Hi my name is Mack Roach,
and I'm a Professor of radiation oncology and
urology at the University of California, San Francisco.
I'm going to talk about radiation for prostate cancer.
I'm going to try to keep it as simple as possible.
Radiation has been used to treat prostate cancer
for more than a hundred years.
It's used to treat a variety of cancers with cure,
everywhere from the head and neck,
brain tumors, lung cancers,
breast cancer, gynecological cancers,
and it's very effective.
The side effects of radiation everywhere are
related to the dose and the volume that are received.
The advances that have occurred over
the last hundred years
have mostly been about being able to
more accurately align the radiation
and minimize the dose to the surrounding normal tissue.
The technology has evolved and I will share with
you some slides here, just a few.
We basically either use linear accelerators.
This is an example of a linear accelerator here
or we use brachytherapy.
The term brachytherapy refers to placement of
seeds directly in a target.
Or we use something like a CyberKnife device,
which is essentially
a compact linear accelerator mounted on
a robotic device that allows us to use hundreds of
beams to deliver radiation
accurately while tracking the patient.
When we do radiation,
we try to maximize the dose to
the prostate and minimize
the dose to the surrounding normal tissues.
This is an example on the left of a CyberKnife treatment.
On the right high dose-rate brachytherapy,
which is also called a temporary implant.
In distinction to a permanent implant,
we place radioactive seeds
in the prostate and leave them there.
The temporary implant involves placing
catheters and connecting it to a robotic device,
delivering the radiation,
and then pulling the catheters out.
Again, the complications are
related to the dose and volume.
What we've tried to do with the CyberKnife is to recreate
the same dose distribution and give
the same doses that we would give with brachytherapy.
But you don't need to have
the anesthesia and you don't need to
have all of the needles stuck in the prostate.
For some of my patients, this is preferable.
It has been compared with IMRT.
I think this comparison is a little bit dated because the
stereotactic body radiotherapy that I use that term
interchangeably with CyberKnife because
that's the type of machine I use,
but you can use a linear accelerator instead,
is more convenient for patients,
we used to use fourteen treatments with
IMRT and now I use four or five treatments.
But the SBRT, stereotactic body radiotherapy,
it's a lot more convenient for
patients and it's actually much less expensive.
The acute side effects tend to be slightly
higher because you're giving
a high dose in a short period of time,
but I think that long-term,
the side-effect profile is similar.
In patients who are obstructed,
that is patients who have locally advanced
disease and are having trouble voiding,
I really prefer SBRT as the treatment of choice.
Now there's been a proliferation of
proton machines around the country.
This shows over time how the first twenty years
ago there were only a handful of centers
and now there are many.
The question is, are they better?
There's no good evidence that they're better.
This is a comparison done at Harvard looking at
the doses to normal tissues
and the prostate in which you can see,
you get a sense that the red area,
which is the high dose area,
this is the prostate and the rectum.
But what you see is the blue
is scattered low dose radiation.
When you use protons, in this case,
they're only using lateral fields
that actually looks like there's more red,
but there's lot less blue.
In fact, the authors
concluded that in the range of 6,000,
the IMRT achieved
significantly better sparing of the bladder,
whereas the rectum was similar with protons.
I'm not going to talk about
the direct comparisons or
surgery versus radiation at this point,
except that you have to be
careful when you read papers that talk about
survival differences with surgery versus
radiation because of
major differences in patient selection.
This is a study that was done years ago where they
tried to adjust for all the variables that they could.
What you can see is a patient,
they had a radical prostatectomy.
They had a higher survival than
people that did not even have cancer.
When you consider the differences between the two,
it's difficult to use that kind of information.
In the limited number of
randomized trials that we have for example,
the protects study,
the ten-year survival rates were superimposable.
Both surgery and radiation
reduce the risk of
metastatic disease in a similar fashion.
In general, continence tends to be
better with radiation.
Rectal injury and rectal irritation
tends to be lower with surgery.
Sexual function is controversial,
but I think that it tends to be better with radiation.
I think that the single most important piece of
equipment and when a patient gets radiated is
the doctor and proper use
of the technology that people have available.
There are many areas where there's controversy.
For example, I personally don't use
SpaceOAR and others do.
Even at my institution,
it is available at UCSF.
But if you look at
the statistics regarding the complication,
reduction, and the risk,
I don't think that the benefits outweigh the risk.
I have serious concerns about
the methodology on which the FDA approval is based.
In patients who have locally
advanced and high-risk disease,
we recommend long-term hormone therapy.
In patients who have what we call an
unfavorable intermediate risk prostate cancer,
we generally recommend
short-term hormone therapy,
meaning four months,
and that hormonal therapy is
typically well-tolerated and certainly for
the short term and
plays an important role in
improving the effectiveness of treatment.
Again, increased frequency burning on urination,
irritation of the urethra,
occasionally urinary tract infections
which are easily managed.
These are all common side effects that patients may have.
We recommend aggressive management of
erectile dysfunction during the treatment and afterwards.
Patients tend to respond very well to drugs like
Viagra when they have
compromised sexual function after radiation.
Again, there's no good evidence
that proton radiation is better.
I think that brachytherapy and stereotactic body
radiotherapy are both at
least as good in terms of treatment,
but proton beam radiation may improve with
advancements in technology that
are being studied now here and elsewhere.
It's been a pleasure serving
UCSF as a radiation oncologist for 30 years
now and I hope that you've found
my relatively informal commentary to be useful.
Thank you for your attention.
Thank you, Dr. Roach.
I'd like to first pitch a question to you,
and if Dr. Feng is present, we're
privileged that we actually have two
radiation oncologists for this session.
The first question to you Mack that was asked in
an earlier section, which is,
is BPH a factor in
the effectiveness of external beam radiation therapy?
Is there ever a role for
a transurethral resection of
the prostate prior to radiations?
I will add, is there a role for giving
the hormones in advance to shrink the cancer?
All are asking the question of
volume and how that affects your approach.
Those are all great questions.
I've been accused of never
recommending a radical prostatectomy to patients,
but that's not actually true.
Bases that have very strong urinary symptoms
or large prostate,
we use a metric called the IPSS,
the International Prostate Cancer Symptom Score
or the AUA symptom score.
If a patient has severe obstruction
due to benign prostatic hypertrophy,
I think those patients are better
served by a radical prostatectomy.
We used to routinely get people hormone therapy to shrink
their prostate for BPH if they had obstructive symptoms,
but I really don't do that anymore.
I think it's probably not the best strategy,
so surgery would be
a good option for such a patient as opposed to radiation.
A question just popped up,
the opposite of the technology, CyberKnife.
Is that used for less aggressive tumors only or would you
contemplate that in
a very aggressive large high Gleason score tumor?
As mono therapy that is CyberKnife for loan by threshold
is favorable intermediate risk prostate cancer patients.
For patients with unfavorable intermediate risk,
I usually will add
hormone therapy and external beam radiation.
Rather than four treatments for a favorable patient,
I will give two treatments for
an unfavorable patient followed by pelvic radiation.
I prefer to do the CyberKnife first
and that can be a 15 minute talk.
It's not going to be today, but I
prefer to use combined therapy.
Some patients though,
I will choose to do only CyberKnife and
a short course of hormone therapy
after the CyberKnife treatment.
Got it. Essentially the take home
for people is CyberKnife is very focused.
That's its attribute and
if you have to worry about the whole pelvis,
CyberKnife is not the way to go at it,
you really need to think if there's lymph nodes involved.
Felix are you present?
I'd like to ask you how you use,
to tag into your earlier talk,
decipher in clinical practice to decide,
for example, who should get hormones with the radiation.
It's a great question.
Patients of low-risk prostate cancer we don't
give hormone therapy to when we give radiation,
we just give radiation alone.
For favorable intermediate risk prostate cancer,
if you didn't have decipher,
you would also just give radiation alone.
Unfavorable intermediate risk,
you would give radiation hormone
therapy for, and high risk,
you would definitely give radiation or
hormone therapy for it.
I think the studies would suggest that
the Genomics Core is probably
the most powerful predictor of aggressive disease.
All of a sudden if I have somebody who has
favorable intermediate risk prostate cancer
with a really high decipher score,
I'll consider adding on hormone therapy.
Conversely, if they have
unfavorable intermediate risk prostate cancer and this
is somebody I would have normally given
hormone therapy too if their decipher scores really low,
I'll be biased against hormone therapy.
Again, I always discuss this with
my patients and this ends up being
a joint decision in
the setting of you trying to understand
the patient preferences and then helping them
align their personal preferences
to the information at hand.
Thank you. Mack,
if you're still present, I have
one more question for you and then we'll move on.
Dr. Carol alluded to ''The
controversy'' around active surveillance
in African-American men,
I'm wondering if you could just give
your perspective on not just active surveillance,
people have talked about adverse outcomes of
definitive local therapy in African-American men,
what's your take on that?
That's a great question too.
One of the problems with the literature is that
everybody doesn't do active surveillance the same way.
You have institutions like UCSF and
Johns Hopkins and places in Canada where people
do active surveillance with
serial biopsies and MRIs and there are
publications that suggests African-American men
are less likely to get an MRI.
We really don't have good data on which to
base a decision about that.
I would argue that there's
no good evidence the biology is different.
There's a review article published by Curtis Pettaway,
who happens to be an African-American urologist from
MD Anderson and he reviewed the literature.
The literature tends to suggest that
African-American men are more
likely to have progression,
but I could explain all of that away based on
the quality of active surveillance.