What Are the Types of Radiation Therapy for Mesothelioma?
In addition to the radiation therapy approach — whether it’s administered before, during or after surgery — there are also different radiation therapy techniques used to treat mesothelioma.
External Beam Radiation Therapy
External beam radiation is noninvasive and directly targets the malignant (cancerous) tumors. During the procedure, a machine is used to radiate through the skin to the tumor.
According to research in 2004, a delivery of high-dose RT to the entire hemithorax in the lung has not been shown to deliver any additional survival benefit.
However, when used during the extrapleural pneumonectomy (EPP) surgery, a higher dose can be provided to the affected area.
The stronger dose has a significant benefit because the treatment it is more localized, meaning there is less chance of the radiation destroying cells surrounding other working organs.
External beam radiation therapy is not carried out after a pleurectomy with decortication (P/D) ‘lung-sparing’ surgery as the radiation may cause more damage than good to the lung.
External beam radiation therapy is painless. The beams are only administered for a few minutes each session, and there are two types of radiation to choose from, depending on the condition of the patient.
The two types of external beam radiation therapy are:
- Three-Dimensional Conformal Radiation Therapy: Radiologists use a scanner to create a three-dimensional image of the pleural tumors. They then examine the data and decide on the intensity of the radiation beam, which will be delivered directly to the tumor. This helps to avoid unnecessary radiation in the healthy tissue surrounding the tumor and just focuses on killing the cancerous cells.
- Intensity-Modulated Radiation Therapy (IMRT): IMRT is often used to treat pleural mesothelioma after surgery, as this particular method of radiation changes the strength, pattern, and shape of the radiation beams to protect the surrounding tissue. It offers a direct impact on the area that needs to be treated, so there is less worry about the tissue surrounding the cancerous cells.
Intraoperative Radiation Therapy (IORT)
IORT is applied to the patient during surgery.
If a patient has early-stage pleural mesothelioma and is eligible to undergo surgery (be it either EPP or P/D), radiation can be directly applied to the area. This has proved very effective as it avoids passing radiation through healthy cells.
This form of RT is less used than external beam radiation therapy as it is still being researched in clinical trials. Instead of radiation being performed on the outside of the skin, brachytherapy entails tiny radioactive seeds being surgically places next to the tumor.
This procedure can be permanent or temporary, though for pleural mesothelioma it tends to be permanent so that the chest does not have to be opened again.
After the radioactive ‘seeds’ have been implanted, they will release radioactive waves to kill off the cancerous cells and, in the process, break down the tumors.
Did You Know?
Permanent brachytherapy usually takes place on an outpatient basis, and the patient will then have radioactive objects residing in their body for life.
Temporary brachytherapy requires more frequent visits to the hospital, but it means that patients can live for a period without the radioactive seeds within them.
A less invasive way of using radioactive objects with brachytherapy is through high-dose surface brachytherapy, in which a radioactive object is placed on the skin near the tumor.
A radioactive application is then placed onto the surgical incisions from the mesothelioma operation, which helps deliver focused radiation to the area. Again, this will halt the spread of mesothelioma cells and kill tumor growth.
However, due to the high dose needed to penetrate the skin, the patient is often required to stay in the hospital overnight to ensure a healthy recovery.
Radiation can often make patients feel fatigued, nauseous, and have an irritable sensation on the skin. They may also have a loss of appetite and energy, so it’s important to rest until side effects subside.