Radiation Therapy for Squamous Cell Carcinoma of the Skin

Radiation therapy uses high-energy rays such as x-rays or particles such as electrons to kill cancer cells. It is sometimes used to help treat squamous cell carcinomas of the skin.

When might radiation therapy be used?

Although surgery is the most common treatment approach for squamous cell carcinoma (SCC) of the skin, also known as squamous cell skin cancer, radiation therapy might be used in some situations. For example, radiation might be an option if:

• A tumor is very large
• A tumor is in an area that makes it hard to remove with surgery
• A person can’t have or doesn’t want surgery for some reason
• Surgery has been done, and there’s a high risk that the cancer will return
• The cancer has spread to lymph nodes or other organs

Radiation can often be effective in treating skin tumors. One drawback is that if a tumor comes back in an area that has already received radiation, giving radiation again might cause more serious side effects. But in some cases it might still be an option.

Situations where radiation is usually avoided

After many years, new skin cancers sometimes develop in areas previously treated by radiation. For this reason, radiation usually is not used to treat skin cancer in young people.

Radiation is also not recommended for people with certain inherited conditions, such as xeroderma pigmentosum, who might be at higher risk for new cancers, or for people with connective tissue diseases such as lupus or scleroderma, which radiation might make worse.

How is radiation therapy given?

The 2 main ways radiation therapy can be used to treat squamous cell skin cancer are external radiation therapy and brachytherapy.

External radiation therapy

In the most common approach, the radiation is focused from a machine onto the tumor. This is often done using a beam of low-energy x-rays (superficial radiation therapy) or electrons (electron beam radiation). These types of radiation don’t go much deeper than the skin, which helps limit the side effects to other organs and body tissues.

The number of radiation treatments a person gets depends on why it’s being given. When radiation is used as the main treatment for a skin tumor or after surgery, it’s often given 5 days a week for several weeks. Another option might be to give higher doses of radiation over fewer treatments, known as hypofractionation.

Each treatment is much like getting an x-ray, but the radiation is stronger and aimed more precisely at the cancer. The procedure itself is painless. The treatment lasts only a few minutes, although the time needed to get you into place for treatment takes longer.

Brachytherapy

Brachytherapy is another way to deliver radiation to skin tumors, especially those on the head and neck. In this technique, a hollow applicator device is placed either on top of the tumor, known as superficial brachytherapy, or directly into the tumor, known as interstitial brachytherapy. A radioactive source is then put into the applicator, usually for a short amount of time. This type of radiation travels only a short distance, so not much of it reaches nearby normal tissues.

One advantage of brachytherapy is that it can typically be done in a small number of treatments, so it can be more convenient for the person getting it.

Possible side effects of radiation

Side effects of radiation are usually limited to the area being treated and can include:

• Skin irritation, ranging from redness to blistering and peeling
• Changes in skin color
• Hair loss in the area being treated
• Damage to saliva-making glands and teeth, resulting in dry mouth and tooth decay, when treating cancers near these structures

With longer treatment, these side effects might get worse.