Lymphoma is a malignancy (cancer) of white blood cells (lymphocytes), which most commonly develops in lymph nodes. It may also arise in other organs such as the gastro-intestinal tract (gut), bone, lung, brain, eye and skin. Lymphoma can develop at any age of life, including in childhood.
Lymphoma can be broadly split into two main subtypes, which are Hodgkins Lymphoma and Non Hodgkins Lymphoma. Within these two main groups, there are many subtypes, whose biological behaviour can vary from being very slow to progress (indolent); to very aggressive, requiring urgent attention.
The treatment options for lymphoma may range from observation only (for indolent lymphomas) to requiring very intensive chemotherapy for the more aggressive types, however many lymphomas require a combination of chemotherapy and radiotherapy for treatment.
What are the Causes of Lymphoma?
The incidence of lymphoma is increasing over time. In the majority of cases, the underlying cause is unknown, but some lymphomas arise in patients who have impaired immune systems, either from immunodeficiency syndromes (lowering immunity to diseases), or from medication that causes them to be immunosuppressed. There is also evolving evidence that some viral infections are behind the development of certain lymphomas.
What are the Symptoms of Lymphoma?
Many lymphomas are found through a patient finding a painless swollen lymph gland (also called a lymph node), or lump, in the neck, armpit or groin. Some patients may also notice generalised symptoms such as feeling unwell, fever, drenching night sweats, loss of weight, and occasionally itch and intolerance of alcohol. Some patients feel completely well, and their lymphoma is only found by accident when being investigated for another condition.
What are the Treatments for Lymphoma?
Treatment is tailored to the type, and extent of lymphoma. Some very slow growing (indolent) lymphomas are observed, and only treated on progression. Many lymphomas are very sensitive to both chemotherapy and radiation therapy, and are managed with a combination of both treatment types. This may allow lower doses of chemotherapy and radiation to be used, to minimise the side-effects.
High dose chemotherapy is used for lymphoma that has come back after initial treatment sometimes with a bone marrow transplant. Lymphomas in children are usually treated in specialist units attached to children’s hospitals, and are mainly treated with chemotherapy.
Radiation therapy is an effective treatment for lymphoma, and is used in both the curative and palliative settings (ie to alleviate pain or other problems when the patient can’t be cured).
In general, lymphomas are very sensitive to radiation therapy, and as a result, respond to lower doses than would be used for other cancers such as prostate cancer, breast cancer or head and neck cancer. Hence treatment courses may vary from one or two treatments to up to twenty treatments over four weeks, depending on the type of lymphoma and the aim of treatment.
It is used as a stand alone curative treatment for localised, low grade non Hodgkin lymphoma. It is also used to palliate a symptomatic lymphoma deposit which may be painful, bleeding, or affecting an organ’s function (ie obstructing a lung). Many patients with early Hodgkin Lymphoma are treated with between two to four cycles of chemotherapy, followed by localised, targeted (involved site or involved node) radiation therapy to the site of the lymphoma.
This is delivered daily over two to three weeks. PET-CT scanning during the treatment course allows the Radiation Oncologist to adapt the total dose of radiation therapy to the response of the lymphoma to chemotherapy. For many patients, this can mean less risk of side-effects in the long term, with the same, or better chance of cure
What are the Side Effects of Radiation Therapy?
In general, the development of side effects during treatment are related to the site being treated and usually becomes apparent towards the end of treatment. For many patients who are having a lymph node group irradiated, they will experience some redness of the overlying skin, transient loss of hair and mild fatigue. Other side effects are related to organs which are close to the lymphoma mass, or involved by lymphoma.
Your Radiation Oncologist will outline any potential side effects related to the treatment site during the consultation. However, any side effects which appear during radiation therapy or shortly afterwards, are usually self-limiting and resolve within two to three weeks.
Late (long term) side-effects are relatively uncommon and may occur many months to years after treatment is completed. Many lymphoma patients are long term lymphoma survivors, so monitoring to prevent development of late side effects is an important aspect of follow –up care. This is especially important for childhood lymphoma patients, who may be followed up long term through specialist late effects clinics. Recent changes in chemotherapy and radiation therapy have been made to limit the rates of late side effects.
More common late effects
Symptoms such as fibrosis (scarring/thickening) of muscles, skin dryness and atrophy, loss of taste and poor saliva production are very uncommon now due to more targeted delivery techniques, smaller radiation therapy treatment volumes, and lower doses.
Hypothyroidism (underactive thyroid gland) is a late complication of irradiation of the head and neck region, and can present with nonspecific symptoms such as fatigue, weight gain and cold intolerance. It is managed with thyroid replacement therapy and monitored with blood tests and thyroid ultrasounds.
Cardiovascular (heart and blood vessel) disease can also develop many years after radiation therapy to the heart and large vessels such as the carotid arteries. Long term survivors require regular checks of their heart health
Less common late effects
Cancers occurring after the original lymphoma (second malignancies) may develop due to an inherent gene sensitivity which has caused the initial lymphoma, or as a result of the radiation therapy itself. Skin cancers may develop in skin over the irradiated site, and cancers may arise in deeper tissues.
Breast cancer rates are increased in young women aged less than 30 years who have had radiation therapy for Hodgkin’s Lymphoma, and for that reason, this technique has been abandoned. Other new cancers may arise in organs that were irradiated many years ago, such as bowel, lung and soft tissue. Because of this, radiation techniques have become much more targeted and precise; and the doses have been decreased.
Other less common or rare side effects (depending on the site treated and the age of the patient) include:
Neurocognitive (learning and memory) problems
The best person to discuss radiation therapy with for Lymphoma is a Radiation Oncologist. You can ask your Surgeon or General Practitioner for a referral to a Radiation Oncologist for a discussion about whether radiation therapy is a suitable treatment for you.
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