GREG'S LEGACY

Specialising in the human experience of Living with prostate cancer – warts and all

Posts Tagged ‘IMRT

Radiation Therapy for Beginners part 1

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IMRT MachineIn this post I would like to offer views on my experience with radiation treatment. I am currently at Nambour QLD, undergoing IMRT (Intensity Modulated Radiation Therapy) and what I have written here is part 1, as I have only completed week three of an 8 week course of therapy. Hopefully some time in the future I can complete part 2 when the treatment is finalised which should give a complete personal account to anyone who may be interested. To begin, I will offer the following technical stuff and will try to make it clear and simple, I will then attempt to describe my experience so far with the treatment.

Technical Stuff:

How does radiation therapy work?

Cancer cells grow and divide more rapidly than many of the normal cells around them. High doses of radiation can kill cells or keep them from growing and dividing, and it has proven to be particularly effective in killing cancer cells and shrinking tumors. Although some normal cells are affected by radiation, most normal cells recover more fully from the effects of radiation than do cancer cells.

What is IMRT (Intensity Modulated Radiation Therapy)?

IMRT involves varying (or modulating) the intensity of the radiation (in this case, X-rays), being used as therapy for cancer. It is a new form of radiation therapy that uses computer-generated images to plan and then deliver more tightly focused radiation beams to cancerous tumors than is possible with conventional radiotherapy. With this capability, clinicians can deliver a precise radiation dose that conforms to the shape of the tumor, while significantly reducing the amount of radiation to surrounding healthy tissues. Consequently, the technique can increase the rate of tumor control while significantly reducing adverse side effects.

IMRT is a more precise form of radiation. It allows physicians to escalate the radiation dose to cancer cells, and in some cases, even more precisely to specific metabolically active regions within a tumor, while keeping the dose to surrounding tissues as low as possible. An analogy might be painting with a paintbrush as compared to using an airbrush and masking tape to protect outlying areas. The airbrush allows you to deposit variable amounts of paint in a highly controlled fashion. IMRT does something similar with radiation.

What kind of radiation is used in IMRT?

Currently, photons (X-rays) are used to deliver IMRT. The radiation is generated by a machine called a medical linear accelerator. This machine stands approximately nine feet tall, is nearly 15 feet long and can be rotated around the patient with great precision. Operationally, microwave energy, similar to that used in satellite television transmission, is used to accelerate electrons to nearly the speed of light. As they reach maximum speed they collide with a tungsten target, which in turn releases photons, or X-rays.

Very small beams with varying intensities can be aimed at a tumor from various angles to attack the target in a complete three-dimensional manner. In fact, IMRT can be delivered with beams the size of 2.5 x 5-millimeter pixels-the size of a pencil tip-each with varying intensity. The idea is to deliver the lowest dose possible to the surrounding tissue, reducing the chance of causing a radiation side effect, while still delivering the maximum dose to the tumor.

Does radiation therapy expose people to radioactive substances?

Many people, when they hear the word “radiation,” think immediately of radioactive substances. However, no radioactive substances are involved in the creation of X-rays or electrons by a medical linear accelerator. When a linear accelerator is switched “on,” radiation is produced and aimed directly at cancer cells. Then, like a flashlight, when the machine is switched off, there is no more radiation-none is “stored” or “transported.”

Personal experienced stuff:

Pre-Planing and Preparation?

Prior to the commencement of my 8 week treatment I underwent a procedure to place three gold seeds within the prostate gland. These seeds are solid gold, about the size of a grain of rice and are now a permanent fixture in my pelvis. Small tattoos were also inscribed, one on each hip and one on the front of the pubic bone. The gold seeds and  tattoos are used in setting up the machine at each session to align the body and tumour so as to administer the dosage correctly. The gold seeds show up very nicely on X-Ray results which are taken prior to each session and the tattoos are used with laser light precision to align the body.

The procedure to insert the gold seeds is similar to a method of prostate biopsy used, where an ultra-sound probe is inserted in the rectum and the seeds are injected via needles through the bowel wall into the prostate. This technique performed without anaesthetic is not one of my most fondest memories of treatment I have received so far along my pathway.

What are the treatment sessions like?

Prior to every treatment you have to ensure you drink at least 600ml of water at least 30 minutes prior to treatment and your bowels should be clear.

Stripped to your undies shirt and gown and entering the room, your eyes are drawn to is this huge machine dominating the scenery. You lay down on a flat bench with your knees over a padded block and your feet inserted into a cushioned block. Assistants then position your body on the bench using the tattoos and laser lights to align you correctly. The neck and head of the machine hovers over you like some alien being. As a matter of fact one of my grandsons summed it up nicely after I explained it to him when he said ” Pop it sounds what being abducted by aliens would be like. ”

The machine takes some X-ray pictures to ensure it is aligned with the gold seeds then proceeds to rotate around your body stopping every so often to radiate the area for seven segments in total. I felt nothing from the radiation and the treatment session takes about 30 minutes in my case.

Abducted by Aliens

What are the side effects like?

After only 3 weeks of treatment it is early days for any serious side effects to be happening, however I can report the following stuff that is beginning to show. I will follow this issue up more fully in my next post toward the end of my treatment.

I am back to urinating several times throughout the evening and with much more urgency throughout the day. I find I am planning my daily trips around the Sunshine Coast with public toilet access in mind. I am starting to feel the pain while urinating (only mild at the moment) that was so familiar and debilitating when I first became ill and after the TURP procedure in May .

My bowel habits have changed considerably with several visits to the loo at the beginning of the day and several more spread throughout the day. It is not like diarrhoea, nor like constipation, but more a lazy bowel motion and is just a nuisance at the moment.

Fatigue is still a major problem for me, but at this time I cannot say for certain, if I am more fatigued than normal as I am still on ADT treatment. Generally I will have a couple of short naps throughout the day and still manage to get to sleep by 9pm or 9.30pm. I am experiencing reflux constantly which is a real nuisance and I will be mentioning it to the doctor today.

To counter my fatigue and other issues I have begun walking approx 6km daily through to the beach and then take a swim in the surf trying to give myself some aqua aerobic exercises for leg strength. I have altered my diet slightly using probiotics and fresh fruit and cut down on my consumtion of red meat.

End of part 1

Lee aka Popeye

Written by Lee

9 November 2012 at 6:00 am