Radiation Therapy in Panama

What is radiation therapy, and what is it used for?

Radiation therapy is a medical treatment that uses high doses of ionizing radiation to destroy cancer cells or stop their growth. It acts directly on the DNA of tumor cells, preventing them from dividing and reproducing.

The doctor prescribes radiation therapy for different purposes depending on the case: to eliminate the tumor with the intent of a cure, to shrink it before surgery, to eliminate residual cells after surgery, or to relieve symptoms in advanced cancer. In all cases, the medical team develops the treatment plan based on the type of cancer, its location, and the patient’s overall condition.

How does radiation therapy work?

Radiation therapy works by damaging the genetic material of tumor cells. When radiation strikes the DNA of a cancer cell, that cell loses its ability to divide. Over time, it dies, and the body eliminates it naturally.

Healthy cells in the surrounding tissue may also be exposed to some radiation, but they are better able to repair themselves. That is why the treatment is administered in scheduled sessions: the interval between sessions gives the healthy tissue time to recover, while the tumor accumulates damage.

What happens to the tumor during treatment?

The tumor does not disappear overnight. The effects of radiation therapy are gradual. Some cells die during the first few sessions; others take weeks or even months to stop growing after the full course of treatment is completed. That is why the doctor schedules follow-up visits and diagnostic imaging during and after treatment to assess the tumor’s response.

Radiation Oncology: The Specialty That Follows Diagnosis

When imaging studies confirm a cancer diagnosis and the treatment plan includes radiation, radiation oncology comes into play. This medical specialty focuses on planning, administering, and monitoring radiation therapy—that is, the controlled use of ionizing radiation to treat tumors in cancer patients.

The radiation oncologist does more than just prescribe the dose. He or she also determines the technique, precisely delineates the area to be treated, shields adjacent healthy tissues, and adjusts the treatment plan if the patient’s response requires it. He or she works closely with medical physicists, radiology technologists, and the rest of the oncology team to ensure that each session targets exactly where it should.

Types of Radiation Therapy

Radiation oncology offers treatment options based on the type of cancer, its stage, and its location. The patient’s overall condition and response to other treatments determine which treatment modality is best suited for each case. Based on the preliminary evaluation, the specialist may recommend one of the following types of therapy:

External-beam radiation therapy

This is the most common type of radiation therapy. Radiation is delivered from a machine located outside the body, and the beams are precisely aimed at the tumor area. Before treatment begins, the specialist determines the exact area to be treated through a process called simulation. Sessions are generally administered five days a week, in cycles of 6 to 8 weeks, and the total dose varies depending on the type of cancer and the treatment goal.

Brachytherapy

Internal radiation therapy, or brachytherapy, involves placing a radioactive source directly into the tumor or very close to it using an applicator inserted in the operating room under anesthesia. This concentrates the dose on the affected area while minimizing the impact on healthy tissue. There are two techniques:

Interstitial brachytherapy: The implant is placed inside the tumor. It is frequently used to treat prostate cancer.

Intracavitary brachytherapy: The implant is placed inside a body cavity, such as the uterus in cases of cervical cancer.

Systemic radiation therapy

In this case, the radioactive source is administered orally or intravenously. Once in the body, it circulates through the bloodstream and accumulates in the tissues where the cancer is located. This is the most commonly used treatment for certain types of thyroid cancer, using radioactive iodine.

Effects of Radiation Therapy

Like any medical treatment, radiation therapy can cause side effects. Most occur in the treated area and appear during or shortly after the course of treatment. Not all patients experience them with the same intensity.

The effects of radiation therapy depend on several factors: the area of the body receiving the radiation, the total dose administered, the duration of treatment, and the patient's individual condition.

Common Side Effects by Treatment Area

The effects of radiation therapy vary depending on the treatment site. In the head and neck area, side effects may include dry mouth, difficulty swallowing, changes in taste, and sores on the mucous membranes. In the chest area, side effects may include a dry cough, difficulty breathing, or inflammation of the esophagus. In the abdomen and pelvis, side effects may include nausea, diarrhea, bladder irritation, or changes in sexual function.

In any area of the body, fatigue and local skin irritation are the most common side effects of radiation therapy. Healthy cells generally recover within weeks after treatment ends.