Advanced Radiosurgery Techniques
June 28, 2021Information
June 27, 2021
Yale Cancer Center
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- 00:00Support for Yale Cancer Answers
- 00:03comes from Smilow Cancer Hospital
- 00:05and AstraZeneca.
- 00:07Welcome to Yale Cancer Answers with your host,
- 00:09Doctor Anees Chagpar.
- 00:11Yale Cancer Answers features the latest
- 00:13information on cancer care by
- 00:15welcoming oncologists and specialists
- 00:17who are on the forefront of the
- 00:19battle to fight cancer. This week,
- 00:21it's a conversation about radiation
- 00:23oncology with Doctor Krishan Jethwa.
- 00:25Doctor Jethwa is an assistant professor
- 00:27of therapeutic radiology at the
- 00:29Yale University School of Medicine,
- 00:31where Doctor Chagpar is a
- 00:33professor of surgical oncology.
- 00:35So maybe you can start off by telling us
- 00:38what exactly is a radiation oncologist?
- 00:41Often I find people confuse a
- 00:44radiation oncologist with a radiologist.
- 00:46So can you tell us the difference?
- 00:49Radiation oncologists
- 00:49are cancer specialists who care
- 00:51for adult and pediatric patients.
- 00:53We use radiation therapy with the
- 00:56goal of curing cancer or to help
- 00:58improve the quality of life for
- 01:01symptoms for patients with cancer,
- 01:03and often that's part of the
- 01:05multidisciplinary care which
- 01:06includes many other specialists.
- 01:08The other question that I often
- 01:10get is the difference between
- 01:13radiation and chemotherapy.
- 01:15So when people are talking about
- 01:18using various modalities to help
- 01:20manage cancer or cure cancer,
- 01:22people often get these mixed up
- 01:25and also mix up the side effects.
- 01:28So can you tell us a little bit
- 01:31about the differences between the two?
- 01:34Medical oncologists are
- 01:36cancer specialists who use medications
- 01:39or drugs to treat the entire body,
- 01:42some of which do include chemotherapy
- 01:45and those specific medications
- 01:47they use can target the cancer
- 01:49and help with cancer control.
- 01:51Radiation therapy is different in
- 01:53that we use typically high energy
- 01:55radiation beams targeting the cancer
- 01:57for a more local treatment effect,
- 02:00as opposed to a whole body
- 02:02wide treatment effect.
- 02:03Often we work together to
- 02:05help with the goals of care,
- 02:08whether it be curative or
- 02:10supportive or symptom directed.
- 02:13And so tell us a little bit
- 02:15about the side effects of each.
- 02:17Very often people are worried
- 02:20about will my hair fall out?
- 02:22Will I get really sick?
- 02:26And so can you talk a little bit
- 02:28about the differences between the
- 02:30side effects of radiation therapy
- 02:33versus more whole body systemic therapies?
- 02:35The side effects are really
- 02:38dependent upon which medication is
- 02:40choosen for systemic therapies.
- 02:42And for radiation therapy
- 02:44it's very much dependent upon
- 02:46which area of the body is treated
- 02:48with radiation therapy in general.
- 02:50Some common side effects of radiation
- 02:53therapy would include fatigue,
- 02:54people may feel tired.
- 02:56And there can be some reaction of
- 02:58the skin similar to that of a very
- 03:01mild sunburn in most instances.
- 03:03That is not always the case,
- 03:05but it can be depending upon
- 03:07what's treated.
- 03:09Apart from those more general side
- 03:11effects it is very much dependent upon
- 03:13which area of the body is focused
- 03:15with radiation therapy and part
- 03:17of the art and care of a radiation
- 03:20oncologist is guiding and supporting
- 03:21a specific patient through those
- 03:23side effects and supporting them
- 03:25as they recover from the treatment.
- 03:27Similarly,
- 03:28with chemotherapy it's very much
- 03:29dependent upon the medication,
- 03:31but there can be the more global
- 03:33general side effects of fatigue
- 03:35that come along with it,
- 03:36but many of the other side effects
- 03:39are dependent
- 03:40on the medication.
- 03:41I think that when
- 03:43people think about radiation, they
- 03:45have seen movies where people
- 03:47were going through cancer care,
- 03:49lose their hair and so on and so forth
- 03:51that frequently is a side effect of
- 03:54chemotherapy and not so frequently
- 03:56a side effect of radiation therapy.
- 03:58Is that right?
- 04:00That's true when we're treating
- 04:02around the brain or head region
- 04:04there can be hair loss
- 04:06from radiation therapy,
- 04:07but apart from that circumstance and
- 04:10hair loss would not be expected from
- 04:12radiation therapy.
- 04:13The other question that I get a
- 04:16lot is if I take one or the other,
- 04:19can I avoid the other?
- 04:21So in other words,
- 04:22if I take radiation,
- 04:24can I avoid chemotherapy?
- 04:25Or if I take chemotherapy,
- 04:27can I avoid radiation?
- 04:28More often than not
- 04:30we combine both
- 04:32systemic treatments like chemotherapy
- 04:34and radiation therapy together
- 04:36because both have different
- 04:38effects on the cancer control.
- 04:41Radiation therapy specifically helps
- 04:42to decrease the risk or control
- 04:45the cancer at the site that it
- 04:48originally grew from.
- 04:49Whereas systemic treatments target
- 04:51the rest of the body to help
- 04:54control any microscopic cancer
- 04:56that may be progressing elsewhere.
- 04:58So typically it's not an either or,
- 05:01but usually and often a combination
- 05:03of both to improve outcomes.
- 05:05Which brings
- 05:06me to the question of surgery and radiation,
- 05:10so surgery, similar to radiation,
- 05:12is a local treatment.
- 05:13Are there instances where you choose
- 05:16between surgery versus radiation,
- 05:18or are there circumstances in
- 05:20which the two are combined?
- 05:22And if so, can you explain why?
- 05:25Again, a very great question.
- 05:28Often we're working with our surgical
- 05:30colleagues to help improve the outcomes
- 05:33with radiation therapy or surgery.
- 05:35In some instances,
- 05:36radiation therapy can be a very
- 05:38appropriate alternative to surgery.
- 05:40For instance, for treatment of
- 05:42many head and neck cancers.
- 05:45Radiation therapy or surgery
- 05:46are very suitable options and
- 05:48similarly with prostate cancers,
- 05:50radiation therapy or surgery,
- 05:52often very suitable options
- 05:54with the goal of cure.
- 05:56Although there are many other
- 05:58circumstances where a radiation
- 06:00therapy is either given before a
- 06:02surgical operation or afterwards
- 06:03to help improve the outcomes,
- 06:05and a great example of that is breast
- 06:08cancer where often we do surgery first,
- 06:11follow it with the radiation
- 06:13therapy to decrease the risk of the
- 06:16cancer coming back.
- 06:18And in terms of radiation therapy,
- 06:19can you talk a little bit about
- 06:21the different kinds of radiation?
- 06:23I know people have
- 06:25heard about things like
- 06:27photons and electrons,
- 06:29and now protons.
- 06:31How does one know what kind
- 06:33of radiation therapy
- 06:34one should be getting?
- 06:36What are the
- 06:37differences?
- 06:39There are a tremendous amount of differences between each
- 06:41of those techniques and in general,
- 06:43radiation therapy comes in many forms.
- 06:45A way of differentiating the major forms
- 06:48would be external beam radiation therapy,
- 06:50which is somewhat similar to standard X rays,
- 06:53where the radiation beams are coming
- 06:56from the outside from a large
- 06:58machine and directed to the tumor.
- 07:00An alternative form to that
- 07:02would be internal radiation.
- 07:04And that could include procedures
- 07:06such as what we call brachytherapy,
- 07:09which involves inserting the
- 07:11radiation therapy device actually
- 07:13into or directly next to the tumor.
- 07:16Or there are some circumstances
- 07:19where we use radiotherapy releasing
- 07:21isotopes into the bloodstream that
- 07:23can be targeted to the tumor.
- 07:26Part of the art and skill of a radiation oncologist
- 07:29is determining the most ideal
- 07:32radiation therapy technique and plan
- 07:35to help design and target the
- 07:37cancer while minimizing radiation
- 07:39exposure to normal organs,
- 07:40and so it's challenging to say
- 07:42you know what questions might a
- 07:45patient ask to help direct which
- 07:47specific technique is used,
- 07:49but I do think it's a fair question to
- 07:52simply ask your radiation oncologist, what
- 07:54type of cancer treatment or radiation
- 07:57treatment am I receiving.
- 07:59And so you know,
- 08:00there are now
- 08:03newer therapies or newer therapeutic
- 08:06modalities that are being considered
- 08:09in radiation for various tumors and so
- 08:11when patients want to get more information
- 08:14for example, breast
- 08:17cancer patients who are often treated
- 08:20with photons but who are now being
- 08:23offered proton therapy and are wondering
- 08:26should I be getting proton therapy?
- 08:29Is that the right thing for me?
- 08:32Where do you suggest that
- 08:34they get more information?
- 08:36Or can you shed a bit of light on
- 08:39in what circumstances different
- 08:42modalities might be better?
- 08:44I love this question because it's
- 08:46one of my real areas of passion.
- 08:48How can we use advanced radiation
- 08:51therapy technologies to improve the
- 08:53outcomes and reduce the side effects
- 08:55of patients as they go through therapy?
- 08:57Standard radiation therapy
- 08:59uses high energy radiation beams and
- 09:02those often are called photons or X
- 09:05rays to be focused on the cancer.
- 09:07A downside of X rays is that they
- 09:10enter the body and they actually pass
- 09:13through the entire body deposit,
- 09:15depositing radiation therapy through
- 09:17their path, and this can include
- 09:20normal organs in many circumstances.
- 09:22Now, unfortunately we have developed
- 09:24many methods to reduce the exposure of
- 09:26normal organs and therefore the side effects.
- 09:29And honestly the technological advances
- 09:31in radiation therapy over the decades
- 09:33have been so immense and very exciting
- 09:35and this has resulted in dramatically
- 09:38better outcomes for patients.
- 09:40Proton therapy, for example,
- 09:41is a real major advancement,
- 09:43and similarly to X rays,
- 09:45proton beams do enter the body and
- 09:48deliver some radiation exposure initially,
- 09:50however,
- 09:51that's where the key advantages is that
- 09:55they can be designed to actually stop
- 09:57shortly after the targeting tumor.
- 09:59So in brief,
- 10:00there is little to no radiation that
- 10:03continues to pass beyond the tumor or
- 10:05through the rest of the patient's body,
- 10:08and this theoretically may
- 10:10substantially improve
- 10:11and benefit some patients.
- 10:13Not all patients,
- 10:14but some patients.
- 10:16That sounds really exciting and
- 10:18certainly we know that there are
- 10:20various proton facilities that have
- 10:22popped up all over the country.
- 10:24If patients are not near a proton facility,
- 10:27should they be looking to go to a
- 10:30facility that offers proton therapy?
- 10:33Or is that something that is pretty
- 10:36specialized and still on clinical trial?
- 10:38Or does it really depend on the tumor type?
- 10:42It's highly dependent
- 10:43upon the tumor type and
- 10:45the individual patient.
- 10:46I would encourage patients to
- 10:49ask their radiation oncologists
- 10:51just the question of what do you
- 10:54think about proton therapy and
- 10:56do you think it would benefit me?
- 10:59And even if they don't live close
- 11:01to a proton therapy center,
- 11:03I do think that an individual radiation
- 11:06oncologist would provide their
- 11:08opinion or thoughts on that technique.
- 11:10I get asked that question actually
- 11:13quite regularly and in many circumstances
- 11:15standard radiation therapy would
- 11:17be equivalent to proton therapy,
- 11:19and I do think that we can
- 11:22deliver exceptional care with
- 11:23standard radiation treatment.
- 11:25As I mentioned,
- 11:26tremendous advancements have been made
- 11:29even with standard X rays or photons.
- 11:32But in some circumstances I must say that
- 11:35I have recommended patients
- 11:37to receive a second opinion
- 11:39at a proton therapy center
- 11:41Can you talk a little bit
- 11:43about some of the other techniques
- 11:45that have been developed using
- 11:48standard radiation therapy that might
- 11:50minimize the dosage to normal organs.
- 11:52Many patients are always worried about,
- 11:55for example, if they're getting
- 11:56radiation therapy after a breast cancer,
- 11:59let's say to their chest.
- 12:01They're worried about the radiation
- 12:03affecting their heart or their lungs.
- 12:05What advancements have been made
- 12:07to protect those organs and should
- 12:10patients be worried about the
- 12:12extra radiation hitting those
- 12:13normal tissues?
- 12:16As a radiation oncologist, these
- 12:17are the things that are on
- 12:19my mind each and every day.
- 12:22How do I design a radiation treatment
- 12:24plan that can minimize effectively
- 12:26the dose of radiation therapy to
- 12:28normal organs and with standard
- 12:30radiation therapy for breast cancer
- 12:33we've come up with very nice ways to
- 12:36displace or move the heart or
- 12:38lungs away from the targeted breast
- 12:40tissue and for other cancers
- 12:43we've developed highly sophisticated
- 12:44X ray techniques such as intensity
- 12:47modulated radiation therapy,
- 12:48which, in simplified terms,
- 12:50involves advanced computer technology
- 12:53and sophisticated radiation beam
- 12:54design to better focus the high doses
- 12:57of radiation therapy to the tumor
- 12:59and spare the normal tissues so we do
- 13:02have very effective alternatives to
- 13:04proton therapy that can effectively
- 13:07and very well treat patients.
- 13:10That's really great to hear,
- 13:11so we're going to pick up this
- 13:13conversation right after we take a
- 13:16short break for a medical minute.
- 13:18Please stay tuned to learn more
- 13:21about radiation oncology with
- 13:22my guest Doctor Krishnan Jethwa.
- 13:24Support for Yale Cancer Answers
- 13:26comes from AstraZeneca, working to
- 13:28eliminate cancer as a cause of death.
- 13:31Learn more at astrazeneca-us.com.
- 13:34This is a medical minute about survivorship.
- 13:38Completing treatment for cancer
- 13:39is a very exciting milestone,
- 13:41but cancer and its treatment can be a life
- 13:45changing experience for cancer survivors.
- 13:47The return to normal activities and
- 13:50relationships can be difficult and
- 13:52some survivors face long term side
- 13:54effects resulting from their treatment,
- 13:57including heart problems,
- 13:58osteoporosis, fertility issues,
- 13:59and an increased risk of second cancers.
- 14:02Resources are available to help
- 14:04keep cancer survivors well and
- 14:06focused on healthy living.
- 14:08More information is available
- 14:10at yalecancercenter.org.
- 14:11You're listening to Connecticut public radio.
- 14:15Welcome
- 14:15back to Yale Cancer Answers.
- 14:18This is doctor Anees Chagpar
- 14:20and I'm joined tonight by
- 14:22my guest Doctor Krishan Jethwa.
- 14:25We're discussing radiation therapy in
- 14:27the treatment of cancers and right
- 14:30before the break we were talking about
- 14:33some advanced techniques that have
- 14:35been developed that can really help in
- 14:37minimizing the side effects of radiation.
- 14:41Before I dive into some specific cancers,
- 14:44one question that we're always asked about
- 14:47is secondary malignancies.
- 14:48In other words,
- 14:51people often say, well, radiation therapy,
- 14:53it's kind of like radiation
- 14:56similar to the sun,
- 14:57but we know that with radiation,
- 15:00whether it's from sunlight or
- 15:03whether it's from nuclear explosions,
- 15:05can cause cancers.
- 15:06So is there a risk of developing
- 15:10a cancer from your radiation
- 15:12therapy which is designed to
- 15:15help you get rid of the cancer?
- 15:18That's a really, really good question,
- 15:20one which I get asked from most patients.
- 15:24And you're exactly right.
- 15:26With radiation therapy,
- 15:27while we focus it directly on to the tumor,
- 15:30and we do a very nice job at doing so,
- 15:34there is theoretically a risk that
- 15:36radiation therapy can increase the risk
- 15:38of developing a new cancer within or
- 15:40adjacent to the radiation therapy field.
- 15:43Thankfully, that risk is not very high.
- 15:45In fact, it's far less than 1%,
- 15:48and if it is to happen,
- 15:50it often takes many,
- 15:51many years to develop and I mean
- 15:545-10, 30-40 years to develop.
- 15:57So there is a relatively low risk of it
- 16:00occurring and it's a more significant
- 16:02risk in patients who are younger,
- 16:05particularly our pediatric patients,
- 16:06but as a radiation oncologist it is
- 16:10always something on my mind when
- 16:11I'm caring for those young patients.
- 16:14And that is one of the benefits of
- 16:16advanced radiation therapy technologies.
- 16:18For instance, proton therapy,
- 16:20that can theoretically decrease the risk
- 16:23of what we call a secondary malignancy.
- 16:26And so during the break
- 16:28you were telling me that your
- 16:30particular focus is on GI cancers.
- 16:32Can you tell us a little bit
- 16:35more about the use of radiation
- 16:37therapy in those cancers?
- 16:39Radiation therapies are used in the vast majority
- 16:41of GI cancer spanning head to toe.
- 16:44It has a role in either the curative
- 16:47intent treatment or in many it would
- 16:50be the symptom directed treatment.
- 16:52So that could be for esophagus cancers,
- 16:54stomach cancers, liver, pancreas,
- 16:56colon, rectal or even anal cancers.
- 16:58And we have a very nice role in doing so,
- 17:02often in combination with our
- 17:04colleagues from medical oncology
- 17:05and surgical oncology to help
- 17:07improve the outcomes for patients.
- 17:11So let's go through each of those in a
- 17:13bit more detail so that you can give us
- 17:16a little bit of color of what radiation
- 17:19therapy is like for each of those.
- 17:22I'd imagine that it's different, for example,
- 17:24in the esophagus versus in liver versus
- 17:27in the pancreas versus in the anal canal.
- 17:29How does radiation vary based on the site?
- 17:33So of course it is a different
- 17:35anatomical site of the body,
- 17:37and in many of those different
- 17:39circumstances we use different
- 17:40radiation technologies, which we
- 17:42think are best for the specific site.
- 17:44So for instance,
- 17:46when we treat an esophagus cancer,
- 17:48what's always on our mind is
- 17:50how do we treat the tumor while
- 17:53minimizing radiation therapy
- 17:54dose to organs like the heart,
- 17:56lungs, liver or even kidneys?
- 17:59Whereas when we're down in the pelvis
- 18:02treating a rectal cancer or an anal cancer,
- 18:05we worry about the radiation effects
- 18:07on the bowel, bladder, genitalia
- 18:09and bones like the femur
- 18:11which can be at risk of weakening or
- 18:14developing fractures as patients get
- 18:16older and there's a lot of nuance and
- 18:18art in how a radiation oncologist
- 18:20designs those fields and is in part
- 18:23why it's nice to have a specialty
- 18:25team involved in the care because
- 18:28there's such tremendous nuance
- 18:30in radiation therapy design and the
- 18:33technical specifics of the treatment,
- 18:35somewhat analogous to the expertise
- 18:37you may have from a surgical
- 18:40team as they design
- 18:42a complex surgical operation.
- 18:44And timing is the other issue too, right?
- 18:47So sometimes radiation
- 18:49is given before surgery,
- 18:50and sometimes it's given after surgery.
- 18:53How do you decide which way that works?
- 18:56For most of the
- 18:59gastrointestinal cancers we've
- 19:00through much research learned
- 19:02that delivering radiation therapy
- 19:05prior to a surgery is beneficial.
- 19:08And often that also includes
- 19:10delivery of the systemic treatment,
- 19:12the chemotherapy before the operation,
- 19:14and we've learned that we
- 19:16improve the cancer control.
- 19:18And in many instances,
- 19:19the survival of patients by
- 19:21delivering both of those treatment
- 19:23techniques before the operation.
- 19:25And that includes esophagus cancer,
- 19:27stomach cancers,
- 19:28pancreas, and rectal cancers,
- 19:30each of which we treat with
- 19:32therapy prior to the operation
- 19:34in many circumstances, and
- 19:36one can imagine that doing so
- 19:39might reduce the tumor burden.
- 19:42But how does that affect scaring
- 19:44for the surgeons?
- 19:46There's many beneficial effects of delivering the
- 19:48radiation therapy or chemotherapy beforehand,
- 19:50one of which is that we can actually
- 19:53see the tumor, rather than treating an
- 19:56area where the tumor has been removed.
- 19:59When we can see the tumor, we can focus
- 20:03the radiation beams more specifically,
- 20:05and often the area that we have to
- 20:07treat is considerably smaller when
- 20:09delivered in the pre surgical setting.
- 20:12That allows us to reduce the side
- 20:15effects that a patient may experience.
- 20:17Additionally, by shrinking down the tumor,
- 20:20it is often easier or more effective for
- 20:23the surgeon to remove all of the tumor
- 20:27with negative margins after the operation.
- 20:30And after doing this for decades and having
- 20:34clinical trials look at this for decades,
- 20:36there doesn't seem to be a dramatic
- 20:39difference in complications from the
- 20:41operation when it's done effectively
- 20:43as part of
- 20:44a multi disciplinary team.
- 20:46And yet in some cancers,
- 20:48radiation is frequently
- 20:49given after the surgery.
- 20:50So you had mentioned, for example,
- 20:53in breast cancer we generally
- 20:55give radiation therapy after
- 20:56the surgery is completed.
- 20:58So why is that?
- 21:00There's a number of reasons for that,
- 21:02and I think in the breast cancer
- 21:05community, now acknowledging I'm
- 21:06not a breast cancer specialist,
- 21:08but the typical paradigm has
- 21:09been to do surgery first,
- 21:11in part for concern of wound complications
- 21:14that may develop along the skin.
- 21:17And in part because it's nice to have
- 21:20an opportunity to look at the cancer
- 21:23under the microscope and see the
- 21:25extent of spread so that we can better
- 21:28design our radiation therapy fields.
- 21:30So it sounds like there's good
- 21:33reasons in GI cancer to do it before
- 21:36good reasons in breast cancer
- 21:38to do it afterwards.
- 21:39So it seems to be really dependent on the
- 21:43tumor itself.
- 21:45And individual patients and again
- 21:48this emphasizes why being
- 21:49seen and cared for amongst a
- 21:51multidisciplinary specialty team,
- 21:53such as that we have at Yale is
- 21:56really so critical in the care of
- 21:59our patients.
- 22:01And you mentioned clinical trials
- 22:03adding to the evidence
- 22:05that we have in terms of what we
- 22:08know works versus doesn't work
- 22:11in terms of radiation therapy.
- 22:13Are there ongoing clinical trials
- 22:15that you're particularly excited about?
- 22:17There's so many.
- 22:19My interests are in using multiple
- 22:22methods of patient and cancer response
- 22:25assessment to guide the care of patients,
- 22:28and that can include advanced imaging.
- 22:31It can involve tumor genetics or genomics.
- 22:35It can include specific targets on a cancer
- 22:39cell that may be targeted by medications.
- 22:43Or it can be specific blood tests
- 22:45that guide the prognosis for patients.
- 22:47Potential therapies for patients
- 22:49can also involve immunotherapy,
- 22:51and specifically in GI cancers
- 22:53we've been utilizing
- 22:54each of those techniques to
- 22:56help risk stratify and guide
- 22:58patients for subsequent therapies.
- 23:00And it's so exciting because many
- 23:02of these developments are relatively
- 23:04recent in the past five to 10 years,
- 23:07and we're really seeing some of the
- 23:10fruits of these clinical trials now.
- 23:13Our major cancer conference is ASCO
- 23:18and it's exciting seeing some of the new
- 23:21clinical trial developments that
- 23:22really improve the survival,
- 23:25but also the quality of life for
- 23:27our patients as they go through therapy.
- 23:30Do you think that these novel markers,
- 23:33the genomic markers,
- 23:34the biomarkers that we're using to tailor
- 23:37chemotherapy and systemic therapy,
- 23:39for example, might actually play
- 23:41a role in terms of deciding,
- 23:43for example, whether radiation therapy
- 23:46should be used or not or what
- 23:49kind of radiation therapy
- 23:50I completely do.
- 23:52I think we're learning so much more
- 23:55about the prognosis of patients
- 23:57and the pathways of cancer spread,
- 23:59which does seem to be influenced
- 24:01by each of these factors,
- 24:03and we're learning how to select
- 24:05patients who may derive more
- 24:07benefit from radiation therapy.
- 24:09And on the contrary, we're learning
- 24:11patients who may derive less benefit,
- 24:13and that in itself is rewarding because
- 24:16that provides an opportunity for a
- 24:18radiation oncologist to help treat patients,
- 24:21but know that if they do have a side effect,
- 24:25it was a side effect that developed in a
- 24:27patient that really needed the treatment.
- 24:30Those who derive less benefit
- 24:32can be spared many of those side
- 24:35effects of therapy.
- 24:36And what about figuring out which
- 24:38tumors are more radiosensitive
- 24:39versus those that are radioresistant?
- 24:42Are there techniques that we
- 24:43can use that will help us to
- 24:46deliver radiation therapy to
- 24:48tumors that might not be as sensitive to it?
- 24:51Yeah, this is another very
- 24:53interesting area of research
- 24:55which I think we've really just
- 24:57hit the tip of the iceberg on.
- 24:59We're learning that genomics or
- 25:01tumor genetics has an impact.
- 25:03We're learning that the tissue
- 25:04surrounding a tumor has an impact,
- 25:06and I do think that with more
- 25:08time we'll learn how to combine
- 25:10new medications with radiation
- 25:12therapy to improve cancer control
- 25:14and will learn that there may be
- 25:17differences in radiation therapy dose.
- 25:18Or areas that we need to treat
- 25:20to derive more benefit.
- 25:22But like I said,
- 25:23it's really the tip of the
- 25:25iceberg in regards to that area of
- 25:27research, which is really exciting.
- 25:29And so as we think about radiation therapy,
- 25:31I mean thus far we've really been talking
- 25:33about using radiation as part of a
- 25:36treatment paradigm for curative intent.
- 25:37But you had mentioned early on at the
- 25:40beginning of the show that radiation
- 25:42can also be used for palliative intent.
- 25:44Can you tell us a little bit
- 25:46more about how radiation therapy
- 25:47is used for symptom control?
- 25:50Radiation therapy is very
- 25:52effective at symptom control,
- 25:53and I tend to quote that about 2/3 or
- 25:56more of patients will derive a benefit.
- 25:59In regards to the specific indications,
- 26:02often it's for pain control when cancer
- 26:05has spread elsewhere in the body,
- 26:08or if it's causing pain in its
- 26:10original site of development or
- 26:12radiation therapy can be used to
- 26:14help prevent organ dysfunction or
- 26:17complications from cancer growth.
- 26:19What do
- 26:20you mean by organ dysfunction?
- 26:22So a common situation that we end up
- 26:25seeing is if cancer has spread to a bone
- 26:28like the spinal column or vertebral body,
- 26:31that cancer can actually grow into the
- 26:33spinal canal and start applying pressure
- 26:36to the spinal cord or to the nerves.
- 26:39And unfortunately,
- 26:40one of the consequences of that is that
- 26:43patients can develop weakness in their
- 26:45legs or in some circumstances even
- 26:48the inability to walk because of it.
- 26:50Radiation therapy can slow down and
- 26:53shrink the cancer in those bones and
- 26:55really help relieve the pressure on
- 26:57the spinal canal or those nerves.
- 26:59And sometimes that's done in combination
- 27:01with surgery and sometimes it's not.
- 27:03We use radiation therapy alone
- 27:05and it's quite effective.
- 27:06One of the
- 27:08things that's so interesting you had
- 27:10mentioned earlier that when you're
- 27:12giving radiation in the pelvis,
- 27:14one of the things you worry about
- 27:16is the side effects on the bone.
- 27:18That radiation could weaken the bone.
- 27:21And yet, at the same time,
- 27:24when we see patients who have,
- 27:26for example, bone metastases,
- 27:28we frequently will use radiation
- 27:31therapy not only to help with pain,
- 27:33but sometimes even to help with patients
- 27:36who might have an impending fracture.
- 27:39Tell me about how that works.
- 27:41That seems to be a dichotomy.
- 27:43Yeah, that's a good question.
- 27:45When I see patients with bone metastases,
- 27:48the common questions I ask myself are,
- 27:50is this metastasis in a bone that
- 27:53is involved in weight bearing
- 27:54like the femurs for example?
- 27:56Or how much of the bone seems to
- 27:59be destroyed because of the cancer?
- 28:02If I do think of patients at very
- 28:04high risk of developing a fracture,
- 28:07I do ask my colleagues in orthopedic surgery
- 28:10or neurosurgery to see the patients as well.
- 28:12Because I do think that surgery
- 28:15can sometimes be warranted.
- 28:16In others where it's not a weight
- 28:19bearing joint or an area that's
- 28:21involved in a lot of mechanical
- 28:24strain then radiation therapy is
- 28:26very effective at shrinking the
- 28:27cancer and getting control of pain.
- 28:29Doctor Krishan Jethwa is an
- 28:32assistant professor of therapeutic
- 28:33radiology at the Yale School of Medicine.
- 28:36If you have questions,
- 28:37the address is canceranswers@yale.edu
- 28:39and past editions of the program
- 28:41are available in audio and written
- 28:43form at yalecancercenter.org.
- 28:44We hope you'll join us next week to
- 28:47learn more about the fight against
- 28:49cancer here on Connecticut Public Radio.
- 28:55Support for Yale Cancer Answers comes from
- 28:58Smilow Cancer Hospital and AstraZeneca.