PROTON BEAM TREATMENT OF PROSTATE CANCER
By David Krieg
Contents
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Introduction: The intent of chapter
I hope that every man who looks at my website, and their loved ones, will at least scan this article. Please read note if you wish to make a copy.
I was diagnosed with prostate cancer (adenocarcinoma) in October 2006 and began treatment in January 2007. My treatment is with a form of radiation: a high-energy proton beam. I scarcely knew anything of this kind of treatment prior to my diagnosis. The major reason I am writing this chapter in my website is that proton beams may be more or less unknown to most of my friends and even to many of your doctors. I believe proton beam therapy has unique advantages over the many other treatments available, and should be considered by anyone with prostate cancer. To learn about it, you may have to search out the pertinent information yourself. For most prostate cancer patients I believe it offers a cure rate as high or higher than other treatments and does so with little or none of the unpleasant side-effects associated with other techniques.
Prostate Cancer and its Detection
Prostate cancer is the second leading cause of cancer death in men and the reported incidence is rising. It is surpassed only by lung cancer. It usually occurs in men over 50, but it can occur earlier. It usually develops slowly; many men who have the disease die of some other, unrelated cause before the cancer has significant effect on them. But for those who die of the disease, it is not a pleasant way to go.
The cancer can be detected early, even before there is any obvious symptom that the man is aware of. Under these conditions, the cure rate is highest and the treatment is easiest and most trouble-free. The five-year survival rate after treatment is virtually 100% for those men whose cancer had not spread beyond the prostate gland. A report from Harvard states that the five-year survival rate for the 31% of patients whose cancer had spread only to tissues around the gland is 94%. In about 11% of the diagnosed cases, the cancer has spread to other parts of the body and the five-year survival rate is only 31%. It seems obvious that regular checkups are desirable so as to permit early treatment.
Indicators used in routine annual medical checkups with your family doctor are DRE and PSA. DRE is the digital rectal examination: When the doctor inserts his finger into the rectum he can feel parts of the prostate and make conclusions as to its size, firmness and regular consistency. Certain departures from the general observations may suggest the possibility of prostate cancer and lead to more definitive tests. It is not definitive, however: sometimes enlargement is benign, not involving cancer. Sometimes cancer is present but not detectable by the DRE. The PSA test is quantitative and more reliable. A small sample of blood is drawn from the arm and a biochemical analysis is made for “Prostate Specific Antigen.” This is normally produced by the prostate gland and present in the circulating blood at a concentration less than 4 unit/ml, often under 1. Cancer cells derived from prostate cells lead to higher amounts of PSA in the blood, for instance 4 or more units – sometimes over 50 units. It is highly desirable that certain precautions be used in the timing of when blood is drawn for a PSA. Sex, bike-riding, the DRE exam and certain other activities during the 3 days prior to drawing the blood may lead to elevation in the PSA level that is spurious and not indicative of cancer. Ask your doctor in advance; not all doctors point this out to their patients. Finding progressively higher PSA results in repeated tests can be more definitive than the magnitude of a single “border-line” reading.
A biopsy is the most definitive diagnostic tool, but it is not normally employed unless the DRE and PSA indicates its pertinence. It is much more elaborate and a rather uncomfortable experience but it allows the actual observation of cancer cells. The experience differs somewhat depending on the doctor performing it, I will describe briefly what I experienced and comment on possible differences. A probe is inserted into the rectum; it contains small sensing device and extraction device. The first allows the doctor to see (on an outside display) an image so he can position the extraction device precisely. The latter extends a needle through the wall of the rectum into the prostate gland. A small sample “core” of prostate tissue is then drawn into the needle and ends up in a vial for laboratory inspection. Since this is only a sample from that particular spot, the needle is repositioned to take additional samples. The more samples, the less likely that the procedure misses a highly localized cancer in a limited region of the gland. In my case the doctor took 12 samples from widely different parts of the gland. I have heard that some doctors take only 6 cores; I consider that too few. Some take 20 samples. I have heard that some doctors do the biopsy without an accompanying note-taker or with limited apparatus and have to remove and reinsert the probe from the rectum after each sample. This greatly lengthens the procedure and compounds its unpleasantness. The patient might wish to ask the doctor in advance of his practices and consider seeking another doctor if he does not like the answer.
My indicators, in case anyone is interested, were:
DRE: Enlargement was found over six years ago and little change found in subsequent annual exams.
PSA: near 10 in three tests over the last year: 10.7 and 10.3 in June and 9.6 in January.
Biopsy: 3 of the 12 cores taken were found by a pathologist to have cancer cells.
Further measures, explained below:
Gleason Score: 3 + 3 = 6
Stage: T1c
American Urological Association Questionaire Score: 23
Gleason Score is a subjective classification by the pathologist of the degree to which the appearance of the cancer cells differs from normal cells. Briefly, two groups of cells are given a rank on a scale from 1 to 5; both my groups were ranked 3. This helps the doctor decide the probability that the cancer has spread beyond the prostate; my results indicated it was almost certainly still localized in the gland. My stage: T1c was another way of expressing that conclusion. The patient also fills out a questionnaire concerning various symptoms relevant to prostate problems, such as urgency, ease and frequency of urination. For instance, I reported going 4 times nightly. My total score of 23 out of 35 was a bit on the high side.
How often should PSA be tested?
Most doctors recommend PSA be measured annually in men over 50 years of age. However, if a man’s father or brother experienced prostate cancer his risk is statistically higher and warrants earlier regular testing. Certain racial and ethnic groups (for instance Blacks) have a higher incidence that also warrants earlier regular testing. Younger men might be tested at less frequent intervals.
A personal note: The reason I did not have annual PSA tests despite having an enlarged prostate is a bit complicated and I now regret it. It appeared that my enlarged prostate was benign and slow-growing. At my advanced age it was not unreasonable to guess that I might die of other causes before ever being troubled by cancer. Moreover, I WRONGLY imagined that the problems often associated with common prostate cancer therapy (such as urinary incontinence and impotence) might be almost as unpleasant as the cancer it prevented. I contemplated the prospect of using a catheter the rest of my life and did not like the idea.
I now realize that Proton Beam treatment can be effective while involving side-effects that are usually only minor, temporary and/or non-existent. Cures are most effective and trouble-free when the cancer is found early, so I now firmly believe in and recommend regular PSA testing.
Treatments to Cure the Cancer
The treatments most commonly used for prostate cancer include: surgery, various radiations from an external source, and brachytherapy. I will give my opinions on them very briefly, but refer you to some references at end of this chapter for more authoritive details.
Removal of the prostate is major surgery. Doctors often consider it too traumatic and risky for patients that are elderly and/or have had heart problems or other severe illness. Cancer cells will be missed in cases where they have spread beyond the gland. Severing of nerves in/near the prostate leads to debilitating results.
“Da Vinci” surgery is a recently developed form that employs special miniaturized tools for imaging and cutting, and may have advantages in removing targeted cells while sparing other nearby structures. I know virtually nothing about it, but presume it still has some of the risks common to surgery and can miss some cancer cells.
Hormonal treatment should perhaps be mentioned, but my understanding is that it does not destroy cancer cells but instead limits their growth. I think it is used primarily to reduce the size of an enlarged gland before other treatment is used to eliminate the cancer, or sometimes to retard the growth of cancer that has spread so widely beyond the gland as to make other treatments impractical.
Brachytherapy (implantation of radioactive seeds within the prostate) appears to have certain advantages. It involves surgery but apparently not as major as removal of the gland. Radioactive material is inserted once and left there. Other forms of radiation treatment usually require numerous repeated doses that may be regarded as inconvenient. The rate at which the seeds emit radioactivity decreases steadily; for instance when an isotope is used that has a 60-day half-life, after sixty days it is 50% as radioactive as at the start, after 180 days is still 12% as radioactive, and after a year is still slightly over 1% as radioactive. However, there are disadvantages that I consider important. It is said that side-effects on the urinary system can be more severe than other ways of delivering radiation, probably due to considerations of geometry resulting in higher doses to the urethra, which passes through the center of the prostate. The most scary thing about brachytherapy, in my opinion, is the report of the radioactive seeds often not staying in place and migrating to other parts of the body or even being transferred to one’s sexual partner during intercourse. Results with brachytherapy vary a lot depending on the particular doctor’s expertise and experience – more so than in the case of external beams of radiation.
X- and Gamma Radiation are commonly delivered from a source external to the body. The beam enters the body at one spot, is aimed at and goes through the prostate gland and exits the other side of the body. Radiation impacts the body all along the beam, most intense at the point of entry and gradually diminishing. The cancer can be destroyed but other tissues also may be affected, hence producing side-effects on the GU (genital-urinary) and GI (e.g., rectum) systems. In computer-assisted, conformal methodology, the treatment is broken up into a number of smaller doses (e.g., 5 days a week for a total of nine weeks). The entry point is varied and the beam is aimed at the target from varied angles. This reduces the exposure in each of the “non-target” organs, relative to the target, but does result in distributing radiation exposure over a considerable area. This imposes a limit on the total dose that can be safely given to the patient’s tumor.
Proton Beam Radiation is also delivered from an external source, but uses charged sub-atomic particles which have some special properties compared to X- and Gamma radiation. The amount of energy transferred from the beam to the body is relatively small where it first enters the body, gradually increases and then peaking at the end of the beam. (This is known as the “Bragg Peak,” named after a physicist who worked on it many years ago.) Tissues beyond the peak are virtually untouched. The peak can be so sharply focused and the distance between entry point and peak so precisely chosen that the dose is delivered to a much more precisely defined volume of the body – sparing other nearby organs. In a further effort to minimize side effects, the patient gets his treatment in many (commonly 44) daily exposures, not all entering the body at the same point. So as to hit any cancer cells that had spread only a short distance from the prostrate gland, the target includes the region up to a half inch around the gland. The early studies verified the expectation that side-effects were reduced, compared to X- and Gamma radiation, and led to trying total doses about 10% higher. That resulted in still higher cure rates with no appreciable increase in side-effects.
I explain all these details in the effort to make clear the theoretical basis of how Proton Beam treatments can permit higher doses with higher cure rates while reducing side effects. As a former physics major who had some graduate study in radiation biology, I see that it makes sense in theory and having read some scientific publications from the doctors who used and evaluated it, I see that it works out in practice.
The machinery needed to produce and control proton beams is big and expensive. Three stories deep underground and $100 million to construct. Proton beams are currently in use medically at three locations in the USA, of which Loma Linda University Medical Center was the first built in a hospital (others were in physics research labs) and its staff has the most experience. They have treated over 10,000 cancer patients since 1991. Its success is becoming recognized and more are being planned or under construction throughout the country. Prostate cancer accounts for most of the applications, but it is also used on many other kinds of cancer whose location is deep, sharply defined and near other critical tissues.
Most patients here report that their family doctors and even local urologists seemed unaware of proton beam therapy or said it is too experimental or otherwise dubious and discouraged patients from using it. This ignorance is unwarranted and should not discourage cancer patients from seeking further information.
As a final note, I should mention that although it would be more expensive than other treatments, it is covered by Medicare and by many supplemental insurance policies. Help is available in getting coverage in cases where a company first denies coverage.
My situation at end of treatments.
To read my graduation talk at the support group, click here. As I write this, I have just completed my prescribed 44 treatments. I have not had any pain or debilitating side-effects. There has been some increase of frequency and urgency of urination, but not severe or leading to lead to embarrassing episodes. I continue to “go” about 4 to 6 times nightly on the average and that is expected to decrease soon. Bowel activity is also somewhat similarly increased, but not a serious problem. Semen is not now being produced by the prostate but potency and orgasm is still possible and enjoyed. My energy level may be slightly reduced, but not enough to prevent my enjoying a weekend at the San Diego Animal Park and another at Indio's Date Festival (like a state fair).
Post-treatnent Update:
My PSA five months after treatments ended was 1.24. I was pleasantly surprised, since I had been told it might be a year before it reached 1 and the nadir usually requires a couple of years.
As to side-effects: Potency (using Viagra) was sort of 50-50 before treatment and somewhat less certain now. I am about to try an alternative to Viagra. Frequency of night-time urination has decreased toward "normal" but I continue to use Flomax.
Some details for those considering treatment.
Treatments generally require being in the hospital more than about 45 minutes each. This includes about 2 minutes beam time, 10 minutes preparation and the rest in the waiting and dressing rooms. Preparation involves lying in a hospital gown on a custom-fitted cot (referred to as a “pod”) that allows the technicians to position the patient exactly so as to get the beam in the right place. Precision is further assured by x-ray guided positioning before the treatment beam begins. My treatment appointment varied from day to day, generally between 5 pm and 8 pm. The center works from 6 am to 10 pm. Some cases (like mine) are routine but treatment of other types of tumors, especially in children, are more complicated and their duration unpredictable – hence their difficulty in giving us a fixed, predictable appointment. Patients who would like an earlier schedule so as to be free the rest of the day can usually get a consistent morning time.
Before we first arrived at Loma Linda,, my medical records were forwarded to a committee of doctors who jointly decided on the most appropriate treatments. Then Anne and I had a consultation with my doctor and his nurse assistant. They reviewed my case and their judgment with us, patiently answering all questions. The first consultation was followed by a CAT scan to precisely locate the gland, then a “fitting” in which my personal pod was tailored to my body dimensions. The nurse gave a general orientation about Loma Linda facilities and referred us to another staff member whose job is to offer all kinds of practical help, e.g., discounted car rentals and cards admitting us to the cafeteria, university library and the recreation center. The latter features a nice big swimming pool and hot tub, exercise equipment and outdoor and indoor running tracks. Anne has enjoyed daily water aerobics classes.
The university and medical center was created and maintained by the Seventh Day Adventists, a protestant Christian denomination. I feared that I would be subjected to proselytizing but that has not happened. The only odd thing has been that the cafeteria food is entirely vegetarian. We have been very pleasantly surprised by the fact that all the doctors and other staff are not only impressively competent professionally but also seem to be genuinely caring about the patient’s welfare and comfort. There are weekly meetings of an evening support group, plus potluck dinners and group outings to local restaurants. Morale is very high among the patients and spouses and people joke about it being a country club rather than a hospital.
Loma Linda is near San Bernardino in southern California, about 60 miles east of downtown Los Angeles. It is a few blocks from Interstate 10. The most convenient airport with commercial flights is in Ontario, CA. The climate is generally mild, but since it is inland and a near-desert it gets colder and hotter than on the coast. The population density is not as intense as in LA, and traffic is significantly easier to cope with. The medical center has staff that helps people find temporary housing during their stay. We used Mission RV Park, less than 4 miles from the hospital and a 12 minute bus ride. From Loma Linda one may reach Palm Springs and other tourist attractions in an hour or two of driving.
People may visit the center to learn about it, may attend a Wednesday evening meeting of the support group to hear from patients and may even seek a consultation with a doctor without making a commitment they will be treated here. The doctor’s income does not depend on your possible treatment and I have heard it said that his advice is objective and he will recommend treatment other than proton beam if he sees that your case warrants it.
Final Remarks
This report is probably longer than it should be, but my remarks are far from complete. If you are personally confronted by prostate cancer you should find out a lot more. My comments are not intended as conclusive, comprehensive information – aside from encouraging regular check-ups, I primarily want to be sure you have heard of proton beam treatment and its possible advantages and to encourage you to find out more and consider it. I think it would be a mistake to rely on the advice of only one doctor, who may understandably direct you only to the kind of treatment he performs.
I would be happy to try to answer any questions you wish to send me. Of course, I am not a medical doctor and cannot make judgments on any particular medical issue, but I am willing to offer an opinion on some general issues and to help direct you to other sources.
Further reading
www.llu.edu/ptoton is a website from the Proton Treatment Center at Loma Linda University Medical Center.
www.protonbob.com is a website from a group of former patients who wanted to keep in touch to compare outcomes and now offers a variety of help to prospective patients. That includes advice on successfully pursuing an appeal if an insurance company turns down coverage of proton beam treatment.
YOU CAN BEAT PROSTATE CANCER, a book by Robert J Marckini (2006). The author was successfully treated about 5 years ago and wanted to help others share his experience. It has far more detail than my report and cites many other resources. Although he is an engineer and MBA – not a medical man – his book has been reviewed and endorsed by professionals. It also chronicles his personal experience in a light, interesting manner and includes testimonials from other patients. I recommend it highly. It might not be easily available at a bookstore but can be purchased from the website www.protonbob.com It costs $20, with any profits going to medical research.
LLUMC Proton Treatment Center: Four Proton Programs – a 45 minute DVD including 3 short excerpts from TV news coverage on ABC and NBC plus a lengthy presentation depicting the construction and operation of the Loma Linda proton treatment center. Available from the center.
A 2-page layman’s condensation of a scientific article from Loma Linda summarizing five years of their proton treatments of prostate cancer is available from Loma Linda.
The following articles are in scientific, medical journals. You might be able access an abstract or the full article at http://www.llu.edu/proton/physician/prolit/index.html or, if you wish to read one of these and do not have access to the above or a medical school library, I might be able to send you a copy.)
Proton Therapy for Prostate Cancer: The Initial Loma Linda Experience, by J. D. Slater, et al. in Int. H. Radiat. Oncol. Biol. Phys. vol 59 pp 348-352 (2004). This gives details on success rate for a large number of patients based on 5 years or more of follow-up. Briefly discusses the low rates of morbidity. Since it is not ethically justifiable to inflict routine biopsies on men who appear clinically free of cancer, in this and other such studies success is defined by finding PSA to be low and not rising. Of the few thus classified as not a success, many are actually not experiencing any relapse or symptoms.
Comparison of Conventional-dose vs. High-dose Conformal Radiation Therapy in Clinically Localized Adenocarcinoma of the Prostate: a Randomized Controlled Trial, by A. L. Zietman, et al in JAMA vol 294, pp 233-1239 (2005). This report was jointly prepared by doctors at Harvard and Loma Linda. It documents that dose levels could be safely increased from those originally used, and thus give a higher cure rate.
Clinical Applications of Proton Radiation Treatment in Loma Linda University: Review of a Fifteen Year Experience, by Jerry D Slater, MD. inTechnology in Cancer Research and Treatment, vol 5 #2, pp 81-89 (April 2006). Written by the head of the department, it summarizes work on a variety of tumors.
Note
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