Fundamentals of Radiation Therapy

A radiation therapy plays a significant role in the treatment of cancer, as a substantial number of cancer patients undergo some form of radiation treatment. The therapeutic procedure is based on the application of high-energy ionizing radiation, which can damage the genetic material (DNA) of cancer cells, thereby reducing their proliferation. The radiation not only targets cancer cells but unfortunately also affects healthy tissues, although these are generally less sensitive to radiation than cancer cells. As a result, the procedure has a selective effect, and treatments have continuously evolved over the past decades, becoming increasingly effective.

Although the goal of radiation therapy is to achieve a definitive cure, in many cases, the result of the treatment is merely the slowing of cancerous tissue growth or the reduction of cancer pain. Radiation therapy can be used as a standalone alternative, but it is often combined with surgical and chemotherapy procedures to maximize treatment effectiveness.

Types of Radiation Therapy

The two main types of radiation therapy are external and internal radiation. In external radiation, a device located at a specific distance from the radiation source delivers the beams, while internal radiation is delivered through a radiation source placed directly inside the body. Internal radiation is most commonly used for treating cancers of the skin, uterus, prostate, and lungs.

The planning of radiation therapy is carried out by a radiation oncologist, who determines the precise size and location of the area to be irradiated using various imaging studies, such as CT or MRI. The treatment plan is created taking into account the type of tumor, its extent, and its sensitivity to radiation, ensuring maximum effectiveness.

How Radiation Therapy is Administered

Radiation therapy takes place in specially designed centers, where the patient lies in the correct position during the treatments. The radiation therapy equipment is controlled by the physician using a computer, which ensures that the radiation is directed precisely at the targeted area. The irradiation process is painless and typically lasts only a few minutes.

The necessary radiation dose is not administered all at once but is given fractionally over several weeks, requiring the patient to visit the treatment facility every day. During the treatment, maintaining a stable body position and even breathing is essential, as these help in the precise direction of the radiation. In some cases, such as prostate treatment, patients are required to arrive for treatment with a full or empty bladder. Additionally, proper nutrition is crucial, as intestinal gases or waste can affect the path of the radiation.

After the treatment, patients do not become radioactive, meaning they pose no danger to their environment. An exception to this is treatments involving radioactive medications, where the patient may temporarily become radioactive.

Side Effects of Radiation Therapy

The side effects of radiation therapy depend on the size of the irradiated area and the amount of radiation administered. The side effects can be categorized into two main groups: early and late side effects. Early effects usually occur at the end of the treatment, gradually intensifying, but generally decrease within 2-4 weeks after treatment. In contrast, late side effects may appear months or even years after the therapy has concluded.

Common general side effects include fatigue, loss of appetite, and skin problems such as hair loss. During radiation, the body uses more energy, which can cause fatigue. After the treatment, this symptom can last for up to 4-6 weeks.

Symptoms on the treated area of the skin may include sunburn-like effects, which can be accompanied by dryness, peeling, and itching. To alleviate these symptoms, it is recommended to use warm water compresses, neutral cleansing products, and moisturizers, while avoiding deodorants and perfumes. Hair loss is generally temporary, but hair regrowth occurs at a slower rate than after chemotherapy.

Specific side effects may include oral problems, such as dry mouth and decreased taste sensation, which can lead to difficulties in eating. Abdominal radiation often leads to diarrhea, while pelvic treatments may cause urination and defecation problems, which can be alleviated with medication. Both men and women may experience a decrease in reproductive ability, so pregnancy should be avoided during radiation therapy due to potential harmful effects.