In patients whose general health isn’t good enough to withstand surgery, radiation may be given as the primary treatment. That’s because radiation can achieve a localized alleviation of symptoms in about 50 percent of patients. This was the finding of a study titled Factors influencing the outcome of radiotherapy in malignant mesothelioma of the pleura—a single-institution experience with 189 patients, published February 1999 in International Journal of Radiation Oncology * Biology * Physics.
The researchers also observed that a better response rate was seen for patients treated with a 4-Gy per fraction (gray per fraction) schedule, as compared with those receiving fractions of less than 4 Gy. A gray is the absorption of one joule (unit) of ionizing radiation by one kilogram of human tissue. The whole radiation dose is fractioned or spread out over a period of time to give normal cells time to recover between treatments and to let tumor cells that were in a radiation-resistant phase of their cell cycle move on to a phase more responsive to radiation before the next treatment.
The dose of radiation therapy for mesothelioma patients is determined by two factors: the necessity of irradiating the entire side of the chest affected by the disease and the concern for the radiation sensitivity of the adjacent heart, lung, esophagus, liver, and spinal cord.
Radiation therapy can also be provided as an adjuvant (secondary) therapy after a thoracoscopy, a procedure in which an endoscope is inserted through a small incision and used to examine the inside of the chest cavity, or a thoracotomy, a procedure to open the chest cavity. That’s because mesothelioma frequently “seeds” (develops) along the tracts of biopsies, chest tubes, and surgical incisions.
In a study titled Prevention of Malignant Seeding After Invasive Diagnostic Procedures in Patients With Pleural Mesothelioma, A Randomized Trial of Local Radiotherapy, published September 1995, in Chest, researchers wanted to examine ways to prevent seeding.
They tracked 40 malignant mesothelioma patients who had undergone thoracoscopy. Twenty patients received three daily sessions of radiation therapy at a dosage of 7 Gy for 10 to 15 days after the surgery. The other 20 patients didn’t receive any. None of the 20 patients treated with radiotherapy showed signs of seeding. However, eight of the 20 who didn’t receive radiation therapy did. This led researchers to conclude that, “These findings confirm the efficacy and safety of early local radiotherapy in preventing malignant seeding after invasive diagnostic procedures in patients with malignant pleural mesothelioma.”
There are side effects to radiation therapy. The Journal of the American Medical Association lists the following:
- Skin redness near the radiated site
- Nausea, vomiting, or loss of appetite
- Hair loss
You can take some steps to help you relieve some of these side effects. The American Society for Radiation Oncology recommends that you:
- Get plenty of rest.
- Call your doctor if you experience a fever of 101 degrees or higher.
- Clean the skin daily with warm water and a mild soap recommended by your nurse.
- Avoid using any lotions, perfumes, deodorants or powders in the treatment area unless approved by your doctor or nurse. Try not to use products containing alcohol and perfumes.
- Avoid putting anything hot or cold on the treated skin. This includes heating pads and ice packs.
- Stay out of the sun. If you must be outdoors, wear clothing to protect your skin. After treatment, use sunscreen with an SPF of at least 15.