Balancing the benefits and risks of radiotherapy for Hodgkin lymphoma

Radiotherapy has been used as a treatment for cancer since the early 1900s. It’s an effective treatment for lymphomas, and relatively modest doses of radiation can kill lymphoma cells.

Alongside chemotherapy, radiotherapy continues to be a standard treatment option for many cancer types but, like most cancer treatments, it comes with its own risks and potential side effects.

Hodgkin lymphoma can appear in many areas, as the lymphatic system spans the whole body. Mantle radiotherapy was originally a standard treatment for Hodgkin lymphoma, and delivered the radiation treatment to a large area of the neck, chest and upper body. However, it has since become much less frequently used, as it has been shown to cause other forms of cancer, strokes and heart disease in patients 10+ years after treatment was finished.

Modern treatment for Hodgkin lymphoma is usually chemotherapy, but radiotherapy still has a role in reducing the chance of lymphoma recurrence.  However there is a need to better understand the risks associated, and how these vary between patients, so to allow patients to make an informed decision about their treatment.

Patients whose Hodgkin lymphoma has affected the lymph nodes in their chest, for example, should take different considerations into account than those with lymphomas in other areas, such as the neck. This is because localised radiotherapy to the chest results in irradiation of the heart, lungs, breasts and other vital organs in close proximity, which can lead to complications later in life, including heart disease and breast cancer. Radiation to the neck alone is associated with less complications.

Dr Rebecca Shakir, Nuffield Department of Population Health, is currently devising a tool which would help patients with Hodgkin lymphoma to decide which treatment options may be best for them, by giving them the individualised information on the benefits and risks. This will allow the patient to make an informed decision based on the chances of lymphoma recurrence if they don’t have radiotherapy vs. the chances of developing radiotherapy side-effects later in life.

Rebecca is using data from over 30,000 previous cancer patients, which details the patient’s different cancer characteristics such as location in the body and proximity to vital organs. Using this data, and other published data, Rebecca will devise models of the risks of radiotherapy using estimates of radiotherapy dose given to certain organs. She will combine this with the known benefits of modern radiotherapy from recent clinical trials. .

In the future, these models will be made into a tool that can provide individualised benefits and risks based on a patient’s lymphoma, and its proximity to major organs. This will help patients to choose the most effective treatment, whilst minimising unwanted side effects.

This study hopes to move the conversation about radiotherapy risks and appropriateness of the treatment to earlier in the cancer treatment process, so that patients feel that they have time to decide for themselves on what course of action to take.

Furthermore, Rebecca is investigating the decision-making process of previous cancer patients, such as what resources and information they found useful, so that the quality of life and experience of patients can be improved in the future.

This work is funded by the National Institute for Health Research, who have awarded Rebecca a Doctoral Fellowship, and Cancer Research UK, who funds the research group which Rebecca works in.