Remote High Dose Rate (HDR) Afterload Brachytherapy for Precision

Remote high dose rate (HDR) afterload brachytherapy is a highly-effective outpatient option that minimizes harmful side effects of oncology treatment, significantly reduces treatment and recovery times and most importantly, minimizes recurrence of many types of cancer. Brachytherapy is the standard term used for a radioactive source applied in or near a tumor. Brachy means near and therapy means treatment.

Brachytherapy is delivered by placing the radiation sources (Ir192) near the tumor. A multichannel Microselectron HDR with TCS remote afterload system is a dedicated machine which delivers radiation in and around the tumor. Brachytherapy can be used in the following:

• Intracavitary for cancer of the cervix and uterus
• Intraluminal for esophagus and bronchus cancer
• Interstitial for breast cancer, soft tissue sarcoma (after initial surgery), prostate and pancreatic tumors
• Surface mold for superficial cancers, especially skin cancer

These procedures may require anesthesia, a surgical procedure and a brief stay in the hospital. Patients with permanent implants may have a few restrictions at first and then can quickly return to their normal activities. Temporary implants are left inside the patient's body for minutes, hours or days, as indicated.

Remote high dose rate (HDR) afterload brachytherapy involves the remote placement of the powerful radiation source, accurately directed by the radiation oncologist and team, into the tumor for several minutes through a catheter. It is usually given in multiple doses once or twice daily or once or twice weekly. The doctor and team control the remote high dose rate (HDR) afterload brachytherapy treatment from outside the treatment room, monitoring the patient as the therapy is being given. The high-dose-rate remote afterloading machines allow radiation oncologists to deliver a brachytherapy treatment quickly, in about 10 to 20 minutes. The patient can usually go home shortly after the procedure.

Most patients feel little discomfort during remote high dose rate (HDR) afterload brachytherapy. If the radioactive source is held in place with an applicator, the only discomfort during the procedure may come from the  applicator.

Depending on the type of remote high dose rate (HDR) afterload brachytherapy given, the patient may need to take some precautions following treatment.

Remote high dose rate (HDR) afterload brachytherapy may be used alone or in conjunction with external radiation treatments.

MedWOW, the multilingual global medical equipment platform, offers a buyers a selection of remote high dose rate (HDR) afterload brachytherapy  units for sale from inventories all over the world. Currently featuring remote high dose rate (HDR) afterload brachytherapy units from Varian and Nucletron Oldelft, with more being added all the time,   locating even difficult-to-find items is easier than ever.

If there is a particular Remote high dose rate (HDR) afterload brachytherapy system or part that you can’t find in MedWOW’s representative inventories, you can post a request or take advantage of any of MedWOW’s location services.

The Function of X-Ray Tubes

An X-ray tube is basically a vacuum tube that produces X-rays, which are used in X-ray machines. X-rays are part of the electromagnetic spectrum, an ionizing radiation with wavelengths shorter than ultraviolet light. X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered in the late 19th century. The discovery of this controllable source of X-rays created the field of radiography: the imaging of opaque objects with radiation that penetrates. X-ray tubes are also used in airport luggage scanners, CAT scanners, X-ray crystallography and for industrial inspection.

As with any other type of vacuum tube, there is a cathode, which emits electrons into the vacuum and an anode to collect the electrons ─ creating a flow of electrical current, known as the beam, through the x-ray tube. A high voltage power source is connected across the cathode and the anode to accelerate the electrons. The X-ray spectrum depends on the anode material and the accelerating voltage.

In many applications, the current flow is able to be pulsed on for between approximately 1ms to 1s. This allows for consistent doses of x-rays, and taking snapshots of motion. Until the late 1980s, X-ray generators were merely high-voltage, AC to DC variable power supplies. In the late 1980s a different method of control emerged, which became known as high-speed switching. This followed the electronics technology of switching power supplies (also known as switch mode power supply), and allowed for: more accurate control of the X-ray unit, higher-quality results, and reduced exposure to X-ray.

Electrons from the cathode collide with the anode material, usually tungsten, molybdenum or copper, and accelerate other electrons, ions and nuclei within the anode material. About 1% of the energy generated is emitted/radiated, usually perpendicular to the path of the electron beam, as X-rays. The rest of the energy is released as heat. Over time, tungsten is deposited from the target onto the interior surface of the x-ray tube, including the glass surface. This slowly darkens the tube and was thought to degrade the quality of the X-ray beam, but research has suggested there is no effect on the quality. Eventually, the tungsten deposit becomes sufficiently conductive that at high enough voltages, arcing occurs. The arc jumps from the cathode to the tungsten deposit, and then to the anode. The arcing causes an effect called "crazing" on the interior glass of the X-ray window. As time goes on, the tube becomes unstable even at lower voltages, and must be replaced. At this point, the x-ray tube assembly (also called the "tube head") is removed from the X-ray system, and replaced with a new tube assembly. The old tube assembly is shipped to a company that reloads it with a new, replacement X-ray tube.

The range of photonic energies emitted by the system can be adjusted by changing the applied voltage, and installing aluminum filters of varying thicknesses. Aluminum filters are installed in the path of the X-ray beam to remove "soft" (non-penetrating) radiation. The numbers of emitted X-ray photons or doses are adjusted by controlling the current flow and exposure time.

In simple terms, the high voltage controls X-ray penetration, and thus the contrast of the image. The tube current and exposure time affect the dose and consequently, the darkness of the image.

Some x-ray examinations (such as: non-destructive testing and 3-D microtomography) need very high-resolution images and therefore require x-ray tubes that can generate very small focal spot sizes, typically below 50 µm in diameter. These tubes are called microfocus x-ray tubes.

There are two basic types of microfocus x-ray tubes: solid-anode x-ray tubes and metal-jet-anode x-ray tubes.

Solid-anode microfocus x-ray tubes are in principle very similar to the Coolidge tube, but with the important distinction that care has been taken to focus the electron beam into a very small spot on the anode. Many microfocus x-ray sources operate with focus spots in the range 5-20 µm, but in rare cases spots smaller than 1 µm may be produced.

The major drawback of solid-anode microfocus x-ray tubes is the very low power in which they operate. To avoid melting of the anode, the electron-beam power density must be below a maximum value. This value is somewhere in the range 0.4-0.8 W/µm depending on the anode material. This means that a solid-anode microfocus source with a 10 µm electron-beam focus can operate in the range 4-8 W.

In metal-jet-anode microfocus x-ray tubes, the solid metal anode is replaced with a jet of liquid metal, which acts as the electron-beam target. The advantage of the metal-jet anode is that the maximum electron-beam power density is significantly increased. Values in the range 3-6 W/µm have been reported for different anode materials (gallium and tin).[4][5] In the case with a 10 µm electron-beam focus a metal-jet-anode microfocus x-ray source may operate at 30-60 W.

The major benefit of the increased power density level for the metal-jet x-ray tube is the possibility to operate with a smaller focal spot to increase image resolution, and at the same time acquire the image faster, since the power is higher (15-30 W) than for solid-anode tubes with 10 µm focal spots.

MedWOW’s inventories feature X-Ray tubes from most of the major manufacturers including: Shimadzu, Varian, Dunlee, Fischer Imaging, GE Healthcare, Philips, Siemens, Picker and Raymed, with more being added all the time, so finding exactly what you need is efficient and simple for busy medical professionals. With dozens of types of x-ray tubes currently featured through MedWOW’s comprehensive online catalogue ─ finding and purchasing your next x-ray tube is trouble- free and as thousands of medical professionals use the MedWOW portal on a daily basis, the prices are always competitive.

MedWOW Explains Digital Radiology (DR)

Digital Radiology (DR) Replaces Standard X-Ray
Digital radiology (DR) may represent the top scientific breakthrough in medical imaging over the last ten years. The use of radiographic films in x-ray imaging might become obsolete in a few years, due to the superiority of digital radiology (DR). An appropriate comparison that is commonly understood is the replacement of standard film cameras with digital cameras. Images can be immediately acquired, deleted, modified, and subsequently sent to a network of computers, which is especially important in the medical field.

Benefits of Digital Radiology (DR)
The benefits from digital radiology (DR) are enormous. It can make a radiological clinic or department filmless. The referring physician can view the requested image on a desktop or a personal computer and often file a report just a few minutes after the examination was completed. The images are no longer held in a single location; but can be seen simultaneously by physicians who are miles apart. In addition, the patient can be given the x-ray images on a CD to take to another physician or hospital for consultation.

Advantages of digital radiology (DR) include time efficiency, as a result of being able to do without the standard chemical processing, as well as the ability to digitally transfer and enhance images. Being able to enlarge and highlight images is of paramount importance in x-rays, and digital radiology (DR) gives physicians and technicians better diagnostic tools, as a result. Also, less radiation can be used to produce an image of similar contrast, which is very important, especially in children and adolescents for whom it is important to keep exposure to radiation at a minimum.

MedWOW’s Digital Radiology (DR) Offerings
MedWOW, the multilingual, global medical equipment marketplace, features medical device inventories from dealers all over the world, so locating the specific digital radiography system or add-on you need from a variety of makes, models and manufacturers in a safe and protected environment, is easy and secure. MedWOW is the leading medical equipment portal for all types of medical equipment trade, and with over 12,000 users visiting the site daily; locating your particular digital radiography system or upgrade is a hassle-free experience. MedWOW also provides free Escrow service, so you can be sure you are getting exactly what you pay for.

Some of the digital radiography systems and add-ons currently available from imaging dealers throughout the world include: DIS Digital Radiography Upgrade Adapter #ezDR4000, RF System Digital Radiography Upgrade Adapter Naomi, DRTECH Digital Radiography Upgrade Adapter FLAATZ 330 and many more options.

The Technology of CT Scanner Detectors: from 1 to 256 Slices and Beyond

The CT scanner is made up of a complex combination of an x-ray source, detectors and computers, which produce high-resolution, cross-sectional images of the body. The patient lies on a table that passes through a gantry which resembles a donut hole, containing the x-ray tube and multiple detectors. The walls of the opening into the gantry are wedge-shaped, designed so that claustrophobia is not a considerable problem in most cases. A series of cross-sectional images are taken of the area to be examined in a matter of seconds. The raw data from the multiple detectors are then reconstructed by specially programmed computers, to present images of the internal structures of the area scanned.

Tomosynthesis Imaging in Mammography Applications

Digital, cutting-edge imaging technologies, such as 3-dimensional tomosynthesis, have already found to be significant in earlier identification and diagnosis of breast cancer. Unlike current mammography systems, which generate a two-dimensional (2-D) image, breast tomosynthesis produces a three-dimensional image. Additionally, it is anticipated that tomosynthesis will enhance new applications, in combination with ultrasound. Using current mammography technologies, usually two x-rays of each breast are taken from different angles: from top-to-bottom and from side-to-side. The breast is pulled away from the body, compressed, and held between two glass plates to make sure that the entire breast can be carefully observed. Standard mammography records the images on film, and digital mammography records the images on computer, which can then be read and interpreted by a radiologist. Breast cancer, which is denser than most healthy nearby breast tissue, appears as uneven white areas which are referred to as shadows.

Mammography is an excellent technology, but also has the following considerable limitations, which tomosynthesis technologies overcome:

• Some women cannot tolerate the breast compression component and find it so uncomfortable that they avoid annual or indicated testing.
• This necessary compression also causes overlapping of the breast tissue. Breast cancer can be hidden in the overlapping tissue and not show up on the mammogram.
• Mammograms take only one picture, across the entire breast, in the two directions as described above. In this limited way, it is possible to miss cancerous areas or lesions that are too small to detect.

Digital tomosynthesis was developed to overcome these limitations. Tomosynthesis takes multiple x-ray pictures of each breast from many angles and the breast is positioned the same way it is in a conventional mammogram, but much less pressure is necessary. Tomosynthesis requires just enough pressure to keep the breast in a stable position during the procedure. The x-ray tube moves in an arc around the breast while 11 images are taken during a 7-second examination. Then the information is sent to a computer, where it is assembled to produce clear, highly focused 3-dimensional images throughout the breast. In this way, none of the tissue is missed as using tomosynthesis, there is no folding or “hiding” of potentially cancerous tissue.

Early results with digital tomosynthesis are promising and it is believed that this new imaging technique will make breast cancers easier to see in dense breast tissue and will make mammography screenings more comfortable.

In addition to mammography, tomosynthesis also gives better results than standard planar X-ray in the following applications:

• Brachytherapy
• Dental imaging
• Chest imaging
• Orthopedics
• Nephrology

Advances in Cardiovascular X-ray Systems

The introduction of flat panel detectors to cardiovascular x-rays have been an important advance in increasing the speed of C-arm rotations and decreasing the time it takes for examinations. The flat panel detector converts the x-rays into signals which the computers use to produce an image. Cardiovascular X-ray Systems are particularly important in difficult or intricate procedures as they optimize the intervention and enhance the power of the entire cath lab, the examination room used to support catheterization for procedures with cardiovascular involvement.

Newer digital cardiovascular x-ray systems provide crystal-clear imaging of cardiac and vascular interventions with versatility in diagnostic imaging, providing lucid visualization of small details and objects for complex interventions. These state-of-the-art cardiovascular x-rays also have the benefit of giving much lower x-ray dosages than their predecessors, which minimizes X-ray dose for cardiac, vascular, and especially pediatric examinations. Now cardiologists can get twice the information with a single contrast injection, which is much safer and easier as it minimizes the dose of radiation to both patients and staff during x-ray examination.

These modern digital cardiovascular x-ray systems allow cardiologists to personalize their settings and conveniently control all movements and interventional tools in order to provide outstanding support for treating congenital heart disease and performing vascular examinations. One of the major advantages of this type of cardiovascular x-ray equipment is that treatment can also be carried out at the same time. Occlusion of the blood vessels can be opened by inflating a balloon catheter and if necessary, a stent can be placed to keep the vessel open.

Some of the most recent models offer navigation for cardiologists for structural heart procedures, utilizing real-time 2D x-ray images and 3D cardiac models from multiple modalities, such as vascular x-ray, CT and MR, and image stabilization features. 3D tools particularly support treatment strategies for coronary angiography procedures as 3D x-ray techniques allow easier visualization of vessels and heart. In addition, 3D angiography delivers a lower patient radiation dose, using less contrast material, as well as being faster and therefore, increasing medical facility efficiency.

Thanks to the technology used in these innovative x-ray systems, interventional procedures, vascular, and cardiovascular applications are streamlined. Because it simplifies cath lab workflow, cardiologists can now completely and more accurately focus on a wider range of cardiac patients and help them deliver faster, more accurate diagnoses and treatment.