Mesothelioma Brachytherapy Treatment

Mesothelioma has no cure as of now and the line of treatment generally followed is the trimodal approach of combining any or all of surgery, chemotherapy and radiation therapy. An advanced form of cancer treatment in use for more than a century is Brachytherapy, a type of radiotherapy.

Traditionally, radiotherapy uses ionizing radiation like x-rays to treat cancers by destroying the cancer cells. This therapy is used both with palliative and curative purposes. There are two types of radiotherapy:

External radiotherapy or tele-radiotherapy: Radiation in this method is delivered from a radioactive source outside the body, usually a linear accelerator

Brachytherapy: This is radiotherapy in which the radioactive source is inside the body instead of outside. The word derives from the meaning of Brachy, which is ‘short,’ and refers to the therapy being localized as opposed to being generalized. Other nomenclature for Brachytherapy is internal radiotherapy, sealed source radiotherapy, seed implantation radiotherapy or endocurietherapy.

The Process

The radioactive source is placed near or inside the cancer tissue. The ionizing radiation given out by the radioactive source kills the mesothelioma cells around it. The rays can penetrate only about 1 cm or so; as a result, the healthy cells beyond the cancerous cells remain unaffected by the radiations of the radioactive source.

Brachytherapy is performed under anesthesia. Some tests like blood tests, chest x-ray and electrocardiography are done to assess the fitness of the patient. An ultrasound scan determines the location, size and extent of the tumor. This enables the radiotherapist to decide where the radioactive seeds will be most beneficial for the patient.

The Radioactive material: The radioactive source (radio-active seeds) is made of Iodine 125, Iodine 131, Palladium 103 and Iridium 192.

Types of Brachytherapy

High dose brachytherapy: Thin catheters are inserted in to the tumor under mesothelioma treatment in an outpatient procedure. An afterloader attached to the catheter contains the radioactive seeds at the end of a wire. One seed at a time is pushed in to the catheters; the time and place of delivering the radiation is computed before hand and monitored by a computer. 12 separate HDR brachytherapy treatments may be given spanning a week or more after which the catheter is removed. High dose rate brachytherapy is usually a temporary brachytherapy.

Low dose rate brachytherapy: Continuous mesothelioma radiation is given in a period of hours or days as an inpatient procedure. The device works over a longer period of time. When seeds are left inside the body, it is called permanent brachytherapy; the seeds lose the radioactivity with the passage of time.

The team performing the procedure will generally include a radiation oncologist, radiation physicist, dosimetrist, and radiation therapist.

Generally considered a safe treatment of cancer, pleural mesothelioma brachytherapy has some side effects reported include soreness, swelling and pain at the site of the procedure, sometimes also bleeding from the site. All these are temporary in nature and disappear with time.