Radiation Therapy for Cancer

Hi Bhawna,
here is your answer:
Radiation therapy is used to treat almost every type of solid tumor, including cancers of the brain, breast, cervix, larynx, lung, pancreas, prostate, skin, spine, stomach, uterus, or soft tissue sarcomas. Radiation can also be used to treat leukemia and lymphoma (cancers of the blood-forming cells and lymphatic system, respectively).

Radiation therapy also can be given to help reduce symptoms such as pain from cancer that has spread to the bones or other parts of the body. This is called palliative radiation therapy. so, radiation therapy is used over chemotherapy.

Different tissues can tolerate various amounts of radiation (measured in centigrays). For example, the liver can receive a total dose of 3,000 cGy, while the kidneys can tolerate only 1,800 cGy. The total dose of radiation is usually divided into smaller doses (called fractions) that are given daily over a specific time period. This maximizes the destruction of cancer cells while minimizing the damage to healthy tissue.

the side effect associated after radiation therapy are:
Most of the side effects of radiation therapy are only in the area being treated. For example, a breast cancer patient may notice skin irritation on her chest, like a mild to moderate sunburn, while a patient with cancer in the mouth may have soreness when he swallows. Some patients who are having their midsection treated may report feeling sick to their stomach.

These side effects are related to injury to rapidly dividing cells. They are usually temporary and can be treated by doctor. Side effects usually begin by the second or third week of treatment, and they may last for several weeks after the final radiation treatment. In rare instances, serious side effects develop after radiation therapy is finished.

The side effect most often reported by patients receiving radiation is fatigue. The fatigue patients experience is usually mild or moderate, differs for each patient, and may also relate to the area being treated and the other therapies, such as chemotherapy, the patient is receiving. Patients may be able to continue all or a portion of their normal daily activities. However, treating cancer often requires considerable mental and physical effort. Whenever possible, try to take time during your treatment to rest and relax.

Hi Amol,
Your 1st que. answer is,
Radiation therapy may be used to treat almost every type of solid tumor, including cancers of the brain, breast, cervix, larynx, lung, pancreas, prostate, skin, spine, stomach, uterus, or soft tissue sarcomas. Radiation can also be used to treat leukemia and lymphoma (cancers of the blood-forming cells and lymphatic system, respectively).

Internal radiation therapy (also called brachytherapy) uses radiation that is placed very close to or inside the tumor. The radiation source is usually sealed in a small holder called an implant. Implants may be in the form of thin wires, plastic tubes called catheters, ribbons, capsules, or seeds. The implant is put directly into the body. Internal radiation therapy may require a hospital stay.
Internal radiation is usually delivered in one of two ways, each of which is described below. Both methods use sealed implants. soa surgery is performed to implant the material.

dear Shirisha
Radiation therapy may be used to treat almost every type of solid tumor, including cancers of the brain, breast, cervix, larynx, lung, pancreas, prostate, skin, spine, stomach, uterus, or soft tissue sarcomas. Radiation can also be used to treat leukemia and lymphoma (cancers of the blood-forming cells and lymphatic system, respectively).

not all cancer but about 2/3rd of all cancer is treated with radiation therapy alone.

Techniques are available to increase the damage to cancer cells without doing greater harm to healthy tissues.
Stereotactic (or stereotaxic) radiosurgery uses a large dose of radiation to destroy tumor tissue in the brain. The procedure does not involve actual surgery. The patient's head is placed in a special frame, which is attached to the patient'skull. The frame is used to aim high-dose radiation beams directly at the tumor inside the patient's head. The dose and area receiving the radiation are coordinated very precisely. Most nearby tissues are not damaged by this procedure.
Stereotactic radiosurgery can be done in one of three ways. The most common technique uses a linear accelerator to administer high-energy photon radiation to the tumor (called “linac-based stereotactic radiosurgery”). The gamma knife, the second most common technique, uses cobalt 60 to deliver radiation. The third technique uses heavy charged particle beams (such as protons and helium ions) to deliver stereotactic radiation to the tumor.
Stereotactic radiosurgery is mostly used in the treatment of small benign and malignant brain tumors (including meningiomas, acoustic neuromas, and pituitary cancer). It can also be used to treat other conditions (for example, Parkinson disease and epilepsy). In addition, stereotactic radiosurgery can be used to treat metastatic brain tumors (cancer that has spread to the brain from another part of the body) either alone or along with whole-brain radiation therapy. (Whole-brain radiation therapy is a form of external radiation therapy that treats the entire brain with radiation).
Stereotactic radiotherapy uses essentially the same approach as stereotactic radiosurgery to deliver radiation to the target tissue. However, stereotactic radiotherapy uses multiple small fractions of radiation as opposed to one large dose. Giving multiple smaller doses may improve outcomes and minimize side effects. Stereotactic radiotherapy is used to treat tumors in the brain as well as other parts of the body.
Clinical trials are under way to study the effectiveness of stereotactic radiosurgery and stereotactic radiotherapy alone and in combination with other types of radiation therapy.
• Three-dimensional (3–D) conformal radiation therapy. Traditionally, the planning of radiation treatments has been done in two dimensions (width and height). Three-dimensional (3–D) conformal radiation therapy uses computer technology to allow doctors to more precisely target a tumor with radiation beams (using width, height, and depth). Many radiation oncologists use this technique. A 3–D image of a tumor can be obtained using computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), or single photon emission computed tomography (SPECT). Using information from the image, special computer programs design radiation beams that “conform” to the shape of the tumor. Because the healthy tissue surrounding the tumor is largely spared by this technique, higher doses of radiation can be used to treat the cancer. Improved outcomes with 3–D conformal radiation therapy have been reported for nasopharyngeal, prostate, lung, liver, and brain cancers.
• Intensity-modulated radiation therapy (IMRT). IMRT is a new type of 3–D conformal radiation therapy that uses radiation beams (usually x-rays) of varying intensities to deliver different doses of radiation to small areas of tissue at the same time. The technology allows for the delivery of higher doses of radiation within the tumor and lower doses to nearby healthy tissue. Some techniques deliver a higher dose of radiation to the patient each day, potentially shortening the overall treatment time and improving the success of the treatment. IMRT may also lead to fewer side effects during treatment.
The radiation is delivered by a linear accelerator that is equipped with a multileaf collimator (a collimator helps to shape or sculpt the beams of radiation). The equipment can be rotated around the patient so that radiation beams can be sent from the best angles. The beams conform as closely as possible to the shape of the tumor. Because IMRT equipment is highly specialized, not every radiation oncology center uses IMRT.
This new technology has been used to treat tumors in the brain, head and neck, nasopharynx, breast, liver, lung, prostate, and uterus. However, IMRT is not appropriate or necessary for every patient or tumor type. Long-term results following treatment with IMRT are becoming available.

Cancer patients receiving radiation therapy are often concerned that the treatment will make them radioactive. The answer to this question depends on the type of radiation therapy being given.
External radiation therapy will not make the patient radioactive. Patients do not need to avoid being around other people because of the treatment.
Internal radiation therapy (interstitial, intracavitary, or intraluminal) that involves sealed implants emits radioactivity, so a stay in the hospital may be needed. Certain precautions are taken to protect hospital staff and visitors. The sealed sources deliver most of their radiation mainly around the area of the implant, so while the area around the implant is radioactive, the patient's whole body is not radioactive.
Systemic radiation therapy uses unsealed radioactive materials that travel throughout the body. Some of this radioactive material will leave the body through saliva, sweat, and urine before the radioactivity decays, making these fluids radioactive. Therefore, certain precautions are sometimes used for people who come in close contact with the patient. The patient's doctor or nurse will provide information if these special precautions are needed

As i said in presentation Gamma rays are chosen since alpha and beta particles would be absorbed by tissues and not be detected outside the body.

Risk associated with radiation therapy are:
Most of the side effects of radiation therapy are only in the area being treated. For example, a breast cancer patient may notice skin irritation on her chest, like a mild to moderate sunburn, while a patient with cancer in the mouth may have soreness when he swallows. Some patients who are having their midsection treated may report feeling sick to their stomach.

These side effects are related to injury to rapidly dividing cells. They are usually temporary and can be treated by doctor. Side effects usually begin by the second or third week of treatment, and they may last for several weeks after the final radiation treatment. In rare instances, serious side effects develop after radiation therapy is finished.

The side effect most often reported by patients receiving radiation is fatigue. The fatigue patients experience is usually mild or moderate, differs for each patient, and may also relate to the area being treated and the other therapies, such as chemotherapy, the patient is receiving. Patients may be able to continue all or a portion of their normal daily activities. However, treating cancer often requires considerable mental and physical effort. Whenever possible, try to take time during your treatment to rest and relax.

CAPSULE WHICH IS IMPLANTED NEAR TUMOUR COTAIN A RADIATION SOURCE SUCH AS X-RAY, GAMMA RAYS, PARTICLE BEAM,PROTON BEAM.

risk of radiation therapy are:
Most of the side effects of radiation therapy are only in the area being treated. For example, a breast cancer patient may notice skin irritation on her chest, like a mild to moderate sunburn, while a patient with cancer in the mouth may have soreness when he swallows. Some patients who are having their midsection treated may report feeling sick to their stomach.

These side effects are related to injury to rapidly dividing cells. They are usually temporary and can be treated by doctor. Side effects usually begin by the second or third week of treatment, and they may last for several weeks after the final radiation treatment. In rare instances, serious side effects develop after radiation therapy is finished.

The side effect most often reported by patients receiving radiation is fatigue. The fatigue patients experience is usually mild or moderate, differs for each patient, and may also relate to the area being treated and the other therapies, such as chemotherapy, the patient is receiving. Patients may be able to continue all or a portion of their normal daily activities. However, treating cancer often requires considerable mental and physical effort. Whenever possible, try to take time during your treatment to rest and relax.