Why use Radiation Therapy?       
How is Radiation Different from Chemotherapy?
Is Radiation Therapy Safe?
Which Cancers can be Treated?    
How Many Forms of Radiation are Used for Treatment?
Do I Get Sick with Radiation?
Will I Lose My Hair?

Why Use Radiation Therapy?

Radiation therapy uses high-energy X-rays to treat diseases, mostly cancers. Living cells when  exposed to radiation become less able to multiply and reproduce. Malignant cells are more susceptible than normal cells, thus as tumors cells gradually dwindle, normal cells recover and rebuild. This unequal effect of radiation on malignant cells and healthy cells forms the basis of the usefulness of radiation in medicine.

Ever since Marie Curie discovered radium in the 19th century, radiation has been shown to shrink cancers. Initially used in large tumors that could not be surgically removed, radiation therapy has been refined over the last several decades to become a sophisticated form of treatment effective on several types of cancers, some of which are at an early stage such as breast cancer.

How is Radiation Different from Chemotherapy?

Radiation is a local or regional form of cancer therapy. It is applied to the area of the body that contains the tumor, unlike chemotherapy which is given by injection or by mouth and travels throughout the body. Both radiation and chemotherapy inhibit cell growth and reproduction but they usually act at slightly different locations within the cell reproductive cycle, thus both therapies can be combined for a greater effect.

Being a local treatment, radiation has advantages over chemotherapy. It is less likely to cause general side-effects (such as nausea, severe fatigue, decrease of blood cell counts). The disadvantage is that it cannot fully treat tumors that have spread beyond the local area.

Note that radiation and chemotherapy do not really compete against each other. Some diseases lend themselves well to radiation, others to chemotherapy, yet others require a combination of radiation and chemotherapy. Surgery also is an important method of treatment and can be used before or after radiation or chemotherapy.

When used properly, radiation is a very potent tool in the oncologist's arsenal for arresting cancer growth. It is estimated that at least 50% of all cancer patients need radiation some time in the course of their illness.

Is Radiation Therapy Safe ?

Radiation is safe when used correctly.  Physicians have learned to strike a reasonable balance between tumor control and side-effects. Doses are very strictly controlled. Safety interlocks and monitoring devices are extensively built into all therapy machines. Radiation devices are calibrated on a regular basis and are subject to very strict government regulations. Radiation Oncologists must have completed a fully-accredited post-M.D. residency in the field of radiation therapy. Radiation Therapists operating the equipment under the physicians' orders have gone through formal training and must be licensed by the State.

When the patient also has had surgery and/or chemotherapy, side-effects from radiation can be more pronounced. This is where the training and experience of the Radiation Oncologist are critical, as the dose and scheduling of radiation may have to be adjusted.

Which Cancers Can be Treated with Radiation ?

Most types of cancer respond to radiation. Those that "shrink" rapidly are termed radiosensitive, others that do not respond are called radioresistant. Still, even the radioresistant tumors can respond if stronger doses of radiation are given.

Not surprisingly, radiosensitive tumors can be cured with radiation. These include cancers of the prostate, breast, cervix, vocal cords, tonsil, mouth, thyroid, rectum / anus, skin (except malignant melanoma).

Other, less sensitive, tumors can be treated with radiation for palliation, which means to decrease tumor size, reduce pain, control bleeding, and thus to prolong lives or improve quality of life for patients with tumors considered incurable.

Note that some cancers which were considered incurable a few years back nowadays can be effectively controlled with newer treatment programs using a combination of surgery, newer chemotherapy drugs and radiation, each exploiting its own specific advantages.

How Many Forms of Radiation Are Used ?

Radiation can be applied externally to the body. Radiation beams produced by powerful linear accelerators are highly penetrating and treat through the skin and soft tissues.

Radiation can be applied internally, via radioactive sources placed inside natural body cavities, or surgically via incisions or punctures through the skin. Some of those implants are left permanently in the tissues (their radioactivity eventually decreases to a negligible level), others are temporary and removed after the calculated treatment time has passed. Radioactive sources used for implants are either low dose rate (taking hours or days to deliver a treatment) or high dose rate (HDR), taking minutes.

Lastly, radiation can be injected intravenously to treat cancer which has widely metastasized to several sites in the bones.

Do I Get Sick with Radiation?

Nausea and vomiting can occur when radiation is given to or near the stomach. Treatment of other body areas typically do not cause those symptoms.

Will I Lose My Hair ?

Loss of scalp hair happens only when radiation is given to the area of the scalp.