Categories
Therapetic treatment

Radiotherapy

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Definition:
Radiotherapy is a way of treating or managing cancer using radiation. It works by damaging cells in the area being treated. Normal cells are able to repair this damage, but cancer cells can’t and are destroyed.
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Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the DNA of exposed tissue, furthermore, it is believed that cancerous cells may be more susceptible to death by this process as many have turned off their DNA repair machinery during the process of becoming cancerous. To spare normal tissues (such as skin or organs which radiation must pass through in order to treat the tumor), shaped radiation beams are aimed from several angles of exposure to intersect at the tumor, providing a much larger absorbed dose there than in the surrounding, healthy tissue. Besides the tumour itself, the radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumor, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumor to allow for uncertainties in daily set-up and internal tumor motion. These uncertainties can be caused by internal movement (for example, respiration and bladder filling) and movement of external skin marks relative to the tumor position.

Radiation oncology is the medical specialty concerned with prescribing radiation, and is distinct from radiology, the use of radiation in medical imaging and diagnosis). Radiation may be prescribed by a radiation oncologist with intent to cure (“curative”) or for adjuvant therapy. It may also be used as palliative treatment (where cure is not possible and the aim is for local disease control or symptomatic relief) or as therapeutic treatment (where the therapy has survival benefit and it can be curative). It is also common to combine radiation therapy with surgery, chemotherapy, hormone therapy, Immunotherapy or some mixture of the four. Most common cancer types can be treated with radiation therapy in some way. The precise treatment intent (curative, adjuvant, neoadjuvant, therapeutic, or palliative) will depend on the tumor type, location, and stage, as well as the general health of the patient. Total body irradiation (TBI) is a radiation therapy technique used to prepare the body to receive a bone marrow transplant. Brachytherapy, in which a radiation source is placed inside or next to the area requiring treatment, is another form of radiation therapy that minimizes exposure to healthy tissue during procedures to treat cancers of the breast, prostate and other organs.

Radiation therapy has several applications in non-malignant conditions, such as the treatment of trigeminal neuralgia, severe thyroid eye disease, pterygium, pigmented villonodular synovitis, and prevention of keloid scar growth, vascular restenosis , and heterotopic ossification. The use of radiation therapy in non-malignant conditions is limited partly by worries about the risk of radiation-induced cancers.

Method of radiotherapy
Radiotherapy can be given as teletherapy (also known as external beam radiotherapy), when a beam of radiation is aimed at the area to be treated from a machine located away from the patient.

Other forms of radiotherapy are high or low-dose brachytherapy, which involves a radioactive source being placed on or in a tumour.

Dose:
The amount of radiation used in photon radiation therapy is measured in gray (Gy), and varies depending on the type and stage of cancer being treated. For curative cases, the typical dose for a solid epithelial tumor ranges from 60 to 80 Gy, while lymphomas are treated with 20 to 40 Gy.

Preventative (adjuvant) doses are typically around 45 – 60 Gy in 1.8 – 2 Gy fractions (for Breast, Head, and Neck cancers.) Many other factors are considered by radiation oncologists when selecting a dose, including whether the patient is receiving chemotherapy, patient comorbidities, whether radiation therapy is being administered before or after surgery, and the degree of success of surgery.

Delivery parameters of a prescribed dose are determined during treatment planning (part of dosimetry). Treatment planning is generally performed on dedicated computers using specialized treatment planning software. Depending on the radiation delivery method, several angles or sources may be used to sum to the total necessary dose. The planner will try to design a plan that delivers a uniform prescription dose to the tumor and minimizes dose to surrounding healthy tissues.

Treatment planning
All patients who are to have radiotherapy need individually tailored treatment so it is given accurately. A lot of information is needed so the doctor can target the tumour while minimising damage to the healthy tissue. This is called treatment planning and there are a number of ways of doing this.

Simulator planning is done using a specialised x-ray machine that can do the same things as the treatment machines except deliver treatment. The simulator allows the doctor to carefully look at the area that needs treatment and plan it precisely. During the planning, the radiographer will draw some marks on the skin using a pen; when the doctor and radiographer are happy they have an accurate plan, the radiographer may need to make two to three permanent marks called tattoos. These tattoos are the size of a pinhead and are used to ensure the radiotherapy is given to exactly the right place.

ACQSIM planning is done using a scanner. Some patients may need to have an intravenous injection before the scan to show up the area to be treated better. The scan usually takes about 15 minutes and the information from the scan is used to produce a treatment map. Sometimes it’s necessary to take some x-rays and measurements to check the treatment map and this is done on the simulator.

What radiotherapy involves
When radiotherapy treatment is being given by external beam, it’s important the patient is in exactly the same position each time. The radiographers will often use pillows and wedges to make sure the patient is comfortable and in the correct position.

Patients having radiotherapy to the head or neck area may need to have a mould made to keep them in the right position. Moulds are made from clear Perspex after a plaster cast has been made of the head and neck. Once the Perspex mould has been made, the radiotherapy is planned while the patient is wearing the mould and marks are drawn on the mask instead of the skin.

Once the radiographers are happy that the patient is in the correct position they will leave the room to switch the treatment machine on. When the machine is on it makes a buzzing noise. The radiographers watch closely on a television screen. Treatment only lasts a few minutes and does not hurt.

Side effect of radiotherapy
Side effects are different depending on the part of the body being treated. Most side effects are temporary but some may continue for weeks or months after treatment is finished. They include:

•Hair loss (alopecia)
•Cerebral oedema (excess fluid accumulating in the brain) can cause changes in mental state, restlessness, irritability, impaired pupil reactions, headache, increase in blood pressure, decrease in pulse and respiration, and nausea
•Dry or sore mouth or throat, changes in taste sensation, skin thickening
•Inflammation of the gullet, indigestion, nausea, lung inflammation
•Nausea and vomiting, diarrhoea, cystitis
•Sexual dysfunction. In males treatment of the abdomen area can cause impotence, sterility. In females it can cause sterility, loss of sexual desire. Irradiation of the pelvis may cause tightening of the vagina, loss of vaginal lubrication, inflammation or ulceration of the vagina. Some women may find intercourse painful
•Treatment of red bone marrow may cause infection and impaired healing, anaemia, increased tiredness, bruising and bleeding

As well as treating cancer the radiotherapy temporarily damages the outer layers of skin. During treatment the skin cannot repair itself as it normally would and it can become sore. But once treatment has finished the skin generally recovers quite quickly – usually within a month. The level of reaction can depend on your skin type, the type and number of treatments you have, and how you would normally react to the sun.

Skin side effects usually happen later on in the course of radiotherapy treatment or sometimes a few weeks after treatment has finished. Many patients do not have any skin changes at all. Skin care advice will be given to the patients by the staff treating them.

A common side effect of radiotherapy is tiredness and fatigue, which often prevents patients from doing normal everyday activities. Fatigue and tiredness are normal results of having radiotherapy and begin in the first week of treatment, reaching a peak after two weeks of treatment and gradually disappearing a few weeks after treatment has finished.

Radiation therapy accidents:
There are rigorous procedures in place to minimise the risk of accidental overexposure of radiation therapy to patients. However, mistakes do occasionally occur; for example, the radiation therapy machine Therac-25 was responsible for at least six accidents between 1985 and 1987, where patients were given up to one hundred times the intended dose; two people were killed directly by the radiation overdoses. From 2005 to 2010, a hospital in Missouri overexposed 76 patients (most with brain cancer) during a five-year period because new radiation equipment had been set up incorrectly.  Although medical errors are exceptionally rare, radiation oncologists, medical physicists and other members of the radiation therapy treatment team are working to eliminate them. ASTRO has launched a safety initiative called Target Safely  that, among other things, aims to record errors nationwide so that doctors can learn from each and every mistake and prevent them from happening. ASTRO also publishes a list of questions for patients to ask their doctors about radiation safety to ensure every treatment is as safe as possible.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://en.wikipedia.org/wiki/Radiation_therapy
http://www.bbc.co.uk/health/physical_health/conditions/in_depth/cancer/carecancer_radio.shtml
http://www.allvitalpoints.com/2010/how-radiotherapy-is-performed/

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Categories
Ailmemts & Remedies

Radiation sickness

Other Names: Acute radiation syndrome or Radiation poisoning.

Description:
Radiation sickness is damage to our body caused by a large dose of radiation often received over a short period of time (acute). The amount of radiation absorbed by the body — the absorbed dose — determines how sick we will be. It is not caused by common imaging tests that use low-dose radiation, such as X-rays or CT scans.

Radiation sickness is serious and often fatal, but it is very rare. Since the atomic bombings of Hiroshima and Nagasaki, Japan, during World War II, most cases of radiation sickness have occurred after nuclear industrial accidents, such as the 1986 explosion and fire that damaged the nuclear power plant at Chernobyl, Ukraine.

The amount of radiation our body gets is measured in an international unit called a sievert (Sv). Symptoms of radiation sickness show up when we are exposed to levels of more than 500 millisieverts (mSv), or half a sievert. More than 4 to 5 Sv is likely to be fatal. The workers who got radiation sickness at Chernobyl received doses that measured 700 mSv to 13 Sv.

Natural radiation is everywhere — in the air, the water, and materials like brick or granite. You typically get only about 3 mSv — three one-thousandths of a sievert — of radiation from these natural sources in a year.

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Man-made sources of radiation from things like X-rays add about another 3 mSv. A CT (computerized tomography) scan, which involves several X-rays taken from different angles, delivers about 10 mSv. People who work in the nuclear industry aren’t allowed to be exposed to more than 50 mSv a year.

Symptoms:
Early symptoms of ARS typically includes nausea and vomiting, headaches, fatigue, fever, and a short period of skin reddening. These symptoms may occur at radiation doses as low as 0.35 grays (35 rad). These symptoms are common to many illnesses, and may not, by themselves, indicate acute radiation sickness

Classically acute radiation syndrome is divided into three main presentations: hematopoietic, gastrointestinal, and neurological/vascular. These syndromes may or may not be preceded by a prodrome. The speed of onset of symptoms is related to radiation exposure, with greater doses resulting in a shorter delay in symptom onset.[2] These presentations presume whole-body exposure and many of them are markers that are not valid if the entire body has not been exposed. Each syndrome requires that the tissue showing the syndrome itself be exposed. The gastrointestinal syndrome is not seen if the stomach and intestines are not exposed to radiation. Some areas affected are:

Hematopoietic. This syndrome is marked by a drop in the number of blood cells, called aplastic anemia. This may result in infections due to a low amount of white blood cells, bleeding due to a lack of platelets, and anemia due to too few red blood cells in the circulation. These changes can be detected by blood tests after receiving a whole-body acute dose as low as 0.25 grays (25 rad), though they might never be felt by the patient if the dose is below 1 gray (100 rad). Conventional trauma and burns resulting from a bomb blast are complicated by the poor wound healing caused by hematopoietic syndrome, increasing mortality.

Gastrointestinal. This syndrome often follows absorbed doses of 6–30 grays (600–3,000 rad). The signs and symptoms of this form of radiation injury include nausea, vomiting, loss of appetite, and abdominal pain. Vomiting in this time-frame is a marker for whole body exposures that are in the fatal range above 4 grays (400 rad). Without exotic treatment such as bone marrow transplant, death with this dose is common. The death is generally more due to infection than gastrointestinal dysfunction.

Neurovascular. This syndrome typically occurs at absorbed doses greater than 30 grays (3,000 rad), though it may occur at 10 grays (1,000 rad). It presents with neurological symptoms such as dizziness, headache, or decreased level of consciousness, occurring within minutes to a few hours, and with an absence of vomiting. It is invariably fatal.

Causes:
Radiation is the energy released from atoms as either a wave or a tiny particle of matter. Radiation sickness is caused by exposure to a high dose of radiation, such as a high dose of radiation received during an industrial accident.

Sources of high-dose radiation
Possible sources of high-dose radiation include the following:

  • An accident at a nuclear industrial facility
  • An attack on a nuclear industrial facility
  • Detonation of a small radioactive device
  • Detonation of a conventional explosive device that disperses radioactive material (dirty bomb)
  • Detonation of a standard nuclear weapon

Radiation sickness occurs when high-energy radiation damages or destroys certain cells in your body. Regions of the body most vulnerable to high-energy radiation are cells in the lining of your intestinal tract, including your stomach, and the blood cell-producing cells of bone marrow.

Complications:
Having radiation sickness can contribute to both short-term and long-term mental health problems, such as grief, fear and anxiety about:

  • Experiencing a radioactive accident or attack
  • Mourning friends or family who haven’t survived
  • Dealing with the uncertainty of a mysterious and potentially fatal illness
  • Worrying about the eventual risk of cancer due to radiation exposure

Diagnosis:
Diagnosis is typically made based on a history of significant radiation exposure and suitable clinical findings. An absolute lymphocyte count can give a rough estimate of radiation exposure. Time from exposure to vomiting can also give estimates of exposure levels if they are less than 10 Gray (1000 rad)

Treatment:
The treatment goals for radiation sickness are to prevent further radioactive contamination; treat life-threatening injuries, such as from burns and trauma; reduce symptoms; and manage pain.

Decontamination:
Decontamination involves removing external radioactive particles. Removing clothing and shoes eliminates about 90 percent of external contamination. Gently washing with water and soap removes additional radiation particles from the skin.

Decontamination prevents radioactive materials from spreading more. It also lowers the risk of internal contamination from inhalation, ingestion or open wounds.

Treatment for damaged bone marrow:
A protein called granulocyte colony-stimulating factor, which promotes the growth of white blood cells, may counter the effect of radiation sickness on bone marrow. Treatment with this protein-based medication, which includes filgrastim (Neupogen), sargramostim (Leukine) and pegfilgrastim (Neulasta), may increase white blood cell production and help prevent subsequent infections.

Treatment for internal contamination:
Some treatments may reduce damage to internal organs caused by radioactive particles. Medical personnel would use these treatments only if you’ve been exposed to a specific type of radiation. These treatments include the following:

  • Potassium iodide (ThyroShield, Iosat). This is a nonradioactive form of iodine.

Iodine is essential for proper thyroid function. If you’re exposed to significant radiation, your thyroid will absorb radioactive iodine (radioiodine) just as it would other forms of iodine. The radioiodine is eventually cleared from the body in urine.

If potassium iodide is taken, it may fill “vacancies” in the thyroid and prevent the absorption of radioiodine. Potassium iodide isn’t a cure-all and is most effective if taken within a day of exposure.

  • Prussian blue (Radiogardase). This type of dye binds to particles of radioactive elements known as cesium and thallium. The radioactive particles are then excreted in feces. This treatment speeds up the elimination of the radioactive particles and reduces the amount of radiation cells may absorb.
  • Diethylenetriamine pentaacetic acid (DTPA). This substance binds to metals. DTPA binds to particles of the radioactive elements plutonium, americium and curium. The radioactive particles pass out of the body in urine, thereby reducing the amount of radiation absorbed.

We may get some Supportive treatment for the following:

  • Bacterial infections
  • Headache
  • Fever
  • Diarrhea
  • Nausea and vomiting
  • Dehydration
  • Burns
  • Sores or ulcers

A person who has absorbed very large doses of radiation has little chance of recovery. Depending on the severity of illness, death can occur within two days or two weeks. People with a lethal radiation dose will receive medications to control pain, nausea, vomiting and diarrhea. They may also benefit from psychological or pastoral care.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
https://en.wikipedia.org/wiki/Acute_radiation_syndrome
https://www.mayoclinic.org/diseases-conditions/radiation-sickness/diagnosis-treatment/drc-20377061
https://www.webmd.com/cancer/radiation-sickness-facts#1

Categories
Diagnonistic Test

Chest X-Ray

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Definition:The chest x-ray is the most commonly performed diagnostic x-ray examination. A chest x-ray makes images of the heart, lungs, airways, blood vessels and the bones of the spine and chest.

An x-ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Imaging with x-rays involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging.

Doctors have used x-rays for over a century to see inside the body in order to diagnose a variety of problems, including cancer, fractures, and pneumonia. During this test, you usually stand in front of a photographic plate while a machine sends x-rays, a type of radiation, through your body. Originally, a photograph of internal structures was produced on film; nowadays, the image created by the x-rays goes directly into a computer. Dense structures, such as bone, appear white on the x-ray films because they absorb many of the x-ray beams and block them from reaching the plate (see Figure 16). Hollow body parts, such as lungs, appear dark because x-rays pass through them. (In some other countries, like the United Kingdom, the colors are reversed, and dense structures are black.)

Back x-rays and chest x-rays are among the most common conventional x-ray tests. You should not have an x-ray if you’re pregnant, because radiation can be harmful to a developing fetus.

A chest x-ray provides black-and-white images of your lungs, ribs, heart, and diaphragm.

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Some common uses:
The chest x-ray is performed to evaluate the lungs, heart and chest wall.

A chest x-ray is typically the first imaging test used to help diagnose symptoms such as:

*shortness of breath
*a bad or persistent cough
*chest pain or injury
*fever.
Physicians use the examination to help diagnose or monitor treatment for conditions such as:

*pneumonia
*heart failure and other heart problems
*emphysema
*lung cancer
*other medical conditions.


How should you prepare for the test?

A chest x-ray requires no special preparation.

You may be asked to remove some or all of your clothes and to wear a gown during the exam. You may also be asked to remove jewelry, eye glasses and any metal objects or clothing that might interfere with the x-ray images.

Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to radiation. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby. See the Safety page for more information about pregnancy and x-rays.

You are usually asked to remove all clothing, undergarments, and jewelry above your waist, and to wear a hospital gown.

What does the equipment look like?
The equipment typically used for chest x-rays consists of a wall-mounted, box-like apparatus containing the x-ray film or a special plate that records the image digitally and an x-ray producing tube, that is usually positioned about six feet away.
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The equipment may also be arranged with the x-ray tube suspended over a table on which the patient lies. A drawer under the table holds the x-ray film or digital recording plate.

A portable x-ray machine is a compact apparatus that can be taken to the patient in a hospital bed or the emergency room. The x-ray tube is connected to a flexible arm that is extended over the patient while an x-ray film holder or image recording plate is placed beneath the patient.

What happens when the test is performed?
Chest x-rays usually are taken while you are standing. A technician positions you against the photographic plate (which looks like a large board) to obtain the clearest pictures. He or she takes pictures from the front and from one side while asking you to take in a deep breath just before each picture. The technician leaves the room or stands behind a screen while the x-rays are taken.

How does the procedure work?
X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special digital image recording plate.

Different parts of the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays to pass through them. As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air appears black.

On a chest x-ray, the ribs and spine will absorb much of the radiation and appear white or light gray on the image. Lung tissue absorbs little radiation and will appear dark on the image.

Until recently, x-ray images were maintained as hard film copy (much like a photographic negative). Today, most images are digital files that are stored electronically. These stored images are easily accessible and are sometimes compared to current x-ray images for diagnosis and disease management.

How is the procedure performed?

Typically, two views of the chest are taken, one from the back and the other from the side of the body as the patient stands against the image recording plate. The technologist, an individual specially trained to perform radiology examinations, will position the patient with hands on hips and chest pressed the image plate. For the second view, the patient’s side is against the image plate with arms elevated.

 

Patients who cannot stand may be positioned lying down on a table for chest x-rays.

You must hold very still and may be asked to keep from breathing for a few seconds while the x-ray picture is taken to reduce the possibility of a blurred image. The technologist will walk behind a wall or into the next room to activate the x-ray machine.

When the examination is complete, you will be asked to wait until the radiologist determines that all the necessary images have been obtained.

The chest x-ray examination is usually completed within 15 minutes.

Additional views may be required within hours, days or months to evaluate any changes in the chest.

What will you experience during and after the procedure?
A chest x-ray examination itself is a painless procedure.

You may experience discomfort from the cool temperature in the examination room and the coldness of the recording plate. Individuals with arthritis or injuries to the chest wall, shoulders or arms may have discomfort trying to stay still during the examination. The technologist will assist you in finding the most comfortable position possible that still ensures diagnostic image quality.
Who interprets the results and how do you get them?
A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will discuss the results with you.

In an emergency, the results of a chest x-ray can be available almost immediately for review by your physician.
What are the benefits vs. risks?
Benefits:

*No radiation remains in a patient’s body after an x-ray examination.
*X-rays usually have no side effects in the diagnostic range.
*X-ray equipment is relatively inexpensive and widely available in emergency rooms, physician offices, ambulatory care *centers, nursing homes and other locations, making it convenient for both patients and physicians.
*Because x-ray imaging is fast and easy, it is particularly useful in emergency diagnosis and treatment.

Risks:

*There is always a slight chance of cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk.

*The chest x-ray is one of the lowest radiation exposure medical examinations performed today. The effective radiation dose from this procedure is about 0.1 mSv, which is about the same as the average person receives from background radiation in 10 days. See the Safety page for more information about radiation dose.

*Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.

How long is it before the result of the test is known?
Although digital images may be available immediately, it will take additional time for a doctor to examine and interpret them. You’ll probably get the results later in the day.

A Word About Minimizing Radiation Exposure:
Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection councils continually review and update the technique standards used by radiology professionals.

State-of-the-art x-ray systems have tightly controlled x-ray beams with significant filtration and dose control methods to minimize stray or scatter radiation. This ensures that those parts of a patient’s body not being imaged receive minimal radiation exposure.

What are the limitations of Chest Radiography?
The chest x-ray is a very useful examination, but it has limitations. Because some conditions of the chest cannot be detected on an x-ray image, this examination cannot necessarily rule out all problems in the chest. For example, very small cancers may not show up on a chest x-ray. A blood clot in the lungs, a condition called a pulmonary embolism, cannot be seen on chest x-rays.

Further imaging studies may be necessary to clarify the results of a chest x-ray or to look for abnormalities not visible on the chest x-ray.

Click for More Additional Information and Resources: ->
*RadiologyInfo: Radiation Therapy for Lung Cancer

*RTAnswers.org: Radiation Therapy for Lung Cancer

Resources:
https://www.health.harvard.edu/diagnostic-tests/chest-x-ray.htm
http://www.radiologyinfo.org/en/info.cfm?PG=chestrad

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