When a cancer patient is irradiated, the ionizing radiation triggers different biological and biochemical reactions in the surrounding tissues. Radiation necrosis, also known as radionecrosis, causes the death of living cells in the organism. The technical language speaks of a pathological decline of the tissue. Radionecrosis is the most serious complication of radiosurgical therapy in the field of brain tumors.
What is Radiation Necrosis?
Radiation necrosis is a late side effect of radiation therapy that cancer patients receive to destroy the tumor cells in the body. This has been continuously improved in recent years in order to keep health risks and side effects as low as possible. The individual state of health of the patient plays an important role. For what is the definition of labyrinthitis, please visit healthknowing.com.
Tumors and cells that exhibit cancer-typical changes react much more sensitively than healthy tissue to ionizing radiation and the energy it releases. If radiation necrosis occurs, healthy tissue is also permanently damaged or destroyed. A particular clinical feature is that radiation necrosis often occurs many months or years after radiation therapy.
The energy released by the radiation damages the genetic material of the tumor cells. It impedes important metabolic pathways and the division of tumor cells. However, it can also cause undesirable side effects such as radiation necrosis after treatment of cerebral tumors.
While radiotherapy focuses specifically on the tumor area, chemotherapy is not only distributed to the tumor tissue, but also to the healthy tissue. The latency period is usually 14 months. However, latency times of more than twenty years are also known.
Pathologically, radiation necrosis is coagulation necrosis that causes the affected tissue to die. Both single and numerous living cells can be affected, causing necrotic tissue areas of varying sizes.
Symptoms, Ailments & Signs
Radiation necrosis of the so-called “white matter” (substantia alba) is described as space-occupying and leads to pathologically increased intracranial pressure, epileptic seizures and focal neurological deficits, which cause functional disorders in other areas of the body due to localized changes in the brain.
Radiation necrosis produces fluid-enriched edema from the breakdown or metabolic products of neighboring tumors. Macrophages are scavenger cells which, as leukocytes (white blood cells), ensure an intact immune system and destroy harmful microorganisms. In this initial situation, however, they cannot reduce the radiation necrosis.
The blood vessels in the necrotic area are very dilated, causing disruptions in the blood flow. The affected tissue is not properly supplied with blood, blood congestion occurs, which causes endogenous (internal) inflammatory processes and infection of the affected tissue.
Diagnosis & course of disease
Due to the often very long latency periods, a final diagnosis is not easy, because the pathological processes that lead to radiation necrosis are still unclear. What is certain, however, is that cellular and molecular mechanisms are involved. Inflammatory gene products and cytokines, which are responsible for differentiation and regulation of cell growth, play an essential role.
To make matters worse, there is still no reliable data, since many patients suffering from brain tumors die before radiation necrosis sets in. For this reason, the distinction between tumor recurrence and radiation necrosis is difficult. Both the new tumor and the radiation necrosis occur in the area of the previously removed tumor or its immediate surroundings.
Necrosis and recurrence are space-occupying and occur within a similar latency period. Various imaging methods are available to enable a final diagnosis. Magnetic resonance spectroscopy (MRS) shows a clear distinction between tumor recurrence and radiation necrosis. While the new tumor has an increased content of choline, the necrotic tissue is characterized by a reduced amount of choline, creatine and N-acetyl aspartate (NAA).
Another diagnostic method is computed tomography (CT). The images of both procedures show the radiation necrosis as a ring-shaped structure surrounded by edema. A contrast medium can clarify the difference to tumor recurrence. With positron emission tomography, the patient is administered the radiotracer F-fluorodeoxyglucose (FDG).
The cells affected by the tumor show an increased uptake of FDG, while the necrotic tissue no longer needs FDG. With PET, the resolution is in the range of a few millimeters, so that a tumor recurrence can only be reliably detected in the event of an increased metabolism. Another diagnostic method based on radiotracers is Th-thallium(I) chloride-based single photon emission computed tomography (SPECT).
In this case, too, the diseased tissue absorbs an increased amount of the radiotracer. A differential diagnosis also excludes similarly progressing diseases such as abscesses and metastases as well as multiple sclerosis, which can occur in connection with a brain tumor.
In the worst case, those affected can die completely from radiation necrosis. As a rule, however, this only occurs with imprecise irradiation or with very high radiation doses. Those affected suffer from a significantly increased pressure in the brain and thus also from severe headaches. Epileptic seizures, which can lead to death, also occur.
The changes in the brain promote neurological and psychological limitations, which also affect the patient’s consciousness. Those affected are confused or can no longer remember other people or events. Inflammation or circulatory disorders can also occur as a result of the disease and have a negative impact on the patient’s quality of life.
In most cases, however, those affected die from the brain tumor before they become ill and die from the consequences and complications of radiation necrosis. Radiation necrosis is treated with the help of surgery or the administration of medication. There are no particular complications. However, areas of the brain that have already been damaged can no longer be easily restored, so that the affected person usually also suffers from limitations in the future.
When should you go to the doctor?
Radiation necrosis must be treated by a doctor. This disease can lead to serious complications and symptoms, which in the worst case can lead to the occurrence of tumors, which can also lead to the death of the person affected. A doctor should be consulted as soon as the first symptoms or signs of radiation necrosis appear, so that these complications do not occur.
A doctor should be consulted if the person concerned suffers from very severe headaches. As a rule, these headaches are permanent and do not go away on their own. Nor can they be treated through self-help measures. Furthermore, epileptic seizures indicate radiation necrosis and must also be examined by a doctor. Severe inflammation in the body can also indicate this disease.
Radiation necrosis can be treated in a hospital. If an epileptic seizure should occur, an ambulance should be called immediately or a hospital should be visited directly. Whether the disease can be completely cured cannot be universally predicted.
Treatment & Therapy
Space-occupying cerebral radiation necrosis is treated with high-dose corticosteroids. Corticosteroids form a group of fifty steroid hormones produced in the adrenal cortex. The drug dexamethasone is often used. It is a synthetic glucocorticoid that has a depressant and anti-inflammatory effect on the immune system. Accessible radionecrosis is surgically removed.
The dose at which radiotherapy causes lasting damage to health depends on which tissue is being irradiated. Blood cells and cells of the immune system are particularly sensitive to the effects of radiation. Modern radiation therapy causes indirect molecular changes in the tumor cells and cancer-typical cells in order to avoid direct cell destruction.
The tumor cells are showered with aggressive molecules, so-called ions, by irradiation. Oxygen-saturated and well-perfused tumor cells are attacked by free radicals of the ions and damaged by reactive molecules. The tumor cells can no longer divide and die. The organism activates its self-healing powers, recognizes the damaged tumor cells and initiates programmed cell death (apoptosis).
As a rule, the aftercare measures for radiation necrosis are significantly limited or are not even available to the patient. The patient is primarily dependent on a quick and, above all, early diagnosis of this disease, so that there are no complications or further spread of the tumor in the further course. Self-healing is usually not possible with this disease.
Most patients with radiation necrosis are dependent on taking various medications. It is always important to ensure that the dosage is correct and that the medication is taken regularly in order to permanently limit the symptoms. Furthermore, the person concerned should contact a doctor if side effects or ambiguities arise.
However, the disease cannot always be completely cured. The further course depends very much on the time of diagnosis, so that a general prediction is usually not possible. The life expectancy of those affected is not reduced by the disease. Furthermore, regular checks and examinations by a doctor are very important in order to detect further damage caused by radiation necrosis at an early stage.
You can do that yourself
In the case of radiation necrosis, there are no self-help measures that would improve the clinical picture in any way. A changed diet, alternative remedies or even non-prescribed medication have no effect. This form of necrosis will usually continue to expand, which can also be fatal depending on the localization.
Accordingly, those affected should not try to do anything themselves. Rather, the very best form of self-help is to seek medical advice and treatment as quickly as possible. Since radiation necrosis is unpleasant and unaesthetic, but can be easily treated, this is also the most sensible way.
Once the diagnosis has been made and a doctor’s opinion has been obtained regarding treatment and surgery, the patient’s only task is rest. On the one hand, this means the patient himself, who may have to prepare himself internally for an operation. On the other hand, this means sparing the tissue in the case of severely advanced necrosis or one that has become acutely noticeable. Radiation necrosis in particular, which is visible and on the outside of the body, should under no circumstances be stressed. This would further damage the tissue and can also allow degradation products or cell toxins to enter the body.