Radiation Therapy for Multiple Myeloma

Radiation therapy is a localized cancer treatment that uses high-energy X-rays or other forms of radiation to damage the DNA of cancer cells, preventing them from continuing to grow and divide. For multiple myeloma, radiation therapy can be highly effective at controlling cancer in a specific area of the body, particularly when abnormal plasma cells are causing bone pain or threatening the stability or function of a nearby structure.

Because multiple myeloma typically involves plasma cells in multiple areas of the bone marrow, radiation therapy usually is not used to treat the disease throughout the body or cure multiple myeloma on its own. Instead, it is generally incorporated into a broader treatment plan that may include systemic therapies. Radiation therapy may also be used as a primary treatment for a solitary plasmacytoma, a localized mass of abnormal plasma cells that can sometimes occur without evidence of systemic multiple myeloma.

At Moffitt Cancer Center, radiation oncologists work closely with malignant hematologists and other specialists to determine when radiation therapy may provide meaningful local disease control or symptom relief. Treatment is carefully planned to deliver an effective dose to the targeted area while limiting radiation exposure to nearby healthy tissue.

Goals of radiation therapy for multiple myeloma

The role of radiation therapy in multiple myeloma differs from its role in many solid tumors. Because myeloma is generally a systemic disease, medications that can reach cancer cells throughout the body are usually central to treatment. Radiation therapy is most often used when focused treatment of a particular lesion or anatomical area would be beneficial.

The healthcare team will explain the purpose of radiation therapy before treatment begins. Depending on the patient’s circumstances, radiation therapy may be used to:

• Relieve pain from bone lesions – Myeloma can weaken and damage bone, sometimes causing significant localized pain. Radiation therapy can destroy myeloma cells at the affected site and may provide substantial pain relief.
• Protect important structures – A plasmacytoma or myeloma lesion can sometimes place pressure on the spinal cord, nerves or other nearby structures. Radiation therapy may be used to rapidly control the lesion and help prevent or reduce neurologic complications.
• Control a localized area of disease – Radiation therapy may be considered when a specific myeloma lesion is causing a significant problem or is not adequately controlled by systemic treatment.
• Treat a solitary plasmacytoma – Radiation therapy is generally the primary treatment for a solitary plasmacytoma of bone or soft tissue when the abnormal plasma cells are confined to one site and diagnostic testing does not show systemic multiple myeloma.

Surgery has a more limited role in multiple myeloma than in cancers that form a single solid tumor. When surgery is necessary—for example, to stabilize a weakened bone, repair a fracture or relieve compression of the spinal cord—radiation therapy may sometimes be incorporated into the treatment plan based on the location and extent of the disease.

If you suspect you may have myeloma, it is important to come to a high-volume program such as ours at Moffitt, so you can receive multispecialty care for this uncommon cancer.

Dr. Rachid Baz

Malignant Hematology Program

Types of radiation therapy for multiple myeloma

External beam radiation therapy is the principal form of radiation used for multiple myeloma and plasmacytoma. The specific technique, radiation dose and number of treatments will be individualized based on factors such as the location and size of the lesion, the goal of treatment, nearby healthy structures and whether the area has previously received radiation.

External beam radiation therapy for multiple myeloma

During EBRT, a machine called a linear accelerator directs high-energy radiation toward a carefully defined treatment area from outside the body. The patient will not feel the radiation as it is delivered and will not become radioactive afterward.

Depending on the clinical situation, the radiation oncology team at Moffitt may use advanced EBRT planning and delivery methods, such as:

• Three-dimensional conformal radiation therapy (3D-CRT) – Detailed imaging is used to shape the radiation beams around the treatment area while reducing unnecessary exposure to surrounding tissues.
• Intensity-modulated radiation therapy (IMRT) – The shape and intensity of the individual radiation beams are adjusted to allow the radiation dose to conform closely to a complex treatment site.
• Volumetric modulated arc therapy (VMAT) – In this advanced form of IMRT, the treatment machine rotates around the patient’s body while continuously adjusting the radiation beam.
• Image-guided radiation therapy (IGRT) – Uses imaging immediately before or during treatment to verify positioning and help ensure the radiation reaches the intended location.
• Stereotactic radiation therapy – Delivers highly focused radiation with substantial precision. Stereotactic body radiation therapy (SBRT) may be considered for select lesions outside the brain, while stereotactic radiosurgery (SRS) can be used for appropriate lesions involving the brain or certain areas of the spine.

Moffitt also offers proton therapy, which uses charged particles rather than X-rays. Because protons deposit their radiation differently from conventional photon beams, proton therapy can reduce the dose received by certain healthy tissues beyond the target. However, proton therapy is not routinely necessary for multiple myeloma, and a radiation oncologist can determine whether it may offer a meaningful advantage in an individual situation.

What to expect before, during and after radiation therapy for multiple myeloma

Radiation therapy will be carefully planned before the first dose is delivered. Understanding the process can make the treatment feel more predictable and provide the patient with opportunities to ask questions and prepare for possible side effects.

Preparing for radiation therapy for multiple myeloma

The treatment process will begin with a consultation with a radiation oncologist, who will review the patient’s imaging studies, medical history, previous treatments and overall multiple myeloma treatment plan. The radiation oncology team may also include medical physicists, dosimetrists, radiation therapists, nurses and other specialists.

If radiation therapy is recommended, the patient will typically undergo a treatment-planning appointment known as simulation. A computed tomography (CT) scan is typically used to create detailed images of the treatment area, and information from magnetic resonance imaging (MRI), positron emission tomography (PET) or other imaging studies may also be incorporated into the plan when appropriate.

During the simulation, the patient will be positioned in the same way they will be positioned for treatment. Depending on the area of the body being treated, customized cushions, molds or masks may be created to help the patient maintain a comfortable and reproducible position. Small skin marks or tattoos may also be used to assist with alignment.

After the simulation, the radiation oncologist, medical physicist and dosimetrist will develop an individualized plan that defines the treatment target, radiation dose and beam arrangement to limit exposure to nearby healthy tissues.

What to expect on radiation treatment days

At each appointment, a radiation therapist will carefully position the patient on the treatment table. Imaging may be performed to verify alignment before the radiation is delivered.

Receiving external beam radiation is painless, much like having an X-ray. Although the radiation therapist will leave the treatment room while the machine is operating, they will still be able to see, hear and communicate with the patient throughout the session.

The actual delivery of the radiation may take only a few minutes, but the entire appointment will be longer to allow for careful positioning, imaging and equipment adjustments.

Radiation treatment schedule

There is no single radiation therapy schedule for multiple myeloma. Some patients who are receiving radiation for symptom relief may require only one treatment or a short series of treatments, while others—such as those who are receiving definitive treatment for a solitary plasmacytoma—may have multiple sessions scheduled over several weeks.

The radiation dose and schedule will be selected based on the treatment goal, location and size of the lesion, surrounding structures, previous radiation exposure and other aspects of the patient’s care. Throughout treatment, the radiation oncology team will monitor the patient’s response and help manage any side effects that develop.

Possible side effects of radiation therapy for multiple myeloma

The side effects of radiation therapy depend heavily on the part of the body being treated, the radiation dose and the amount of healthy tissue within the treatment field. Many side effects develop gradually during treatment and improve in the weeks afterward.

The radiation oncology team can explain which side effects are most likely based on the patient’s specific treatment plan and recommend strategies to prevent or manage them.

Common side effects and proactive management

Side effects of radiation therapy for multiple myeloma may include:

• Skin changes – The skin within the treatment field may become red, dry, sensitive or irritated. The radiation oncology team can recommend appropriate cleansers, moisturizers, clothing and sun protection and explain which products should be avoided.
• Fatigue – Some patients may experience increasing tiredness as treatment progresses. Balancing rest with appropriate light activity, staying hydrated and maintaining adequate nutrition can help support energy levels.
• Changes in blood cell counts – Radiation therapy that exposes a substantial amount of bone marrow can temporarily reduce blood cell production. If this is a concern, blood cell counts may be monitored, particularly if the patient is also receiving systemic multiple myeloma treatment.
• Throat or swallowing discomfort – Radiation therapy delivered near the neck, upper spine or chest can sometimes irritate the esophagus. Dietary modifications, medications and other supportive measures can make swallowing more comfortable.
• Digestive changes – Radiation therapy involving the abdomen or pelvis may cause nausea, diarrhea or other gastrointestinal symptoms. Medications and nutritional adjustments can help manage these side effects.
• Other site-specific effects – Radiation delivered near the chest, pelvis, head, spine or other anatomical areas can affect nearby healthy tissues differently. Before treatment begins, the radiation oncologist will discuss the effects that are relevant to the specific treatment field.

Possible long-term and late-onset side effects

Long-term effects of radiation therapy for multiple myeloma can vary depending on the treatment site, radiation dose and amount of healthy tissue exposed. Some patients may develop lasting changes in the treated tissues, such as fibrosis, which can cause firmness or stiffness. Physical or occupational therapy may help preserve mobility and function when appropriate.

Other potential late effects are specific to the anatomical area that received radiation. The healthcare team will consider these risks when designing the treatment plan and can recommend appropriate long-term monitoring.

Managing daily life during radiation therapy for multiple myeloma

Many patients receive radiation therapy on an outpatient basis. How treatment affects their daily activities can vary, particularly because some patients with multiple myeloma may also be receiving systemic therapy or managing symptoms caused by the disease itself.

Several strategies can help support comfort and well-being during treatment:

• Protect the treated skin – Use gentle skin care products recommended by the radiation oncology team and protect the treatment area from excessive heat, friction and direct sunlight. Avoid placing adhesive tape or unapproved creams on the treatment field.
• Prioritize nutrition and hydration – Adequate calories, protein and fluids can help the body maintain strength during treatment. Moffitt’s registered dietitians can provide individualized nutritional guidance if eating or maintaining weight becomes difficult.
• Stay appropriately active – Gentle activity can help preserve strength and may lessen fatigue, but exercise recommendations should account for any areas of bone weakened by myeloma. The healthcare team can advise which activities are safe if there is a risk of fracture.
• Use available supportive services – Moffitt offers supportive resources that can help patients manage physical symptoms, emotional concerns and practical challenges throughout cancer treatment.

Radiation therapy clinical trials for multiple myeloma at Moffitt Cancer Center 

Clinical research is an integral part of cancer care at Moffitt, the only National Cancer Institute (NCI)-designated Comprehensive Cancer Center based in Florida. Moffitt maintains an active multiple myeloma clinical trials program investigating new approaches to controlling the disease and managing its complications.

Available studies change over time, and not every clinical trial involves radiation therapy. For patients who may benefit from an investigational treatment approach, the healthcare team can determine whether an appropriate clinical trial is available and explain how participation would fit into the overall treatment plan.

Frequently asked questions (FAQs) about radiation therapy for multiple myeloma 

Patients who are considering radiation therapy for multiple myeloma often have questions about its purpose, effectiveness and potential effects, such as:

When is radiation therapy used in the treatment of multiple myeloma?

Radiation therapy is most often used to control myeloma in a specific area of the body, such as a painful bone lesion or a tumor that is pressing on the spinal cord, nerves or another important structure. It may also serve as the primary treatment for a solitary plasmacytoma when the disease is confined to one site.

Can radiation therapy relieve bone pain from multiple myeloma?

Yes. Radiation therapy can be highly effective for relieving localized bone pain caused by myeloma because it can reduce the number of abnormal plasma cells at the affected site. The amount and timing of pain relief can vary among patients.

Can radiation therapy prevent fractures from myeloma lesions?

Radiation therapy can reduce or eliminate myeloma cells at the treated site, but it cannot immediately restore the structural strength of a severely weakened bone. If a bone is at substantial risk of breaking, the healthcare team may consider additional measures, such as orthopedic stabilization, bone-strengthening therapy or activity modifications.

How long does a typical radiation therapy session for multiple myeloma take?

The radiation itself often takes only a few minutes to deliver, but the treatment appointment will generally take longer because the radiation therapist must carefully position the patient and may perform imaging to verify alignment before delivering the radiation.

Will localized radiation for myeloma weaken the immune system or blood counts?

It can in some circumstances. Because bone marrow produces blood cells, radiation therapy involving a large amount of active bone marrow or multiple treatment areas can lower blood cell counts, particularly when combined with systemic myeloma therapies. The healthcare team can monitor blood counts when clinically appropriate.

Can radiation therapy cure multiple myeloma?

Radiation therapy generally cannot cure systemic multiple myeloma because the disease may involve plasma cells in multiple areas of the bone marrow. However, radiation therapy can provide excellent control of individual lesions and may be used with curative intent for a solitary plasmacytoma when there is no evidence of systemic myeloma.

Does radiation therapy make the patient radioactive?

No. External beam radiation therapy passes through the body during treatment and does not remain there afterward. The patient will not be radioactive and can safely be around family members and others after a treatment session.

The Moffitt Cancer Center approach to radiation therapy for multiple myeloma

Multiple myeloma treatment often requires expertise across several specialties because the disease can affect the bone marrow, bones, kidneys and other parts of the body. At Moffitt, the specialists in our Malignant Hematology Program collaborate with radiation oncologists and other experts to determine how localized radiation fits into each patient’s comprehensive treatment plan.

Moffitt’s Radiation Oncology Program is accredited by the American College of Radiology and offers advanced radiation planning and delivery technologies, including IMRT, IGRT, VMAT, stereotactic radiation therapy and proton therapy. This breadth of expertise allows the healthcare team to select a radiation approach based on the location of the disease, treatment objective and surrounding healthy tissues rather than relying on a one-size-fits-all technique. Moffitt also maintains an active multiple myeloma research program, providing eligible patients with opportunities to participate in clinical trials evaluating emerging approaches to treatment.

To learn more about radiation therapy for multiple myeloma, you can request an appointment with a specialist in Moffitt’s Malignant Hematology Program by calling 1-888-663-3488 or submitting a new patient registration form online. We do not require referrals.