External Beam Radiation Therapy

The therapy which I am going to discuss in this post is the most common one, which is external beam radiation therapy. The reason for the frequent use of this therapy as it uses a machine outside the patient’s body to perform the treatment. LINAC (Linear Accelerator) is the most common machine used in this therapy. 

How does it work?

Photon beams of radiation light are guided on the place of the tumor and destroying the cancerous cells and through this stops them to spread and develop. These photon beams are constitutes of x-rays that is of a bit low energy level or either it can be of gamma rays that is highest energy level.

The radiation oncologist, who uses this treatment for cancer and mesothelioma, is a well- trained physician. It can take up to several weeks to complete the course of treatment. Patient receives this treatment at the hospital or clinic, but does not need to stay overnight.

How does it work for Mesothelioma?

External beam radiation therapy is used in treating the most common types of mesothelioma that are pleural mesothelioma (which affects the lungs) and peritoneal mesothelioma (which affects the abdominal cavity). But, surgery is the primary treatment for it; it means, a patient will undergo the surgical process and then opt for the secondary treatment that is radiation therapy. The radiation treatment is done to eradicate and damage the remaining cancerous cells, which were left behind after the surgical process.  

When pleurectomy/decortications surgery (P/D) is done on pleural mesothelioma patient, administrating radiation is really hard as there is much risk of damaging of lungs not only this there may be chances of inflammation of lungs (pneumonitis).

If a patient undergoes extrapleural pneumonectomy surgery (EPP) there is a great chance of lengthens survival rates. In this surgical process, the affected lung is removed and the radiation can be easily delivered to the cavity without damaging the healthy lung. But, there is still possibility of inflammation of lungs. 

Image Guided Radiation Therapy

Image-Guided Radiation Therapy, also called IGRT, is another specialized radiation treatment, which is very precise when targeting the tumor by delivering the radiation beam on the affected area without harming the tissues and organs that surrounds the tumor. The image-guided radiation therapy (IGRT) is done by the radiation oncologist by using a very precise imaging system or equipment and LINAC (Linear accelerator) to deliver the radiation onto the tumor. This imaging system is really helpful as it let the radiation oncologists to observe the tumor before, during and after the treatment. In other words, one can see the every step of the treatment.

When starting the therapy session for mesothelioma cancer, first the patient is lay on the treatment table so that marks can be made on the treatment area, which are in position with the path of the radiation beam. Then, the images are being taken, first for the preliminary stage when the therapy is being started for the patient. With the use of computer software these images are then compared and analyzed throughout the therapy sessions. All these comparisons are being made just to ensure whether the adjustments need to be made to the position of patient and also for the path of radiation beams. Sometimes adjustments are needed then; we have to take new set of images, which are then compared with the old set to make sure the tumor is being targeted really precisely. 

What are the equipments used in taking images?

Magnetic Resonance Imaging

 

Magnetic Resonance Imaging or MRI is a kind of imaging process that uses a radio waves and magnetic field to create three dimensional images. These images came very handy if we want to view from variety of angles.

Computed Tomography (CT Scan)

 

CT scan or CAT scan makes use of multiple images, which are then combined by the computer to show the cross-sectional and three dimensional views of the tumor.

Ultrasound

 

Transducer is a small device, which is being passed all along the area, which is to be tested. Sound waves are being produced by this device through bouncing off the tissues that produce echoes.

Positron Emission Tomography

 

In Positron Emission Tomography or PET scan, a very small quantity of a radioactive material is given to the patient either via breathing in, injection or orally. Eventually, this radioactive material collected in the affected area and can be acknowledged as a bright spot on the scan. 

This therapy can offer better understanding of the movement of tumor before, during and after the treatment in the near future, which I truly believe.

Proton Therapy

What is proton therapy? Why should we go for it?

In the course of their treatment, Mesothelioma patients often receive radiation therapy, although most of the time the delivery is imprecise. Because of this imprecision, radiation can easily damage the healthy tissues or cells. Right now, the therapy that I want to discuss is the Proton therapy. The most beneficial thing about this therapy is that it beams highly energized protons straight where the growth of cancer is. That is why is considered to be one of the most specialized types of radiation particle therapy. Protons hardly ever go outside the area of treatment, as it can travel through some centimeters of the affected tissue. Thus, it reduces the risk of damaging the healthy tissues surrounds the affected area like in pericardial mesothelioma it is heart and in pleural mesothelioma there are lungs.

Who are eligible for this therapy?

If the cancer in patient is metastasized (the cancer is spread out all through the body), in general this therapy is not given to him as this is a very location specific treatment. It is more appropriate for the patient in their advance stage of cancer to go for chemotherapy that will be more responsive than other ways of treatment. Therefore, a patient at his early stage of mesothelioma cancer can go for proton therapy, which can play an effective role at this point. Other requirement is the patient should not weigh more than 360 pounds as it is impossible for the equipment to accommodate heavy person. The patient should stay near the treatment facility so he/she can easily commute to it on a daily basis.

Proton therapy is delivered noninvasively so it is a type of mesothelioma treatment, which is treated externally. Protons are delivered to the tumor through moving or steady beam, this technique is said to be as pencil beam scanning proton therapy. Through pencil beam scanning proton therapy, the oncologists delivered the beam at the affected area without damaging healthy tissues, vital organs or the areas, which is already being treated or radiated. Furthermore, the intensity of protons can easily adjust by the radiation therapists or oncologists so that the protons cannot penetrate into the area, which is beneath the tumor. Because of this, the radiation will remain in the area of the tumor.  The patient received proton therapy in cycles of up to 7-8 weeks. The time duration of the mesothelioma cancer treatment depends upon the dose of radiations. Like if the higher doses of radiation are delivered, then there will be shorter cycles of treatment whereas if the low doses are given, then there will be longer cycles. Before starting the proton therapy, the patient will undergo a simulation session (generally a week earlier the actual treatment), so that he/she can be prepared for the treatment.

Now, there must be a question come up in your mind… How is it done?

Patients are lay on a device, which prevents them to move throughout the proton therapy session. After that the radiation therapists position the radiation beam, on the markings made on the body that is required to treat during simulation sessions. Furthermore, radiation therapist also administrates the dose of radiation from the control room. Generally, it is a 30-90 minutes session and during the treatment the patient can communicate with the radiation therapist through a two-way intercom. Don’t worry the procedure is completely painless and the great thing about this that after the sessions the patient is not considered to be radioactive.

As already have been told about proton therapy that the healthy tissues are not affected by the radiation. Just 20% surrounding tissues has an effect of the radiation, but this is too weak to cause a considerable side-effects.

Let me, share a study that when pleural mesothelioma patients undergo proton therapy session, it exhibited lower post-treatment radiation in the regions like heart, kidneys, spinal cord healthy or non- cancerous lung and liver as compared to the levels of radiation in the organs of the patients, who are treated with other type of radiation treatments. 

Luckily now the mesothelioma is detected much earlier. So, many patients are qualifying for this one of the most sophisticated treatment. In 2005, 20 mesothelioma patients from Sweden are qualified for the proton therapy. In United States, it has been used since 1990 in clinical cancer treatments. In 2009 survey, there are 38 facilities of proton therapy available worldwide, including the University of Florida Proton Therapy Institute and the Proton Therapy and Treatment Center at Loma Linda University.

If you want to go through this treatment the very first eligibility is that the mesothelioma cancer should be detected at early stage or stage 1, then you can qualified for this treatment!