If electromagnetic radiation is capable of removing electrons from atoms or molecules—that is, if it can be used to destroy cells—then radiation therapy is being used. This is also referred to as radiatio, radiotherapy, or irradiation.
Positive, or ionizing, particle radiation forms the basis of medical radiation therapy. The benefit of this may sound like a contradiction: the radiation has a harmful effect on living cells—that is, on the tissue. High-dose radiation damages the genetic material of both healthy and diseased cells—that is, cancer cells—in equal measure. However, healthy cells survive the procedure and can repair the damage, while cancer cells die.
Radiation therapy is categorized into soft radiation (up to 100 kV), hard radiation (more than 100 kV), and megavolt therapy (over 1000 kV). Soft radiation is generally used for superficial tumors, while megavolt therapy is used for deep-seated tumors. In most cases, radiation therapy is used curatively—that is, to cure the disease. If the goal is simply to improve quality of life or relieve pain—as in the case of incurable diseases—radiation therapy is also used, but in a palliative setting. Radiation therapy may be administered alone or in combination with chemotherapy.
The choice of radiation therapy depends on many factors, which is why it is usually developed collaboratively by experts from various disciplines. The most common tumors treated with radiation are breast cancer, lung cancer, and prostate cancer.
General Information on Radiation Therapy
Radiation therapy, also known as radiation oncology or radiotherapy, is an important form of treatment for cancer and certain benign conditions.
Radiation therapy is generally a locally targeted treatment in which high-energy radiation beams are focused as precisely as possible on the tumor. Since cancer cells are more sensitive to radiation than healthy cells, the cancer cells are damaged to the point that they die.
In contrast, healthy tissue is spared by the localized application, keeping the side effects of radiation therapy to a minimum.
What does radiation therapy achieve?
In most cases, the goal of radiation therapy is to cure the disease (curative radiation therapy). Today, for example, about one-third of tumors that have not yet formed secondary tumors (metastases) can be cured using radiation therapy techniques such as brachytherapy, intraoperative radiation therapy, or percutaneous radiation therapy. Ideally, the tumor should be completely removed after radiation treatment.
However, not all tumors respond equally well to radiation treatment. As a result, specialists in radiation therapy (radio-oncology) distinguish between radiation-sensitive and radiation-resistant tumors.
The effectiveness of radiation therapy can, however, be improved by administering cytostatic drugs to the patient, which make the tissue more sensitive to radiation (radiochemotherapy), selectively heat the tumor tissue (deep hyperthermia, or hyperthermia for short), or by dividing the total planned radiation dose into multiple treatments (fractionated radiation therapy or fractionation).
The goal of neoadjuvant radiation therapy is to shrink the tumor to such an extent that subsequent surgery or chemotherapy is more likely to be successful.
In contrast, tumor cells that remain in the body after surgery (e.g., for breast cancer or a brain tumor) are to be removed through subsequent radiation therapy; this is referred to as adjuvant radiation therapy.
In palliative radiation therapy, the focus is no longer on a cure but on improving or maintaining quality of life—for example, to relieve pain caused by bone metastases.
For which diseases is radiation therapy used?
Today, more than 50 percent of patients with, for example,
- brain tumors,
- breast cancer,
- prostate cancer,
- colorectal cancer,
- lung cancer, or
- cervical cancer
radiation therapy.
In addition to treating tumors, radiation therapy is also used for pain management. Low-dose X-rays (X-ray stimulation therapy) are used to treat
- chronic pain, particularly in the musculoskeletal system—such as tennis elbow, painful shoulders, or hip joint pain associated with osteoarthritis—
- and benign conditions, such as keloids, Dupuytren’s contracture, or psoriasis,
when other treatments have not produced the desired results.
What procedures are used in radiation therapy?
In the radiation oncology treatment of cancer and pain management, radiation therapy specialists have a wide range of techniques at their disposal.
The classic procedure used in radiation therapy clinics is percutaneous radiation therapy, in which the patient—or the tissue to be irradiated—is positioned beneath a radiation device similar to an X-ray machine. High-energy rays are then directed from outside the body through the skin (percutaneously) into the body.
During radiation therapy, the patient must remain still to prevent the rays from damaging healthy tissue. Since even breathing can have negative consequences—for example, in breast cancer radiation therapy—techniques have been developed in which radiation therapy is synchronized with breathing (breath-triggered radiation therapy).
© Thomas Hecker / Fotolia
In contrast, in brachytherapy—also known as short-distance radiation therapy—the radiation source (so-called “seeds,” tiny radioactive metal pellets) is implanted directly into the tumor tissue or into a body cavity. The main areas of application for brachytherapy are gynecological tumors and carcinomas of the esophagus and prostate.
In intraoperative radiation therapy, the tumor is irradiated directly during surgery. This allows the organs located within the treatment field to be better protected by simply moving them aside. The video explains the principle of brachytherapy:
Intensity-modulated radiation therapy (IMRT) allows for precise, tissue-sparing irradiation by repeatedly adjusting the direction of the radiation beam. This high level of precision is also achieved with tomotherapy, in which a radiation source rotates from all sides around the area of the patient’s body to be treated. Computed tomography is used to verify the tumor’s location and adjust the radiation dose (image-guided radiation therapy) to avoid underdosing the tumor and overdosing normal tissue.
Another form of radiation therapy is performed using a green laser (Greenlight laser). The laser’s wavelength lies within the visible green spectrum and is absorbed by the red blood pigment. The laser beams penetrate only the surface of the tissue, thereby destroying tumor growth. The Greenlight laser is also used to treat an enlarged prostate. The video shows the green therapeutic laser in use in the trachea:
In stereotaxy—or, more precisely, stereotactic radiosurgery—the tumor is “cut out” using high-energy doses. This procedure is used in particular for brain tumor radiation therapy.
A relatively new form of radiation oncology is proton therapy, which is currently available only at a few centers and clinics specializing in radiation therapy. The advantage of this form of radiation therapy is that the main radiation dose can be precisely targeted at the tumor, while the tissue above and below it is largely spared.
In addition to these localized procedures, there is also total-body irradiation, in which leukemia or lymphoma cells circulating in the body are destroyed by irradiating the entire body. This method is also used to eradicate the body’s own bone marrow prior to a bone marrow or stem cell transplant.
X-ray stimulation therapy is used in pain management. There are several theories regarding the effects of X-ray stimulation therapy. It is hypothesized that low-dose radiation stimulates metabolism, influences the acid-base balance, or inhibits autoimmune processes and blood flow.
What side effects can be expected with radiation therapy?
Side effects of radiation therapy can occur in healthy tissue depending on the radiation dose, penetration depth, number of treatments, and the tissue being irradiated. Early reactions to radiation therapy include, for example
- skin redness
- Mucosal inflammation
- A feeling of fullness
- Nausea
- Diarrhea
- and, rarely, hair loss.
Late effects may include, for example, vascular constriction, scarring, skin discoloration, or dry mouth; in the case of radiation therapy for breast cancer, coronary heart disease may also occur.
The development of a radiation-induced secondary tumor or germline damage is very rare.
Which specialists perform radiation therapy?
Radiation therapy should be performed by an experienced specialist in radiation therapy/radio-oncology or radiology. A specialist in radiation therapy has completed five years of advanced training following medical school.
How do I find the “best hospital” for radiation therapy (radio-oncology)?
It is not possible to designate a single clinic as the “best clinic” or “top clinic” for radiation therapy (radio-oncology). However, there are certainly doctors and clinics that specialize in the radiation oncology treatment of cancer and pain management using radiation and have extensive experience. You can find these experts in radiation therapy (radiation oncology) in the Leading Medicine Guide.
What makes our doctors specialists in radiation therapy (radio-oncology)?
The Leading Medicine Guide features only select, highly qualified medical experts and specialists. All listed doctors possess a high level of professional expertise, have extensive experience in the field of radiation therapy and radiation oncology, and meet the Leading Medicine Guide’s strict admission criteria.
