Radiation Oncology: Promising New Therapies

Like all medical specialties, the field of therapeutic radiology continues to make advances in knowledge and technology. Many new radiation modalities are being used and studied to find more effective treatments for cancer and other conditions which may be treated with radiation.

What new therapies are being developed?

Some of the more promising new therapeutic radiation therapies are described below:

• radiation and chemotherapy in combination
  It has been discovered that radiation may, in some cases, improve the effects of chemotherapy, and that chemotherapy, in some cases, may improve the effects of radiation. Research continues in this area to establish treatment protocols which may provide the greatest efficacy of chemotherapy and radiation.
• endovascular brachytherapy
  The use of interventional procedures such as angioplasty, stents, and other procedures has increased greatly in the past 20 years. Angioplasty and stents are used to open blocked areas in blood vessels.

  Unfortunately, there is a good probability that newly opened areas in blood vessels may close after an angioplasty or stent procedure, usually occurring within 3 to 6 months after the procedure.

  The use of radiation at the site of angioplasty or stent has been shown in research studies to decrease the chance of vessel closure after these procedures. Endovascular brachytherapy continues to be studied at this time.

• intraoperative irradiation
  Intraoperative irradiation is the use of external beam radiation therapy during surgery to treat cancerous tumors or certain other forms of cancer. Benefits of intraoperative irradiation include a decreased area of irradiated tissue, as the target area is directly visible, and a more effective dose of radiation may be used. The use of intraoperative irradiation, when used in conjunction with surgery, external beam therapy, and/or chemotherapy, has been shown to improve the outcome of cancer treatment in certain situations.

• stereotactic irradiation
  The use of stereotactic irradiation has added an important new treatment modality to the area of brain cancer treatment. Stereotactic irradiation is the use of a single high dose of radiation sent into the diseased tissue with very narrow beams of radiation. The two main forms of stereotactic irradiation are linear acceleration and the gamma knife. The precision, as well as the lower amount of invasiveness offered by stereotactical surgical procedures has been shown to lower the length of hospital stay and the associated costs for certain brain cancers and conditions.
• particle radiation therapy
  Particle radiation therapy is the use of higher-energy radiation particles in cancer therapy. This type of radiation therapy offers benefits related to the individual cells under treatment. Two types of particle radiation therapy are under study: fast neutron therapy and charged particle therapy.

  Fast neutron therapy may be used in the treatment of certain inoperable or recurrent tumors. Because of the cost of the equipment and the need for improved technology, there are only three centers in the US and 10 centers in the entire world which offer fast neutron therapy.

  There are a few more centers offering charged particle therapy. However, only a small number of patients have been treated with this type of radiation therapy.
• three-dimensional (3D) conformal radiation therapy
  Before the development of computed tomography (CT), exact targeting of a lesion or tumor for radiation therapy was difficult. CT provided a 2-dimensional means of visualizing the treatment area. However, a 3-dimensional visualization is necessary to define all borders of the lesion or tumor for the most precise treatment planning and implementation. Protocols and techniques for 3-dimensional conformal radiation therapy are being developed and refined to improve the application and outcomes of radiation therapy.
• thermoradiotherapy (hyperthermia)
  The use of elevated temperatures at the site of treatment has been shown experimentally to improve the response of certain cancers to other forms of radiotherapy, as well as chemotherapy. However, further study is needed to document the efficacy of thermoradiation therapy.
• radioimmunotherapy
  Radioimmunotherapy is a type of radiation therapy that involves using antibodies "tagged" with a radiopharmaceutical substance. These tagged antibodies recognize tumor cells and bind with them, thus bringing the radiopharmaceutical directly to the tumor tissue. The tagged antibodies may be administered intravenously, directly into an artery, under the skin, or directly into a body cavity such as the uterus. One advantage of radioimmunotherapy is that it may be used to treat metastases (sites away from the original lesion or tumor to which cancer has spread) that are not visible by diagnostic means, thus helping to eliminate the spread of the disease.