The Simulation

Three months have now gone by since I began my Androgen Ablation therapy. To date I have had no serious adverse reactions to this treatment. It will continue concurrently with the IMRT for another 3 months. My literary research has indicated that the treatment has probably shrunk my prostate to half of its original size by this time. In addition to starving the androgen dependent cancer cells, the smaller prostate will be beneficial during the radiation phase. This is due to the fact that it presents a more concentrated target and that the spacing between it and other organs, better kept from radiation, has increased. The normal distance between the end of the rectum and the prostate is about 1/2". Anything which permits better concentration on the prostate to the exclusion of the rectum, the bladder etc. would be highly beneficial. As I would learn today, 1/2" or 12.7mm, would seem like a mile to the precisely focused radiation beam.

This is my second visit to this facility and, as I sit in the small, third floor secluded waiting, area I am struck by an observation I first observed on my initial visit. That observation being that this does not seem like a hospital. There is not an endless stream of hospital personnel hurrying through the halls, there are no bells, chimes or calls for medical personnel. I seldom see another patient on this floor.

During both visits to this facility my path has never crossed with more than two other patients at any given time. I will learn today how remarkable this is. Considering the IMRT therapy alone, and there are other forms of treatment in progress, there are 5 3-D machines in use. Each machine has a total of thirty patients signed up for its use at 15 minute intervals. This continues all day long on a five day per week basis.

Combined with this are many patients undergoing initial testing and both men and women undergoing treatment for various types of cancer. I am told today that this facility has treated 11,412 patients with the 3-D equipment since 1990 and that I will be patient #11,413. This is a massive backlog of experience of course and one which spins off great masses of data which was used to develop the advanced procedure of IMRT to ultimate perfection.

The atmosphere one senses, while waiting in the pleasant waiting area, is one of scientific research facility. Along the corridors are various rooms, each neatly identified with small lettering and all with closed doors. Passing quietly down the corridors or working with their scientific specialty in each of the rooms, is a staff of young and vibrant medical and scientific personnel. This is a staff of the best and the brightest drawn from medical schools all over the nation. I would guess that the average age is in the range of midthirties to midforties. I have never seen any one person whom I would estimate was older than 55 although they must exist in some region of this facility I have yet to explore.

My thoughts touch upon the aspect that here are the children of my generation practicing the latest technology which will now save the generation of their parents.

I had an initial meeting with my radiation oncologist who wanted a report on my experience with the Hormonal Androgen Ablation treatment to date .I reported that I have had virtually no adverse side effects except perhaps some slight experience with hot flashes for 15 minutes or so shortly after I retire. I have been taking the Casodex at about 7PM each night - the Lupron shot continues to work its magic through the previous injection.

My doctor indicates that "You are lucky!". Some men report more severe response to the treatment with longer and more prominent hot flash episodes. I wonder if this is truly a side effect of the treatment or a personal response by individuals who are likely to cringe at any change in normal body chemistry or pain.

The objective of today's visit is to undergo the "simulation" which will provide data for the 3-D machine to do its work properly. I am led down one of the quiet hallways and behind one of the closed doors into a room which more resembles a room for advanced and specialized physics research. In the middle of the room sets a huge, black, machine which seems to be resulting from the marriage between a CT Scanner and an X-Ray machine. In front of the machine is a long sliding table which can be positioned to give infinite adjustments in body position to within millimeters. The identification tag on the machine reads simply "Simulator".

The lights dim in the room and an two women begin their well choreographed dance. As the room darkens I now see red beams of laser energy shooting from the walls and ceiling to converge on the table upon which I now lie. I am positioned into exactly The same position I will assume upon the IMRT machine. Lying face down I have my legs raised about 4" and placed on foam blocks. A wedge template is temporarily placed between my upper legs to produce an angle of about thirty degrees.

Small marks are made on my body - one behind each knee one by the outside if the right and left thigh, one on each side of my upper inside buttocks at the base of the spine and one in midback. Each of these benchmarks is now the target for one of the laser beams crisscrossing across the room in the darkness. Using these reference points, the position of my body is recorded with the precision of one millimeter in any direction - the thickness of the laser beam. Through all of this absolute stillness on my part is vital.

The two women then prepare to make a mold of my body. They take a sheet of thermoplastic about 3 feet square to which is attached a firm non thermoreactive edge on two sides. The sheet is then placed in hot water and becomes soft. The softened sheet is then placed over my back to cover an area between my lower back and upper thigh. The calibrating wedge between my legs remains in place. The softened plastic is then placed over my body by the two women feeling like a hot turkish towel. It is worked into place and conforms to the exact shape of my body. The two side edges, which contain about 8 - 1/2" holes are then formed into flanges and bolted down to the table. This will be the exact position my body will assume when I finally begin the 3-D treatment and it can be duplicated exactly in another room where the treatment will take place.

The mold is now removed but my body remains motionless with the red lasers assuring that all of the benchmark targets are still being hit perfectly. Each of the reference points on my body is then tattooed with a small permanent dot about the size of a pin head. A 35mm flash camera is then used to record the exact location of the tattooed marks in addition to the similar information recorded elsewhere. My body is now essentially calibrated so that it can be positioned to the EXACT same position during each of my subsequent visits.

While I am positioned on the "Simulator" My radiation oncologist makes an appearance. He advises me of something which gives further credence to the wisdom of having this type of treatment done by a facility which has thousands of prior patients - not simply hundreds - certainly NOT a facility just beginning the treatment. Remember, this cancer treatment facility has done over 11,000 of these treatments over 6 years. Yet the doctor has something to tell me which is the product of the ever changing base of knowledge being provided by the virtually endless stream of data accumulation being generated by case studies.

The normal treatment is 42 sessions. In my case that would amount to 75.6 Gray of radiation (7,560 Rads). It is well known that higher radiation levels lead to better cure rates but this must be tempered with great experience and precision to prevent collateral damage to nearby organs.

My radiation oncologist now reports that, within the last week, they have enough data to indicate that they can boost the radiation to 45 treatments or 81.0 gray (8,100 Rads) without increasing collateral damage. With patients having a PSA over 10 this assures even a higher cure rate. I give him the O.K. to proceed in accordance with the latest findings. My treatment will be on the cutting edge!

Having completed the calibration procedure, and mold making, on the simulator, I now am taken to another "laboratory" containing a Cat Scan and put under the supervision of two different young medical personnel.

The lights dim and I find that I am once again reclining in the same position as I had assumed with the simulator. The now familiar red lasers crisscross the room from the walls and the ceiling, the mold is refastened to my body and clamped down to the movable table which feeds into the CT Scan machine. My position is exactly identical to that I had taken earlier on the Simulator. It is absolutely imperative that I remain absolutely motionless during the 20 minutes that the CT Scan takes cross sectional pictures of my abdominal area. Following the session on the CT Scan I have an opportunity to discuss some of the technical background with the medical personnel - specifically, how this data is transferred into the IMRT machine.

First, I am advised that this facility will soon be combining the Simulator and the CT Scan in a single room. The patient will remain in position, on the table, after the Simulator and will be rolled to the CT Scan on a rail system so that repositioning will no longer be necessary. At present there exists no satisfactory way to transmit data from the CT scan into the IMRT machine. This is done by making photographs of the CT Scan data and then scanning them into the computer which controls the IMRT machine.

Once programmed into the IMRT computer, this visual presentation of my internal organs and prostate are studied by a physicist and my radiation oncologist . A consultation is then held between my doctor, the physicist, a computer programmer, and other pertinent staff members to plan a specific treatment program custom designed to my anatomy and my exact cancer geometry. The objective is to design a program which focuses the high radiation beam exactly where it is needed and to have it miss the areas where it could do damage.

Five planes of radiation will be oriented as follows:

While I am lying on my stomach the Zero Degree reference is a plane perpendicular to my back. My right side will be 90 degrees. My feet will be 180 degrees and my left side will be 270 degrees. The procedure being used in my case is called "Multiplanal". A more exact description might be "Pentaplanal Radiation".

The beam emits from a small rectangular shaped slot in the eye of the collimator which focuses the radiation. As the beam travels toward the patient it expands into an ever enlarging rectangular shape as the distance increases - much the same as a rectangular opening in the lens of a 35mm projector is seen on a screen.

Hence, the distance between the collimator and the patient becomes another critical variable. Surrounding the slot in the collimator are a number of shaping fingers which are computer controlled and which both shape and block radiation from undesired areas near the primary target

. So it is that the radiation filling the rectangular area, as it strikes the patient, can be shaped into any configuration, including cylindrical, and effectively blocked from striking organs which should be protected from the radiation. As I learned last week the radiation decreases in a gradient from the central target. It is therefore impossible to have a high dosage immediately adjacent to a very low dosage, but rather to reduce the damage to areas needing protection as much as possible.

The gantry, containing the collimator, swings in an arc to allow the radiation planes to enter the top, the sides, and the bottom of my body. Specifically, the angles of the radiation planes are: 225 - 285 - 0 - 75 - and 135 degrees. The amount of radiation along each plane may vary slightly but each plane delivers about the same radiation dose of 36 RAD (Radiation Absorbed Dose) for a total of 180 RAD per session (1.8 Gray). The computer has calculated the amount of radiation necessary to penetrate my body mass and to enter the prostate adequately from planes along all of the selected angles and still minimize exposure to other organs as much as possible. The radiation planes focus on the prostate as a common target and stops there.

Based on the data from the MRI, and various scans by the particle accelerator and x-rays, the computer has generated a hard copy color image of my prostate and has also overlaid all of the radiation fields from the particle accelerator. To view the printed image is the same as being able to see the combined effects of all five planes of radiation simultaneously and to see a cross sectional view of the prostate with all of the various segments of the radiation beams broken into sub fields which are quantified by the percentage of total radiation to be applied. All of this is presented in seven colors for easy interpretation.

Moving outward from the prostate in nongeometric shapes are wave forms which indicate radiation in five more decreasing levels down to 10%. The lower levels impinge upon organs for which minimal radiation is desired. So it is that you can actually see the well defined fields that the particle accelerator saturates with each treatment. Once a week a series of "films" or negatives is taken of the prostate using the same planes of radiation as the treatment itself to monitor that the desired pattern is being maintained. In a precision treatment like this great care is employed every step of the way to insure perfection.

Hence, the prostate itself is surrounded by a tight yellow circle which signifies that everything within that circle will receive the full 8,100 RADS or 100% radiation. Several small "islands" within the prostate itself are a darker orange which means they receive 107% or 8,670 RADS.

Now, the 12.5 mm between the top of the rectum and the prostate seems like a mile when compared to a precise and calibrated energy beam. Once the treatment procedure has been defined, it is placed before a review panel and approved. This custom designed procedure is then placed on a computer disk and will become the memory of the computer's brain as it controls the IMRT machine during my treatment. I will meet with my. radiation oncologist once a week to verbally discuss my treatment as it proceeds.

About two weeks will be required to formulate a treatment program for me. My next visit will be on April 10th 1997.

The specific program being designed for me is based upon a technological innovation within the existing technology of 3-D Conformal Radiotherapy. It is called Intensity Modulated Radiation and employs the delivery of different intensity levels within the intended target at which it is aimed.

During the next visit a computer program will be used to control a machine similar to the IMRT machine but one which uses low energy x-rays rather than high energy accelerated energy beams. With the completion of this "dry run" the computer program will be confirmed as will the other variables in the operation. Successful completion of the "dry run" will lead to finally beginning treatment on the IMRT machine.

That treatment will proceed 5 days a week for 45 sessions which will end in mid-June 1997. I had remarked to one of the medical personnel in the CT Scan room that it was important to select the best treatment facility available as well as the best possible form of treatment. "Salvage Operations" after an unsuccessful treatment by any method are either difficult or not particularly profitable. He assured me that after this procedure there would be no "Salvage Operation" since the success rate has been very high with over 11,000 treated at this facility and with still ever greater experience, gained along, the way the success rate should improve.

I am pleased that I chose this method of treatment and I am VERY impressed with the skill and precision of all the personnel I have dealt with so far at this facility. My personal respect for my doctor has been enhanced along the way on two fronts. (1) He is obviously a dedicated and brilliant young man (2) He has been able to maintain an excellent "common touch" with me - always treating me as an equal with respect and dignity. Our rapport grows at every meeting. Along the way I had met far too many doctors who thought they were special creatures, and that the patient was something less than an equal human being.

While riding back to my home on the train I reflected on an overview of what has transpired so far and my reactions to events of the past seven months since my last PSA test produced results of 15 - subsequently reduced to 10 by additional testing . Still - much too high.

It had been a long road to reach this point in my adventure. I had studied and had become very knowledgeable about prostate cancer and all the various forms of treatment. I had chosen the IMRT treatment because it appealed to me as the best form of treatment for my case while having the potential for the least negative side effects. My path had led me through two hospitals, several Radiologists, four different Urologists, and countless tests. There was the ever present digital rectal exam (D.R.E) which seemed to almost take the place of a handshake whenever I encountered a new doctor. There was the repetitive blood testing. There was the Bone Scan and the MRI which was like riding in a steel drum with someone pounding on the outside with a hammer. Finally there was the "Simulation" and the CT Scan.

I am sure that patients look at all of this from different points of view depending upon their own background. To some it is little more than one unpleasant experience after another. To someone with technical, scientific, or engineering training, it is nothing short of fascinating. My personal training and experience, not to mention scientific curiosity is making this a most fascinating adventure. I have had training or experience in most of the disciplines I am now encountering including: engineering, physics, mathematics, computer technology, radiation, and plastics technology. So it is that I see each of these experiences as a dance of scientific precision and fascination. I see the laser beams tracing specific angles throughout the air in a darkened room as a three dimensional problem in trigonometry or analytic geometry reminiscent of two dimensional problems I have solved before. I understand the photography and imaging required. As well, I appreciate the computer technology involved. At the base of all of this is the biochemistry involved with the hormonal therapy and the biology of the cancer itself.

Combining all of these in an adventure in which YOU are involved and are literally betting your life, is a fascinating experience.

As the train rumbled along toward home another vision appeared in my mind. On this visit to the New York facility I had gained entrance to some of the inner sanctum. I had experienced things behind some of those closed doors. However, I had yet to see the greatest machine of them all - the IMRT machine.

While the Linear Accelerator is a fascinating piece of machinery, it is the carefully crafted computer program, assembled by skilled doctors, engineers, physicists, and scientists, and based on data input from the patient's work up, that works the wonder of treatment here. This program gives the Linear Accelerator the ability to send out precise beams of radiation in an infinite number of different directions, to focus these beams, to modulate them, and to control them precisely through undulating and masking fingers which are computer controlled in the eye or collimator of this amazing machine.

The simulation will provide information to the computer detailing the exact position of the prostate, seminal vesicles, rectum, and bladder. This information will be used to determine how the radiation beams should enter the body, as well as the shape of the beams. The radiation will be given from a rotating gantry which transverses an arc of 180 degrees. The program is designed in such a way as to permit the beams to bypass the critical organs, as much as possible, but yet converge on the prostate to form a high dose region. As many as 16 distinct and separate beams will be controlled by the computer during this operation.

On April 10, 1997 the "Dry Run" took place. By this time, the results of the Simulation had been evaluated by a team of Radiologists, Medical Oncologists, and Physicists. The x-rays from the Simulation plus the previous MRI studies were used to devise a computer program which would be custom designed to treat my specific prostate cancer. The treatment which will be based on exact quantitative, targeted radiation and the determination of proper angles for the radiation beams to strike the prostate while minimizing damage to the adjacent organs.

This program is then copied to a 3 1/4" floppy disk which controls the operation of the particle accelerator, the collimator which focuses the particle beam, and the gantry which controls the angle at which the radiation beams enter the body.

During the dry run all the systems are in place and I am positioned on the table, face down, under my custom built mold. The computer program operates the system, but only low powered x-rays are used to check out the accuracy of the computer program.


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