Overview of Palliation Radiation Therapy of the Spinal Cord
Radiation therapy is a treatment often used in healthcare to try to cure diseases or to help ease symptoms for patients who are very sick. When a type of tumor, called a neoplasm, spreads to a person’s spine, it can cause severe back pain and problems with how the nerves in the body work. These problems can include causing a person to lose feeling, muscle strength, or control of their bowel and bladder, which can lead to incontinence (the inability to control the urge to pee or poo).
Radiotherapy, which is a type of radiation treatment specifically for the spine, can help ease some of the pain for about two-thirds of patients. However, it is less likely to completely get rid of the pain, with fewer than 15% of patients experiencing total relief from pain.
About half of the people diagnosed with cancer will have radiation therapy as part of their treatment at some point. Around 40% to 50% of these individuals will have this treatment to relieve their symptoms. Also, between 5% to 10% of cancer patients will develop a condition where their spinal cord is compressed due to the spread of their disease. Some types of cancer, like breast, lung, and prostate cancers, as well as multiple myeloma, non-Hodgkins lymphomas, and kidney cancers are more likely to spread to the spine. In children, this condition is often caused by types of cancers called sarcomas, neuroblastomas, or from a type of kidney cancer that often occurs in children, called a Wilm tumor.
Anatomy and Physiology of Palliation Radiation Therapy of the Spinal Cord
In adults, most tumors that put pressure on the spinal cord are found within the spinal column, mostly at the front of the spinal cord. However, in children, these tumors usually come from an area next to the spinal column. This can cause pressure on the sides or at the back of the spinal cord.
In palliative radiation therapy, a treatment used to alleviate pain, the relief is not instantaneous. This is because the radiation only kills the cells when they divide or multiply, therefore, it might take a few days after starting the treatment to feel better.
Radiation therapy works by aiming at cancerous cells and disrupting the cell’s DNA, which is essential for cell growth and division. This therapy is usually given over the course of multiple treatments to limit harm to healthy cells and to specifically target cells that multiply rapidly. Radiation therapy works in two ways:
1: It directly causes single and double DNA breaks.
2: Indirectly, it generates free radicals from the ionization, or the addition or removal of an electron, from the water inside cells.
One benefit of radiation therapy is that it stimulates the NFκB pathway. The NFκB pathway is a part of the cell that, when activated, increases the susceptibility of the cancer cells to the treatment, making it more effective.
Why do People Need Palliation Radiation Therapy of the Spinal Cord
Palliative radiation therapy, a type of treatment used to relieve symptoms and improve quality of life, can be used in many situations by those suffering from cancer. Its most common use is to ease pain, particularly when cancer has spread to areas like the spine or the upper leg bone, where it can cause severe discomfort. The therapy can also be used as a precautionary step to prevent fractures in the spine or limbs, which can occur when the bones are weakened by cancer.
Another use for this therapy is to manage wounds or sores that are not healing properly due to the presence of a cancerous mass. In cases involving tumors with a large number of blood vessels, radiation therapy can assist in controlling bleeding.
While it’s less common, palliative radiation therapy can come to the rescue during cancer emergencies. For example, it can be used when cancer impacts the spinal cord or brain, leading to compression – which means pressure is put on these crucial parts of the body, causing serious symptoms.
Preparing for Palliation Radiation Therapy of the Spinal Cord
Many tumors, especially those located in the spine, require a specific type of scan called a magnetic resonance imaging (MRI) for doctors to closely examine the spinal cord and the size of the tumor. However, if someone has a spine hardware like rods or screws from a previous surgery, an MRI might not give clear images because of the metal. In such cases, a different type of scan called a computed tomography (CT) myelogram can be used.
Before starting the therapy, patients need to be secured in place using a rigid body immobilization device. This helps to keep the patient very still, preventing small movements. This is crucial for ensuring that radiation is delivered precisely to the tumor.
Doctors also need to come up with a plan to deliver the right amount of radiation to the tumor. This is for the purpose of treatment, while being cautious of nearby organs, such as the spinal cord and esophagus, that could be at risk. The positioning of the radiation delivery device, called the gantry, also needs to be carefully considered to optimize the treatment.
How is Palliation Radiation Therapy of the Spinal Cord performed
Radiation therapy is a form of treatment that uses high-energy x-ray beams to attack diseased areas. These x-rays are produced by machines called linear accelerators. Unlike intense radiation therapy, which is given in many small doses with the aim of completely getting rid of disease, palliative treatments instead use lower amounts. The idea here is to ease the symptoms caused by tumors, especially those located on the spinal cord.
By giving larger doses daily, doctors can lessen the overall intensity of the treatment and finish the course quicker. New techniques like targeted stereotactic radiotherapy are even more effective because they deliver focused treatment to a smaller area, and in doing so, they limit the damage to the healthy tissue around the diseased area.
Possible Complications of Palliation Radiation Therapy of the Spinal Cord
Radiation therapy is a treatment that uses high-energy particles to destroy or slow the growth of cancer cells. However, it’s not an exact science, so healthy cells near the cancerous ones can also get damaged. This concern becomes more significant when treating the spine, as the spinal cord might also get injured. To minimize this, doctors use advanced techniques and plan the procedure carefully.
Interestingly, research shows that radiation therapy doesn’t only affect cells that are directly near the cancerous ones. There’s something called the “bystander effect”, where even cells far from the radiation’s path can get damaged. This can result in more healthy cells dying, and causing various changes on a cellular level. This unintended damage can cause unwanted effects in healthy tissues.
There’s also a debate on when to give radiation therapy when a patient needs palliative surgery (a type of surgery to relieve symptoms, rather than cure the disease). Should the radiation therapy be given before or after the surgery? Well, both options have risks. If radiation therapy is given after surgery, the dose needs to be higher, which can lead to a higher chance of scarring and fluid build-up. On the other hand, giving radiation before surgery can increase the chance of complications relating to the surgical wound.
What Else Should I Know About Palliation Radiation Therapy of the Spinal Cord?
If pressure is applied to your spinal cord, it can cause damage to the nerves, leading to symptoms like pain, weakness, or numbness. This is a medical emergency and needs immediate treatment to prevent permanent nerve damage. The usual treatment consists of radiation therapy, which uses high-energy rays to destroy the cancer cells causing the pressure, and steroids, which can reduce inflammation and swelling.
If cancer has spread to your spine (known as metastatic lesions), it’s important to seek advice from a specialized surgeon. These surgeons, usually orthopedic or neurological, are experts in treating conditions affecting the spine. Their job is to assess how stable your spine is despite the cancer spread.
To do this, they use the Spinal Instability Neoplastic Score (SINS) – a widely accepted tool for evaluating spinal stability in people with metastatic lesions. This scoring system takes into consideration six factors:
- The area of the spine where cancer has spread
- Whether you’re experiencing pain because of movement or pressure
- The nature of the bone abnormality caused by the cancer spread
- If there’s abnormal bending or misalignment at the affected area
- The extent of cancer spread in the spinal bone
- Whether the back section of the vertebra (which helps protect your spinal cord) is involved
Based on these factors, they’ll calculate a total score, which helps to identify whether your spine is “stable,” “potentially unstable and might need surgical stabilization,” or “unstable and requires surgical stabilization”. This scoring system is crucial in determining the best course of your treatment.