Here is an interesting article about the patients with high-grade gliomas treated with chemoradiation after surgery. They are looking at the risk factors and implication of neurological side effects that are not known. The article is a clinical studies article, but it is a retrospective analysis of high-grade gliomas studies. The connection between acute and late toxicity was analyzed using logistic regression model. High grade-gliomas is common type of brain tumors in adults.
Patients with high-grade glioma treated with radiation therapy experience common side effects, including dermatological, endocrine, systemic and neurological damage. From examining the data, they have concluded six variables associated with acute neurological toxicity and four variables association with late neurological toxicity. The six variables associated with acute neurological toxicity are Zubrod performance status, previous surgery type, neurological functions, mental status and twice-daily biological dose of radiation. The four variable associated with late neurological toxicity are once-daily radiation, biological equivalent radiation and previous occurrence of acute neurological toxicity. The data that was done suggests that there is a statistical significance associated with acute central nervous system toxicities and late central nervous system toxicities. One variable is not mentioned that is associated with acute neurological toxicity and late neurological toxicity is that once diagnosed that the patient has acute neurological and late neurological toxicity, they are likely to die within three months of treatment. The explanation for death due to the neurological toxicities whether late or acute is tissue damage. There is downfall in the clinical studies, physicians have difficulty in assessing tumor symptoms and acute neurological toxicity symptoms.
The article is interesting to read, but questions did arise when reading the article. One of the questions is why did physicians have difficulty is assessing in tumor symptoms and acute neurological toxicity symptom. From what is mentioned in the article the chemoradiation treatment and symptoms of the tumor are similar, so a person can understand why the physician could not differentiate between the two. However, it is possible to get a measure of the neurological toxicity. From the research I have done, there is not a method to measure the neurological toxicity. Another question is if there is a method, it is possible to remove the effects of acute neurological effects. The article mention that by the time they find out the subject has acquired acute neurological effects, they will die within three months of treatment trying to get rid of the neurological toxicity. At first, I thought why not manage the neurological toxicity in the body, why treat it; just maintain the “normal levels” of neurological toxicity that the body can handle. So, is it possible for the body to handle neurological toxicity? From the article “Acute Neurological Toxicity Tied to Overall Survival,” having acute neurological toxicity means death; whether treating it or not the end result is death.
Let’s look at the cost-benefit analysis of radiation therapy. The radiation therapy used for treating high-grade glioma has various side effects which were mentioned earlier. The one that caught my attention was the neurological side effects of radiation therapy. One of the neurological side effects of radiation therapy is the death of oiligodendroglial precursor cells leading to demyelination. Knowledge from previous classes, the oiligodendroglial is glial cells which are non-neuronal cells. These cells are part of the central nervous system; once they are damage, they do not have the ability to regenerate. If these cells are demyelinated then that means slow propagation. If these cells do become damage due to the radiation therapy then the person would experience similar symptoms as a person with multiple sclerosis. Also the radiation therapy would cause motor/sensory disturbances. These disturbances can occur in a circuit, but these disturbances are from the central nervous system then perhaps these disturbances can lose the cause the loss of functions of the nocioceptive, mechanoreceptive, and procioceptive neurons; these neurons perhaps can still function, but there could be possibility that the person can not control their body or feel pain or feel touch, basically no longer a signal to the brain. If a subject experiences some disturbance of their motor or sensory neurons then the subject could have similar symptoms as person with peripheral neuropathy. On top of that there is the possibility of the neuronal toxicity due to the radiation therapy. If radiation therapy was a success, almost all high-grade gliomas eventually come back because the tumor cells have grown into the normal brain. Also there is a high possibility the radiation could cause damage to brain which leads to the cognitive impairment. So why go through the radiation therapy if does more harm than good? The reason most people go through the radiation therapy is because they have hope, faith or want to believe that they are the exception, that the radiation therapy would cure them.
