Radiation Oncology (sometimes called radiation therapy or radiotherapy) is the medical use of radiation in the treatment of various diseases, primarily cancer. At Cebu Doctors' University Hospital - Radiation Therapy Center (CDUH-RTC) the treatments are given by a machine called a Medical Linear Accelerator (LINAC). The radiation produced by the linac is computer controlled to destroy abnormal cells while preserving the normal, surrounding tissue. In many cases, radiation therapy is the single best method for the treatment of diseases such as cancer, but it also may be combined with surgery and/or chemotherapy.
Our objective is to deliver the prescribed dose of radiation to the accurately localized cancer-bearing tissues in order to produce tumor control and restrict the dose to surrounding normal tissues so that the probability of clinically significant damage to normal tissues is kept to an acceptable level. Providing radiation therapy is a team effort composed of the radiation oncologist, assisted by a medical physicist, radiation therapists, and a radiation oncology nurse. Each team member is trained, certified, or licensed as a specialist.
The tumor volume and organs at risk are identified and their depths determined using 2D or two dimensional simulation and treatment planning with the aid of simulator radiographs
This requires Computed Tomography (CT-Scan) simulation and treatment planning to allow more accurate definition of tumor volume and anatomy of critical normal structures, and optimization of the radiation dose distribution
This is more advanced approach to 3-D treatment planning and conformal radiation therapy by a dynamic delivery of radiation resulting to the modulation the intensity of radiation delivered to the tumor volume. This allows for higher doses of radiation delivered to the tumor volume while sparing the normal neighboring tissues.
External Beam Radiation Therapy uses high-energy radiation which is delivered by a machine outside the body to shrink tumors and kill cancer cells.
Radiation therapy kills cancer cells by damaging their DNA (the molecules inside cells that carry genetic information and pass it from one generation to the next).
Radiation therapy can either damage DNA directly or create charged particles (free radicals) within the cells that can in turn damage the DNA. Cancer cells whose DNA is damaged beyond repair stop dividing or die.
When the damaged cells die, they are broken down and eliminated by the body's natural processes.
NO! radiation therapy can also damage normal cells, leading to side effects. Doctors take potential damage to normal cells into account when planning a course of radiation therapy. The amount of radiation that normal tissue can safely receive is known for all parts of the body. Doctors use this information to help them decide where to aim radiation during treatment.
Radiation therapy is sometimes given with curative intent (that is, with the hope that the treatment will cure a cancer, either by eliminating a tumor, preventing cancer recurrence, or both). In such cases, radiation therapy may be used alone or in combination with surgery, chemotherapy, or both. Radiation therapy may also be given with palliative intent. Palliative treatments are not intended to cure. Instead, they relieve symptoms and reduce the suffering caused by cancer. Some examples of palliative radiation therapy are:
A radiation oncologist develops a patient's treatment plan through a process called treatment planning, which begins with simulation. During simulation, detailed imaging scans show the location of a patient's tumor and the normal areas around it. These scans are usually computed tomography (CT) scans, but they can also include magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasound scans.