Radiation Therapy for Peritoneal Mesothelioma

Quick Summary

Peritoneal mesothelioma is a rare cancer form affecting the peritoneal mesothelium which is the abdomen lining. Also called the peritoneum, this is a protective membrane covering the abdominal organs. The peritoneum allows abdominal organs to separate and freely move within the abdominal cavity. Peritoneal mesothelioma is caused by ingesting asbestos fibers and has no known cure as yet. However, peritoneal mesothelioma cases can be managed through radiation therapy in conjunction with other multimodal treatments. Patient life expectancy and life quality can improve with radiation therapy.

Radiation Therapy for Peritoneal Mesothelioma Overview

Peritoneal mesothelioma is a very rare aggressive cancer accounting for 20-25% of mesothelioma cases while even rarer forms make the remainder. Peritoneal mesothelioma is directly caused by asbestos exposure and there is no other known primary contributor. There is also no known cure for peritoneal mesothelioma. Cases can only be managed by multimodal intervention through experienced multidisciplinary medical teams.

Fortunately for patients with peritoneal mesothelioma, it’s considered the most treatable mesothelioma type. Peritoneal mesothelioma responds well to radiation therapy working with surgical procedures and chemotherapy treatment.

Peritoneal mesothelioma results from ingesting asbestos fibers into the digestive tract. This happens from airborne asbestos fibers contaminating solid food or liquids that are swallowed. The sharp fibers stick to the stomach lining, then travel through to the peritoneum. Asbestos fibers can’t be expelled. The eventually cause scar tissue which turns into cancer tumors.

Peritoneal mesothelioma has a shorter latency period than pleural mesothelioma. Peritoneal symptoms can present within 10 years of when the patient experienced asbestos exposure. It’s an aggressive cancer form. Left untreated, peritoneal mesothelioma can claim a patient’s life in 6 months to a year after turning malignant. It’s highly important to diagnose peritoneal mesothelioma at an early stage and immediately begin treatment. This includes administering the right method of radiation therapy.

What Is Radiation Therapy for Peritoneal Mesothelioma?

Radiation therapy, or radiotherapy, is one of three primary treatment methods for controlling peritoneal mesothelioma. Working in conjunction with surgical procedures and chemotherapy, radiation assists managing cancer tumors by killing active mesothelioma cells and preventing new ones to colonize and flourish. The use of several therapies to manage peritoneal mesothelioma is called a multimodal approach.

It involves three processes aligning as a team.

  • Surgery: Peritoneal mesothelioma requires a unique surgical procedure called cytoreduction, or “debulking”. It’s an invasive process where the surgical oncologist removes the entire diseased portion of the peritoneum. Patients usually display tumors across the entire region. Therefore, it’s extremely difficult to remove all cancerous cells. Often, microscopic cancer cells remain. These are managed with complementary treatment from chemotherapy and radiation.
  • Chemotherapy: Chemotherapy involves administering drugs or chemicals usually into the patient’s bloodstream. Currently, a treatment called Hyperthermic Intraperitoneal Chemotherapy (HIPEC) or “hot chemo” is proving effective. It involves heated chemicals being flushed into the abdominal cavity immediately following surgery that kill microscopic remaining cancer cells. Other chemotherapies are administered orally or through IV injection.
  • Radiation Therapy: Radiation involves two types of high-intensity photons or light beams targeted at cancer tumors. Gamma Rays are extremely powerful. They’re used where high-dose applications are required. Most radiation treatment involves modulated X-rays similar to what’s used in medical imagery. Radiation therapy can be applied externally or internally. Unfortunately for peritoneal mesothelioma patients, tumors are usually widespread making overall body radiation impractical. In these cases, radiation therapy focuses more on palliative management of pain and discomfort symptoms while surgery and chemotherapy are the main controls.

What Are the Goals for Radiation Therapy for Peritoneal Mesothelioma?

Medical teams view treating peritoneal mesothelioma as a case-management approach. At this time, medical science and applied technologies can’t cure peritoneal or other types of mesothelioma. They can only manage the disease to increase patient survival time and offer them an improved life quality. This involves radiation therapy working with other multimodal treatments.

Generally, these are goals set for peritoneal radiation therapy:

  • Shrinking Tumors: Large peritoneal tumors are challenging to remove entirely during a cytoreduction surgical procedure. Radiation can be effective in shrinking large tumors to the point where surgery is more practical.
  • Killing Remaining Microscopic Cancer Cells: Once a peritoneal tumor is removed, or what’s called debulked, microscopic cancer cells are bound to remain. Radiation therapy is much more effective in killing small cancer cells posing a threat to expand.
  • Preventing Seeding: Seeding is the term oncologists use to describe distributing cancer cells to unaffected tissues during surgical intervention. Surgery incisions are susceptible to contamination from existing tumors being removed. Radiation therapy works to manage accidental cancer cells seeding.
  • Palliate Symptoms: Palliative care refers to managing peritoneal mesothelioma symptoms and improving patient comfort. Like all mesothelioma forms, peritoneal tumors can be painful. Radiation therapy is effective in reducing tumor pain and offering patients a better quality of life.

Radiation for Peritoneal Mesothelioma Approaches

Peritoneal mesothelioma radiation therapy approaches describe when and how radiation applications are administered. This is on a case-by-case and decided upon while developing the patient’s overall treatment plan. Radiation treatment effectiveness depends a lot on timing. Administering radiation therapy has three main approaches:

  • Adjuvant radiotherapy is the commonest radiation treatment approach. Adjuvant refers to the Latin term for helping, which is what radiation therapy is designed to do. Adjuvant approaches are used after surgery and during the follow-up period.
  • Neoadjuvant radiation therapy begins before any surgical procedure starts. The focus is slowing tumor expansion or shrinking it before physical intervention like cytoreductive surgery.
  • Intraperitoneal approaches employ radiation therapy techniques that directly enter the peritoneum. That’s done by open surgery or robotic placement of radioactive treatment devices.

How Is Radiation Therapy for Peritoneal Mesothelioma Administered?

Patients receive peritoneal mesothelioma radiation therapy either externally or internally. External radiation is the oldest administration method and is the least invasive. Internal radiation therapy requires surgically implanting a device like a small capsule containing controlled radioactive particles. These are the three common administrations for radiation therapy:

  • External Beam Radiation Therapy (EBRT): A machine containing a lineal accelerator shoots charged particles directly at the peritoneal tumor. High-tech equipment now allows precise beam placement through three-directional application. This ensures minimal damage to surrounding healthy tissues.
  • Brachytherapy: An internal process where radioactive material is surgically planted next to tumorous tissues. Capsules with radiation particles effectively kill cancer cells by proximity. Robotic brachytherapy techniques are replacing direct, open-cavity surgical procedures.
  • Intraperitoneal: A new technique showing promise, intraperitoneal radiation involves inserting radioactive liquid into the abdomen through a thin tube.

What Are the Results of Radiation Therapy for Peritoneal Mesothelioma?

Radiation therapy for peritoneal mesothelioma has little results unless used with systemic chemotherapy and surgical procedures. Radiation’s primary purpose is reducing tumor size and preventing cancer cell regrowth after surgery. Radiation is highly effective in pain reduction in managing palliative care.

Possible Side Effects of Radiation Therapy for Peritoneal Mesothelioma

By nature, peritoneal mesothelioma covers a wide area. When diagnosed, it’s usually spread across the abdomen. Whole body radiation is not used due to massive and intolerable side effects. Radiation therapy is limited to localized areas and usually has little side effects.

Patients treated with external beam therapy usually report sunburn-like skin effects. Brachytherapy side effects are more prominent. They’re described as flu-like with headache, chills, sweats, nausea, dizziness and weakness being the main complaints.

Seeking Radiation Therapy for Peritoneal Mesothelioma

Top peritoneal mesothelioma treatment centers rely on a multidisciplinary team approach. That includes surgical and radiography oncologists, assistants, nurses and social support staff. It also includes the patient as a team member involved in developing the treatment plan. Although peritoneal mesothelioma can’t yet be cured, medical and technological advancements considerably extend life expectancy and greatly improve patient comfort.

For more information on radiation therapy for peritoneal mesothelioma, contact our Patient Advocates today.

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Sources
  1. National Cancer Institute, “Radiation Therapy for Cancer”, Retrieved from https://www.cancer.gov/about-cancer/treatment/types/radiation-therapy  Accessed on February 21, 2018
  2. Canadian Cancer Society, “Treatment of Peritoneal Mesothelioma”, Retrieved from http://www.cancer.ca/en/cancer-information/cancer-type/mesothelioma/treatment/peritoneal-mesothelioma/?region=sk  Accessed on February 21, 2018
  3. ASCO Cancer.net, “Mesothelioma Treatment Options”, Retrieved from  https://www.cancer.net/cancer-types/mesothelioma/treatment-options   Accessed on February 21, 2018
  4. U.S. National Institute of Health, “Peritoneal Mesothelioma: A Review”, Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994863/  Accessed on February 21, 2108

Last modified: May 8, 2018