Introduction
Your Radiation Oncology Treatment Team
What is Cancer?
How Is Cancer Treated?
What is radiation therapy?
What will happen if I need radiation therapy?
Cancer Research
Introduction
For patients who are diagnosed with cancer, it is very important to know their treatment options and discuss each one with their physicians. Some forms of cancer require surgery, others require radiation therapy or chemotherapy. Often, patients need a combination of all three. Naval Medical Center, Portsmouth provides a multidisciplinary, comprehensive approach to its cancer patients. The radiation oncology team includes three radiation oncologists, five radiation therapists, two medical physicists, one dosimetrist, two oncology nurses, and support personnel including corpsmen and secretaries.
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Your Radiation Oncology Treatment Team
Radiation Oncologist
The Radiation Oncologist (your 'Doctor') oversees and directs the care of each patient. He/she develops and prescribes each cancer patient's treatment plan. He makes sure that every treatment is accurately given. The Radiation Oncologist monitors the patient's progress and adjusts treatment to ensure quality care throughout treatment. Radiation Oncologists also help identify and treat any side effects that might occur during or after radiation therapy. They work closely with other physicians and all members of the the radiation oncology team to make sure each patient is getting the best treatment.
Radiation Oncology Nurses
Radiation oncology nurses help doctors educate each patient and his/her family about cancer and radiation treatment. They provide resources for emotional support to patients and their families and can arrange consultation with social workers if home health care is required. They also help evaluate patients during treatment. These examinations generally take place weekly during treatment and help the doctor care for any side effects that might occur as the result of treatment.
Medical Radiation Physicists
Medical physicists work under the direction of the radiation oncologist. They oversee the work of the radiation dosimetrists and are responsible for complex 3-dimensional radiation treatment planning. Medical physicists are responsible for developing and directing quality control programs for equipment and procedures. They are responsible for making sure the equipment works properly. Medical radiation physicists take precise measurements of radiation beam characteristics and do other safety measurements on a regular basis.
Dosimetrists
Dosimetrists carefully calculate the dose of radiation to make sure the tumor gets enough radiation. They develop a number of treatment plans that can best destroy the tumor while sparing the normal tissues. They work with the radiation oncologist and medical physicist to choose the treatment plan that is just right for each patient.
Radiation Therapists
Radiation therapists work with the radiation oncologists in treatment setup (simulation) and delivery of treatment. They actually deliver the radiation treatments to each patient under the physician's prescription. They maintain daily treatment records and regularly check the treatment machines to make sure they are working properly.
Secretaries and Hospital Corpsmen
The secretaries and the hospital corpsmen in the Division of Radiation Oncology will schedule your initial appointment as well as follow-up appointments after you complete treatment. The corpsmen will also take your vital signs (weight, blood pressure, etc.) and draw routine blood tests as needed during your course of radiation therapy.
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What is Cancer?
Normally the cells in your body grow and divide to maintain normal function of your body. Sometimes, however, cells lose their ability to limit and direct their growth, and they divide rapidly without any order. These cells grow into
masses of tissue known as tumors. Tumors can be either benign or malignant. Benign tumors are not cancer. They usually grow slowly, and generally do not spread to other parts of the body. Benign tumors can usually be removed surgically without any further problems.
Malignant tumors are cancer. They are usually capable of invading adjacent tissues or metastasizing (spreading) to other parts of the body. The most common methods for cancer to spread are through the lymphatics to regional lymph nodes or through the bloodstream to distant organs. Because cancer can spread, it is important to detect it as early as possible so treatment can be initiated while the cancer is limited. Cancers are most curable when they are localized.
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How Is Cancer Treated?
There are three major methods of treating cancer - surgery, radiation therapy, and chemotherapy.
Surgery involves the removal of the tumor and some of the surrounding normal tissues. This a very localized form of treatment.
Radiation therapy involves the use of high energy rays to destroy cancer cells. Radiation therapy is also a localized form of treatment. However, it is broader in scope than surgery because organs that cannot be removed surgically can usually be treated with irradiation.
Chemotherapy uses anticancer medication to destroy cancer cells. The drugs may be given by mouth, intramuscularly, or intravenously. Because the chemotherapy travels throughout the body, it can eradicate cancer cells in remote locations.
Many cancers are treated with a combination of these treatment modalities. This is one reason why multidisciplinary care is so important. It is very important that patients know their treatment options. They should talk with their doctors to determine which treatment or combination of treatments is best for them.
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What is radiation therapy?
Radiation therapy is the careful use of high energy x-rays, gamma rays, and electrons to treat cancer. Radiation is effective in treating cancer because it damages cancer cells more than it does normal cells. However, normal tissues may also be damaged, which is one reason why side effects can occur. The goal of radiation therapy is to destroy the cancer with as little injury as possible to the surrounding normal tissues. The purpose of radiation therapy is often to cure the patient of cancer. Such treatment is called curative radiotherapy. To be curative, the treatment must eradicate every cancer cell or prevent them from growing and multiplying. High doses are often required when the aim of the radiation therapy treatment is to cure.
Radiation therapy may also be used to relieve cancer symptoms, even when cure is not possible. This type of treatment is called palliative radiotherapy. Palliative radiotherapy may be given to relieve pain due to bone invasion, headaches due to brain metastasis, paralysis due to spinal cord compression, or to stop bleeding due to involvement of the skin, bladder, or bowels. Palliative radiation therapy usually requires fewer treatments than curative radiation therapy because not all of the cancer cells have to be eradicated to relieve the symptoms.
More than half of all cancer patients in the United States are treated with radiation therapy sometime during the course of their illness. About half of these are treated for cure, and half for palliation.
How Is Radiation Therapy Given?
There are two basic types of radiation therapy - external beam radiation therapy and radioactive implants. With external beam radiation therapy, a machine is used to direct the radiation to the cancer through the skin. Most of the patients who are treated with radiation therapy are treated with external beam irradiation.
With radioactive implants, radioactive sources are placed inside the body within or next to the tumor. Radioactive implants are often used to treat well-localized cancers because a greater dose of radiation can be given to the tumor with less dose to surrounding health tissues. It is not unusual for a patient to receive a combination of external beam radiation therapy followed by a radioactive implant.
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What will happen if I need radiation therapy?
Consultation
Patients will usually be seen for initial consultation in the Radiation Oncology clinic. Some patients are seen as hospital inpatients. Patients will most often be seen by both an Oncology Nurse and a Radiation Oncologist (sometimes the first visit with the nurse will be after the radiation therapy has already started). A history and physical examination will be performed in addition to a discussion of the indications for radiation therapy and risks and benefits of treatment. A decision on whether or not to proceed with radiation therapy may be made at the initial consultation, or may be made at a later date. Some reasons that a decision may be delayed include patient desire to consider options, additional xrays or other tests not yet completed, or consultation with other specialists still pending. Once a decision has been made to begin radiation therapy, the patient will be scheduled for a simulation.
Simulation
Patients undergo simulation prior to starting radiotherapy. Simulation is like a rehearsal for the actual treatments. This rehearsal helps assure the radiation oncologist that the treatment will be given to the correct target volume. Simulation is performed with a special machine called a "simulator."
During simulation, the patient lies on the simulation table and the simulation therapist takes several x-ray images of the region targeted for irradiation. Often, certain devices will be used to help make each daily treatment more reproducible. These "immobilization" devices include plastic mesh face masks, "vac-lock" bags which are bean bags that form to the patients body, and special reclining arm rest devices for breast cancer patients. The radiation oncologist studies the images to determine where and how to direct the radiation beam to best treat the patient's tumor. When a treatment arrangement has been selected, the area to be treated is marked on the patient's skin.
A CT scan is often performed either prior to radiation therapy or early on in the course of treatment. The data from the CT scan can be directly downloaded to the radiation therapy treatment planning system allowing for more complex 3-dimensional planning for treatment delivery.
Treatment Planning
After simulation, treatment planning computers are used to map out the radiation dose in and around the tumor and to determine the dose of radiation to critical normal tissues and organs. Our treatment planning system uses true 3-dimensional planning. Three-dimensional (3-D) treatment planning allows more accurate delivery of treatment to the tumor while reducing the amount of radiation to normal structures.
Treatments
External Beam Treatments
Radiation treatments are usually delivered daily, five days a week. In some situations, radiation therapy is delivered two times per day, usually about 6 hours apart. Each treatment only takes a few minutes, but the patient can expect to be in the clinic for about one-half hour. Most of that time is taken to make sure the radiation beam is directed as planned during the simulation. The radiation treatments are painless and similar to having a diagnostic x-ray examination. The patient will be alone in a shielded treatment room, but the therapist is in continuous contact through closed circuit television and a two-way intercom system.
Side Effects
Patients can develop side effects during the course of treatment. The side effects that occur depend on the area being treated. For example, irradiation of the head and neck may result in a sore throat; irradiation of the upper abdomen may result in nausea; and irradiation of the lower abdomen may result in diarrhea. Patients do not usually lose their hair unless the scalp is being irradiated. At the beginning of treatment, the radiation oncologist will explain to the patient the specific side effects that may occur with the treatment to be received. Your Radiation Oncologist and Oncology Nurse will more thoroughly explain the possible and probable side effects.
Radioactive Implants
With radioactive implants, radiation sources are placed directly into the tumor or into a body cavity next to the tumor. This technique delivers a high dose to the tumor with minimal irradiation of adjacent healthy tissues. Implants are often used for treating cancers of the cervix, uterus, vagina, or head and neck.
Radioactive implants are usually performed in the operating room. Following the procedure, the patient is taken to the Radiation Oncology clinic for x-rays to be used for dose computation. In some situations, the radioactive sources are left in place permanently and the radioactivity dies out on its own. In other situations, the sources are removed after a few days. Most patients are required to stay in the hospital while the implant is in place, and they can have only limited contact with visitors during this period.
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Cancer Research
Clinical treatment protocols are available at NMCP through participation in many national cooperative groups including the Radiation Therapy Oncology Group (RTOG), the Cancer and Leukemia Group B (CALGB), the Pediatric Oncology Group (POG)(recently merged with Childrens Cancer Group), the National Surgical Adjuvant Breast Program (NSABP), and the Gynecological Oncology Group (GOG). We are also a participating institution for the Center for Prostate Disease Research (CPDR).
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For more information on Radiation Oncology, please go to the Radiation Oncology page of the ONCOLINK web site.
