Advanced Radiosurgery Techniques

Transcript

00:00 --> 00:02Support for Yale Cancer Answers
00:02 --> 00:05comes from Smilow Cancer Hospital
00:05 --> 00:07and AstraZeneca.
00:07 --> 00:09Welcome to Yale Cancer Answers with your host,
00:09 --> 00:11Doctor Anees Chagpar.
00:11 --> 00:13Yale Cancer Answers features the latest
00:13 --> 00:15information on cancer care by
00:15 --> 00:17welcoming oncologists and specialists
00:17 --> 00:19who are on the forefront of the
00:19 --> 00:21battle to fight cancer. This week,
00:21 --> 00:22it's a conversation about radiation
00:22 --> 00:24oncology with Doctor Krishan Jethwa.
00:24 --> 00:26Doctor Jethwa is an assistant professor
00:26 --> 00:28of therapeutic radiology at the
00:28 --> 00:30Yale University School of Medicine,
00:30 --> 00:32where Doctor Chagpar is a
00:32 --> 00:34professor of surgical oncology.
00:35 --> 00:38So maybe you can start off by telling us
00:38 --> 00:41what exactly is a radiation oncologist?
00:41 --> 00:43Often I find people confuse a
00:43 --> 00:45radiation oncologist with a radiologist.
00:45 --> 00:48So can you tell us the difference?
00:48 --> 00:49Radiation oncologists
00:49 --> 00:51are cancer specialists who care
00:51 --> 00:53for adult and pediatric patients.
00:53 --> 00:55We use radiation therapy with the
00:55 --> 00:58goal of curing cancer or to help
00:58 --> 01:00improve the quality of life for
01:00 --> 01:02symptoms for patients with cancer,
01:02 --> 01:05and often that's part of the
01:05 --> 01:06multidisciplinary care which
01:06 --> 01:08includes many other specialists.
01:08 --> 01:10The other question that I often
01:10 --> 01:12get is the difference between
01:12 --> 01:14radiation and chemotherapy.
01:14 --> 01:17So when people are talking about
01:17 --> 01:19using various modalities to help
01:19 --> 01:22manage cancer or cure cancer,
01:22 --> 01:24people often get these mixed up
01:24 --> 01:28and also mix up the side effects.
01:28 --> 01:31So can you tell us a little bit
01:31 --> 01:33about the differences between the two?
01:33 --> 01:36Medical oncologists are
01:36 --> 01:38cancer specialists who use medications
01:38 --> 01:42or drugs to treat the entire body,
01:42 --> 01:44some of which do include chemotherapy
01:44 --> 01:46and those specific medications
01:46 --> 01:48they use can target the cancer
01:48 --> 01:50and help with cancer control.
01:50 --> 01:52Radiation therapy is different in
01:52 --> 01:55that we use typically high energy
01:55 --> 01:57radiation beams targeting the cancer
01:57 --> 01:59for a more local treatment effect,
01:59 --> 02:02as opposed to a whole body
02:02 --> 02:03wide treatment effect.
02:03 --> 02:05Often we work together to
02:05 --> 02:07help with the goals of care,
02:07 --> 02:09whether it be curative or
02:09 --> 02:11supportive or symptom directed.
02:12 --> 02:15And so tell us a little bit
02:15 --> 02:17about the side effects of each.
02:17 --> 02:19Very often people are worried
02:19 --> 02:22about will my hair fall out?
02:22 --> 02:25Will I get really sick?
02:25 --> 02:28And so can you talk a little bit
02:28 --> 02:30about the differences between the
02:30 --> 02:32side effects of radiation therapy
02:32 --> 02:35versus more whole body systemic therapies?
02:35 --> 02:37The side effects are really
02:37 --> 02:40dependent upon which medication is
02:40 --> 02:42choosen for systemic therapies.
02:42 --> 02:44And for radiation therapy
02:44 --> 02:45it's very much dependent upon
02:45 --> 02:48which area of the body is treated
02:48 --> 02:50with radiation therapy in general.
02:50 --> 02:52Some common side effects of radiation
02:52 --> 02:53therapy would include fatigue,
02:53 --> 02:55people may feel tired.
02:55 --> 02:58And there can be some reaction of
02:58 --> 03:00the skin similar to that of a very
03:00 --> 03:02mild sunburn in most instances.
03:02 --> 03:04That is not always the case,
03:04 --> 03:07but it can be depending upon
03:07 --> 03:08what's treated.
03:08 --> 03:10Apart from those more general side
03:10 --> 03:12effects it is very much dependent upon
03:12 --> 03:15which area of the body is focused
03:15 --> 03:16with radiation therapy and part
03:16 --> 03:19of the art and care of a radiation
03:19 --> 03:21oncologist is guiding and supporting
03:21 --> 03:23a specific patient through those
03:23 --> 03:25side effects and supporting them
03:25 --> 03:27as they recover from the treatment.
03:27 --> 03:27Similarly,
03:27 --> 03:29with chemotherapy it's very much
03:29 --> 03:30dependent upon the medication,
03:30 --> 03:33but there can be the more global
03:33 --> 03:34general side effects of fatigue
03:34 --> 03:36that come along with it,
03:36 --> 03:38but many of the other side effects
03:38 --> 03:39are dependent
03:39 --> 03:40on the medication.
03:40 --> 03:42I think that when
03:42 --> 03:44people think about radiation, they
03:44 --> 03:46have seen movies where people
03:46 --> 03:48were going through cancer care,
03:48 --> 03:51lose their hair and so on and so forth
03:51 --> 03:53that frequently is a side effect of
03:53 --> 03:55chemotherapy and not so frequently
03:55 --> 03:58a side effect of radiation therapy.
03:58 --> 03:59Is that right?
04:00 --> 04:02That's true when we're treating
04:02 --> 04:04around the brain or head region
04:04 --> 04:06there can be hair loss
04:06 --> 04:07from radiation therapy,
04:07 --> 04:09but apart from that circumstance and
04:09 --> 04:12hair loss would not be expected from
04:12 --> 04:12radiation therapy.
04:12 --> 04:16The other question that I get a
04:16 --> 04:19lot is if I take one or the other,
04:19 --> 04:20can I avoid the other?
04:20 --> 04:22So in other words,
04:22 --> 04:23if I take radiation,
04:23 --> 04:25can I avoid chemotherapy?
04:25 --> 04:27Or if I take chemotherapy,
04:27 --> 04:28can I avoid radiation?
04:28 --> 04:30More often than not
04:30 --> 04:31we combine both
04:31 --> 04:33systemic treatments like chemotherapy
04:33 --> 04:36and radiation therapy together
04:36 --> 04:38because both have different
04:38 --> 04:40effects on the cancer control.
04:40 --> 04:42Radiation therapy specifically helps
04:42 --> 04:45to decrease the risk or control
04:45 --> 04:47the cancer at the site that it
04:47 --> 04:49originally grew from.
04:49 --> 04:50Whereas systemic treatments target
04:50 --> 04:53the rest of the body to help
04:53 --> 04:55control any microscopic cancer
04:55 --> 04:57that may be progressing elsewhere.
04:57 --> 05:00So typically it's not an either or,
05:00 --> 05:03but usually and often a combination
05:03 --> 05:05of both to improve outcomes.
05:05 --> 05:06Which brings
05:06 --> 05:09me to the question of surgery and radiation,
05:09 --> 05:11so surgery, similar to radiation,
05:11 --> 05:13is a local treatment.
05:13 --> 05:15Are there instances where you choose
05:15 --> 05:18between surgery versus radiation,
05:18 --> 05:20or are there circumstances in
05:20 --> 05:22which the two are combined?
05:22 --> 05:25And if so, can you explain why?
05:25 --> 05:27Again, a very great question.
05:27 --> 05:30Often we're working with our surgical
05:30 --> 05:32colleagues to help improve the outcomes
05:32 --> 05:34with radiation therapy or surgery.
05:34 --> 05:35In some instances,
05:35 --> 05:38radiation therapy can be a very
05:38 --> 05:40appropriate alternative to surgery.
05:40 --> 05:42For instance, for treatment of
05:42 --> 05:44many head and neck cancers.
05:44 --> 05:46Radiation therapy or surgery
05:46 --> 05:48are very suitable options and
05:48 --> 05:50similarly with prostate cancers,
05:50 --> 05:52radiation therapy or surgery,
05:52 --> 05:54often very suitable options
05:54 --> 05:56with the goal of cure.
05:56 --> 05:58Although there are many other
05:58 --> 05:59circumstances where a radiation
05:59 --> 06:01therapy is either given before a
06:01 --> 06:03surgical operation or afterwards
06:03 --> 06:05to help improve the outcomes,
06:05 --> 06:08and a great example of that is breast
06:08 --> 06:10cancer where often we do surgery first,
06:10 --> 06:12follow it with the radiation
06:12 --> 06:15therapy to decrease the risk of the
06:15 --> 06:17cancer coming back.
06:17 --> 06:18And in terms of radiation therapy,
06:18 --> 06:21can you talk a little bit about
06:21 --> 06:23the different kinds of radiation?
06:23 --> 06:24I know people have
06:24 --> 06:26heard about things like
06:26 --> 06:28photons and electrons,
06:28 --> 06:30and now protons.
06:30 --> 06:32How does one know what kind
06:32 --> 06:33of radiation therapy
06:33 --> 06:35one should be getting?
06:35 --> 06:36What are the
06:36 --> 06:38differences?
06:38 --> 06:40There are a tremendous amount of differences between each
06:40 --> 06:42of those techniques and in general,
06:42 --> 06:45radiation therapy comes in many forms.
06:45 --> 06:47A way of differentiating the major forms
06:47 --> 06:50would be external beam radiation therapy,
06:50 --> 06:53which is somewhat similar to standard X rays,
06:53 --> 06:55where the radiation beams are coming
06:55 --> 06:58from the outside from a large
06:58 --> 07:00machine and directed to the tumor.
07:00 --> 07:02An alternative form to that
07:02 --> 07:04would be internal radiation.
07:04 --> 07:06And that could include procedures
07:06 --> 07:09such as what we call brachytherapy,
07:09 --> 07:11which involves inserting the
07:11 --> 07:13radiation therapy device actually
07:13 --> 07:16into or directly next to the tumor.
07:16 --> 07:18Or there are some circumstances
07:18 --> 07:21where we use radiotherapy releasing
07:21 --> 07:23isotopes into the bloodstream that
07:23 --> 07:26can be targeted to the tumor.
07:26 --> 07:29Part of the art and skill of a radiation oncologist
07:29 --> 07:32is determining the most ideal
07:32 --> 07:34radiation therapy technique and plan
07:34 --> 07:36to help design and target the
07:36 --> 07:38cancer while minimizing radiation
07:38 --> 07:40exposure to normal organs,
07:40 --> 07:42and so it's challenging to say
07:42 --> 07:44you know what questions might a
07:44 --> 07:47patient ask to help direct which
07:47 --> 07:48specific technique is used,
07:48 --> 07:51but I do think it's a fair question to
07:51 --> 07:54simply ask your radiation oncologist, what
07:54 --> 07:57type of cancer treatment or radiation
07:57 --> 07:58treatment am I receiving.
07:58 --> 08:00And so you know,
08:00 --> 08:03there are now
08:03 --> 08:05newer therapies or newer therapeutic
08:05 --> 08:08modalities that are being considered
08:08 --> 08:11in radiation for various tumors and so
08:11 --> 08:14when patients want to get more information
08:14 --> 08:17for example, breast
08:17 --> 08:19cancer patients who are often treated
08:19 --> 08:22with photons but who are now being
08:22 --> 08:25offered proton therapy and are wondering
08:25 --> 08:28should I be getting proton therapy?
08:28 --> 08:31Is that the right thing for me?
08:31 --> 08:33Where do you suggest that
08:33 --> 08:35they get more information?
08:35 --> 08:38Or can you shed a bit of light on
08:38 --> 08:41in what circumstances different
08:41 --> 08:44modalities might be better?
08:44 --> 08:46I love this question because it's
08:46 --> 08:48one of my real areas of passion.
08:48 --> 08:50How can we use advanced radiation
08:50 --> 08:52therapy technologies to improve the
08:52 --> 08:54outcomes and reduce the side effects
08:54 --> 08:57of patients as they go through therapy?
08:57 --> 08:58Standard radiation therapy
08:58 --> 09:01uses high energy radiation beams and
09:01 --> 09:04those often are called photons or X
09:04 --> 09:07rays to be focused on the cancer.
09:07 --> 09:10A downside of X rays is that they
09:10 --> 09:13enter the body and they actually pass
09:13 --> 09:15through the entire body deposit,
09:15 --> 09:16depositing radiation therapy through
09:16 --> 09:19their path, and this can include
09:19 --> 09:21normal organs in many circumstances.
09:21 --> 09:23Now, unfortunately we have developed
09:23 --> 09:26many methods to reduce the exposure of
09:26 --> 09:28normal organs and therefore the side effects.
09:28 --> 09:30And honestly the technological advances
09:30 --> 09:33in radiation therapy over the decades
09:33 --> 09:35have been so immense and very exciting
09:35 --> 09:37and this has resulted in dramatically
09:37 --> 09:39better outcomes for patients.
09:39 --> 09:41Proton therapy, for example,
09:41 --> 09:43is a real major advancement,
09:43 --> 09:45and similarly to X rays,
09:45 --> 09:47proton beams do enter the body and
09:47 --> 09:50deliver some radiation exposure initially,
09:50 --> 09:50however,
09:50 --> 09:54that's where the key advantages is that
09:54 --> 09:57they can be designed to actually stop
09:57 --> 09:59shortly after the targeting tumor.
09:59 --> 10:00So in brief,
10:00 --> 10:02there is little to no radiation that
10:02 --> 10:05continues to pass beyond the tumor or
10:05 --> 10:08through the rest of the patient's body,
10:08 --> 10:10and this theoretically may
10:10 --> 10:11substantially improve
10:11 --> 10:12and benefit some patients.
10:12 --> 10:14Not all patients,
10:14 --> 10:15but some patients.
10:16 --> 10:17That sounds really exciting and
10:17 --> 10:19certainly we know that there are
10:20 --> 10:21various proton facilities that have
10:21 --> 10:24popped up all over the country.
10:24 --> 10:27If patients are not near a proton facility,
10:27 --> 10:30should they be looking to go to a
10:30 --> 10:32facility that offers proton therapy?
10:32 --> 10:35Or is that something that is pretty
10:35 --> 10:38specialized and still on clinical trial?
10:38 --> 10:41Or does it really depend on the tumor type?
10:41 --> 10:43It's highly dependent
10:43 --> 10:45upon the tumor type and
10:45 --> 10:46the individual patient.
10:46 --> 10:48I would encourage patients to
10:48 --> 10:50ask their radiation oncologists
10:50 --> 10:54just the question of what do you
10:54 --> 10:56think about proton therapy and
10:56 --> 10:58do you think it would benefit me?
10:58 --> 11:01And even if they don't live close
11:01 --> 11:03to a proton therapy center,
11:03 --> 11:06I do think that an individual radiation
11:06 --> 11:07oncologist would provide their
11:07 --> 11:10opinion or thoughts on that technique.
11:10 --> 11:12I get asked that question actually
11:12 --> 11:15quite regularly and in many circumstances
11:15 --> 11:16standard radiation therapy would
11:16 --> 11:19be equivalent to proton therapy,
11:19 --> 11:21and I do think that we can
11:21 --> 11:23deliver exceptional care with
11:23 --> 11:24standard radiation treatment.
11:24 --> 11:26As I mentioned,
11:26 --> 11:28tremendous advancements have been made
11:28 --> 11:31even with standard X rays or photons.
11:31 --> 11:35But in some circumstances I must say that
11:35 --> 11:37I have recommended patients
11:37 --> 11:39to receive a second opinion
11:39 --> 11:40at a proton therapy center
11:40 --> 11:43Can you talk a little bit
11:43 --> 11:45about some of the other techniques
11:45 --> 11:47that have been developed using
11:47 --> 11:49standard radiation therapy that might
11:49 --> 11:52minimize the dosage to normal organs.
11:52 --> 11:54Many patients are always worried about,
11:54 --> 11:56for example, if they're getting
11:56 --> 11:58radiation therapy after a breast cancer,
11:58 --> 12:00let's say to their chest.
12:00 --> 12:02They're worried about the radiation
12:02 --> 12:05affecting their heart or their lungs.
12:05 --> 12:07What advancements have been made
12:07 --> 12:09to protect those organs and should
12:09 --> 12:11patients be worried about the
12:11 --> 12:13extra radiation hitting those
12:13 --> 12:15normal tissues?
12:15 --> 12:16As a radiation oncologist, these
12:16 --> 12:19are the things that are on
12:19 --> 12:21my mind each and every day.
12:21 --> 12:23How do I design a radiation treatment
12:23 --> 12:25plan that can minimize effectively
12:25 --> 12:28the dose of radiation therapy to
12:28 --> 12:30normal organs and with standard
12:30 --> 12:32radiation therapy for breast cancer
12:32 --> 12:35we've come up with very nice ways to
12:35 --> 12:37displace or move the heart or
12:37 --> 12:40lungs away from the targeted breast
12:40 --> 12:42tissue and for other cancers
12:42 --> 12:44we've developed highly sophisticated
12:44 --> 12:46X ray techniques such as intensity
12:46 --> 12:48modulated radiation therapy,
12:48 --> 12:50which, in simplified terms,
12:50 --> 12:52involves advanced computer technology
12:52 --> 12:54and sophisticated radiation beam
12:54 --> 12:56design to better focus the high doses
12:56 --> 12:59of radiation therapy to the tumor
12:59 --> 13:02and spare the normal tissues so we do
13:02 --> 13:04have very effective alternatives to
13:04 --> 13:06proton therapy that can effectively
13:06 --> 13:09and very well treat patients.
13:09 --> 13:10That's really great to hear,
13:10 --> 13:13so we're going to pick up this
13:13 --> 13:15conversation right after we take a
13:15 --> 13:18short break for a medical minute.
13:18 --> 13:20Please stay tuned to learn more
13:20 --> 13:22about radiation oncology with
13:22 --> 13:24my guest Doctor Krishnan Jethwa.
13:24 --> 13:26Support for Yale Cancer Answers
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13:34 --> 13:37This is a medical minute about survivorship.
13:37 --> 13:39Completing treatment for cancer
13:39 --> 13:41is a very exciting milestone,
13:41 --> 13:44but cancer and its treatment can be a life
13:44 --> 13:47changing experience for cancer survivors.
13:47 --> 13:49The return to normal activities and
13:49 --> 13:51relationships can be difficult and
13:51 --> 13:54some survivors face long term side
13:54 --> 13:56effects resulting from their treatment,
13:56 --> 13:57including heart problems,
13:57 --> 13:59osteoporosis, fertility issues,
13:59 --> 14:01and an increased risk of second cancers.
14:01 --> 14:04Resources are available to help
14:04 --> 14:06keep cancer survivors well and
14:06 --> 14:07focused on healthy living.
14:07 --> 14:09More information is available
14:09 --> 14:10at yalecancercenter.org.
14:10 --> 14:15You're listening to Connecticut public radio.
14:15 --> 14:15Welcome
14:15 --> 14:17back to Yale Cancer Answers.
14:17 --> 14:19This is doctor Anees Chagpar
14:19 --> 14:22and I'm joined tonight by
14:22 --> 14:24my guest Doctor Krishan Jethwa.
14:24 --> 14:27We're discussing radiation therapy in
14:27 --> 14:29the treatment of cancers and right
14:29 --> 14:32before the break we were talking about
14:32 --> 14:34some advanced techniques that have
14:34 --> 14:37been developed that can really help in
14:37 --> 14:39minimizing the side effects of radiation.
14:40 --> 14:43Before I dive into some specific cancers,
14:43 --> 14:46one question that we're always asked about
14:46 --> 14:48is secondary malignancies.
14:48 --> 14:50In other words,
14:50 --> 14:53people often say, well, radiation therapy,
14:53 --> 14:55it's kind of like radiation
14:55 --> 14:57similar to the sun,
14:57 --> 15:00but we know that with radiation,
15:00 --> 15:02whether it's from sunlight or
15:02 --> 15:04whether it's from nuclear explosions,
15:04 --> 15:06can cause cancers.
15:06 --> 15:09So is there a risk of developing
15:09 --> 15:12a cancer from your radiation
15:12 --> 15:14therapy which is designed to
15:14 --> 15:17help you get rid of the cancer?
15:18 --> 15:20That's a really, really good question,
15:20 --> 15:24one which I get asked from most patients.
15:24 --> 15:25And you're exactly right.
15:25 --> 15:26With radiation therapy,
15:26 --> 15:30while we focus it directly on to the tumor,
15:30 --> 15:33and we do a very nice job at doing so,
15:33 --> 15:36there is theoretically a risk that
15:36 --> 15:38radiation therapy can increase the risk
15:38 --> 15:40of developing a new cancer within or
15:40 --> 15:42adjacent to the radiation therapy field.
15:42 --> 15:45Thankfully, that risk is not very high.
15:45 --> 15:47In fact, it's far less than 1%,
15:47 --> 15:49and if it is to happen,
15:49 --> 15:51it often takes many,
15:51 --> 15:54many years to develop and I mean
15:54 --> 15:565-10, 30-40 years to develop.
15:56 --> 15:59So there is a relatively low risk of it
15:59 --> 16:02occurring and it's a more significant
16:02 --> 16:04risk in patients who are younger,
16:04 --> 16:06particularly our pediatric patients,
16:06 --> 16:09but as a radiation oncologist it is
16:09 --> 16:11always something on my mind when
16:11 --> 16:13I'm caring for those young patients.
16:13 --> 16:16And that is one of the benefits of
16:16 --> 16:18advanced radiation therapy technologies.
16:18 --> 16:19For instance, proton therapy,
16:19 --> 16:22that can theoretically decrease the risk
16:22 --> 16:25of what we call a secondary malignancy.
16:26 --> 16:28And so during the break
16:28 --> 16:30you were telling me that your
16:30 --> 16:32particular focus is on GI cancers.
16:32 --> 16:34Can you tell us a little bit
16:34 --> 16:36more about the use of radiation
16:36 --> 16:38therapy in those cancers?
16:38 --> 16:41Radiation therapies are used in the vast majority
16:41 --> 16:43of GI cancer spanning head to toe.
16:43 --> 16:46It has a role in either the curative
16:46 --> 16:49intent treatment or in many it would
16:49 --> 16:51be the symptom directed treatment.
16:51 --> 16:54So that could be for esophagus cancers,
16:54 --> 16:55stomach cancers, liver, pancreas,
16:55 --> 16:58colon, rectal or even anal cancers.
16:58 --> 17:02And we have a very nice role in doing so,
17:02 --> 17:03often in combination with our
17:03 --> 17:05colleagues from medical oncology
17:05 --> 17:07and surgical oncology to help
17:07 --> 17:09improve the outcomes for patients.
17:10 --> 17:13So let's go through each of those in a
17:13 --> 17:16bit more detail so that you can give us
17:16 --> 17:19a little bit of color of what radiation
17:19 --> 17:21therapy is like for each of those.
17:21 --> 17:24I'd imagine that it's different, for example,
17:24 --> 17:26in the esophagus versus in liver versus
17:26 --> 17:29in the pancreas versus in the anal canal.
17:29 --> 17:32How does radiation vary based on the site?
17:32 --> 17:35So of course it is a different
17:35 --> 17:36anatomical site of the body,
17:37 --> 17:38and in many of those different
17:38 --> 17:40circumstances we use different
17:40 --> 17:41radiation technologies, which we
17:41 --> 17:44think are best for the specific site.
17:44 --> 17:45So for instance,
17:45 --> 17:48when we treat an esophagus cancer,
17:48 --> 17:49what's always on our mind is
17:49 --> 17:52how do we treat the tumor while
17:52 --> 17:54minimizing radiation therapy
17:54 --> 17:56dose to organs like the heart,
17:56 --> 17:58lungs, liver or even kidneys?
17:58 --> 18:01Whereas when we're down in the pelvis
18:01 --> 18:04treating a rectal cancer or an anal cancer,
18:04 --> 18:06we worry about the radiation effects
18:06 --> 18:08on the bowel, bladder, genitalia
18:08 --> 18:10and bones like the femur
18:10 --> 18:13which can be at risk of weakening or
18:13 --> 18:15developing fractures as patients get
18:15 --> 18:18older and there's a lot of nuance and
18:18 --> 18:20art in how a radiation oncologist
18:20 --> 18:23designs those fields and is in part
18:23 --> 18:25why it's nice to have a specialty
18:25 --> 18:28team involved in the care because
18:28 --> 18:30there's such tremendous nuance
18:30 --> 18:32in radiation therapy design and the
18:32 --> 18:35technical specifics of the treatment,
18:35 --> 18:37somewhat analogous to the expertise
18:37 --> 18:39you may have from a surgical
18:39 --> 18:41team as they design
18:41 --> 18:44a complex surgical operation.
18:44 --> 18:47And timing is the other issue too, right?
18:47 --> 18:48So sometimes radiation
18:48 --> 18:50is given before surgery,
18:50 --> 18:53and sometimes it's given after surgery.
18:53 --> 18:55How do you decide which way that works?
18:55 --> 18:58For most of the
18:58 --> 19:00gastrointestinal cancers we've
19:00 --> 19:02through much research learned
19:02 --> 19:04that delivering radiation therapy
19:04 --> 19:07prior to a surgery is beneficial.
19:07 --> 19:09And often that also includes
19:09 --> 19:11delivery of the systemic treatment,
19:11 --> 19:13the chemotherapy before the operation,
19:13 --> 19:15and we've learned that we
19:15 --> 19:17improve the cancer control.
19:17 --> 19:19And in many instances,
19:19 --> 19:20the survival of patients by
19:20 --> 19:23delivering both of those treatment
19:23 --> 19:24techniques before the operation.
19:25 --> 19:27And that includes esophagus cancer,
19:27 --> 19:28stomach cancers,
19:28 --> 19:29pancreas, and rectal cancers,
19:29 --> 19:32each of which we treat with
19:32 --> 19:34therapy prior to the operation
19:34 --> 19:36in many circumstances, and
19:36 --> 19:38one can imagine that doing so
19:38 --> 19:41might reduce the tumor burden.
19:41 --> 19:44But how does that affect scaring
19:44 --> 19:46for the surgeons?
19:46 --> 19:48There's many beneficial effects of delivering the
19:48 --> 19:50radiation therapy or chemotherapy beforehand,
19:50 --> 19:53one of which is that we can actually
19:53 --> 19:56see the tumor, rather than treating an
19:56 --> 19:59area where the tumor has been removed.
19:59 --> 20:02When we can see the tumor, we can focus
20:02 --> 20:04the radiation beams more specifically,
20:04 --> 20:07and often the area that we have to
20:07 --> 20:09treat is considerably smaller when
20:09 --> 20:12delivered in the pre surgical setting.
20:12 --> 20:14That allows us to reduce the side
20:14 --> 20:17effects that a patient may experience.
20:17 --> 20:19Additionally, by shrinking down the tumor,
20:19 --> 20:23it is often easier or more effective for
20:23 --> 20:27the surgeon to remove all of the tumor
20:27 --> 20:30with negative margins after the operation.
20:30 --> 20:33And after doing this for decades and having
20:33 --> 20:36clinical trials look at this for decades,
20:36 --> 20:39there doesn't seem to be a dramatic
20:39 --> 20:41difference in complications from the
20:41 --> 20:43operation when it's done effectively
20:43 --> 20:44as part of
20:44 --> 20:45a multi disciplinary team.
20:45 --> 20:47And yet in some cancers,
20:47 --> 20:48radiation is frequently
20:48 --> 20:50given after the surgery.
20:50 --> 20:52So you had mentioned, for example,
20:52 --> 20:54in breast cancer we generally
20:54 --> 20:56give radiation therapy after
20:56 --> 20:57the surgery is completed.
20:57 --> 21:00So why is that?
21:00 --> 21:02There's a number of reasons for that,
21:02 --> 21:04and I think in the breast cancer
21:04 --> 21:05community, now acknowledging I'm
21:05 --> 21:07not a breast cancer specialist,
21:07 --> 21:09but the typical paradigm has
21:09 --> 21:11been to do surgery first,
21:11 --> 21:14in part for concern of wound complications
21:14 --> 21:16that may develop along the skin.
21:16 --> 21:19And in part because it's nice to have
21:19 --> 21:22an opportunity to look at the cancer
21:22 --> 21:24under the microscope and see the
21:24 --> 21:27extent of spread so that we can better
21:27 --> 21:29design our radiation therapy fields.
21:30 --> 21:32So it sounds like there's good
21:32 --> 21:35reasons in GI cancer to do it before
21:35 --> 21:37good reasons in breast cancer
21:37 --> 21:39to do it afterwards.
21:39 --> 21:43So it seems to be really dependent on the
21:43 --> 21:45tumor itself.
21:45 --> 21:47And individual patients and again
21:47 --> 21:48this emphasizes why being
21:48 --> 21:50seen and cared for amongst a
21:50 --> 21:52multidisciplinary specialty team,
21:52 --> 21:56such as that we have at Yale is
21:56 --> 21:59really so critical in the care of
21:59 --> 22:01our patients.
22:01 --> 22:02And you mentioned clinical trials
22:02 --> 22:05adding to the evidence
22:05 --> 22:08that we have in terms of what we
22:08 --> 22:10know works versus doesn't work
22:10 --> 22:12in terms of radiation therapy.
22:12 --> 22:14Are there ongoing clinical trials
22:14 --> 22:17that you're particularly excited about?
22:17 --> 22:19There's so many.
22:19 --> 22:21My interests are in using multiple
22:21 --> 22:24methods of patient and cancer response
22:24 --> 22:27assessment to guide the care of patients,
22:27 --> 22:31and that can include advanced imaging.
22:31 --> 22:35It can involve tumor genetics or genomics.
22:35 --> 22:39It can include specific targets on a cancer
22:39 --> 22:42cell that may be targeted by medications.
22:42 --> 22:44Or it can be specific blood tests
22:44 --> 22:47that guide the prognosis for patients.
22:47 --> 22:49Potential therapies for patients
22:49 --> 22:51can also involve immunotherapy,
22:51 --> 22:53and specifically in GI cancers
22:53 --> 22:54we've been utilizing
22:54 --> 22:56each of those techniques to
22:56 --> 22:57help risk stratify and guide
22:57 --> 22:59patients for subsequent therapies.
22:59 --> 23:02And it's so exciting because many
23:02 --> 23:04of these developments are relatively
23:04 --> 23:07recent in the past five to 10 years,
23:07 --> 23:10and we're really seeing some of the
23:10 --> 23:12fruits of these clinical trials now.
23:12 --> 23:15Our major cancer conference is ASCO
23:18 --> 23:20and it's exciting seeing some of the new
23:20 --> 23:22clinical trial developments that
23:22 --> 23:24really improve the survival,
23:24 --> 23:27but also the quality of life for
23:27 --> 23:30our patients as they go through therapy.
23:30 --> 23:33Do you think that these novel markers,
23:33 --> 23:34the genomic markers,
23:34 --> 23:36the biomarkers that we're using to tailor
23:36 --> 23:38chemotherapy and systemic therapy,
23:38 --> 23:40for example, might actually play
23:40 --> 23:43a role in terms of deciding,
23:43 --> 23:46for example, whether radiation therapy
23:46 --> 23:48should be used or not or what
23:48 --> 23:50kind of radiation therapy
23:50 --> 23:52I completely do.
23:52 --> 23:54I think we're learning so much more
23:54 --> 23:56about the prognosis of patients
23:56 --> 23:59and the pathways of cancer spread,
23:59 --> 24:01which does seem to be influenced
24:01 --> 24:03by each of these factors,
24:03 --> 24:05and we're learning how to select
24:05 --> 24:07patients who may derive more
24:07 --> 24:08benefit from radiation therapy.
24:08 --> 24:11And on the contrary, we're learning
24:11 --> 24:13patients who may derive less benefit,
24:13 --> 24:16and that in itself is rewarding because
24:16 --> 24:18that provides an opportunity for a
24:18 --> 24:20radiation oncologist to help treat patients,
24:20 --> 24:24but know that if they do have a side effect,
24:24 --> 24:27it was a side effect that developed in a
24:27 --> 24:29patient that really needed the treatment.
24:29 --> 24:31Those who derive less benefit
24:31 --> 24:34can be spared many of those side
24:34 --> 24:35effects of therapy.
24:35 --> 24:37And what about figuring out which
24:37 --> 24:39tumors are more radiosensitive
24:39 --> 24:41versus those that are radioresistant?
24:41 --> 24:43Are there techniques that we
24:43 --> 24:46can use that will help us to
24:46 --> 24:48deliver radiation therapy to
24:48 --> 24:50tumors that might not be as sensitive to it?
24:50 --> 24:53Yeah, this is another very
24:53 --> 24:54interesting area of research
24:54 --> 24:56which I think we've really just
24:56 --> 24:58hit the tip of the iceberg on.
24:58 --> 25:00We're learning that genomics or
25:00 --> 25:02tumor genetics has an impact.
25:02 --> 25:04We're learning that the tissue
25:04 --> 25:06surrounding a tumor has an impact,
25:06 --> 25:08and I do think that with more
25:08 --> 25:10time we'll learn how to combine
25:10 --> 25:12new medications with radiation
25:12 --> 25:14therapy to improve cancer control
25:14 --> 25:16and will learn that there may be
25:16 --> 25:18differences in radiation therapy dose.
25:18 --> 25:20Or areas that we need to treat
25:20 --> 25:21to derive more benefit.
25:21 --> 25:22But like I said,
25:22 --> 25:24it's really the tip of the
25:24 --> 25:27iceberg in regards to that area of
25:27 --> 25:28research, which is really exciting.
25:28 --> 25:31And so as we think about radiation therapy,
25:31 --> 25:33I mean thus far we've really been talking
25:33 --> 25:35about using radiation as part of a
25:35 --> 25:37treatment paradigm for curative intent.
25:37 --> 25:39But you had mentioned early on at the
25:39 --> 25:41beginning of the show that radiation
25:41 --> 25:43can also be used for palliative intent.
25:43 --> 25:45Can you tell us a little bit
25:45 --> 25:47more about how radiation therapy
25:47 --> 25:49is used for symptom control?
25:50 --> 25:51Radiation therapy is very
25:51 --> 25:53effective at symptom control,
25:53 --> 25:56and I tend to quote that about 2/3 or
25:56 --> 25:59more of patients will derive a benefit.
25:59 --> 26:02In regards to the specific indications,
26:02 --> 26:05often it's for pain control when cancer
26:05 --> 26:07has spread elsewhere in the body,
26:07 --> 26:10or if it's causing pain in its
26:10 --> 26:11original site of development or
26:11 --> 26:14radiation therapy can be used to
26:14 --> 26:16help prevent organ dysfunction or
26:16 --> 26:18complications from cancer growth.
26:18 --> 26:19What do
26:19 --> 26:21you mean by organ dysfunction?
26:21 --> 26:24So a common situation that we end up
26:24 --> 26:27seeing is if cancer has spread to a bone
26:27 --> 26:30like the spinal column or vertebral body,
26:30 --> 26:33that cancer can actually grow into the
26:33 --> 26:35spinal canal and start applying pressure
26:35 --> 26:39to the spinal cord or to the nerves.
26:39 --> 26:39And unfortunately,
26:39 --> 26:43one of the consequences of that is that
26:43 --> 26:45patients can develop weakness in their
26:45 --> 26:47legs or in some circumstances even
26:47 --> 26:50the inability to walk because of it.
26:50 --> 26:52Radiation therapy can slow down and
26:52 --> 26:54shrink the cancer in those bones and
26:54 --> 26:56really help relieve the pressure on
26:56 --> 26:59the spinal canal or those nerves.
26:59 --> 27:01And sometimes that's done in combination
27:01 --> 27:03with surgery and sometimes it's not.
27:03 --> 27:04We use radiation therapy alone
27:04 --> 27:06and it's quite effective.
27:06 --> 27:08One of the
27:08 --> 27:10things that's so interesting you had
27:10 --> 27:11mentioned earlier that when you're
27:11 --> 27:13giving radiation in the pelvis,
27:13 --> 27:15one of the things you worry about
27:15 --> 27:18is the side effects on the bone.
27:18 --> 27:20That radiation could weaken the bone.
27:20 --> 27:23And yet, at the same time,
27:23 --> 27:26when we see patients who have,
27:26 --> 27:28for example, bone metastases,
27:28 --> 27:30we frequently will use radiation
27:30 --> 27:32therapy not only to help with pain,
27:32 --> 27:36but sometimes even to help with patients
27:36 --> 27:39who might have an impending fracture.
27:39 --> 27:41Tell me about how that works.
27:41 --> 27:43That seems to be a dichotomy.
27:43 --> 27:45Yeah, that's a good question.
27:45 --> 27:47When I see patients with bone metastases,
27:47 --> 27:50the common questions I ask myself are,
27:50 --> 27:52is this metastasis in a bone that
27:52 --> 27:54is involved in weight bearing
27:54 --> 27:56like the femurs for example?
27:56 --> 27:59Or how much of the bone seems to
27:59 --> 28:01be destroyed because of the cancer?
28:01 --> 28:04If I do think of patients at very
28:04 --> 28:06high risk of developing a fracture,
28:06 --> 28:09I do ask my colleagues in orthopedic surgery
28:09 --> 28:12or neurosurgery to see the patients as well.
28:12 --> 28:14Because I do think that surgery
28:14 --> 28:16can sometimes be warranted.
28:16 --> 28:18In others where it's not a weight
28:18 --> 28:21bearing joint or an area that's
28:21 --> 28:23involved in a lot of mechanical
28:23 --> 28:25strain then radiation therapy is
28:25 --> 28:27very effective at shrinking the
28:27 --> 28:29cancer and getting control of pain.
28:29 --> 28:31Doctor Krishan Jethwa is an
28:31 --> 28:33assistant professor of therapeutic
28:33 --> 28:35radiology at the Yale School of Medicine.
28:35 --> 28:37If you have questions,
28:37 --> 28:38the address is canceranswers@yale.edu
28:38 --> 28:40and past editions of the program
28:40 --> 28:42are available in audio and written
28:42 --> 28:44form at yalecancercenter.org.
28:44 --> 28:46We hope you'll join us next week to
28:46 --> 28:49learn more about the fight against
28:49 --> 28:51cancer here on Connecticut Public Radio.
28:54 --> 28:57Support for Yale Cancer Answers comes from
28:57 --> 29:00Smilow Cancer Hospital and AstraZeneca.

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June 27, 2021

Yale Cancer Center

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