Radiation / Oncology

Radiation and Oncology Services

Radiation Oncology encompasses the broad field of cancer therapy involving radiation.

External Beam Radiation

External beam radiation therapy is delivered by a machine that aims radiation at your cancer. 

The treatment is local, which means it targets a specific area of your body. 

You will receive radiation only to your chest if you have cancer in your lung, for instance.

Radiation therapy machines typically use photon beams. 

X-rays also use photons, but their doses are much lower. 

Photon beams can penetrate deep into the body and reach tumors. 

Photon beams scatter radiation along their paths as they travel through the body. 

Upon reaching the tumor, the beams do not stop but continue into normal tissue beyond it.

A proton is a particle with a positive charge. 

The proton beam can also penetrate deep within the body, similarly to photon beams. 

However, proton beams do not scatter radiation as they travel through the body; once they reach a tumor, they stop. 

Doctors believe proton beams might reduce the amount of normal tissue exposed to radiation.

Particles with a negative charge are electrons. 

Electron beams cannot penetrate very deep into the body. 

Due to this, their use is limited to tumors on the skin or near the surface of the body.

Radiation therapy external beams can take many forms, but they all share the objective of delivering the highest dose of radiation to the tumor while sparing the surrounding normal tissues. 

Computers analyze images of the tumor to determine the most accurate dose and treatment path.

3-D Conformal Radiation Therapy

3D conformal radiation therapy is a common form of external beam radiation therapy. 

Simulations are used to plan treatment areas based on images from CT, MRI, and PET scans. 

The images are analyzed by a computer program to create radiation beams that match the tumor’s shape.

3D conformal radiation delivers several beams in different directions to conform to the tumor’s shape. 

By precisely shaping the radiation beam, it is possible to deliver higher radiation doses to the tumor without damaging healthy tissues.


A type of radiation therapy that is used to treat cancer is called brachytherapy. 

It is also known as internal radiation.

When compared to conventional radiation therapy (external beam radiation), which projects radiation from a machine outside the body, brachytherapy uses higher doses of radiation to target a specific area of the body.

Compared to external beam radiation, brachytherapy has fewer side effects and usually has shorter treatment times.

It can be used alone or in conjunction with other cancer treatments. 

Brachytherapy, for example, is sometimes used after surgery to eliminate cancer cells that remain. 

It can also be used in conjunction with external beam radiation.

Side Effects

The side effects of brachytherapy depend on the area being treated. 

Radiation from brachytherapy is focused on a small area, so only that area is affected.

Tenderness and swelling may occur in the treatment area. 

Talk to your doctor about other possible side effects.

Types of Cancer Treated

Radiation oncologists treat a variety of cancers, ranging from cancers in the bone or soft tissue of the body (sarcoma) to neurologic cancers that affect the central nervous system (the brain and spinal cord). 

Here are some of the more common cancers they treat:

Breast Cancer

Breast cancer is a type of cancer that forms in the breast cells.

Breast cancer is the second most common cancer diagnosed in women in the United States, after skin cancer. 

Breast cancer can affect both men and women, but it is more common among women.

The growth of abnormal breast cells leads to breast cancer. 

These cells divide rapidly and accumulate, forming a lump or mass. 

Your breast cancer cells may spread (metastasize) to your lymph nodes or to other parts of your body.

Usually, breast cancer starts in the milk-producing ducts (invasive ductal carcinoma). 

Breast cancer may also develop in glandular tissue called lobules (invasive lobular carcinoma) or in other cells or tissues of the breast.

A number of factors may increase your risk of breast cancer, including hormonal, lifestyle, and environmental factors. 

However, it is still unclear why some people without risk factors develop cancer, but others with risk factors do not. 

Your genetic makeup and your environment likely play a role in causing breast cancer.

Genetics can also play a role in getting breast cancer. 

There is about a 10% chance of the diseased genes being passed on to children.

Lung Cancer

Lung cancer develops in tissues of the lung, usually in the cells that line the airways. 

For both men and women, lung cancer is the leading cause of cancer death.

In the United States, lung cancer is the third most common cancer. 

The disease is most common in males, and in the U.S. black men are 15% more likely to get it than white men.

Small cell lung cancer and non-small cell lung cancer are the two main types. 

Their growth patterns and treatments differ. 

Most lung cancers are non-small cell lung cancers.

Cells in the lungs divide uncontrollably when cancer develops. 

Tumors grow as a result. They can limit a person’s ability to breathe and spread to other parts of the body.

Lung cancer can affect anyone, but cigarette smoking and exposure to smoke, chemicals, or other toxins can increase the risk significantly.


Having leukemia causes your bone marrow to make a lot of abnormal cells. 

White blood cells are most commonly affected. 

These abnormal cells accumulate in your bone marrow and blood. 

They crowd out the healthy blood cells and make it difficult for your cells and blood to function properly.

Leukemia comes in different forms. 

The type of leukemia you have depends on the blood cells that become cancerous and the rate at which they grow.

Treatment for leukemia depends on the type of leukemia, the severity of the disease, your age, your overall health, and other factors.

Brain Cancer

Most primary brain tumors originate in the brain itself or nearby tissues, such as the brain-covering membranes (meninges), cranial nerves, pituitary gland or pineal gland.

Brain tumors develop when normal cells develop mutations (disruptions) in their DNA. 

The DNA of a cell contains instructions that tell it what to do. 

Mutations cause cells to grow and divide rapidly and to continue to live when normal cells would die. 

The result is a tumor, which is a mass of abnormal cells.

Primary brain tumors are much less common than secondary brain tumors, in which the cancer originates elsewhere and spreads into the brain.

Cancer that begins elsewhere in the body and spreads (metastasizes) to the brain results in secondary (metastatic) brain tumors.

Those with a history of cancer are more likely to develop secondary brain tumors. 

Rarely, a metastatic brain tumor is the first sign of cancer that started elsewhere in the body.

Skin Cancer

Skin cancer is the most common cancer

Skin cancer is usually caused by the UV radiation from the sun.

If you believe you may have skin cancer, contact your dermatologist (a doctor who specializes in skin conditions) and set up an appointment. 

They can then check for signs of skin cancer.

Anybody can get skin cancer, and it can be permanent, though it is rarely life-threatening.

The easiest way to treat skin cancer is by avoidance.

Keeping to shady areas whenever possible, wearing sun-protective clothing, applying sunscreen with an SPF of 30 or higher and avoiding tanning beds can help you avoid getting skin cancer.

Gastrointestinal Cancer

The GI (gastrointestinal) tract is a 25-foot pathway that extends all the way from the mouth to the anus. 

All food you consume passes through the esophagus and gets processed in the stomach and small intestines to extract nutrients. 

In the end, the colon and rectum are responsible for removing waste from the body. 

It is possible for a tumor to form in one of these organs when mutations in the DNA cause abnormal cells to grow. 

This is known as gastrointestinal cancer.

Gastrointestinal cancer is a common condition that affects people worldwide. 

Cancer treatment is more effective when it is detected at an early stage – something that can be challenging, unfortunately.

Men are more likely to develop gastrointestinal cancers, and the risk increases as they age. 

These cancers have been linked to smoking, alcohol consumption, and unhealthy diets.

Gynecologic Cancer

Gynecologic cancer occurs in the female reproductive system. 

A woman’s reproductive organs are affected by five main types of cancer: cervical, ovarian, uterine, vaginal, and vulvar. 

They are collectively known as gynecologic cancers. 

The sixth type of gynecological cancer is the very rare fallopian tube cancer.

All five gynecologic cancers begin in different places within the pelvis, which is the area below the stomach and between the hip bones. 

Each type of gynecologic cancer has its own signs and symptoms, risk factors, and prevention strategies.

Gynecologic cancers are relatively rare compared to other types of cancer (such as breast or colon cancer), occurring in about 100,000 U.S. women each year. 

All women are at risk of developing gynecologic cancer, and the risk increases with age. 

It’s crucial to know the warning signs of cancer, because treatments are most effective when cancer is detected early.

Radiation / Oncology Frequently Asked Questions

In many cases, external beam radiation therapy is an effective treatment for cancer and other diseases.

However, incorrect delivery of high doses required for tumor control can have serious complications in normal tissue, and geographic misses of the tumor can result in tumor recurrence.

A beam or several beams of high-energy x-rays are delivered through external beam therapy (EBT), also called external radiation therapy. 

These beams are generated outside the patient (typically by a linear accelerator) and are directed at the tumor.

When compared to conventional radiation therapy (external beam radiation), which projects radiation from a machine outside the body, brachytherapy uses higher doses of radiation to target a specific area of the body.

Radiation therapy, or brachytherapy, treats prostate, breast, head and neck cancers, among others. 

Doctors insert tiny radioactive pellets into or near tumors. 

The pellets emit radiation that destroys cancer cells. 

The treatment spares healthy organs and tissue nearby.

Radiation therapy that conforms to the shape of a tumor is known as 3D conformal radiation therapy.

Cancer is the uncontrolled growth and spread of cells throughout the body. 

Both chemotherapy and radiation therapy are treatments for cancer. 

Chemotherapy uses special drugs to shrink or kill cancer cells. 

By using high-energy beams of light, such as X-rays or protons, radiation therapy kills cancer cells.