, and the candidate must be ACLS certified and have worked in clinical field for at least 2 years post-certification. Additionally, the candidate is responsible for filing paperwork for the clinical site they have chosen to act as an affiliate, and there must also be a nuclear medicine physician or radiologist who agrees to work as the candidate’s preceptor during clinical assignment.

More information on the NMAA can be found at the links below:

Nuclear Medicine Technologist Certification Board 

Society of Nuclear Medicine: NMAA Scope of Practice

University of Arkansas for Medical Sciences

The process by which the FDA reviews medical devices has recently come under increasing criticism. Both consumer and manufacturing groups are frustrated with the slow pace and nature of the medical device review process.

In 1938, Congress first regulated medical products for safety and effectiveness, although at the time these were mainly drugs and not medical devices. In 1976 the FDA took sole responsibility to regulate the medical device industry in the US; two competing goals were the focus: to provide the public reasonable assurances of safe and effective medical devices and to avoid overregulation of the industry. The most recent reorganization of medical device regulation came in 2002 as the Medical Device Fee and Modernization Act (MDUFMA), which was interpreted by the FDA as a shift towards the least burdensome approach to medical device approval. The FDA, and more specifically, the Center for Radiological Health (CDRH), offers two paths to approval. First, is the Premarket Approval Process (PMA), typically used for products which support or sustain human life. This process is lengthy and intensive. The second path is the 510(k) approval process, which was designed for use with lower risk products as well as changes made to existing products, or those that are substantially equivalent to previously approved products. Regardless of the approval process, the federal Food Drug and Cosmetic Act requires reasonable assurance of safety and effectiveness before a product reaches the market.

Recently, the 510(k) process has become burdened beyond its design. In 2009, 90% of new medical devices were approved through 510(k) and the FDA received 4,000 submissions for approval. A 2011 Archives of Internal Medicine article, by Diana Zuckerman et al., reported that of the 113 Class I recalls of medical devices (Class I is the strictest recall of a product which has the potential to cause serious health problems), 71% were approved through 510(k) while only 19% through PMA.

Concerns about the 510(k) process, its evaluation of new devices, and increased prevalence of recalls led the FDA to take a two-pronged approach in September of 2009. The FDA conducted its own internal review of 510(k) to analyze what changes could be made to improve consistency in the program, and commissioned an independent study by the Institute of Medicine (IOM).

In August 2010, the FDA and the CDRH released a two-volume report which outlined proposed changes to the current 510(k) process. The goal of the FDA working group was to recommend reforms to the 510(k) process and make more effective use of science in regulatory decision making. The Journal of Medical Device Regulation reported on the FDA’s recommendations in a November 2010 special issue. The plan specified 25 specific actions to be taken, or at least begun, in 2011 in order to overhaul the 510(k) process. Overall the working group left the current regulatory framework intact, but with substantial revisions. Some of the proposed changes include streamlining of the ‘de novo’ process for low-risk devices, creation of a new class of device, IIb, to aid in categorization of moderate-risk devices, development of a network of scientific experts that can be called upon to help the agency evaluate new products as well as a senior science council aid in science-based decision making, and increased cooperation between submitters and scientific reviewers during presubmission. The updated regulatory framework set forth by the FDA puts an emphasis on the scientific evaluation of medical devices in hopes to avoid future recalls by approving innovative, safe products. In his congressional testimony, Dr. Jeffery Shuren stressed greater use of outside scientific experts, as well as better training for in-house reviewers, which will “provide greater clarity for industry through guidance and greater interactions about what we need from them to facilitate more efficient, predictable reviews.”

The second prong of the 510(k) process evaluation, the IOM report, was released in July 2011. Two questions were posed to evaluate the fate of 510(k): first, “Does the current 510(k) process protect patients optimally and promote innovation in support of public health?” and second, “If not, what legislative, regulatory, or administrative changes are recommended to achieve the goals of the 510(k) process optimally?” A major flaw (in two parts) in 510(k), noted by the IOM, is the substantial equivalency clause. First, as it has been used recently, a device can gain approval by citing substantial equivalence to devices that were approved prior to the current Medical Device Amendments and therefore were not subject to current standards. The FDA does not currently require proof of safety and effectiveness for predicate devices, which compounds the problem with this type of approval. Second, under the current system a device can apply for approval as a split predicate, those where a device claims equivalence to intended use of one predicate and the technology of another. The 510(k) designation was designed for this type of moderate-risk predicate device. This precipitated a letter to Dr. Jeffery Shuren, CDRH director, on behalf of the IOM, in which Dr. David Challoner concluded that the 510(k) approval process is not a determination that a device is safe and effective, and lacks legal basis to be a reliable pre-market screen for moderate-risk devices.

The IOM committee also outlined deficiencies in the current post-market surveillance, which could dramatically reduce the prevalence of large-scale recalls. Ultimately, the IOM report recommended the FDA abandon 510(k) and put in place an integrated premarket and post-market regulatory framework that provides a reasonable assurance of safety and effectiveness throughout the device life cycle (Institute of Medicine report, July 2011). Dr. Gregory Curfman, editor of the New England Journal of Medicine (NEJM), has also called for scrapping 510(k) in a recent NJEM article saying, “It is important to maintain and encourage innovation in medical devices. But true innovation requires that safety and effectiveness be proven by scientific study in clinical trials” (Curfman and Redberg, 2011).

Whatever the form that medical device reform ultimately takes, device makers have valid concerns about process as well as the end result. Medical device manufacturers worry that increased regulations in the new approval process would create uncertainty and stifle innovation. Mark Leahey, president of the Medical Device Manufacturers Association, said, “We remain concerned about efforts to overhaul a regulatory pathway that would create additional uncertainties and slow patient access to medical therapies.” Congressman Erik Paulsen, MN, disagreed with the IOM’s recommendation to scrap 510(k) altogether: “The medical technology industry is already facing unprecedented challenges – a job-stifling innovation tax and an increasingly out-of-touch FDA – and eliminating the 510(k) process would give Europe another leg up in competing for these made-in-America technologies, what the medical devices manufacturers need is consistency in the approval process, not more uncertainty.”

While the FDA aims to streamline the medical device approval process known as 510(k), others, such as the IOM, wonder if such changes are possible within the existing regulatory structure or if more radical changes are necessary – and device manufacturers and consumers are left uncertain as to the future of medical device regulation.

Read more about author, Ryan Hamilton, PhD

References

Curfman GD, Redberg RF. Medical devices – balancing regulation and innovation. N Engl J Med. August 10, 2011.

Institute of Medicine. Medical devices and the public’s health: the FDA 510(k) clearance process at 35 years. Washington, DC: National Academies Press, 2011.

Shuren, Jeffery, MD, JD. Statement to the House, Subcommittee on Oversight and Investigations Committee on Energy and Commerce. Regulaory Reform Series #5 – FDA Medical Device Regulation: Impact on American Patients, Innovation and Jobs, Hearing, July 20, 2011. Available at: http://republicans.energycommerce.house.gov/Media/file/Hearings/Oversight/072011/Shuren.pdf; Accessesd: 8/14/11.

Zuckerman DM, Brown P, Nissen SE. Medical device recalls and the FDA aproval process. Arch Intern Med. 2011;171:1006-1011.

Technetium-99m (Tc-99m) is the most used radioactive tracer with over 30 million tests per year done all over the world. When tagged to a pharmaceutical or biological marker, it helps evaluate, diagnose or manage cancer spread, blood flow and cardiac function; brain activity and thyroid disease; and detect osseous metastasis, fractures and infections (bone scan). Radiology professionals inject this radioisotope to gauge blood flow to the organs and detect cancer spread much earlier and with greater precision than many other methods, including PET or CT scan. Tc-99m, with a half-life of just 6 hours, is the most preferred radioactive tracer—it emits high energy 142.7 keV gamma rays, allowing very high resolution imaging without posing any danger of long-term radiation damage to the internal organs. Lately, Tc-99m supply chain has come under stress. In the January 21, 2011 issue of Science, Robert F. Service wrote that due to the 2009 temporary closure of NRU and Petten reactors and resulting shortage of Tc-99m, “physicians were forced to use less Tc-99m for many procedures, ration what scant supplies remained, and find less desirable substitutes.”

Tc-99m is a metastable (“m” for metastable) isotope of molybdenum-99 (Mo-99) which is a fission product of highly-enriched Uranium (U-235). Mo-99 has a half-life of 2.7 days; it is normally produced at Research Reactors around the world, and shipped encased in technetium generators to hospital radiopharmacies.

Mo-99 is currently made at five nuclear facilities around the world. Most of the Mo-99 used in the United States is imported from Chalk River, Ontario-based National Research Universal (NRU) reactor. NRU and High Flux Reactor (HFR) at Petten (in Netherlands) together supply nearly three-quarters of all worldwide demand for Mo-99, the rest coming from reactors in Belgium (BR2 reactor at Mol), France (Osiris reactor at Saclay), and South Africa (Safari reactor at Palindaba); Australian OPAL reactor in Sydney also makes some Mo-99. Both NRU and Petten reactors are half a century old (52- and 47-years old, respectively) and have had their share of shutdowns and repairs, disrupting supplies and creating real shortages. When NRU was closed for repairs between May 2009 and August 2011, the radiation departments all over the country found themselves looking for alternate sources, where there was none! The situation became worse when Petten reactor was also briefly closed in May 2009 to fix corroded pipes.

There is an urgency to the long-term Mo-99 supply situation, since the NRU reactor is slated to permanently close in 2015. The alternatives to using Tc-99m imaging are inadequate—doctors could order CT or PET scans, but these methods expose patients to a much higher radiation dose; cost more; or provide relatively poor quality images. Several commercial and federal initiatives are attempting to address the looming Mo-99 shortage. In a recent article in The Scientist, Robert Schenter, CSO of Kennewick, Wash.-based Advanced Medical Isotope Corp., described two technological initiatives under development that may address Mo-99 shortage in the United States: Robert Schenter’s company is developing a proprietary method of producing Mo-99 by passing a beam of electrons through a tube containing deuterium oxide (heavy water) and U-235. Splitting of deuterium nuclei by photons (a result of electron beam) and the release of neutrons initiates U-235 fission and Mo-99 production; another company, Babcock & Wilcox Company, Lynchburg, Virginia, is developing a patented aqueous homogeneous reactor (AHR) technology that uses low-enriched uranium. In addition, GE Hitachi Nuclear Energy in Wilmington, North Carolina, is developing a neutron capture method that may eliminate the use of high-enriched U-235. Scientists at the National Measurement Standards in Ottawa, Canada, have recently developed a method to knock neutrons out of Mo-100 atoms using an electron linear accelerator to produce Mo-99; thus, eliminating the need to use highly-enriched Uranium. In the United States, two federal facilities can be tapped to meet emergency demand: the University of Missouri Research Reactor Center (MURR) and Annular Core Research Reactor (ACRR) at Sandia National Laboratories, Albuquerque, New Mexico. In September 2010, IAEA held a conference where various stake holder countries re-affirmed the goal of completely phasing out highly-enriched uranium (which can be diverted towards producing nuclear weapons) and developing alternate strategies to meet Mo-99 demand—U.S. is a signatory to this agreement. Time is running out, but hopefully some of the initiatives above will mature before NRU and Petten are consigned to Smithsonian history along with Shuttles Challenger and Columbia.

Read more about author, Medical Writer and Cancer Biologist, Ajay Malik, PhD

References:

Scrambling to Close the Isotope Gap. Service RF. Science. 2011 Jan 21;331(6015):277-279 | DOI | GoogleScholar |

Desperately Seeking Radioisotopes. Schenter RE. The Scientist. 2011 July 1; 25(7):26 | FullText |

Battling the Bottleneck: Critically Needed Diagnostic Isotope’s Supply Remains Uncertain. Kidambi M. IAEA Bulletin. 2011; 52(2) | PDF Link |

Medical Isotope Production Without Highly Enriched Uranium (2009). Nuclear and Radiation Studies Board (NRSB). [web page] National Academy of Sciences, Washington D.C., web site. http://www.nap.edu/openbook.php?record_id=12569&page=55.  Accessed July 19, 2011.

The Good and Bad of the Situation

Google has announced in their official blog that their Personal Health Record (PHR) experiment is coming to an end on January 1, 2013. If you have data entered on their site there will be enough time to safely export the data to another application. However, this announcement, like many events in life, is not all good or all bad for the average healthcare consumer. There are still many useful, and free, options for the empowered patient. Microsoft’s HealthVault is available, as well as an AHIMA version, MyPHR which can cover the needs of most, if not all, consumers. What then is lost, really, from this announcement? Not as much as you might initially think.

First and foremost the Google name brought attention to the important idea of patient empowerment. Unfortunately, after the initial surge, the interest trailed off. One difficulty may have been that the people who are likely to use this application, Baby Boomers for example, may not have been aware of the existence of Google Health, or they may not have had the inclination to use an electronic version of any paper records they may have collected. This is a challenge that must be overcome for any electronic platform to be successful.

Secondly, the benefits of increasing the awareness of patients and their families of the care they receive can also influence the quality of the care delivered. Hopefully this attention will be diverted to other PHR solutions. When more people are included in a process, accountability becomes shared and fewer mistakes can occur. By creating free, portable, electronic versions of something as vital as an electronic health record, it will continue to be an asset to improving care for large numbers of people.

Finally, one of the bigger disappointments comes from the loss of a large source of creative energy that will not be applied to solving the problems of adoption of PHRs.  Google has found ways to improve the quality of our digital lives, and hopefully this setback will lead to other solutions from other places. Even with this setback, we are one step closer to the answer, even if we only figure out what doesn’t work.

Read more about author and Clinical Informatics Educator, Paul Dow, BS, RT(R)(CT)