Radiation Treatments for Kidney Cancer
The mainstay of treatment for kidney cancer (renal cell carcinoma) is surgery. Typically, when a patient has kidney cancer, part or all of the kidney is removed, during a surgery called a nephrectomy. Sometimes, chemotherapy is needed as well. The ultimate combination of treatment depends on a number of factors, including the type, location and size of the tumor as well as the patient's age and general health. Renal cell carcinomas are tumors that originate, or start, within the kidneys. Some other types of cancer can originate within the kidney, and tumors can also develop in the kidneys after metastasizing from another site.
Historically, radiation therapy has had a limited role in the treatment of kidney cancer, largely because renal cell carcinoma has classically been considered "radioresistant" - or resistant to the effects of radiation. However, for some patients, there is a role for radiation therapy in kidney cancer. Radiation can be given over the course over 3-7 weeks. In this setting, a small amount of radiation is given each day. This is known as fractionated radiation therapy and can be given with either photon or particle therapy, including proton beam and carbon ion therapy.
More recently, a type of treatment called stereotactic body radiation therapy (SBRT) has been developed and shown to be useful in the treatment of kidney cancers. In this setting, a higher daily dose of radiation is given to a specific area of the kidney or surgical bed, using a fewer total number of treatments. Another type of radiation, known was intraoperative electron radiotherapy has also been used after surgery in the treatment of kidney cancer.
In addition to treatments that are directed at the kidney, treatments are sometimes needed for other parts of the body to which kidney cancer has spread. These may include the bones and/or brain.
Your radiation oncologist will work with your treatment team to decide on the best technique for your treatment.
Treatment Techniques for Kidney Cancer
The following treatment techniques are utilized to deliver fractionated radiation therapy and stereotactic body radiation therapy (SBRT). Your clinical team will decide which method is most appropriate for treating your particular case.
Stereotactic body radiation therapy (SBRT) is a technique that is now commonly used for the lung and can also be applied to the kidney. Unlike fractionated radiation therapy, SBRT is delivered using higher doses of radiation with each session than is used with fractionated radiation therapy.
In SBRT, a focused high-intensity beam of radiation is used to target the tumor. It can use several technologies to deliver this intense beam including:
- Intensity Modulated Radiation Therapy (IMRT): Multiple beams are used at different angles and the dose is dynamically modulated in different parts of the target area to conform to the size and shape of the target and to avoid the nearby normal organs, such as the liver, small bowel, and/or contralateral kidney which would decrease the risk of side effects.
- Volumetric Modulated Arc Therapy (VMAT): In VMAT, an advanced linear accelerator is used to circle around the patient at a speed that is up to eight times faster than what was previously possible with standard radiation therapy. Special software is used again to modulate the beam as it moves around the patient to deliver a high dose to the target and avoid the normal, non-cancerous tissue. VMAT can deliver the dose to the entire tumor in a single (or back-and-forth) rotation in a few minutes.
- Either IMRT or VMAT can be combined with image-guided radiation therapy (IGRT) which uses images taken just prior to the patient’s treatment. It then compares these images to what the images should look like based off of the planning scan. Sometimes it uses x-rays and sometimes it uses modified CT scans, known as cone-beam CT scans. In addition, small metallic markers can be implanted into or near the tumor before treatment starts. The location of markers is then compared to the original planning scan and an image right before the patient’s treatment.
- The original planning scan, or simulation scan, is performed using computed tomography (CT scan), however, in addition to this, magnetic resonance imaging (MRI) and/or positron emission tomography (PET scan) can also be used in addition to CT to help define the area of the tumor.
There is a role for particle therapy in the treatment of kidney cancer, either using proton beam therapy or heavy particles such as carbon ion therapy. Both of these technologies may be used to spare organs uninvolved with cancer that are beyond the tumor itself.
Lastly, intraoperative electron radiotherapy can be given after resection of a kidney tumor or after nephrectomy. It is administered in a single session while the patient is still in the operating room. The area targeted is where there may be microscopic tumor (few cells) left behind. Shielding devices are used to protect the surrounding normal tissue. This type of treatment can also be combined with fractionated radiotherapy, as described above, that begins after the patient has started recovering from surgery.
Possible Side Effects of Radiation Treatment for Kidney Cancer
The doses of radiation used to destroy cancer cells can also hurt normal cells. Thus the side effects are directly related to the area of the body being treated. Side effects are caused by the cumulative effect of radiation on the cells. Most patients do not experience any side effects until a few weeks into their treatments. While side effects may be unpleasant, there are treatments to help manage them, and most side effects are temporary, disappearing gradually after therapy is complete.
Most radiation oncologists see their patients at least once a week while the patient is receiving treatment. This visit with the healthcare team serves as an opportunity to ask questions, discuss any side effects, and implement any necessary interventions to help relieve the side effects. However, you can report concerning symptoms anytime to the treatment team.
The following list includes some of the most common side effects of radiation therapy for kidney cancer. Remember that the treatment can affect each patient differently and you may not experience these concerns. Talk with your radiation oncologist and health care team about what you can expect from your specific treatment.
- Skin irritation: Your skin may become red, irritated, dry, or sensitive. This may progress to look like a sunburn. Treat the skin gently to avoid further irritation, and bathe carefully using only warm water and mild soap. Avoid perfumed or scented lotions or soaps, as these may cause further irritation. Avoid sun exposure, which can worsen the irritation.
- Fatigue is very common with radiation treatment and tends to begin a few weeks into therapy. Fatigue typically resolves slowly over the weeks and months following treatment.
- Loss of hair, also known as alopecia, in the treatment area. Hair typically starts to regrow a month or so after treatment. However, your hair might not grow back exactly as it was before treatment and for some, the hair loss becomes permanent.
- Nausea and/or vomiting can occur. Your healthcare team can prescribe medications to manage nausea. Dietary changes can also help.
Long-Term Side Effects
The side effects discussed thus far tend to occur during treatment up until a few months after treatment. Long-term effects can occur months to many years after cancer treatment and the risks vary depending on the areas included in the field of radiation and the radiation techniques that were used, as these continue to develop and improve. Some of the potential long-term side effects of radiation to the kidney includes:
- There is a low risk of developing a second cancer in or near the radiation field. These are called secondary cancers, and they develop as a result of the exposure of healthy tissue to radiation. Modern radiation techniques are designed to limit this exposure, but it is not always possible to prevent all exposure and still achieve the desired outcomes.
- Stereotactic radiation treatment for kidney cancer is relatively new and research is ongoing into late effects of this treatment.
After treatment, talk with your oncology team about receiving a survivorship care plan, which can help you manage the transition to survivorship and learn about life after cancer. You can create your own care plan using the OncoLife Survivorship Care Plan.