Radiation Fibrosis Syndrome: What It Is and How to Treat It
Radiation therapy, like surgery and chemotherapy, is a mainstay of cancer treatment. The reason radiation is used to treat cancer is that it is usually toxic to the fast growing cancer cells while supposedly having little adverse effects on the slow growing and relatively radiation resistant normal body cells. Unfortunately, normal cells are often affected by radiation in a variety of ways, especially over time. One of these changes is the abnormal production of the protein, fibrin, which accumulates in and damages the radiated tissue. This process is known as radiation fibrosis (RF).
Any tissue within the radiation field can be affected including nerves, muscles, blood vessels, bones, tendons, ligaments, heart or lungs. The clinical manifestations (i.e., signs and symptoms) that result from RF are called radiation fibrosis syndrome (RFS). RF can occur a few weeks or months after radiation treatment and continues for the duration of a cancer survivor’s life. The patient and their doctor may not notice RFS until years after treatment. Unfortunately, there is no way to stop the progressive RF that results from radiation treatment. There are, however, ways to treat the signs and symptoms of RFS and improve the quality of life of most patients afflicted by this disorder.
Not all patients treated with radiation develop clinically significant RFS. Standard therapy for common disorders such as prostate and breast cancers use limited radiation fields (the part of a person’s body treated with radiation) in doses that are generally well tolerated. Only patients who are very sensitive to the effects of radiation will experience complications. Radiation treatment for other types of cancer, however, may produce a much higher risk of developing RFS. Patients treated with mantle field, periaortic, inverted-Y, or total nodal radiation therapies for Hodgkin lymphoma (HL), especially if given before the 1990’s, are at particular risk of developing RFS since much higher doses of radiation were generally used. Similarly, patients with head and neck cancer (HNC) may also have a higher risk for developing RFS due to the high doses of radiation they receive and the critical structures that are often included in the radiation treatment field.
The clinical complications of RFS vary greatly from patient to patient and depend upon a number of factors. These factors include the type and dose of radiation given, how the radiation was delivered (i.e., how many treatment sessions), and perhaps most importantly, the radiation field. Other critically important determinates of how the radiation is tolerated include the age of the patient, their overall health, and any medical co-morbidities such as diabetes, heart disease, and arthritis. Radiation issues tend to worsen over time; the more time that has elapsed since treatment, the more likely a patient is to develop RFS. This tends to cause much confusion for both patients and their physicians who often have difficulty believing that a new symptom they develop could be due to in whole or in part to radiation they received years or even decades ago.
It is impossible to cover all the potential complications resulting from radiation in a short article since literally every organ system in the body can be affected. If a large area of the body is affected, as in the case of HL survivors, then very significant side effects can result. The two most ominous late-term effects faced by many HL survivors treated with mantle and other types of radiation are a greatly elevated risk of secondary cancers and cardiac disease. Multiple cancers are seen including thyroid, breast and lung cancers as well as sarcomas. Cardiac disease not only includes accelerated atherosclerosis, but valvular heart disease, pericardial disease, cardiomyopathy, and arrhythmias. Close monitoring is recommended to help identify and manage problems early.
Neuromuscular and functional problems are also very common in HL survivors. The spinal cord, nerve roots, plexus, peripheral nerves, and muscles within the radiation field can be affected. Common manifestations of radiation treatment in HL survivors include neck extensor weakness (a.k.a., dropped head sydrome), neck and shoulder pain, weakness, fatigue, gait and dexterity problems, numbness, tingling, and difficulty performing activities of daily living. All too often these problems are misdiagnosed by physicians unfamiliar with the long-term sequelae of radiation as being due to fibromyalgia, chronic fatigue syndrome, neuropathy of various types, spinal stenosis, or disk herniations. In many instances the physician just tells the patient there is nothing wrong with them. For many patients this leads to years of suffering, isolation, inappropriate treatment such as unneeded surgeries, and lost quality of life.
HNC patients are another group who often develop complications of radiation therapy. As with the HL survivors and other patients with RFS, the issues seen depend on the radiation field treated, the dose given, and factors unique to the patient such as age and medical co-morbidities including cervical arthritis and carotid atherosclerosis. Surgery is often used to resect HNC tumors and may contribute significantly to disabilities in this population. Even so, radiation is often the major source of long-term issues in this group. Common radiation-induced complications include trismus (decreased mouth opening), cervical dystonia (neck spasms, pain, and tightness), facial lymphedema (swelling), as well as difficulties with speech and swallowing.
Treatment of the complications of RFS depends entirely on the issue faced by the patient. The patient’s primary oncologists can usually direct the care of cancer-related medical issues that develop for at least the first few years after treatment. This group includes most HNC patients, breast and prostate cancer patients and others. Survivorship clinics have been established at many major cancer centers to provide guidance on medical matters such as how best to screen for cardiac disease and secondary malignancies in high-risk HL survivors. These clinics are intended for patients who no longer need the care of their primary oncologist but have cancer treatment-related medical issues.
Unfortunately, even at the top cancer centers, there are not enough resources available to evaluate and treat the rehabilitation issues faced by patients with RFS. For instance, HL survivors often have neuromuscular and musculoskeletal pain, as well as problems with function. These can be highly complex with multiple interrelated diagnoses and require a comprehensive and highly specialized multidisciplinary approach so that they can be accurately evaluated and comprehensively and effectively treated. Prescribing a treatment plan that maximizes the function and quality of life of certain patient populations, such as HL survivors, can be extremely challenging. Physical, occupational, and lymphedema therapy are often major components of their rehabilitation program and requires specialized skill sets from highly trained therapists with extensive experience. At Memorial Sloan-Kettering Cancer Center, a patient is often co-treated by several therapists during the course of their treatment to take advantage of advanced myofascial, neuromuscular reeducation, and manual lymphatic drainage techniques.
Physical therapy is highly individualized to the patient and involves normalizing body balance by stretching tight structures, strengthening weakened muscles, and retraining the body’s sensory organs to re-establish coordination. For instance, in the case of HL patients with dropped head syndrome and severe neck pain, functional deficits are not just a simple matter of the patient not having enough strength and endurance to lift their head. Invariably their chest wall and pectoral girdle are tight and bound down with their shoulders forward which puts their neck in a flexed position. All of this must be released which is where advanced myofascial techniques come into play. Their core muscles must also be strengthened and conditioned as they are almost always very weak. The fibrosis restricts the flow of lymph fluid throughout their chest and thorax creating a barrier that must be mobilized if the proprioceptors (sensory organs that provide position sensation) are to function effectively. Without properly functioning proprioceptors, the patient cannot even tell that their head is upright without their eyes open making them more prone to fatigue. Only after these tasks and many more are accomplished can we finally have hope of returning the head to its “upright and locked position” and keeping it there with much less effort and pain. In many cases we use orthotic collars such as the Headmaster™ cervical collar. When necessary, nerve stabilizing and pain relieving medications such as pregabalin (Gabapentin®) are often needed to reduce neuropathic pain and muscle spasms associated with RFS.
In HNC patients, the principles of treatment are similar but the disorders they face are very different. For instance, dropped head syndrome is less common but severe neck spasms (termed “radiation-induced cervical dystonia”) are often seen. This can be treated effectively with specialized physical therapy, nerve stabilizing agents, and in selected cases, botulinum toxin injections. Caution is advised for patients seeking botulinum toxin injections for this disorder as very few clinicians have the clinical skills and experience necessary to perform this procedure safely and effectively in this high-risk population. Another common problem in HNC patients is trismus. Physical therapy is the initial treatment modality in mild cases but a jaw stretching device is necessary for most patients. At MSKCC we use a device called the Therabite which is inexpensive and easy to obtain for patients who develop trismus immediately after treatment (i.e., in the first 6 months). For patients with more chronic trismus, however, we switch to a device called the Dynasplint as it is customizable and uses a better mechanism of jaw opening that is much safer and more effective. Botulinum toxin injections can help relieve the muscle spasms associated with trismus but jaw stretching is still the mainstay treatment.
RFS is a common complication of radiation for certain types of cancer. While there is no cure, there are treatments that can improve the function and quality of life for most patients. Programs specializing in the treatment of the medical complications of cancer survivors are currently being established across the country. More work has yet to be done to develop programs specializing in the physical rehabilitation of cancer survivors. For now, patients who do not have access to specialized cancer rehabilitation programs should take advantage of the general rehabilitation programs in their community and continue to advocate for the creation of more specialized rehabilitation programs.
The information found here is not intended to provide nor should it be interpreted to provide professional medical, legal or financial advice. You should consult a trained professional for more information.