Hi, I'm Dr. Puja Venkat. I'm an Assistant Professor in the Department of Radiation Oncology at UCLA.
I'm here to talk to you about a specialized cancer treatment called brachytherapy.
So, what is brachytherapy?
This is a question I get asked by patients, family members, and even other medical colleagues, because it is not a very well-known term.
Brachytherapy comes from a Greek word meaning
"near" or "next to," and
it's a type of treatment
in which we treat with radiation, from within or just near or next to cancer or tumors.
So, this slide demonstrates that we
treat a large scope of cancers with this type of treatment. We can treat prostate cancers,
gynecologic cancers, head and neck, breast, skin, endobronchial, lung cancers, even intraocular
cancers, intra-abdominal, esophageal, and anal cancers, as well.
In reality, we feel that any type of tumor can be treated with brachytherapy.
This is an example of one of my patients with breast cancer.
Typically, for breast cancer, we treat the whole breast,
but there are some patients who are candidates for a more targeted type of treatment called partial breast irradiation.
Not all patients are candidates for this type of treatment. It depends on a number of different factors, such as age of the patient and
surgical pathologic features, such as how aggressive the tumor is, the margins on the tumor, and what the tumor looks like under the microscope.
But if you are candidate for partial breast irradiation,
interstitial brachytherapy is an extremely good technique to treat it, and this picture helps me demonstrate why.
If you look here, in red is my target. This is where the tumor was,
where the surgeon removed the tumor from.
The blue line here is my 100% isodose line. That is the 100%
prescription dose that I'm delivering to the target, and you can see my target is very well-covered.
Looking at these outer lines, this white line is the 50% dose. This illustrates how quickly
the radiation dose falls off, allowing me to spare
normal structures nearby, such as the skin, the nipple,
the breast implant here, and as well as the lung that is all the way over here.
This happens to be a right-sided tumor, but for left-sided lesions, this allows me to spare structures such as the heart, as well.
We also treat a lot of skin cancers with brachytherapy.
If you look here, this is a lesion on the cheek. The skin, the target, is right here on the skin, and
this area is very close to the bone.
I want to spare the bone, and I also want to spare the ocular structures over here. So you can see this blue line,
my target is well-covered.
But this white line, you can see all the ocular structures are spared, and there's minimal dose delivery to that bone.
Over here, I brought a
customized brachytherapy mold that we made for one of my patients.
What's interesting about this
mask, this mask is made to fit an individual's face,
so it's customized to an individual, and then we place these tubes or catheters
and attach them to our mask
to fit the contour of the nose,
and then along each of these tubes, I
attach a radiation wire to my radiation robot, and the robot
delivers a radioactive seed through each of these tubes, and it can stay at 5 millimeter increments
along these tubes for as short or as long as
we tell it to, so we're able to shape our dose lines extremely well with this treatment, even over
areas that are highly contoured.
Here, I have a picture of one of the patients we treated with this technique. You can see her lesion on the skin right here,
pretreatment and then post treatment.
There's almost no change to that skin.
So, not only is this treatment highly effective at curing cancers,
but because of the radiation delivery technique, it allows me to treat cancers with very good cosmetic outcomes,
which, particularly for the face, is extremely valuable.
As I mentioned before, we also treat prostate cancer, with brachytherapy.
There's two types of brachytherapy for prostate cancer that are used, generally,
across the world--one is a low dose rate, or
radioactive seed brachytherapy, and one is high dose rate brachytherapy.
Here at UCLA,
we have moved towards only using high dose rate brachytherapy,
and the main difference between the two techniques is that with low dose rate
radiation, you're actually putting radioactive
material into the prostate and you're leaving it there forever. What we do instead is we actually use
similar tubes to what we used for the skin cancer, and we place these tubes into the prostate in a
predetermined location. Here, you can see my target in red. That's my prostate, and
here are those tubes we put in. You can see all 17 of these tubes.
The blue line shows the prescription dose that's actually delivered to my target,
and then this white line shows 50% of the dose. Once again, you see that
rapid dose fall-off, which allows us to spare normal structures, like the rectum here.
You can see only a little bit of that rectum is getting even 50% of the dose.
This has led to really good outcomes, in terms of cure rates for prostate cancer as well as toxicity.
We use a very similar technique for gynecologic cancers. Here, you see a very large cervical tumor,
which I am was able to cover
completely with radiation and
deliver relatively low dose to the rectum and the bladder.
So, this technique allows us to fit high doses of radiation into very small spaces and spare normal tissue.
Long brachytherapy is a
specialized technique that we have started doing at UCLA in the last year.
It's not a very common technique,
but we feel like there's value in it for select patients.
Here you see a tumor in the lung, and
we have placed a needle right through the middle of this tumor.
This needle right here that we've placed through this lung tumor are very similar to the tools we have right here.
So, it allows us to deliver radiation
right to the center of this lesion, and you can see my target here in red, which is the lung tumor, my blue line,
which is, once again, the radiation
I've delivered, my 100% prescription dose, and then the 50% line is right here.
I'm able to spare the remaining lung tissue and largely spare the heart, which is right here, and very well spare the spinal cord,
which is right here.
This is a technique--in this case, we've used it for a tumor in the lung, but this technique is
something we can use throughout the body.
Anywhere we can put a needle in, we are able to treat with this technique, and one thing we've really
worked on at UCLA in the brachytherapy department is using this interstitial brachytherapy
technique for many different cancers and many different parts of the body.
This is my amazing team. It takes a village to do what we do here. It's not just physicians.
We have a physicist right here. This is Dr. Sang-June Park. Behind him is a dosimetrist. They, really, are the two people who
help us make our radiation plans
impeccable. They allow us to treat our target, but also to spare those normal structures.
We have multiple nurses in this picture, back here and over here.
We have a physician's assistant, Lalaine Zaide, who has been doing just brachytherapy for over ten years.
And back here in blue are our wonderful radiation therapists who also only treat brachytherapy,
and they know more about how to set up patients, and they actually helped me
design these. What I bring to the team is a
patient and a tumor, and we all work together to come up with a customized treatment and a
specific anatomical-driven radiation plan.
Right here in the front, our Dr. Demanes, who is
considered one of the biggest names in brachytherapy.
He started doing this over 30 years ago and built the program here over 10 years ago.
Dr. Albert Chang has taken over as our leader, and I'm
over here right next to him.
So, this is my team. There's actually more people than are in this picture, because, as I mentioned, it really does take a village,
so I just wanted to
list some names and to thank you for taking the time to listen to me speak today.
If you have any questions, please feel free to reach out to the Radiation Oncology Department at UCLA.
Thank you.