Types of Mesothelioma Radiation
There are different types of mesothelioma radiation therapy. The newest types are more effective at killing cancer cells while avoiding damage to healthy tissue.
Written by Jenna Campagna, RN
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Important Facts About the Types of Mesothelioma Radiation
- There are three types of mesothelioma radiation: photon, proton and intensity-modulated. Most cancer centers use intensity-modulated, which is more targeted than photon beams.
- Each type is limited just to pleural mesothelioma, as radiation isn’t an accepted therapy for peritoneal mesothelioma.
- Radiation is often used along with other therapies, most notably surgery. Radiation can be administered either before (neoadjuvant), during (intraoperative) or after (adjuvant) surgery.
What Are the Types of Radiation for Mesothelioma?
The types of radiation include photon radiation therapy, intensity-modulated radiation therapy (IMRT), and proton radiation therapy. These three constitute the options mesothelioma patients will have when electing which method to receive.
Photon Radiation
Photon radiation, also called external beam radiation, sends a radiation beam at the tumor site. For mesothelioma, this is most often the chest. The beam travels through the chest cavity and into the pleura.
Photon beams are used in X-rays for imaging scans, but radiation requires a higher dose. Photo beams can reach tumors deep in the thorax, but they often scatter bits of radiation and damage surrounding healthy tissue. Photon beams also go through tumors and can damage healthy tissue on the other side.
Photon radiation lasts up to 30 minutes and usually occurs five days a week. Patients may receive photon radiation for 1-2 months.
IMRT
IMRT, which stands for intensity-modulated radiation therapy, sends targeted beams at the tumor site. It limits damage to healthy tissue and the remaining lung if used after extrapleural pneumonectomy surgery.
IMRT usually lasts around 15-30 minutes and usually occurs five days a week. An entire regimen may last up to two months.
Proton Beam Radiation
Proton radiation therapy is the newest type used for mesothelioma. It’s usually available at proton radiation centers rather than general cancer centers.
The sessions last around 15 minutes and occur a few times per week. According to a proton radiation specialist at the New York Proton Center, programs for patients can last 2-6 weeks.
When to Use Radiation for Mesothelioma
Doctors and cancer centers have varying views on when to use radiation in multimodal treatment for mesothelioma:
- The traditional thought is to use radiation after surgery, which is called adjuvant radiation treatment.
- Some may use it during surgery, which is called intraoperative radiation therapy (IORT).
- The newest approach is using radiation before surgery, which is called neoadjuvant radiation treatment.
Neoadjuvant Radiation
Neoadjuvant radiation for mesothelioma mostly refers to using the therapy prior to surgery. Another term for this is SMART for mesothelioma, an acronym for “surgery for mesothelioma after radiation therapy.” It started at Princess Margaret Cancer Center in Toronto and now is the featured program of Michigan Medicine cancer center.
Neoadjuvant radiation shrinks the size of tumors and makes removal during surgery easier. This approach has median survival times of 2-5 years, with variances depending on the cancer center, surgeon and patient selection.
Intraoperative Radiation
Intraoperative radiation targets tumors either during surgery or immediately following surgery, before the operation concludes. The intent is to target tumors without needing to pass through skin or other healthy tissue.
One of the side effects of radiation is damage to healthy tissue. IORT is an attempt to sidestep this side effect.
Brachytherapy
Brachytherapy is a type of intraoperative radiation therapy for mesothelioma. Doctors implant a small radioactive pellet into the tumor. This pellet provides a continuous dose of radiation after surgery.
Temporary brachytherapy implants are removed minutes after surgery ends. Permanent implants work for up to 10 months.
Adjuvant Radiation
Adjuvant radiation is the oldest and most common approach to multimodal mesothelioma therapy. The intent is to target any tumors not removed during surgery.
Taking out all mesothelioma tumors is difficult through surgery. Most patients still have microscopic tumors or ones too close to organs for safe removal. Adjuvant radiation can either kill these tumors or contain them to their current size and location.
Sources & Author
- External Beam Radiation Therapy for Cancer. National Cancer Institute. Retrieved from: https://www.cancer.gov/about-cancer/treatment/types/radiation-therapy/external-beam. Accessed: 05/26/2021.
- Brachytherapy Frequently Asked Questions. American Brachytherapy Society. Retrieved from: https://www.americanbrachytherapy.org/resources/for-patients/brachytherapy-frequently-asked-questions/. Accessed: 05/26/2021.
- Radiotherapy doubles survival for patients with mesothelioma. European Society for Radiotherapy and Oncology. Retrieved from: https://www.sciencedaily.com/releases/2019/04/190429125437.htm#:~:text=Summary%3A,affected%20side%20of%20the%20trunk. Accessed: 05/26/2021.
