Radiation oncology is the sub specialty of cancer treatment where radiation is used to treat patients. The physician is the radiation oncologist who is supported by many highly trained staff. That entire team cares for the patient. High energy radiation is used to kill malignant cells and thus treat the cancer. Great care must be taken in delivering radiation treatment.
Radiation is very effective in treating cancerous tissues but also can cause damage to some normal tissues. The experience and expertise of the radiation oncologist and the staff along with the quality of the equipment is critical in making the treatment effective while minimizing the risk of side effects.
At Texas Oncology, patients receive today's most precise radiation applications due to our advanced technology. Your treatment may include one or more of the following technologies.
Virtual CT Simulator
The goal of radiation is to deliver the highest dose possible to the cancer while minimizing the dose to the normal tissue. The first step in this process is CT simulation. The patient undergoes a special type of CT scan. At this time, the patient is positioned a particular way and 3 dimensional anatomical data is obtained. The radiation oncologist then identifies the areas to be treated and those to be avoided. This information is then used to create a treatment plan.
Highly sophisticated planning computers are used to determine the best way to treat the particular tumor. With these systems the direction of radiation is determined and the treatment is optimized. Specially trained staff known as physicists and dosimetrists work with the radiation oncologist to create the plan.
Intensity Modulated Radiation Therapy (IMRT)
IMRT is an advanced form of non-invasive radiation treatment that uses highly sophisticated planning systems and linear accelerators to deliver high doses to a tumor while minimizing the dose to normal surrounding tissues. Highly focused radiation beams of varying intensity are used to maximize the possibility of a cure while decreasing the chance of toxicity.
Image Guided Radiation Therapy
Tightly focused radiation treatment requires a great deal of precision. Since radiation is delivered on a daily basis over several weeks. It is critical that every day the patient is in the same position and the tumor is in the expected location. IGRT allows for daily visualization of the targeted area so radiation may be delivered more effectively.
The term brachytherapy refers to the placement of radioactive seeds or pellets directly into a cancerous organ. In the case of prostate cancer, radioactive seeds are placed directly into the prostate with an ultrasound probe positioned in the rectum to guide seed placement.
This new form of treatment is increasing in popularity because of its minimally invasive nature and quick recovery. The procedure is generally done on either an outpatient basis or with an overnight hospital stay. There is some pain associated with the actual seed placement and, for that reason, general anesthesia is required. The entire procedure typically takes two to two and one-half hours.
Not all patients with prostate cancer are candidates for brachytherapy. One of the most critical prerequisites for this form of treatment is a prostate small enough to allow adequate dosing of the radiation to the entire prostate gland. This so-called dosimetry is important because the radiation must be evenly distributed throughout the prostate gland in order to ensure complete eradication of the tumor. Ordinarily, brachytherapy would only be considered in a patient with cancer confined to the prostate gland.
If a patient with prostate cancer is found to have a prostate too large for brachytherapy, but is otherwise felt to be a candidate for this form of treatment, it can be administered at a reduced dose following a course of conventional external beam radiation. Another option is the administration of androgen (testosterone) blocking medication prior to brachytherapy in order to shrink the prostate gland.
High Dose Rate Brachytherapy (HDR)
High Dose Rate Brachytherapy (HDR) uses a radioactive source that is placed inside the body part to be treated. Then, a high dose of radiation is projected upon a limited area of the body, sparing the surrounding normal tissue. The treatment may be given in either an inpatient or outpatient setting and generally is over fewer days than external radiation. The main advantage of brachytherapy is the ability to give very high doses to the tumor while minimizing exposure to tissues more than a few centimeters away.
Low Dose Rate (LDR) Brachytherapy Radioactive Seed Implants
Low Dose Rate (LDR) Brachytherapy Radioactive Seed Implants are often used for prostate cancer. This treatment involves surgically implanting radioactive “seeds” into the tumor, which deliver a high dose of radiation. The seeds are permanently in place, but become inactive after a period of weeks or months.
Most patients now have multiple imaging studies performed at various times. With special fusion software, doctors can combine many of these studies to more effectively utilize all the information to optimize the treatment plan.
External Beam Radiotherapy
External beam radiotherapy is a primary treatment for a variety of cancers. It uses a high-energy X-ray machine to deliver ionizing radiation to specific parts of the body. The goal of the treatment is to give a high dose of radiation to the tumor while sparing as much of the normal tissue as possible.
In urology, radiation is typically used to treat prostate, testicular and bladder cancers. It is occasionally used to treat kidney cancer.
In radiotherapy, the localized radiation damages targeted cancer cells and kills them. The body then processes the cells, effectively destroying the tumor.
For early stage prostate cancer, radiation is often the primary treatment. In some cases, it is paired with surgery. For advanced cancer, it is often paired with hormone therapy. For metastatic cancers, radiation can be used as a palliative treatment.
External beam radiotherapy is typically given in multiple treatment sessions that take place over several weeks. This type of regimen is called a fractionated treatment regimen. In some cases, external beam radiation is prescribed over a shorter period of time — one to five treatments — a regimen called stereotactic radiation.
When treating prostate cancer, external beam radiation is generally delivered five days a week, for 7.5 - 8.5 weeks.
At Texas Urology Specialists, radiotherapy is provided as part of our intimate working relationship with Texas Oncology. Radiation treatments are provided by experienced Texas Oncology radiologists using state-of-the-art radiation oncology technologies. These include Intensity-Modulated Radiation Therapy (IMRT) and Image-Guided Radiation Therapy (IGRT).
Patient Management System
All of this technology enables better treatment of patients. However, it is important that all of the equipment is integrated in it's function and that we are able to verify that what is being delivered is what was intended. This quality assurance is enabled with the use of radiation management systems with record and verify functionality.
For more information on cancer treatment and what to expect from radiation therapy, please visit these Texas Oncology pages & press releases:
Texas Urology Specialists Radiation Treatment Centers: