Radiation therapy (also called radiotherapy) is commonly used to treat solitary plasmacytoma – an early stage of multiple myeloma involving a single lesion in the bone or soft tissues. Plasmacytoma that occurs in the soft tissues is known as extramedullary plasmacytoma. Radiotherapy may be used as the only treatment for plasmacytoma or may be given during or after surgery to remove lesions. Radiation therapy may also be used to treat multiple myeloma in cases where chemotherapy has been ineffective at reducing pain in a limited number of bone sites. Radiotherapy is overseen by a radiation oncologist.
Radiation interferes with cell division. Since cancer cells divide much more rapidly than normal cells, they are more vulnerable to radiation. Radiation kills cancer cells, but the normal, healthy cells of your body are better able to survive and heal. Radiation therapy can help shrink tumor size, slow or prevent the spread of tumors, and may strengthen the bone and help treat pain.
What does it involve?
Radiation therapy comes in two main forms, external beam radiation and internal radiation. External beam radiation is the most common form used for plasmacytoma. In external beam radiation, beams of energy are projected from a machine into your body, carefully targeted onto the location affected by plasmacytoma.
When you arrive for your first external beam radiation appointment, the radiation therapist will take an x-ray called a port film to establish the best position for you to be in during treatment. They may make small permanent or semi-permanent marks on your skin to indicate where the beam should be targeted. Do not try to wash this off or retouch it. In each appointment, the therapist will position you carefully on the table. You will need to lie still while the radiation is delivered. Try to stay relaxed. You will not feel anything during the treatment, although gradually over several treatments, your skin in that area will develop a burn like a sunburn. This may be painful, but can be treated with topical ointments.
Radiation schedules differ based on the size, location, and type of tumor, other treatments you are receiving, and additional factors. Radiation therapy is usually delivered five days a week during the treatment period, which is most commonly about four weeks, although it can last between two and 10 weeks. Receiving the treatment takes about 30 minutes, but preparation time may take longer.
During and after radiation therapy, take extra care of your health by eating a nutritious diet, getting plenty of sleep, and exercising regularly. These measures will help you feel your best and recover more quickly from radiotherapy. Care for your skin where it was affected by radiation by wearing loose clothing and keeping it shielded from the sun.
Radiation therapy can reduce pain by shrinking tumors. Radiation therapy helps prevent cancer progression and relapse by killing cancer cells, shrinking tumors, and destroying any remaining cells after tumors have been removed.
Solitary plasmacytomas of the bone are responsive to radiotherapy in 80 to 90 percent of cases. Radiotherapy appears most effective in tumors that are less than 5 centimeters in diameter.
In one summary of several research studies, people who received localized radiotherapy for solitary plasmacytoma in the bone had a 12 percent rate of relapse versus a 60 percent rate of relapse for those who did not undergo radiotherapy.
Most common side effects of external beam radiation are short-term. These include fatigue, swelling, nausea, diarrhea, and skin damage similar to sunburn. These changes are usually gone within six to 12 months after external beam radiation treatment ceases but may linger for as long as two years.
Less common side effects include nerve damage that can leave parts of the body feeling painful, weak or numb.
A very rare but serious side effect of external beam radiation can include developing a different type of cancer called angiosarcoma.
For more details about this treatment, visit:
Radiation Therapy – Leukemia & Lymphoma Society
Treatment Options for Multiple Myeloma, by Stage – American Cancer Society
Radiation Therapy for Multiple Myeloma – American Cancer Society
Radiotherapy treatment – Cancer Research UK
External Beam Radiation Therapy – American Cancer Society
Diagnosis and management of solitary plasmacytoma of bone – UpToDate