What is Hyperbaric Soft Tissue Radionecrosis?
Soft tissue radionecrosis is a condition that occurs as a delayed side effect of radiation therapy, causing the breakdown of body tissue due to limited blood supply in areas damaged by radiation. Radiation can harm small blood vessels, leading to a lack of oxygen in the affected tissue, which results in damage and scarring. These changes can happen over time, even long after the initial radiation exposure.
The condition can develop anywhere from 6 months to several years after radiation exposure. Though the body tries to repair the damaged area by growing new blood vessels through a process called angiogenesis, these new vessels can be disorganized in the damaged tissue, leading to a condition called telangiectasias. This irregular growth of new blood vessels often can’t support the tissue properly, causing further damage and even skin ulceration, which is when the skin breaks down and develops sores.
Even a minor injury or surgical procedure can make the tissue break down and cause ulceration. Both the surface and the deeper layers of tissue can be affected by the radiation. When the condition affects the tissue in the spine and brain, it can be particularly difficult to treat. This condition usually happens when the radiation dosage exceeds 5000 cGy (a unit that measures radiation exposure), but it can also occur at doses as low as 3000 cGy.
What Causes Hyperbaric Soft Tissue Radionecrosis?
Soft tissue radionecrosis is a condition that can happen in any body part that has received a large amount of radiation, usually as a treatment for cancer. This radiation can damage the DNA of the cells in the tissue. If the damage is severe, the cells can’t recover and die. While this is the desired effect for cancer cells, it’s not good when it happens to normal, healthy tissue.
At first, this damage causes swelling and inflammation in the tissue, which can appear as redness on your skin. After this initial redness, the tissue can develop a condition called obliterative endarteritis. This condition can decrease the amount of oxygen in the tissue and lead to fibrosis, or tissue scarring.
These changes in the tissue are the first step towards the final effects of radiation therapy. The damaged tissue doesn’t have normal small blood vessels, and there’s an increase in other structures that make the tissue appear and feel scarred. This scarred tissue doesn’t get enough oxygen because there are fewer blood vessels for oxygen to travel through from the red blood cells.
Not only are there fewer blood vessels, but the ones that remain are often disorganized and can’t supply the tissue with enough oxygen. The scarring and changes in the blood vessels make the tissue more likely to break down on its own or due to injury or infection. These effects of radiation often happen 6 months to years after the initial radiation treatments.
Risk Factors and Frequency for Hyperbaric Soft Tissue Radionecrosis
In the United States, over 1.2 million invasive cancer cases are reported every year. Around half of these patients undergo radiation therapy as part of their cancer treatment. However, about 3% to 5% of these patients might experience delayed side effects from the radiation therapy. These can include issues such as soft tissue radionecrosis, a type of tissue damage, or problems with wound healing. The risk of developing these problems depends on factors like the amount of radiation used, the type of radiation, and the area of the body that received the radiation.
- Over 1.2 million cases of invasive cancer are reported yearly in the United States.
- About half of these patients will receive radiation treatment for cancer.
- About 3% to 5% of the patients who have had radiation therapy will develop delayed side effects.
- These side effects can include radionecrosis (tissue damage caused by radiation) or problems with wound healing.
- The risk of these problems depends on the radiation amount, type, and the affected body part.
Signs and Symptoms of Hyperbaric Soft Tissue Radionecrosis
Getting a detailed patient history is vital when dealing with a patient who has received radiation therapy. It’s crucial to know when the treatment took place, the type of radiation used and the overall dose of radiation received by the patient. Other factors should also be considered, especially if the patient has a problematic wound that isn’t healing well. These factors can include malnutrition, diseases affecting large blood vessels, smoking, diabetes, age, and recurrent injury to the tissue from pressure or rubbing.
For instance, a wound in the pelvic area might not be healing due to continuous pressure on it and previous radiation treatment for pelvic cancer. It’s also important to consider any surgical procedures performed on the wound. If the tissue has undergone radiation therapy before, especially if the tissue has hardened or fibrotic changes, wound healing can be problematic.
Acute effects of radiation therapy may cause redness, swelling of tissues, changes in skin color, hair loss, and ulcers in the skin or mucous membrane. These effects are usually temporary and manageable with supportive care like rest and proper nutrition and prescribed medication if there’s an infection due to skin ulceration. Acute radiation damage typically recovers within a month as inflammation and swelling decrease and the damaged cells in the inner lining of blood vessels are repaired.
If the small arteries fail to recover, the tissue may become oxygen-deprived, leading to permanent hardening and causing delayed effects of radiation therapy. This state can lead to wounds that take a long time to heal. The tissue undergoes a narrowing and blockage of its small arteries, reducing blood supply, leading to a lack of oxygen or hypoxic state in the tissue eventually resulting in typical hardening changes.
The affected skin often appears shrunken, feels hard when touched, and may have a shiny, waxy appearance. Tiny broken blood vessels or spider veins may be visible on the skin’s surface, and it’s common for the skin to develop ulcers either from minor injury or on its own. Delayed effects can occur anytime from six weeks to years after completing radiation therapy.
Testing for Hyperbaric Soft Tissue Radionecrosis
When looking at a wound on a tissue that has been exposed to radiation, it’s important to make sure that the problem is actually due to radiation damage and not something else. Usually, these problems occur when the build-up of radiation dosage has exceeded 3000 cGy, and more often than not, it is 5000 cGy. For example, if someone had skin cancer which was treated with 1000 cGy of radiation, it would be very unlikely that they would later develop a skin ulcer due to the radiation therapy. It’s more plausible in this case that the skin ulcer might be a returning sign of skin cancer, hence a biopsy would be required to ensure it isn’t.
To address a problematic wound in a tissue affected by radiation, it is recommended to follow a systematic approach including these elements:
* Assess if there is sufficient blood flow to the tissue.
* Check for any ongoing infections and make sure that conditions favouring wound healing are in place (proper nutrition, quit smoking, minimize pressure and repeated injury to the tissue).
* Figure out if the ulceration or symptoms are due to returning cancer.
Blood flow to the wound, in areas such as limbs, can be assessed by feeling the pulses, measuring the ankle-brachial index (a test that compares blood pressure in your ankles and arms), arterial duplex (combination of ultrasound and Doppler evaluation), and performing angiography if required. Also, transcutaneous oxygen measurement (or TCOM) can gauge the tissue’s oxygen level, with an ideal reading being above 40 mm Hg PaO2 to predict good wound healing prospects.
Wound cultures or tissue biopsies can assist in identifying secondary infections to inform targeted treatments. Often it’s challenging to determine if tissue decay is due to the late effects of radiation or another infection. Methicillin-resistant Staphylococcus aureus, also known as MRSA, can be tough to treat due to its resistance to many antibiotics.
Always remember that symptoms could be due to returning or secondary cancers. It’s better to do a biopsy soon if one suspects this. Radiation therapy can cause damage to DNA which can lead to cell mutation and development of cancer.
In some cases, it’s not easy to identify radiation damage just by a physical examination. In such situations, additional imaging procedures might be required to understand the patient’s symptoms properly. For example, bladder issues or inflammation of the rectum called ‘proctitis’ can be latent side effects of radiation therapy for cancers affecting the pelvis. These conditions often need examination by colonoscopy or cystoscopy. During such procedures, a biopsy can be performed to confirm the diagnosis, monitor for recurring or secondary cancers. Often, the diagnosis can be established by CT scan or MRI. Another side effect could be the demyelination of the spinal cord from the late effects of radiation therapy and electric-like pains running into the lower limb while extending the back might indicate radiation damage to the spine.
Treatment Options for Hyperbaric Soft Tissue Radionecrosis
Normal treatments for deep wounds that are struggling to heal and uncontrolled bleeding, usually seen in damages caused by radiation to soft tissues, are often not successful. This is because the affected tissue lacks an adequate blood supply, which would provide necessary oxygen and nutrients for healing. Surgery also has a high rate of failure, as it can potentially cause further harm to an already damaged tissue. Furthermore, tissue that has been damaged by radiation is more prone to infection, especially after surgery.
An alternative treatment, Hyperbaric oxygen therapy, can be beneficial in treating such damages caused by radiation. This treatment works by enhancing the oxygen supply to the damaged tissue, promoting the formation of new blood vessels, a process known as angiogenesis. Usually, a course of 30 to 40 treatments is needed for this therapy. This leads to a stronger blood flow and improvements in tissue health due to better oxygen supply overall. Symptoms such as dry mouth due to insufficient saliva production can improve with this therapy. Damages caused by radiation can occur in any part of the body that was within the radiation field. However, such damages commonly occur in the head, neck, breast or chest wall, and pelvic organs such as bladder and rectum.
Generally, Hyperbaric oxygen therapy has an approximately 80% success rate in improving the symptoms of patients with tissue radiation damage. However, the tissue never fully recovers to its original state. Clinically, the results can be seen as an improvement in tissue changes caused by scarring or fibrosis, reduced bleeding in ulcerated mucosal tissue, better functioning of bone cells in radiation-damaged bone, and an improvement in nerve-related symptoms.
Hyperbaric oxygen therapy presents certain risks. These include a drop in blood sugar level in diabetic patients, especially those using insulin and other blood sugar-lowering agents, ear discomfort due to pressure changes, lung collapse, and seizures due to oxygen toxicity. Also, cancer patients who have previously undergone treatment with a chemotherapy drug known as bleomycin are at an increased risk of developing lung scarring, even if the chemotherapy was administered a long time before they received hyperbaric oxygen therapy.
Beyond wound healing, there are certain scenarios in which hyperbaric oxygen therapy might be beneficial, such as in the treatment of brain radiation damage. However, more research is needed in this area to establish the best treatment options, and whether hyperbaric oxygen therapy should be included. In theory, the use of hyperbaric oxygen therapy should aid the formation of new blood vessels and repair of brain radiation damage. An interesting area of future research is how hyperbaric oxygen therapy can work in conjunction with stem cells to repair damaged tissue. The theory is that hyperbaric oxygen therapy can direct stem cells towards damaged tissue, where the stem cells can then transform into the cells most needed for tissue repair.
What else can Hyperbaric Soft Tissue Radionecrosis be?
When doctors are looking to diagnose soft tissue radionecrosis, which is the death of body tissue due to radiation, they need to consider several other medical conditions that can cause similar symptoms. They need to rule out these conditions to give a correct diagnosis:
- Necrotizing infections, particularly those caused by Staphylococcus or Streptococcus bacteria. This should be excluded through a specific assessment of the wound and a deep tissue culture.
- Issues with wound cultures, as they can often be inadequate. They can fail to identify the problem, or they might reveal organisms that are merely present but not causing the issue.
- Arterial insufficiency ulcers and tissue damage from macrovascular insufficiency. These are more common in those with risk factors such as smoking, high blood pressure, and diabetes.
- A condition where the body tissue is at risk of bleeding due to weak, frangible blood vessels, which are a result of sudden inflammation and expansion.
- Hemorrhagic cystitis, a complication from radiation in the pelvic region. The delayed effects can be very hard to treat and often lead to more damage to the bladder after specific treatments.
- Proctitis, a delayed result of soft tissue radionecrosis that can result in significant rectal bleeding, sometimes requiring multiple blood transfusions and creating significant health concerns.
It is also essential to ensure that there is not a return of cancer or a secondary carcinoma or a precancerous growth causing the bleeding. Doctors often have to perform a cystoscopy or colonoscopy with a biopsy to exclude cancer and confirm that soft tissue radionecrosis is causing the symptoms.
Surgical Treatment of Hyperbaric Soft Tissue Radionecrosis
Radionecrosis is a condition where tissues are damaged because of radiation exposure. There are many types of this disease, including damage to the brain and spinal cord (central nervous system radionecrosis), bladder (radiation cystitis with hemorrhage), rectum (radiation proctitis), vagina (vaginal radionecrosis), and throat (laryngeal radionecrosis). This condition is serious and can cause many health problems. In fact, if someone with this condition needs surgery in the future, there’s a 50% chance they may have complications.
In the United States, this happens to between 6,000 to 30,000 people every year. But there’s some good news for those suffering from radiation cystitis with hemorrhage, a condition causing bleeding in the bladder. Approximately 80% of patients notice either complete disappearance or substantial lessening of blood in the urine. However, it’s important to note that amongst these patients, there’s a chance of around 12% per year that the symptom could reappear.
What to expect with Hyperbaric Soft Tissue Radionecrosis
Hyperbaric oxygen therapy has long-lasting effects due to the strength of the new blood vessels that form in the tissue. This therapy results in enhanced tissue blood supply and improved wound healing. The greatest benefits are derived when it’s used alongside good surgical practice. This has been proven through the extensive research conducted by Dr. Marx on a condition called osteoradionecrosis of the jaw, which led to the creation of the Marx protocol.
Dr. Marx showcased the advantages of giving the patient 20 to 30 hyperbaric oxygen treatments before reconstructive surgery or bone cleaning of the jaw, followed by an extra ten treatments to aid the healing of post-surgical tissue and grafts. His study in 1993 yielded impressive results, with wound splitting reduced from 48% in the untreated group to 11% in the treated group. Additionally, infection rates dropped from 24% to 6%, while delayed healing decreased from 55% to 11%.
Approximately 80% of patients with bloody urine (hemorrhagic cystitis) from tissue damage due to radiation therapy (soft tissue radionecrosis) will respond positively to this therapy. Owing to this, these patients will experience a reduction or potentially complete cessation in their bleeding issues. If the bleeding problem still persists, then a repeat cystoscopy (a procedure to inspect the inner lining of the bladder) with a biopsy to check for cancer recurrence is recommended.