Me and the Machine

Collimater--the EYE of the machine
All images from: Bing Images
There are only Seven Cyber-Knife Machines in North Carolina.
 

On a recent Thursday in my life, I took a ride in a wheelchair through the basement level of the hospital where I receive treatments for my disease. I can walk, but because of hospital safety rules I rode. Through hall after hall, a young woman pushed me. The rhythmic tapping of her shoes allowed me to feel the passing of each of the 360 seconds that it took to reach the room for my turn with the life extending Cyber-Knife machine.

Light beige walls, polished floors, a black phone and a red one decorating a few otherwise empty walls were added to my memories of what it is like to be a cancer patient. With every change in direction, I saw another hallway. I passed rooms with closed doors, rooms with open doors. Quick glimpses allowed me to see other people sitting, waiting. I was struck by how odd the eeriness of each quiet hallway felt. It made me question whether I was riding toward the extension of my life or toward my departure from it.

I wished I would have been allowed to walk. It would have helped distract my thoughts away from the unknown before me; it would have lessened my fear about what was happening inside my body. With no systemic treatment since September 8th, I was feeling completely vulnerable to my tiny monsters. Thankfully, TDM-1 has a long half-life meaning it continues to stay active in the body for weeks after treatment.

My chair ride came to a stop momentarily inside a narrow room. To my left were several computer monitors. In a split-screen format, one of the monitors provided a view into another room. That room held my future with this disease. After giving my name and date of birth, the woman pushed me farther out of this room and into the other. Before me, in a room with no windows, was the Cyber-Knife machine.

I arose from the chair and was dressed in a special vest that would soon have probes attached to it to monitor my breathing. After placing myself in a vertical position on the table in the middle of this room, nestling into the mold made especially for me, I was told not to move at all--don’t scratch, don’t wiggle, stay-put. The two technicians soon departed leaving me alone. Now, it was just me and the machine.

In the quietness of the room, I had only my brain to entertain me. I added more memories to my on-going story as I took surveillance of the room. My sight was limited since I wasn’t supposed to turn my head. Despite this, I managed to see the machines important in this treatment.  Near the ceiling, two cameras were attached, one in front of me, the other to my right. Those allowed the technicians to view me and the objects in the room. A red beam of light painted the ceiling perpendicular to my body. It extended between two ceiling-mounted machines. Those were the x-ray machines. Every 60 seconds a picture would be taken to keep track of the four gold fiducial markers inside and surrounding my tumor ensuring the Cyber-Knife machine sends radiation to the desired location.

My study of the room was soon interrupted by a clicking noise. The machine was coming to life.  I followed the robotic arm as it moved the emission head up, down, sideways, closer to and farther away from my body. The machine located every physicist directed and computer calculated angle as it prepared to shoot the light beams into my tumor. Luckily, my healthy tissue radiation exposure would be limited; the greatest concentration of radiation would occur where each beam crisscrossed all others.

The emission head housed a metal attachment called a collimater. The tiny orifice in its middle measured 15 millimeters. I know that because of the carved out number with the mm beside it. Later a different collimater with an orifice of 10 mm would replace the existing one. Those holes determined the size of the photon beam penetrating my body. I learned from one of the technicians that--in my case--two were used so every area of the tumor was radiated. Let me take a moment to explain by using this example: Pretend my tumor is a golf ball. The larger sized beam stamps a 15 mm diameter sized beam all over the outside. As you know, when four circles are pushed beside one another there is a place in the center that remains untouched. That is why a second beam is needed. The machine shoots those beams at all the places around the golf ball untouched by the first beam.

I watched as the tiny black hole moved around my chest. The movements would end abruptly and then ever so slightly continue to move correcting its position as I breathed. A high-pitched humming noise let me know the machine was fully prepared to begin shooting invisible x-rays through my tumor’s cells causing their demise. It was a weird and wonderful at the same time.

What is actually happening in my body during this treatment is interesting. I have done a lot of reading and had a conversation with one of the technicians handling my treatment in an effort to grasp the simplified version of how this process works. The more detailed version involves quantum physics. I will not venture there. If I get something wrong, please let me know in the comments.

Bing Image below

Photons are light particles that make-up different electromagnetic waves. In my case, x-rays are used. These waves are long enough to penetrate my tissue and reach my tumor. The photon particles are energized inside the linear accelerator at the end of the Cyber-Knife’s robotic arm. These highly-charged particles penetrate each cell in the path of the beam—the good and bad ones. Once inside, they change the atoms within the cell by taking away one of their electrons. This creates an ion. That is why it is called ionizing radiation. The chemistry change of the atoms disrupts cellular function. It destroys proteins and damages the DNA of the cells. As the cell continues through the phases of rest, growth, and division, it is halted at the division phase and the cell dies--apoptosis. That is why this treatment continues to work weeks and months after completion. I don’t have to tell you how good that is for the patient.

Initially, after treatment, I felt no pain. But after the second session when I breathed deeply or when I attempted to sleep on my right side, it hurt. In the morning I felt no more pain only tightness around the radiation site.The evenings after the rest of the treatments, I experienced pain only when I laughed. It, too, was gone by the morning.

There were a total of five treatments (fractionated-a lower dose at each treatment) altogether. My last one was yesterday. I feel like I am radioactive and a danger to my family. I asked about that and was told not to worry.

The last few weeks I have spent considerable time driving east and west on I-40. It will be good to get back to the routine I have grown accustomed to of infusions every three weeks. For now, my encounter with the machine has reached the end.

On Monday, I will begin treatment again with TDM-1. On that day I will be told when my next scan will occur. Until then I will continue to remain hopeful that this treatment will get my condition back to “no evidence of active disease”.

Note: I asked how it is determined if future cancers were caused by the radiation a person received. The answer was not as easy as I anticipated thinking there would be a cellular identifier in the cancer indicating its type. Apparently, it is not always completely clear if the cancers are caused by the radiation. But, cancers that occur years (10-15) after radiation in the position where the radiation occurred are considered a result of radiation. Typically radiation is avoided in young children because their life expectancy is far longer than someone of my age. At my age and diagnosis, it is definitely a risk worth taking. 

Cyber-Knife to the Rescue!

Fiducial Markers and Cyber-Knife Preparation

Cyber-Knife Bing Image

Four in the morning has never been a good time for me to start my day. But, when I have a 2 hour and 15 minute drive before an important appointment, I manage to spring out of bed without hitting the snooze button on my alarm. Such was the case on an early October Friday a couple of weeks ago. Why I was wide awake and jumped out of bed as quickly as I did, making it out the door earlier than expected, had everything to do with GOLD. In the dark, my husband and I began our westward trip on I-40 to Chapel Hill.

We sailed smoothly into my 8:00 am appointment for the processing of paperwork and for my physical preparation for the fiducial markers placements. All the steps needed for this procedure were happening quickly. But, then it wasn’t. Everything slowed to--what felt like--a stopping of time. I reclined on a gurney, my husband--i-Pad in hand-- in the chair beside me. We waited . . . and waited. It was well beyond my scheduled time before I was pushed to the room where the procedure would take place.

A nurse did arrive that day, pushing me to whatever room I was destined for. As the wheels on my gurney rolled, she asked how I was. I replied, “Not dying as long as there are options.”

“Never heard that one before,” she said.

In the room at last, I moved my body onto a table where the procedure would take place. I was strangely calm. In the past, my body has visibly shook from the terror inside me that I could not control. On this day, I did not need a “calm me down drug”.  As I said, I was strangely calm.  I believe the familiarity of lying on a table with people moving around me going about their particular roles is not as frightening to me anymore. It has become all too commonplace. 

Once secured on the table, pictures were needed of my lung, so through the big white doughnut scanner I went. It was quick and easy.

Next, since the procedure was occurring to my right lung, I was placed on my left side. It was not the most comfortable of positions—right arm resting on the side of my head, left arm tucked along the left side of my body. I looked forward. My eyes immediately caught the image of my lung with the circular white spot clearly visible. There was a black line pointing to the spot with a measurement of 6.99 cm labeled on the screen. That was the distance the needle was going to penetrate my body in order to reach my tumor. 

The awareness of my surroundings ended as soon as I felt the sedation taking me away to nothingness.

So much time went by before I regained complete consciousness, but of course I didn’t know this until I was told. I learned that when the needle entered the plural cavity that surrounds my lung, a pressure change occurred, air entered that space and my lung collapsed—a pneumothorax. Upon hearing this, I was having no difficulty breathing so I thought, “All must be fine.” It was—now. Since my lung collapsed, a chest tube had to be inserted allowing an exit route for the air so my lung could re-inflate. My lung didn’t cooperate completely. There remained a small pneumothorax. Thankfully, the procedure continued. While in recovery, I had two more x-rays done over a two hour period—of which I mostly slept--before it was decided it was not necessary for me to spend the night in the hospital.

In the middle of all that waiting for my lung to recover, I threw-up. The first time was rather comical. The first x-ray was about to be done via a traveling machine. The technician had placed the machine outside my recovery station. I must have just awakened because I remember looking toward her and saying, “Oh no”, I feel sick. As I tried to delay the actual act of throwing-up, the x-ray tech could only offer me a trash can. A trash can! Can you believe that? In a hospital, I was offered a trash can. What is even more maddening is this: after being questioned about medications by the in-take nurse updating my information in the computer when I first arrived, I told her I will throw-up when given any kind of anesthesia. She made a note of it. Only later did I discover that no one took that seriously. I was not given an anti-nausea medication. My husband said that in the beginning of my recovery, one nurse handed my care off rather abruptly to another nurse—no idea why. Maybe she had to go to the bathroom. The new nurse asked me if I felt nauseated. I said, "No." The medication to relieve nausea was placed on the table beside me and was left there clearly not doing me any favors.  Wow, thanks! I warned someone this was going to happen. It seems pretty important to pay attention to a patient that says they throw-up especially when the procedure they are undergoing involves being stabbed in the lung. Patient neglect is simply not cool.

Through another bout of throwing up—this time in a more appropriate receptacle—I learned that 4 gold flakes had been placed inside my tumor increasing my total worth. Four, because these fiducial markers will sometimes dislodge and move to new locations because of the lung’s continuous motion.

Fiducial marker placement is necessary in Sterotactic Body Radiotherapy (SBRT) done by a Cyber-Knife machine. Though I didn’t witness my procedure, I imagine it went something like this: A needle was inserted creating a path to the tumor. Then a guide wire with the gold flake on the tip was pushed through the tube and into the tumor. The guide wire was then pulled back out, prepared with another flake and re-inserted. When the flakes were in their places, the needle was removed. Blood from my own body was injected into the area. I am guessing that helped with clotting.

After I was given the “OK” for release, the chest tube was removed from my side. I was bandaged-up, and we headed home. What a day it was. I missed most of it even sleeping on the trip home.

Simulation For Cyber-Knife Radiation
On the following Friday I had the simulation for Cyber-Knife treatment done. A mold of my body was made so I wouldn’t move during the radiation procedure. Another scan was done so the final measurements could be calculated. Those measurements insured the least amount of damage to my healthy tissue from the radiation. The gold (metal) flakes will be the beacon for the machine. The radiation beams will hit my tumor killing every single tiny monster housed within--I hope.

I can’t wait. It starts this Thursday!  


For those who want more information about this treatment please go to:

UNC Cyber-Knife Center, Department of Radiation Oncology

http://www.med.unc.edu/radonc/patient/treatments/ck

and http://www.radiologyinfo.org/en/info.cfm?pg=stereotactic

What equipment is used?
There are three basic kinds of equipment, each of which uses different instruments and sources of radiation:
1. The Gamma Knife®, which uses 192 or 201 beams of highly focused gamma rays all aiming at the target region. The Gamma Knife is ideal for treating small to medium size intracranial lesions. See the Gamma Knife page for more information.
2. Linear accelerator (LINAC) machines, prevalent throughout the world, deliver high-energy x-rays, also known as photons. The linear accelerator can perform SRS on larger tumors in a single session or during multiple sessions, which is called fractionated stereotactic radiotherapy. Multiple manufacturers make this type of machine, which have brand names such as Novalis Tx™, XKnife™, Axesse™ and CyberKnife®. See the Linear Accelerator page for more information.
3. Proton beam or heavy-charged-particle radiosurgery is in limited use in North America, though the number of centers offering proton therapy has increased dramatically in the last several years.
See the Proton Therapy page for more information.