This type of treatment uses radiation to target and kill cancer cells. Specialists use radiation to treat all stages of mesothelioma, but how they administer radiation depends on the individual’s diagnosis. Some patients get radiation before surgery while others get radiation after chemotherapy.
Benefits of Radiation Therapy
Noninvasive: Radiation therapy is one of the most easily applied mesothelioma treatments. Treatment is quick and painless.
Pain Relief: Radiation can shrink large, painful tumors for patients with any type of mesothelioma. This makes radiation a go-to treatment for late-stage patients.
All Stages: Radiation has a benefit for patients with any stage of mesothelioma. Combined with surgery, radiation is an effective treatment for early-stage patients.
Like all mesothelioma treatments, there are side effects of radiation therapy, the most common being nausea. But the benefits of radiation generally outweighs these side effects.
How Radiation Helps
Radiation therapy can be used with surgery and chemotherapy in a multimodal course of treatment. Patients eligible for surgery often receive radiation before their procedure to shrink tumors before the operation. Doctors may also prescribe radiation after surgery to kill leftover cancer cells, or sometimes radiation is applied during the surgery itself.
For patients with pleural mesothelioma, doctors have successfully shrank tumors before surgery in a relatively new procedure called SMART, which stands for “surgery for mesothelioma after radiation therapy.”
Radiation therapy is also used as a palliative measure. It’s proven effective in decreasing the pain and discomfort caused by mesothelioma symptoms in patients with advanced mesothelioma (stages three and four).
Treatment Process and Side Effects
Radiation Therapy Process: Before administering radiation therapy to a patient, a radiation oncologist (a doctor who specializes in treating cancer with radiation) locates the affected area. A specialist uses a diagnostic imaging test, such as a CT scan, to locate the are where they will apply the radiation.
When the scanning is complete, a few marks are made on the patient’s skin to help the oncologist line up the beams of radiation correctly during the actual application of the therapy.
The treatment itself generally takes about 30 minutes and is administered every day over the course of 5 to 6 weeks.
Side Effects: Radiation waves enter through the patient’s body tissue, which means healthy cells are also affected during radiation therapy. When radiation kills healthy cells in the body, the result are the side effects most patients experience.
The most common side effects may include:
- Hair loss where the radiation beam is applied
- Redness and irritation
- Sore throat
- Difficulty swallowing
- Stiffness and aching in the chest or shoulder
The radiation oncologist may require their patient to see a physiotherapist after treatment. Exercising the body regularly after treatment can help reduce stiffness and aching after therapy. The trade-off between healthy cells killed and mesothelioma cells is worth it for most patients. The healthy cells killed in the process are martyrs to the overall goal of making the patient healthier.
Types of Radiation Therapy
There are several ways radiation oncologists administer radiation therapy. Each type of therapy has its own pros and cons. Only a mesothelioma specialist can determine the most beneficial radiation treatment for each patient.
Proton therapy (External Beam Radiation): Radiation specialists use proton therapy to deliver precise doses of radiation to a tumor without extra exposure that can damage surrounding tissues. The beam is made of energized protons that damage the DNA of cancer cells, causing their death. Treatment is given daily over a 5 to 6 week period.
Brachytherapy: This type of radiation involves the placement of radioactive implants, such as small tubes or pellets, inside the patient’s body. These implants are sealed inside safety containers, which allow high doses of radiation to enter the area surrounding the implant. The implant is place near the tumor. Delivering radiation through small tubes or pellets restricts damage done to healthy tissues (thus reducing side effects) by concentrating radiation on the tumor.
Intensity-Modulated Radiation Therapy (IMRT): Mesothelioma specialists administer IMRT with a machine regulated by a computer, which allows it to deliver pre-measured doses of radiation. It can also change the size of the radiation beam according to the shape of its target, the mesothelioma tumor. This is helpful and efficient, especially in the case of mesothelioma, whose tumors tend to spread out in an irregular pattern. Like the small implants in used in brachytherapy, IMRT lowers the risk of damaging healthy tissue surrounding the mesothelioma.
Volumetric-modulated arc therapy (VMAT): This treatment passes radiation beams in arcs, or half-circles, around the patient. VMAT cuts down on the treatment time and allows for more accurate targeting.
Photodynamic therapy (PDT): Although not strictly a radiation treatment, PDT involves the use of a medication, called a photosensitizer, whose cancer-killing properties are activated by light. A specialist injects the photosensitizer into the patient’s bloodstream, where cancer cells absorb the medication. Low-level beams of light are then applied to the mesothelioma tumor, inside of which the photosenitizer and the light react. The reaction releases a large amount of oxygen that eventually destroys cancer cells and shrinks the tumor. This is a novel mesothelioma treatment.
A recent study on the effectiveness of PDT combined with a pleurectomy, a lung sparing surgery, showed that the median overall survival rate for all patients was 31.7 months.
Improving Prognosis With Radiation
When used alongside other forms of treatment, radiation therapy can help improve a patient’s prognosis.The delivery of radiation therapy with curative surgery and chemotherapy is currently being refined in clinical trials.
One study reported that the use of IMRT before surgery resulted in a 3 year survival rate of 84 percent. This means that 84 percent of the patients treated with adjuvant IMRT lived 3 years after having the procedure.
Enough studies have shown that the use of radiation therapy in a multimodal course of treatment with surgery and chemotherapy can increase the survival time of mesothelioma patients.