Introduction
Newly diagnosed prostate cancer is not a single disease but a spectrum
of diseases ranging from very low-risk, prostate-confined variants up
to high-grade disease that has already spread outside the prostate. In
Part One of this series, Risk Category staging was explained in careful detail.
This article (Part Two) will define treatment options for patients with
the earliest stage of disease, patients with Risk Category IA; these
are the patients who have less than a 10% chance of microscopic spread
of cancer to a location outside the prostate. Part Three will define
treatment options for patients in higher risk categories, i.e. those
who have a greater than 10% chance of microscopic spread of cancer to
a location outside the prostate.

Reprinted from Part one
Side-Effects, Not Survival
Risk Category-IA (RC-IA) patients have such a long prostate-cancer-related
survival expectation that it is virtually impossible to claim that one
form of treatment will make a patient live longer than any other. A good
example of this is the experience of Drs Blasko and Grimm from a seed
implant series in which 125 patients were implanted with radioactive
seeds between 1988 and 1990. The majority of men in this study had RC-IA
disease, but there was also a significant minority with RC-IB disease.
(RC-IB means that the risk of micro-metastasis ranges between 10% and
25%). In this study, ten years after the implantations, 15% of the men
had suffered PSA relapse. None of these 19 men who relapsed had died
of prostate cancer ten years later; men with low-grade disease tend to
have few relapses; the rare individuals who do relapse have low grade,
slow growing relapses. Even in the rare cases when there is concern
about more rapidly progressive disease, hormone
blockade can be initiated with very prolonged (>10 year) responses.
As yet, there is no proven survival difference for RC-IA patients regardless
of the treatment selected. This is not to say that all treatment options
are equally well suited for all patients. Issues such as the side-effects
of treatment, age, sexual functioning, preexisting prostate problems, and
personal preference are all relevant in the decision-making process. Since
personal preferences carry a great deal of weight in this process, patients
themselves have to be well informed about all the treatment alternatives;
after all, only the patient himself can factor in his own personal life-style
preferences and his own quality of life related goals and then render a
final decision about the treatment best suited to him.
Presently all the prostate cancer treatment options have drawbacks. Using
a shopper’s analogy: nothing is free; you can only aim to get the
best deal available. Good shoppers comparison-shop trying to get the best
quality item for the lowest available price. Treatment quality relates
to cancer control rates. Treatment “cost” relates to side-effects,
especially permanent ones.
Therefore, the aim of this article is to be informative and descriptive
so that men contemplating therapy for Risk Category IA disease can be
introduced to the advantages and disadvantages of seven of the possible
treatment
choices. Treatment options for men who fall into higher Risk Categories
will be the subject of Part Three of
this article.
The seven treatments options that will be discussed are:
1. Deferred therapy (previously known as watchful waiting)
2. Androgen deprivation therapy (ADT)
3. Brachytherapy (Seeds)
4. Surgery (radical prostatectomy)
5. Intensity modulated radiation therapy (IMRT)
6. Cryotherapy (Cryo)
7. High Dose Radiation (HDR) Monotherapy
1. Deferred Therapy
Watching cancer without treatment has long been a standard approach in
the very elderly. One advantage of watchful waiting is that delaying
treatment affords the possibility that improvements in future technology
may lead to more effective, less toxic alternatives. Hence, it would
seem that waiting for better, less-toxic treatment makes sense if it
is not too risky to wait. There are logical reasons to consider that
deferred therapy in younger, good-risk (RC-IA) patients might be safe;
small amounts of lowgrade prostate cancer are known to be present in
30% of the general population over age 50. In the great majority,
the disease remains dormant for life. Modern ultrasound-directed biopsy techniques are detecting more and more of these low-grade variants; too
often, this leads to unnecessary treatment that places men at risk for
the toxic effects of such treatments.
Studies of men with low grade disease show that they rarely develop detectable
metastasis within 10 years of diagnosis even though these were studies
of men with higher than risk category IA disease. More recent studies
of the deferred therapy approach indicate that careful surveillance with
intervention at the first sign of progression may be a safe approach. Presently
the only way to find these non-progressing patients is by selecting men
with low-grade disease and closely monitoring them to see which individuals
will evidence tumor growth. If there is no evidence of growth, presumably
there is no need for invasive treatment.
However, because of the risks associated
with delaying treatment in more aggressive forms of prostate cancer,
selection criteria for deferring therapy
should be stringent; it is a fundamental error to mistakenly assume that
a high-grade tumor is low grade. Men with RC-IA disease who have any
of the following conditions are not the best candidates for deferred therapy:
- Gleason
score > 6
disease
- More than one core biopsy
positive
- More than 50% involvement of a biopsy core with cancer
- PAP elevated
above the normal range
Potential watchful-waiting candidates should be screened for more advanced
disease missed on initial biopsy. Imaging techniques such as spectrographic endorectal MRI or high-resolution color
doppler ultrasound can help
confirm that the cancer is indeed small. Not everyone with good biopsy
results has small-volume disease. Imaging techniques may also be helpful
when used along with PSA and digital
rectal exam to monitor for any evidence
of tumor progression. When there is ambiguity regarding tumor status, a
repeat biopsy can be considered.
A new nomogram has been developed at Memorial Sloan Kettering that appears
able to predict the presence of a small, insignificant cancer with 82-90%
accuracy. This may offer RC-IA patients an additional tool to help decide
when deferred therapy is a reasonable option.
Deferred therapy is usually implemented along with substantial dietary
changes. Low-fat and low sugar diets help impede prostate cancer progression.
An excellent book on the topic of diet and cancer is Verne Varona’s
work, Nature’s Cancer Fighting Foods. (Prentice Hall 6/2001, ISBN
0130170879)
Deferred Therapy
Advantages
1. No toxic side-effects
2. Technological advances may lead to less toxic therapy in the future.
3. May motivate positive diet or life style changes
Disadvantages
1. Requires close surveillance
2. Psychological struggle of “living with cancer.”
3. Dietary discipline is required
4. The risk of delaying treatment has not been well quantified
|
2. Androgen Deprivation Therapy (ADT)
Traditionally, androgen deprivation therapy (ADT) has been reserved for
the advanced stages of prostate cancer, after it has metastasized to
bone. The benefits of ADT have also been documented in localized prostate
cancer. ADT induces prostate cancer cell death via a mechanism called
apoptosis, which is automated cell death (cell suicide). All the cells
of the body contain suicide genes that can be activated under different
circumstances. For example, white blood cells that fight infection only
live about 8 to 10 days before initiating apoptosis, dying, and making
way for new more vibrant cells to carry on the fight. Apoptosis occurs
in prostate gland cells and prostate cancer cells when the quantity of
androgen (testosterone) drops below certain levels in the blood stream.
When used in the context of prostate cancer, the term “Androgen
deprivation therapy” describes treatment to reduce the activity of the male hormone, testosterone.
Testosterone is a hormone secreted into the blood by the testicles
(and to some degree the adrenal glands). Testosterone causes secondary
male characteristics such as muscle and hair growth, increased
libido, and the enlargement of sexual glands and organs. The prostate exists
in a vestigial state before puberty and will not develop without the large
increase in testosterone blood levels occurring at puberty. Therefore,
the cells of the prostate gland are inordinately sensitive to the presence
or absence of testosterone in the blood. This sensitivity can be exploited
advantageously as a therapy for prostate cancer because prostate cancer
cells are derived from the prostate gland and retain the need for testosterone
to remain viable. This need for testosterone is unique to prostate cancer,
and it is almost universally present when prostate cancer is still in its
early stages.
The amount of cancer cell death from ADT in early-stage prostate cancer
is usually dramatic. On rare occasions, no cancer at all can be found in
the surgically removed prostate glands of men who underwent surgery after
ADT. More typically, there is a drastic reduction in the number of cancer
cells, but not total elimination. Androgen deprivation therapy also appears
to have the ability to put some prostate cancer cells to “sleep.” What
all this means is that the effect of ADT on different cells in a prostate
cancer tumor can be variable; many of the cancer cells are killed, but
others are simply inhibited from growing.
Modern testosterone-blocking medications work by three primary mechanisms.
LHRH agonists such as Lupron
or Zoladex are injectable hormonal analogs that reduce luteinizing hormone
(LH) causing the testicles to stop testosterone
production. Anti-androgen blocking agents such as Casodex, Eulexin and
Nilutamide are medications in pill form that work by blocking access of
testosterone to androgen receptors located inside the cancer cell. Five-alpha
reductase inhibitors such as Proscar and Avodart block the conversion of
testosterone into dihydrotestosterone, which is a much more potent form
of testosterone. These three classes of therapeutic agents can be used
either by themselves or in combination. The advantages and disadvantages
of using agents singly or in combination in early stage disease are too
extensive to expound in detail in this short article. Suffice it to say
that one typical protocol we use for newly diagnosed patients is administering
one drug from each class for about one year.
In our practice, we stop ADT treatment after a year of therapy, except
for ongoing suppressive therapy with Proscar or Avodart. Proscar and Avodart
have minimal side effects, and we have found that they can be very effective
at inhibiting the rise in PSA after the ADT has been stopped. We recently
evaluated the results of using Proscar in our practice and found that men
treated with Proscar remained off Lupron an average of three times longer
then men who did not use Proscar.
One concern that is repeatedly raised about the use of ADT for early stage
patients is the potential for developing hormone resistance. Studies show
that even when ADT is administered to patients with higher risk categories
than IA, hormone resistance within five years of starting treatment appears
to be a very rare event.
Side-effects of ADT are common but can be controlled. Once treatment is
stopped, testosterone levels recover and side-effects are reversed. While
a patient is on treatment, however, a number of potential side-effects
have to be addressed and counteracted with medications or exercise, as
shown in Table 2.
Table 2. Treatments for ADT Side-Effects
| Side Effect |
Treatment* |
| Osteoporosis (the loss of calcium from the bones) |
Can be prevented with once a week administration of Actonel or Fosamax |
| Hot flashes |
Can be treated with Effexor, Neurontin, or Megace |
| Joint pains |
Joint pains Respond to Celebrex and glucosamine |
| Muscle atrophy and tiredness |
Can be prevented with strength training |
| Emotional swings |
Reversible with low doses of Paxil or Zoloft |
| Impotence and penile atrophy |
Can be reversed with Viagra |
| Anemia |
Reversible with synthetic erythopoetin (if it occurs) |
* There is no effective treatment as yet for loss of libido (loss of sexual
desire). The potential for weight gain can only be handled by a low calorie
diet.
Androgen deprivation therapy can be a first step for some patients who
are undecided about what form of local therapy to choose. Early in the
treatment, a patient’s PSA response and his experience of its side-effects
can allow a first-hand evaluation of the effectiveness and tolerability
of the treatment. If side-effects prove unacceptable, therapy can be stopped.
Androgen Deprivation Therapy (ADT)
Advantages
1. Has an anticancer effect in the prostate and also in the rest of the body.
2. Is the only treatment proven to prolong survival.
3. Side-effects are reversible when therapy is discontinued.
4. Can improve the cure rates of other treatments if local therapy is later
selected.
5. Prostate gland shrinkage may lessen some side-effects of local treatments
if local treatment is later selected
Disadvantages
1. Suppressive not curative so requires ongoing surveillance.
2. Reduces or eliminates libido (sexual desire) while on treatment; diminished
libido can persist after ADT is stopped.
3. Treatment may have to be repeated at some point in the future.
4. May reduce potency rates if subsequent nerve sparing surgery is performed.
5. Dry orgasms while on treatment with slow recovery afterward.
6. Loss of muscle strength, can be offset by strength-training exercises.
7. Weight gain, which can be offset by dietary discipline.
|
Local Therapies
There are five commonly used
local therapies for prostate cancer: Brachytherapy, Surgery, Intensity
Modulated Radiation Therapy (IMRT), High Dose Rate
temporary seeds (HDR), and Cryosurgery. The term local therapy describes
treatment that has an effect only in the prostate gland. Such treatments
make sense in patients with Risk Category IA disease because there
is less than a 10% risk of the cancer being outside the gland. The
only
reason for hesitation with these alternatives relates to their potential
for permanent side-effects.
There is one other concern with local therapy that needs emphasis. Good
local therapy to the prostate, i.e. therapy that minimizes the chance for
side-effects as much as is humanly possible, can only be confidently obtained
at select centers of excellence. None of the statistics quoted going forward
from this point are in any way relevant outside of this imperative. There
is even a large difference in quality between academic physicians from
world famous institutions. This means that it is not enough to go to the
best institutions; one must seek out the best physicians at the best institutions
if one plans to replicate the statistics we are quoting. The quality
of the physician determines the outcome.
3. Brachytherapy (Implanted Radioactive Seeds)
In Brachytherapy treatment, radioactive seeds are implanted in the prostate
gland. These seeds, which emit radiation over a short, measurable distance
can, if properly localized, be used to increase the total dose of radiation
to “cancer fatal levels” without affecting the surrounding
tissue. Fortunately, the prostate gland itself is a non-essential organ
and can be sacrificed (although this results in dry orgasms). Massive
doses of radiation carefully applied throughout the gland will destroy
it (and any cancer contained within it) but will spare the bladder and
rectum that are in close proximity.
The advances in localizing technique that have developed over the last
15 years are the real reason brachytherapy has come to the forefront as
a leading option for control of localized prostate cancer. Figure 2 illustrates
how the modern technique of implanted radioactive seeds accomplishes consistent
spacing and a high dose of radiation spread evenly throughout the prostate gland.

Figure 2. Seed Implantation into the Prostate. With the patient lying
on his back, tiny catheters are guided into the prostate via a template,
in which the pattern of holes has been specifically chosen for the patient.
Radioactive Iodine or Palladium seeds are then pushed through these catheters
into target sites of the prostate. Above photo shows the seed used for
implantation in comparison to the tip of an index finger.
The dose of radiation delivered is so intense that over a period of time
the prostate gland is “vaporized.” The amount of radiation
administered in external beam equivalents is thought to be about 10,000
rads! The destructive force of this high dose radiation is well demonstrated
by digital prostate exam a year or two after treatment. No prostate can
be felt!
The main side-effect of concern from brachytherapy is radiation effect
on the urethra, the small passageway that carries urine out of bladder,
through the prostate, and out the penis. The urethra gets a maximum dose of radiation because it is in
the center of the prostate. The side-effects of radiation on the urethra,
termed urithritis, can include any of the following symptoms: urgency to
urinate, painful urination, urinary frequency, slow urination, and occasionally
complete blockage of urination requiring the temporary placement of a catheter to drain the urine. About two-thirds of men, treated with brachytherapy
have short-term symptoms of urithritis that last a couple of months after
the implant.
Short-term symptoms can usually be endured. Of greater concern are the
5-10% of men who have symptoms lasting up to a year, and occasionally longer. Certain
medications such as Flomax and Celebrex can reduce but not eliminate these
symptoms. Men with larger prostates and men with preexisting urinary symptoms
are at much greater risk. However, there is no way to accurately predict
who will develop long-term effects.
Another potential side-effect of brachytherapy, indeed all forms of radiation,
is called the PSA “bump” phenomenon. The PSA “bump” is
a delayed PSA rise occurring after the radiation finishes. Although the
exact cause of PSA “bump” is not known with certainty, it is
believed to result from irritation of the residual prostate gland by radiation.
The “bump” follows a benign clinical course and usually resolves
itself within a year. The main danger of the PSA “bump” comes
when physicians mistakenly conclude that the rising PSA represents recurrent
cancer and decide to start ADT when no cancer is present.
Brachytherapy (Implanted Seeds)
Advantages
1. High cure rates are comparable to those of Surgery and IMRT
2. Established track record of effectiveness
3. Convenient one-day out patient administration
Disadvantages
1. Short-term urithritis in two-thirds of patients
2. Long-term urithritis in 5-10% of patients
3. Impotence rates comparable to those of surgery by the very best surgeons
4. Skill procedure necessitating application by a top-flight specialist
5. PSA “bump” can cause confusion about cancer relapse
6. Dry orgasms for life
7. Can aggravate preexisting problems with urination.
8. Not appropriate for men with excessively large prostates though this problem
can often be rectified with short-course hormone blockade
9. Not usually the best option for men who have been previously treated with
TURP
10. Treatment of local recurrences, should they occur, is difficult, and there
is a high risk of permanent side-effects |
4. Surgery
The advantage that surgery has over the other treatment options is its
ability to accurately determine the extent and grade of the cancer. Needle
biopsies only provide a sampling of the cancer while surgical removal
of the gland allows the whole cancer to be thoroughly evaluated. Surgery
provides information about tumor size and aggressiveness by looking for
the presence or absence of invasion into or through the capsule of the
prostate. Also, by examining the whole tumor, pathologists may discover
areas of high-grade disease that may have been missed by a random needle
biopsy.
The improved staging information obtained via surgery can engender new
questions in the process of treatment selection. A small minority of properly
staged RC-IA patients will be found to have higher-grade disease after
surgery. Findings such as positive surgical margins or seminal vesicle
invasion are indications of a substantially increased risk of future relapse.
This surgically obtained information can be valuable for making timely
decisions about further anticancer treatment while the cancer is still
at an early stage.
Judging the value of this higher quality staging information is difficult.
Recent studies have shown that biopsy inaccuracies can be minimized by
using more thorough biopsy techniques. Better imaging studies with color
Doppler ultrasound or spectrographic MRI also improve preoperative staging.
Even so, it is clear that none of these techniques can match the ability
of a trained pathologist who does a careful microscope review of the surgically
removed gland.
Surgery has some side-effects distinctive from the other treatment options.
Incontinence (urine leakage) is more frequent with surgery than with other
treatments and occurs in 5-8% of men treated by top-flight surgeons. The
severity of incontinence is variable and many men can handle the problem
with a pad. Severe cases of incontinence may need surgical correction with
the placement of an artificial sphincter, a surgical procedure that is
usually successful when performed by qualified experts.
Scarring and blockage of the urethra (urinary passage) also seems to occur
about 5% of the time. This problem usually responds to periodic stretching
of the urethra with dilators inserted though the end of the penis but on
occasion the scarring progresses into an intractable problem that can result
in incontinence. A detailed review of radical prostatectomy was recently
published in Insights.
Surgery
Advantages
1. High cure rates comparable to those of Seeds and IMRT
2. Provides the best staging information and as such may signal a need for additional
treatment with radiation or hormone blockade when the disease is more advanced
than what had been estimated from the needle biopsy.
3. Recurrences are detected early and without ambiguity (no risk of PSA “bump”)
4. Established track record from large institutions
5. Local recurrences easier to treat than with the radiation recurrences
Disadvantages
1. The option most dependent on the excellent skills of the doctor
2. With even the finest surgeons, the impotence rates are comparable to those
of seeds or IMRT treatments
3. Like any major surgery, it has attendant risks of bleeding, infection, blood
clots, etc
4. Some incontinence in 5-10% of patients
5. Urethral stenosis in 5% of patients (scarring and blockage of the urethra)
6. Risk of penis shrinkage in about 50% of patients (shortening from 0.5 to 4cm)
7. Dry orgasms for life
8. Requires placement of a catheter for first week or two after the surgery
9. Post-op pain syndrome occurs in a minority of patients (<5%)
10. The frequency of side-effects increases sharply in men over age 70 |
5. Intensity Modulated Radiation Therapy (IMRT)
Intensity modulated radiation therapy (IMRT) is the latest and most developed
form of external beam radiation available. IMRT is a third generation
form of external beam radiation that is the culmination of an evolutionary
process starting with the old four-field beam radiation techniques that
later evolved to second generation three-dimensional conformal radiation.
IMRT represents an advance over these previous techniques because it
does the best job of delivering high uniform doses of radiation to the
prostate while sparing the bladder and rectum.
IMRT accomplishes this feat by modulating the intensity of the radiation
beam over the width of the beam (see Figure 3). Such modulation is necessary
because the prostate is a spherical target. When a beam of radiation is
used, the thicker, middle portion of the prostate needs relatively higher
doses of radiation to penetrate the gland fully, whereas the thinner, peripheral
part of the gland can be covered with smaller amounts of radiation. Only
IMRT can modulate the intensity of the beam to make allowance for these
anatomical realities.
Figure 3. Intensity Modulated Radiation Treatment (IMRT). Thousand
of tiny “beamlets” from multiple directions; highest
doses to target with greatest sparing of normal tissue.
Unfortunately, because the anterior rectal wall is so close to the prostate,
a small portion of the rectum has to be included in the radiation field.
This means that a small minority of patients will develop proctitis, a
non-healing radiation burn of the rectum. However, IMRT has the lowest
incidence of proctitis of all the forms of beam radiation. Symptoms of
proctitis vary but can include rectal urgency, pain, bleeding, and incontinence.
There are some medications that can reduce the symptoms of proctitis, but
nothing cures the problem. Severe bleeding problems, should they occur,
can usually be controlled with laser therapy. Men who develop proctitis
often adhere to strict diets attempting to minimize irritation to the rectum.
Urithritis is also starting to be reported more frequently as the doses
of radiation are escalated above 8000 rads. At doses around 7800 rads,
as is typically being administered in the community in 2003, the incidence
of long-term urithritis is very low. Impotence occurs with IMRT at a rate
similar to well-performed surgery or seeds. The onset of impotence may
be delayed for several years. Short-term effects of IMRT also occur, but
are milder than the other treatments. There is some risk of urinary and
rectal irritation for a month or two. Energy levels may also be reduced
for a similar period.
Intensity Modulated Radiation Therapy
(IMRT)
Advantages
1. High cure rates comparable to those of Surgery and Brachytherapy
2. Fewest short term side-effects of all the local options
Disadvantages
1. Requires 5-day-a-week presence at a specialized site for two months
2. A skill procedure requiring application by top-flight physicians using the
latest
technology
3. Impotence rates comparable to surgery by the best surgeons
4. Risk of long term Proctitis (rectal burn) is approximately 5%
5. More radiation to the lower body, bladder and rectum than implanted radiation
so may be less desirable in men in younger age groups
6. PSA “bump” can occur
7. Dry orgasms for life
8. Short-term hormone blockade may be needed to shrink an enlarged prostate
9. Treatment of local recurrences is permanent and difficult, and has a high
risk of side-effects |
6. Cryotherapy
Cryotherapy has developed into a favored method of treating men with local
relapse after radiation, but it is also be used in men with newly diagnosed
disease. Cryotherapy has the advantage of a short hospital stay as well
as being a treatment that can be repeated if necessary. Performed under
either general or spinal anesthesia, the Cryosurgery procedure itself involves
the controlled freezing of the gland in order to destroy both the prostate
gland and the cancer it contains. Four to eight Cryo probes are introduced
through the perineum (skin surface between the rectum and scrotum) and
advanced to pre-selected locations in the prostate gland using ultrasound
guidance. After a warming device is placed to protect the urethra, the
freezing process begins by circulating liquid Argon through the probes
resulting in the formation of an ice ball that encompasses the whole gland.
Two cycles of freezing and thawing constitute the treatment. After the
probes are removed, the patient is discharged the next morning with a Foley
catheter that remains in place for two to three weeks.
The complications of cryotherapy are dependent on the skill of the cryotherapist.
A conservative estimate of the most common side effects was reported by
six prominent cryotherapists in 2001. In that study, 93% of men became
impotent, 7.5% became incontinent, 13% needed a transurethral resection
to clear out dead tissue, and one half of one percent had the dreaded complication
of a fistula connection between the bladder and rectum. However, this study
probably overestimates modern complication rates because the article included
statistics from patients who were treated in the early years of cryotherapy
development.
Cryotherapy
Advantages
1. Minimally invasive: no blood loss and no surgical incision
2. Cure rates comparable to those of surgery and radiation
3. Can be performed as an outpatient under spinal anesthesia
4. Can be repeated if there is local recurrence of cancer
Disadvantages
1. Requires excellent physician skills for consistently good results
2. Has the highest propensity for impotence (85-95%)
3. Requires a catheter for a few weeks after treatment
4. Sloughing of dead prostate tissue may require transurethral surgery for treatment
in 5-10% of cases
5. Short term hormone blockade may be needed to shrink the prostate prior to
cryotherapy in cases where the gland is too large
6. The risk of incontinence, even in the best hands, may be as high as 5%
7. Post-operation pain syndrome occurs in a minority of patients (<5%)
8. Published data documenting long term outcome is limited |
7. High Dose Radiation (HDR) Monotherapy
High dose radiation, otherwise known as temporary seeds, has been used
since 1980 but has been traditionally offered only in conjunction with
external beam radiation. HDR monotherapy is a newer approach that involves
two separate implants, thereby forgoing the external beam radiation portion.
This newer approach, termed a tandem implant, or HDR monotherapy, is an
attractive option for Risk Category IA patients as it avoids the low-dose
radiation exposure to the pelvic organs caused by the beam radiation.
Theoretically, the advantage of HDR over brachytherapy is that the doctor
performing HDR has the capacity to alter the radiation dose during the
course of treatment. Thus, the argument in favor of HDR is its flexibility
in controlling the dose and location of the radiation. In theory, then,
an attempt can be made to steer the radiation dose away from the urethra,
the structure most at risk from high-dose temporary seed radiation.
The procedure itself involves the placement of small hollow plastic tubes
through the perineum into the prostate. Ultra high intensity radioactive
seeds (iridium 192) are pushed into the tubes. The seeds are only left
in place for only a matter of minutes. This process is repeated on three
separate occasions over a 24-36 hour period. Historically, the implant
has been routinely followed by five weeks of external beam radiation, and
there is convincing literature documenting the effectiveness of this older
approach to control cancer.
The tandem, or monotherapy approach substitutes a second implant applied
a week to a month later in place of the external beam radiation. However,
there are not as yet any studies definitely proving that HDR monotherapy
reduces urithritis. Clearly, the procedure is attractive on paper and is
quite likely to be effective in RC-IA patients. Even so, there are still
no published studies proving the effectiveness of this newer approach.
High Dose Radiation (HDR) Monotherapy
Advantages
1. Theoretically may have best chance for limiting side effects such as urethral
damage because the radiation dose can be “fine-tuned” during
the procedure
Disadvantages
1. Tandem implants are an unproven, relatively new development with no published
literature quantifying effectiveness or side effects
2. Requires uncomfortable immobilization during two hospitalizations
3. Skill procedure necessitates topflight application
4. Risk of radiation-induced urithritis
5. Impotence rates probably similar to surgery by the best surgeons but no statistics
are available
6. Potential confusion about relapse from the PSA “bump”
7. Dry orgasms for life
8. Can exacerbate preexisting urinary symptoms
9. Short-term hormone blockade may be required to shrink the prostate
10. Local recurrences would be difficult to manage |
General Comments
Age is a major factor in determining treatment; very old men can easily
be managed with watchful waiting since there is no early mortality for
RC-IA patients. On the other hand, IMRT may not be the best option for
very young men since there are other treatment options that avoid exposure
of the pelvic organs to radiation.
The characteristics of the prostate gland itself can make certain local
treatment options less attractive; men with very large prostates, excessive
urinary problems, or a previous history of prostate surgery for a benignly
enlarged prostate risk greater side-effects with brachytherapy. An enlarged
prostate can be reduced with 3-6 months of ADT if brachytherapy is strongly
preferred, and ADT side-effects are less when it is only administered for
3-6 months. Even so, long-term effects on libido can occasionally occur.
Quality cancer staging is fundamental to prostate cancer treatment. Biopsy
techniques, Gleason scoring, and prostate scanning can be misleading when improperly
performed. Suboptimal staging risks under-treatment of high grade disease.
As was previously stated, the quality of the physician determines outcome.
Summary
After they review the pros and cons of all different treatment options,
many men logically conclude that they personally have several plausible
options. Relatively small issues such as ease of administration may surface
as the most important factor in the treatment selection process. There
would be little controversy about treatment if a completely non-toxic
option existed. Unfortunately, all the effective treatments have some
negative aspects and no single treatment stands out as being clearly
better or worse than all the others; since there is no single, medically
preferred option, the onus for treatment selection inescapably remains
with the patient. .
Part 1 deals with
diagnosis and risk category staging.
Part 3 deals with
higher risk of disease at diagnosis.
References
1. Grimm PD, Blasko JC, Sylvester JE, et al. 10-year biochemical (prostate-specific
antigen) control of prostate cancer with 125I brachytherapy. Int. J.
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