Breakthrough Radiotherapy Provides New Options for Patients

Transcript

00:00 --> 00:02Funding for Yale Cancer Answers is
00:02 --> 00:04provided by Smilow Cancer Hospital.
00:06 --> 00:08Welcome to Yale Cancer Answers
00:08 --> 00:10with Doctor Anees Chagpar.
00:10 --> 00:12Yale Cancer Answers features the
00:12 --> 00:14latest information on cancer care
00:14 --> 00:15by welcoming oncologists and
00:15 --> 00:17specialists who are on the forefront
00:17 --> 00:19of the battle to fight cancer.
00:19 --> 00:21This week it's a conversation about
00:21 --> 00:23advances in radiotherapy for cancer
00:23 --> 00:26patients with Doctor Kimberly Johung.
00:26 --> 00:28Doctor Johung is an associate
00:28 --> 00:29professor of therapeutic radiology
00:29 --> 00:31at the Yale School of Medicine,
00:31 --> 00:33where Doctor Chagpar is a
00:33 --> 00:34professor of surgical oncology.
00:36 --> 00:38Dr. Johung, let's have you
00:38 --> 00:40tell us a little bit about
00:40 --> 00:43yourself and what it is you do.
00:44 --> 00:47Absolutely. I'm a radiation oncologist
00:47 --> 00:49and I specialize in the treatment
00:49 --> 00:50of gastrointestinal malignancies.
00:51 --> 00:52I think the first question often is,
00:52 --> 00:54well, what is radiation therapy and
00:54 --> 00:56what is the radiation oncologist,
00:56 --> 00:58so I'll address that first.
00:58 --> 01:01So radiation therapy is the use of
01:01 --> 01:04ionizing radiation to kill cancer cells,
01:04 --> 01:08one of our main modalities for the
01:08 --> 01:09treatment of cancer, along with
01:09 --> 01:11surgery and of course chemotherapy.
01:11 --> 01:13We deliver our radiation
01:13 --> 01:14from a linear accelerator,
01:14 --> 01:16a machine that basically,
01:16 --> 01:20I would say precisely targets high
01:20 --> 01:22energy X-rays towards tumors,
01:22 --> 01:25leading to DNA damage in the
01:25 --> 01:27cancer cells and cell death.
01:27 --> 01:29And so I found myself in radiation
01:29 --> 01:32oncology because I really liked the
01:32 --> 01:34multidisciplinary aspect of care
01:34 --> 01:37both within our department we work
01:37 --> 01:40with physicists who help us devise
01:40 --> 01:43the plans along with the medical
01:43 --> 01:45dosimetrist and also a great team of
01:45 --> 01:47radiation therapists who deliver the
01:47 --> 01:49daily treatments for our patients
01:49 --> 01:51and I found myself specializing in GI
01:51 --> 01:53cancers mostly because the opportunity
01:53 --> 01:55arose when I was early in my career.
01:57 --> 02:00Tell us a little bit
02:00 --> 02:03more about what kinds of GI
02:03 --> 02:06cancers you target in particular and
02:06 --> 02:09that you work most commonly with and how
02:09 --> 02:12does radiation therapy really play into
02:12 --> 02:15those patients treatment algorithm?
02:15 --> 02:18In the GI tract the
02:18 --> 02:20main cancers that we employ radiation
02:20 --> 02:23therapy for would be esophageal cancers,
02:23 --> 02:26pancreatic cancers, colorectal cancers,
02:26 --> 02:29some liver tumors and anal cancers.
02:29 --> 02:32And so for some of these cancers
02:32 --> 02:33the radiation therapy actually
02:33 --> 02:36is critical to cure the cancer.
02:36 --> 02:39We can use radiation therapy in
02:39 --> 02:42conjunction with chemotherapy to cure anal
02:42 --> 02:44cancers as well as esophageal cancers.
02:44 --> 02:47Sometimes surgery is also employed
02:47 --> 02:49for patients with esophageal cancers.
02:49 --> 02:51For the other cancers I mentioned,
02:51 --> 02:52we use radiation therapy as what
02:52 --> 02:55we would call part of a combined
02:55 --> 02:56modality treatment program,
02:56 --> 02:59so along with chemotherapy and surgery
02:59 --> 03:01to give patients the best outcomes.
03:01 --> 03:04So for example, in pancreatic cancer,
03:04 --> 03:06radiation therapy is often employed
03:06 --> 03:09prior to surgery to help improve the
03:09 --> 03:11likelihood of achieving a complete
03:11 --> 03:14resection of a pancreatic tumor.
03:14 --> 03:16And then we also use radiation
03:16 --> 03:18therapy for those patients who may
03:18 --> 03:19not be candidates for surgery.
03:19 --> 03:22And we are trying in that instance to
03:22 --> 03:24provide local control of the tumor and
03:24 --> 03:26often to control the onset of local
03:26 --> 03:28symptoms that may be a result of a
03:28 --> 03:30cancer growing in a particular location.
03:31 --> 03:33Terrific. So it sounds like radiation
03:33 --> 03:36therapy has all kinds of utilities for
03:36 --> 03:39many different cancers in the GI tract.
03:39 --> 03:41Now at the top of the show,
03:41 --> 03:43you had mentioned this
03:43 --> 03:44new technology RefleXion.
03:44 --> 03:47Can you tell us a little bit more
03:47 --> 03:50about what exactly that is and how
03:50 --> 03:52it plays into the workings of
03:52 --> 03:54radiation therapy for these patients?
03:55 --> 03:57Absolutely. So the Reflexion
03:57 --> 03:58is a linear accelerator,
03:58 --> 04:02which I mentioned is the machine that directs
04:02 --> 04:04focused radiation beams towards tumors.
04:04 --> 04:07And what's unique about the RefleXion
04:07 --> 04:10is that it combines PET imaging
04:10 --> 04:12technology with radiation therapy.
04:12 --> 04:14So I think to better understand
04:14 --> 04:16how the RefleXion is novel
04:16 --> 04:18and what the benefits are,
04:18 --> 04:19it's best to probably first talk
04:19 --> 04:22about what is a PET scan and how
04:22 --> 04:24is that used in combination with
04:24 --> 04:26radiation therapy on the RefleXion.
04:26 --> 04:29So a PET scan is a common imaging technique,
04:30 --> 04:32as you know, used in cancer care.
04:32 --> 04:34These are scans that are
04:34 --> 04:36standard way to image tumors.
04:36 --> 04:39I would say screen for sites of metastases
04:39 --> 04:42and also monitor response to treatment.
04:42 --> 04:46The way a PET scan works is that we first
04:46 --> 04:49inject a radioactive tracer into the patient.
04:49 --> 04:52The radio tracer can be used for
04:52 --> 04:55cancer detection because it's a
04:55 --> 04:57glucose or a sugar analog that is
04:57 --> 05:00attached to a radioactive marker.
05:00 --> 05:02So that means that active cancer cells
05:02 --> 05:04will consume more of the radio tracer.
05:04 --> 05:07We call it FDG for the most common type
05:07 --> 05:11of PET scan and it consumes that FDG at
05:11 --> 05:14a greater rate than normal healthy tissues.
05:14 --> 05:16So the radioactive signal can be detected
05:16 --> 05:19and then reconstructed with a CAT scan.
05:19 --> 05:21So you basically get a three-dimensional
05:21 --> 05:24image where the amount of tracer uptake
05:24 --> 05:26would correlate with the metabolic
05:26 --> 05:29activity or I would say that the tumor
05:29 --> 05:31activity in that area of the body,
05:31 --> 05:34basically a PET scan is a whole body
05:34 --> 05:37scan and it shows us where tumors
05:37 --> 05:40are located in the body and how much
05:40 --> 05:43the areas light up on the PET scan
05:43 --> 05:45would correlate with how active
05:45 --> 05:47cancer cells are in those areas.
05:47 --> 05:50So on the RefleXion
05:50 --> 05:52the SCINTIX technology,
05:52 --> 05:55which is basically the program
05:55 --> 05:58that has been incorporated into this Linac,
05:58 --> 06:01tracks the PET tracer emissions from
06:01 --> 06:05cancer cells and that is used to determine
06:05 --> 06:08where to direct the radiation even if
06:08 --> 06:10a tumor is moving during treatment.
06:10 --> 06:14So the novel technology is combining the
06:14 --> 06:18PET imaging as a means to guide where and
06:18 --> 06:21when to deliver the radiation therapy.
06:22 --> 06:24Well, you know,
06:24 --> 06:26so that sounds really exciting,
06:26 --> 06:28but also it seems to kind of make
06:28 --> 06:30sense that you would have some
06:30 --> 06:33sort of an imaging modality to
06:33 --> 06:35direct the radiation therapy to
06:35 --> 06:37what you wanted to treat prior
06:37 --> 06:41to this RefleXion technology.
06:41 --> 06:42How is that being done?
06:43 --> 06:45So what we do for radiation therapy
06:45 --> 06:48is we start with a planning CAT scan.
06:48 --> 06:51This is a three-dimensional image of a
06:51 --> 06:53patient in the position for radiation
06:53 --> 06:56treatment and we use those images to
06:56 --> 06:59define the target volumes being the
06:59 --> 07:01tumor and any at risk areas as well as
07:01 --> 07:04the normal tissues that we want to try
07:04 --> 07:07to minimize radiation dose delivery to.
07:07 --> 07:08With those CAT scans,
07:08 --> 07:11we generate a plan to direct the
07:11 --> 07:13radiation at the sites of interest and
07:13 --> 07:16we deliver that plan on the Linac with
07:16 --> 07:18very focused beams that are shaped
07:18 --> 07:20across the face of the beam to match
07:20 --> 07:22the shape of the tumor from the angle
07:22 --> 07:24that the beam is being delivered.
07:24 --> 07:26We combine that with imaging on
07:26 --> 07:29the machine on a daily basis,
07:29 --> 07:31so we can obtain a CAT scan or X-ray
07:31 --> 07:33imaging to look at the patient anatomy
07:33 --> 07:36on the day that they come in for
07:36 --> 07:38treatment and move the patient on the
07:38 --> 07:40treatment table in order to get the
07:40 --> 07:43patient in position for treatment.
07:43 --> 07:45What this does not help us see is
07:45 --> 07:47motion that occurs during treatment and
07:47 --> 07:49that's where this technology
07:50 --> 07:52really is novel in providing added benefits.
07:54 --> 07:58And it sounds like this
07:58 --> 08:01technology is certainly exciting in the
08:01 --> 08:03sense that it can see tumors moving,
08:03 --> 08:05but it also sounds like it
08:05 --> 08:06might be really expensive.
08:06 --> 08:09So I have just a couple of questions.
08:09 --> 08:11One, how expensive is this and
08:11 --> 08:13is it covered by insurance?
08:13 --> 08:16And two, how often do tumors
08:16 --> 08:18really move during treatment?
08:18 --> 08:19In other words,
08:19 --> 08:22is this really something that's necessary
08:22 --> 08:25for the vast majority of patients or
08:25 --> 08:27could this simply be an added expense?
08:28 --> 08:31So this is currently approved by
08:31 --> 08:34insurance companies and the cost to the
08:34 --> 08:36patient would be no different than the
08:36 --> 08:38cost of a program of radiation therapy
08:38 --> 08:40that is approved by your insurance
08:40 --> 08:42company with the added cost to the
08:42 --> 08:44insurance company of course of the
08:44 --> 08:46PET scan that would be delivered for
08:46 --> 08:48treatment planning and during treatment.
08:48 --> 08:50But it has been approved by
08:50 --> 08:52insurance companies and we would of
08:52 --> 08:54course make sure that's authorized
08:54 --> 08:56prior to proceeding with any treatment.
08:56 --> 08:59In regards to the the tumor motion
08:59 --> 09:02and how this is beneficial,
09:02 --> 09:04I think it would be interesting
09:04 --> 09:06to talk about treatment of a lung cancer
09:06 --> 09:08to try to envision how the RefleXion
09:08 --> 09:11technology really provides benefits.
09:11 --> 09:15So how often a patients tumors moves
09:15 --> 09:17would be very common when we're
09:17 --> 09:19considering a lung cancer, for example.
09:19 --> 09:21So this means that when you're
09:21 --> 09:22targeting a lung cancer,
09:22 --> 09:24you're basically trying to target a
09:24 --> 09:26moving target with radiation precisely.
09:29 --> 09:33So typically how we would take this
09:33 --> 09:35into account with radiation therapy
09:35 --> 09:38is that the radiation field would
09:38 --> 09:40have to be expanded to encompass the
09:40 --> 09:43path a lung tumor takes while the
09:43 --> 09:45patient breathes in order to fully
09:45 --> 09:49dose the radiation to the tumor.
09:49 --> 09:51And we also have to take into
09:51 --> 09:53account not only motion of tumors
09:53 --> 09:55but also motion of the patient.
09:55 --> 09:58So a patient may move and even a small
09:58 --> 10:01amount of motion say millimetres during
10:01 --> 10:04treatment could move the tumor outside
10:04 --> 10:06of the high dose radiation region.
10:06 --> 10:09So we would further expand the
10:09 --> 10:11radiation field to take into
10:11 --> 10:12account that potential motion.
10:13 --> 10:14So with the RefleXion
10:14 --> 10:17they're calling it biologically
10:17 --> 10:18guided radiation therapy.
10:18 --> 10:21So rather than taking into
10:21 --> 10:24account the natural motion of the
10:24 --> 10:27tumor or the motion of a patient
10:27 --> 10:28with larger treatment fields,
10:28 --> 10:31the field can be smaller because the
10:31 --> 10:34PET signal from the tumor is tracked
10:34 --> 10:36by the RefleXion to guide where
10:36 --> 10:38and when to deliver the radiation.
10:39 --> 10:41So you can imagine it is as if
10:41 --> 10:43the radiation treatment plan is
10:43 --> 10:45moving with the tumor.
10:45 --> 10:47If the tumor naturally moves,
10:47 --> 10:49such as a lung cancer or
10:49 --> 10:51if the patient may wiggle a little bit
10:51 --> 10:53on the treatment table during treatment.
10:53 --> 10:56And so if you can narrow the radiation
10:56 --> 10:59field to just target the tumor and
10:59 --> 11:01not have to expand the field to
11:01 --> 11:04account for all of this motion,
11:04 --> 11:06you might have fewer side effects too, right?
11:07 --> 11:08That's exactly what I was
11:08 --> 11:09going to say, Doctor Chagpar.
11:09 --> 11:12The main benefit really is that we can
11:12 --> 11:15reduce the volume of normal healthy
11:15 --> 11:18tissue surrounding the tumor and the
11:18 --> 11:20exposure of those tissues to high
11:20 --> 11:22doses of radiation and that in turn
11:22 --> 11:25can significantly reduce side effects.
11:26 --> 11:28And so it sounds
11:28 --> 11:30like this is novel technology.
11:30 --> 11:33Has that actually been looked at
11:33 --> 11:35in terms of studies where you can
11:35 --> 11:38actually say that there is A-X percent
11:38 --> 11:41difference in terms of the side effects
11:41 --> 11:43that patients may have to face.
11:43 --> 11:46So for example, in the case
11:46 --> 11:49of lung cancer that there might be
11:49 --> 11:52less radiation induced pneumonitis or
11:52 --> 11:55less cardiac toxicity with the use
11:55 --> 11:57of this new technology versus what
11:57 --> 12:00we have historically always used.
12:00 --> 12:01That's a great question.
12:01 --> 12:02So what has
12:02 --> 12:05been studied so far since this is such a
12:05 --> 12:07novel technology is that with the PET,
12:07 --> 12:11with the PET tracking you are in fact
12:11 --> 12:13delivering adequate dose to the tumor
12:13 --> 12:16and if anything able to better deliver an
12:16 --> 12:18ablative dose and full coverage of the
12:18 --> 12:21tumor while it moves during treatment.
12:21 --> 12:24What we have open right now at Smilow
12:24 --> 12:26is a registry trial.
12:26 --> 12:29So this is a trial for patients who
12:29 --> 12:31are being treated on the RefleXion machine,
12:31 --> 12:34we are collecting data prospectively
12:34 --> 12:41in terms of their tumor type outcomes,
12:41 --> 12:44in terms of response to treatment
12:44 --> 12:46and using that data in order to
12:46 --> 12:48understand their response to therapy,
12:48 --> 12:51how to predict response,
12:51 --> 12:56but also being able to quantify how the
12:56 --> 12:59delivery of treatment on the RefleXion
12:59 --> 13:02might reduce the risk of side effects.
13:03 --> 13:06Fantastic. Well, we are going to talk more
13:06 --> 13:08about these interesting breakthroughs
13:08 --> 13:11in terms of radiation therapy,
13:11 --> 13:13but first we need to take a short
13:13 --> 13:15break for a medical minute.
13:15 --> 13:17Please stay tuned to learn more
13:17 --> 13:18about this breakthrough radiation
13:18 --> 13:20therapy with my guest,
13:20 --> 13:21Doctor Kimberly Johung.
13:22 --> 13:24Funding for Yale Cancer Answers
13:24 --> 13:26comes from Smilow Cancer Hospital,
13:26 --> 13:28where their Prostate and Urologic cancers
13:28 --> 13:31program is comprised of a team dedicated
13:31 --> 13:32to managing the diagnosis, evaluation,
13:32 --> 13:35and treatment of urologic cancers,
13:35 --> 13:38including testicular cancer.
13:38 --> 13:42Smilowcancerhospital.org.
13:42 --> 13:45Genetic testing can be useful for people with certain types of
13:45 --> 13:47cancer that seem to run in their families.
13:47 --> 13:49Genetic counseling is a process
13:49 --> 13:51that includes collecting a detailed
13:51 --> 13:52personal and family history,
13:52 --> 13:54a risk assessment,
13:54 --> 13:57and a discussion of genetic testing options.
13:57 --> 13:59Only about 5 to 10% of all cancers
13:59 --> 14:01are inherited and genetic testing
14:01 --> 14:03is not recommended for everyone.
14:03 --> 14:05Individuals who have a personal
14:05 --> 14:08and or family history that includes
14:08 --> 14:10cancer at unusually early ages,
14:10 --> 14:12multiple relatives on the same side
14:12 --> 14:14of the family with the same cancer,
14:14 --> 14:17more than one diagnosis of cancer in
14:17 --> 14:19the same individual, rare cancers,
14:19 --> 14:22or family history of a known altered
14:22 --> 14:24cancer predisposing gene, could be
14:24 --> 14:26candidates for genetic testing.
14:26 --> 14:28Resources for genetic counseling and
14:28 --> 14:31testing are available at federally
14:31 --> 14:32designated comprehensive cancer
14:32 --> 14:34centers such as Yale Cancer Center
14:34 --> 14:36and Smilow Cancer Hospital.
14:36 --> 14:39More information is available
14:39 --> 14:40at yalecancercenter.org.
14:40 --> 14:42You're listening to Connecticut Public Radio.
14:43 --> 14:45Welcome back to Yale Cancer Answers.
14:45 --> 14:47This is Doctor Anees Chagpar and
14:47 --> 14:48I'm joined tonight by my guest,
14:48 --> 14:50Doctor Kimberly Johung.
14:50 --> 14:53We're talking about a new
14:53 --> 14:54breakthrough radiotherapy.
14:54 --> 14:57It's actually a technique called RefleXion
14:57 --> 15:00which kind of pairs radiation
15:00 --> 15:03therapy delivery with what sounds
15:03 --> 15:07like real time PET scan techniques,
15:07 --> 15:08essentially allowing radiation
15:08 --> 15:11therapists like Doctor Johung to
15:11 --> 15:15kind of track that tumor as it moves
15:15 --> 15:17and as a patient moves during therapy
15:17 --> 15:20with the PET imaging and deliver the
15:20 --> 15:23radiation therapy more precisely.
15:23 --> 15:26So Kim, you were talking
15:26 --> 15:29earlier on about this technology
15:29 --> 15:31and you were saying that you
15:31 --> 15:33actually specialize in GI cancer.
15:34 --> 15:36We kind of took a little bit of
15:36 --> 15:38a detour to kind of get a sense
15:38 --> 15:41of how this technology might work
15:41 --> 15:43in terms of lung cancers where
15:43 --> 15:46you can imagine that as people
15:46 --> 15:48breathe their tumors might move.
15:48 --> 15:51Can you talk a little bit more
15:51 --> 15:54about its particular utility
15:54 --> 15:56in GI cancers?
15:57 --> 15:58Absolutely.
15:58 --> 16:02We did talk a lot about how the RefleXion
16:02 --> 16:04can optimize the treatment of cancers that
16:04 --> 16:06move during treatment.
16:06 --> 16:09And where this comes into play for GI
16:09 --> 16:12cancers would be in the delivery of what
16:12 --> 16:15we call stereotactic body radiation therapy.
16:15 --> 16:18So stereotactic body radiation therapy,
16:18 --> 16:21that's a mouthful I'll call it SBRT,
16:21 --> 16:24is a specialized type of radiation
16:24 --> 16:26therapy in which very precise high
16:26 --> 16:29doses or ablative doses of radiation
16:29 --> 16:32can be delivered to small tumors.
16:32 --> 16:36So typically between 1-5 treatments
16:36 --> 16:40for tumors that are very localized.
16:40 --> 16:42And in this situation it becomes
16:42 --> 16:44very important to precisely
16:44 --> 16:46be able to track tumors.
16:46 --> 16:48So we know that stereotactic
16:48 --> 16:50radiation can be an effective,
16:50 --> 16:53non invasive way to treat not
16:53 --> 16:55only early stage lung cancers,
16:55 --> 16:57but also liver tumors that may
16:57 --> 16:59not be able to be resected,
16:59 --> 17:01pancreatic tumors that also
17:01 --> 17:02cannot be resected,
17:02 --> 17:04or metastatic sites with these
17:04 --> 17:08ablative doses that can be effective
17:08 --> 17:10without concurrent chemotherapy.
17:10 --> 17:12So I did mention the liver tumors
17:12 --> 17:13and the pancreatic tumors.
17:13 --> 17:15Those would be primary tumors
17:15 --> 17:17that develop in those organs.
17:17 --> 17:20But for metastatic sites,
17:20 --> 17:23one area where SBRT has very
17:23 --> 17:24promising data is in the treatment
17:24 --> 17:26of oligometastatic disease.
17:28 --> 17:29So tell tell us more about that,
17:29 --> 17:33what exactly is oligometastatic disease
17:33 --> 17:37and how does this work in those patients?
17:38 --> 17:41Absolutely. So oligometastatic disease
17:41 --> 17:44would be primary tumors that arise in,
17:44 --> 17:46if we're talking about the GI tract,
17:46 --> 17:47we'll use for example,
17:47 --> 17:50the colon or the anus and then have
17:50 --> 17:52spread to a limited number of sites,
17:52 --> 17:53typically under 5 sites.
17:53 --> 17:57And what we've seen is that this is a
17:57 --> 17:59subtype of metastatic disease where
17:59 --> 18:01patients actually can have very good
18:01 --> 18:04outcomes that we can see long term
18:04 --> 18:06survival and this is achieved with
18:06 --> 18:09definitive treatment of the primary tumor.
18:09 --> 18:11So that would typically
18:11 --> 18:13involve chemotherapy, surgery,
18:13 --> 18:15often radiation therapy to
18:15 --> 18:17address the primary tumor.
18:17 --> 18:20And then if a good response is achieved,
18:20 --> 18:21you can provide local therapy
18:21 --> 18:24to those one to five limited
18:24 --> 18:26sites of metastatic disease.
18:26 --> 18:28So local therapy can be surgical resection,
18:28 --> 18:30but when surgery for these
18:30 --> 18:32metastatic sites is not feasible,
18:32 --> 18:35particularly if we're talking about
18:35 --> 18:38multiple sites of oligometastatic disease,
18:38 --> 18:41then SBRT or the stereotactic
18:41 --> 18:43radiation can provide high load
18:43 --> 18:46rates of local control with minimal
18:46 --> 18:49toxicity in a way that's non invasive.
18:49 --> 18:51And there are other local treatments
18:51 --> 18:54that can be provided for oligo-
18:54 --> 18:56metastatic disease such as ablation
18:56 --> 18:58techniques like microwave ablation
18:58 --> 18:59or radiofrequency ablation.
19:01 --> 19:04So in terms of of using this
19:04 --> 19:06technique of RefleXion
19:06 --> 19:09it sounds like that is really
19:09 --> 19:13specific to ablating these tumors
19:13 --> 19:17with SBRT as opposed to microwave or
19:17 --> 19:20other techniques that you mentioned,
19:20 --> 19:21is that right?
19:21 --> 19:24Yes, the RefleXion technology with the
19:24 --> 19:26PET tracking or biologically guided
19:26 --> 19:29radiation therapy as we're calling it
19:29 --> 19:33really is to be used in conjunction with
19:33 --> 19:36radiation therapy for the delivery of
19:36 --> 19:38stereotactic body radiation therapy.
19:38 --> 19:41And right now the SBRT is
19:41 --> 19:44approved for the treatment of lung
19:44 --> 19:48tumor sites and bone tumors though we
19:48 --> 19:50expect those disease sites to expand.
19:50 --> 19:52So when we're talking about GI cancers
19:52 --> 19:55and the use of the RefleXion technology,
19:55 --> 19:57where it really would come into play
19:57 --> 19:59right now is for the treatment of all
19:59 --> 20:01oligometastatic disease in the lung
20:01 --> 20:04or the bone from a primary GI cancer.
20:05 --> 20:08You know, one would think that if it was
20:08 --> 20:12good to treat lung cancers where they
20:12 --> 20:15move and perhaps bone oligometastatic
20:15 --> 20:19disease just because of the intensity,
20:19 --> 20:21it sounds like when we're doing
20:21 --> 20:23these ablative therapies,
20:23 --> 20:25it's really a more intense form of
20:25 --> 20:28radiation therapy than standard radiation.
20:28 --> 20:30And so when you're targeting
20:30 --> 20:32these metastatic sites,
20:32 --> 20:34you want to be more precise about it,
20:34 --> 20:34is that right?
20:35 --> 20:37That's correct. So when we're delivering
20:37 --> 20:40the stereotactic body radiation therapy,
20:40 --> 20:42each dose of radiation on a particular
20:42 --> 20:45day can be upwards of 10 times
20:45 --> 20:48the amount that we would give on a
20:48 --> 20:50standard radiation therapy program.
20:50 --> 20:52And so there it becomes extremely
20:52 --> 20:55important to be very precise with where
20:55 --> 20:58that delivery of radiation is and to
20:58 --> 21:00protect the surrounding normal tissues.
21:00 --> 21:02And when we discussed the ability
21:02 --> 21:04to reduce the treatment field with
21:04 --> 21:06the use of RefleXion technology,
21:06 --> 21:09that benefit in terms of decreasing the
21:09 --> 21:12risk of normal tissue exposure really
21:12 --> 21:14is increased when you're delivering the
21:14 --> 21:17higher doses of radiation for SBRT.
21:18 --> 21:20You know, when we think about
21:20 --> 21:22colorectal cancer, for example,
21:22 --> 21:24it seems that
21:24 --> 21:27we would think that the most common
21:27 --> 21:29place for colorectal cancer to
21:29 --> 21:31metastasize would be to the liver.
21:31 --> 21:35And so is there a reason why
21:35 --> 21:38RefleXion currently isn't used for
21:38 --> 21:40these oligometastatic sites in the
21:40 --> 21:43liver or did I misunderstand and it
21:43 --> 21:45really is being used in the liver?
21:46 --> 21:48We expect that the RefleXion technology
21:48 --> 21:50will be used for oligometastatic in
21:50 --> 21:53the liver because as you mentioned,
21:53 --> 21:54especially for colorectal cancer,
21:54 --> 21:58this is often where we see sites of
21:58 --> 22:00oligometastatic disease and where we've
22:00 --> 22:02seen excellent long term outcomes.
22:02 --> 22:05So what is in development right now
22:05 --> 22:08is being able to detect the PET tracer
22:08 --> 22:10activity from the metastatic site
22:10 --> 22:13or the tumor site in the liver and
22:13 --> 22:15be able to differentiate that from
22:15 --> 22:17the background uptake because there
22:17 --> 22:20is a certain degree of background
22:20 --> 22:22PET uptake in the liver.
22:22 --> 22:24So to be able to precisely
22:24 --> 22:25track a liver tumor,
22:25 --> 22:29one must be able to have a ability to
22:29 --> 22:30differentiate some slight differences
22:30 --> 22:33in PET activity or PET uptake between
22:33 --> 22:35the tumor and the normal tissue.
22:36 --> 22:38You really can use this technology
22:38 --> 22:42when the the PET scan is able to show
22:42 --> 22:44you a spot that lights up that's
22:44 --> 22:46very different from normal tissue,
22:46 --> 22:48and if that degree of separation
22:48 --> 22:50isn't always present in the liver,
22:50 --> 22:52then there might be more work
22:52 --> 22:54to be done in that area.
22:54 --> 22:56I can imagine that another metastatic
22:56 --> 22:59sites where it would be really helpful
22:59 --> 23:02to be very precise about targeting
23:02 --> 23:04radiation therapy would be the brain.
23:04 --> 23:07And so is it the same kind
23:07 --> 23:09of consideration for using
23:09 --> 23:11this technology in the brain,
23:11 --> 23:14the idea that there might not be that
23:14 --> 23:16difference in terms of resolution
23:16 --> 23:19between background and signal exactly.
23:19 --> 23:22So we often don't use PET scans in order
23:22 --> 23:24to detect brain metastases for that very
23:24 --> 23:26reason that you mentioned Doctor Chagpar.
23:26 --> 23:29And thankfully brain metastases
23:29 --> 23:32or primary brain tumors typically
23:32 --> 23:35don't move as much during treatment.
23:35 --> 23:37So we have other ways when we're
23:37 --> 23:39delivering high doses of radiation or
23:39 --> 23:41stereotactic radiation to make sure
23:41 --> 23:43that the patient doesn't move during
23:43 --> 23:46treatment such as immobilizing the patient
23:46 --> 23:49very precisely on a different platform
23:49 --> 23:51for stereotactic radiation delivery,
23:51 --> 23:53which is called the Gamma Knife that
23:53 --> 23:55we do have at our Cancer Center.
23:56 --> 23:59So we've talked a little bit
23:59 --> 24:02about using this technology for targeting
24:02 --> 24:06these oligometastatic sites for ablation
24:06 --> 24:11particularly in the lung and in bone.
24:11 --> 24:13Does it have any utility in the
24:13 --> 24:16GI tract for treating primary
24:16 --> 24:18cancers for example?
24:18 --> 24:22Currently I think that there are benefits that
24:22 --> 24:25will be coming into development because
24:25 --> 24:29GI cancers by nature will move with
24:29 --> 24:31respiration or with normal movement of
24:31 --> 24:34the gut or the organs within a patient.
24:34 --> 24:37And so I think that being able
24:37 --> 24:40to more precisely differentiate,
24:40 --> 24:42as you mentioned, the pet uptake or
24:42 --> 24:45activity from a tumor to those background
24:45 --> 24:47organs will be critical to moving
24:47 --> 24:49forward with using this technology
24:49 --> 24:53to treat primary GI cancers.
24:53 --> 24:55What about for other tumors?
24:55 --> 24:58I mean, you mentioned that for lung cancer,
24:58 --> 25:01it seems to make sense to use this.
25:01 --> 25:03I would imagine that this is now
25:03 --> 25:05being used for primary lung cancers.
25:05 --> 25:07Is that right? And is it being
25:07 --> 25:08used for any other cancers?
25:09 --> 25:11So currently we're focusing on early
25:11 --> 25:14stage lung cancers for patients who
25:14 --> 25:15are not surgical candidates where
25:15 --> 25:18we do see excellent outcomes with
25:18 --> 25:21stereotactic body radiation therapy.
25:21 --> 25:22And so that would typically be
25:22 --> 25:243 to 5 treatments to the lung.
25:24 --> 25:25Outside of that,
25:25 --> 25:28the focus is on ogliometastatic disease.
25:28 --> 25:31And right now we are limited
25:31 --> 25:32to treatment of metastatic
25:32 --> 25:34sites in the lung and the bone.
25:34 --> 25:36We can use the RefleXion
25:36 --> 25:38technology to deliver treatment
25:38 --> 25:40without the PET guidance as well.
25:40 --> 25:42And there are benefits to treatment
25:42 --> 25:45on the RefleXion outside of the
25:45 --> 25:46biologically guided radiation therapy.
25:46 --> 25:49So this would include basically
25:49 --> 25:51any tumor site and we can deliver
25:51 --> 25:53intensity modulated radiation therapy
25:53 --> 25:55using the RefleXion machine.
25:55 --> 25:58So intensity modulated radiation therapy
25:58 --> 26:00is different from stereotactic radiation
26:00 --> 26:03in that we are now delivering small
26:03 --> 26:05doses of radiation on a daily basis,
26:05 --> 26:08typically over the course of weeks.
26:08 --> 26:13And the reason for the small doses over days,
26:13 --> 26:15every day over weeks rather is that
26:15 --> 26:16that allows the normal tissues to
26:16 --> 26:18heal in between each treatment.
26:18 --> 26:20So while we are taking into
26:20 --> 26:21account tumor motion,
26:21 --> 26:23it is less critical because we
26:23 --> 26:25do have the time in between each
26:25 --> 26:27treatment for normal tissues to heal.
26:28 --> 26:29The benefit of the RefleXion
26:29 --> 26:32technology is that we do have high
26:32 --> 26:34quality imaging on the RefleXion
26:34 --> 26:36machine such that we can use a CAT
26:36 --> 26:38scan or a high quality CAT scan
26:38 --> 26:41or a pair of X-rays in order to
26:41 --> 26:43align the patient for those daily
26:43 --> 26:45treatments on the RefleXion.
26:45 --> 26:48So not only can the RefleXion
26:48 --> 26:50deliver the biologically guided
26:50 --> 26:52radiation therapy with PET guidance,
26:52 --> 26:55but also can be used to deliver more
26:55 --> 26:58standard radiation therapy such as IMRT.
26:59 --> 27:02And so in terms of using the
27:02 --> 27:05reflection without the PET,
27:05 --> 27:07is that with continuous imaging,
27:07 --> 27:10how is the RefleXion
27:10 --> 27:12without PET any different than
27:12 --> 27:14a standard linear accelerator?
27:15 --> 27:17Well, one of the benefits of the
27:17 --> 27:20RefleXion actually is the ability to treat
27:20 --> 27:23multiple tumor sites at the same time.
27:23 --> 27:26So typically we'll go back to the
27:26 --> 27:29example of the oligometastatic sites, right.
27:29 --> 27:32So if you were not to use biologically
27:32 --> 27:34guided radiation and you are treating
27:34 --> 27:36multiple tumor sites at the same time,
27:36 --> 27:40this would typically require one
27:40 --> 27:42treatment plan for the first site
27:42 --> 27:44and then realigning the patient
27:44 --> 27:46and treating the second site.
27:46 --> 27:48But the RefleXion is able to
27:48 --> 27:50simultaneously deliver treatment to
27:50 --> 27:52those two sites at the same time.
27:52 --> 27:54And if you were to be treating a
27:54 --> 27:56tumor in the lung that's moving,
27:56 --> 27:58it would be able to track and treat
27:58 --> 28:00those two tumors at the same time.
28:00 --> 28:02So the benefits would be the ability
28:02 --> 28:04to treat multiple sites simultaneously
28:04 --> 28:07and also that the while the RefleXion
28:07 --> 28:09does provide the typical radiation
28:09 --> 28:12treatments that other Linacs provide,
28:12 --> 28:14we have found that the quality of
28:14 --> 28:16the imaging that we take before each
28:16 --> 28:19treatment is delivered is of a higher
28:19 --> 28:23quality such that we are bit better
28:23 --> 28:25able to discern borders between normal
28:25 --> 28:27tissue structures and the tumor and
28:27 --> 28:30make sure that the patient is aligned
28:30 --> 28:32with millimeter precision for treatment.
28:32 --> 28:35Doctor Kimberly Joung is an associate
28:35 --> 28:37professor of therapeutic radiology
28:37 --> 28:39at the Yale School of Medicine.
28:39 --> 28:41If you have questions,
28:41 --> 28:43the address is canceranswers@yale.edu
28:43 --> 28:45and past editions of the program
28:45 --> 28:48are available in audio and written
28:48 --> 28:49form at yalecancercenter.org.
28:49 --> 28:51We hope you'll join us next week to
28:51 --> 28:53learn more about the fight against
28:53 --> 28:55cancer here on Connecticut Public Radio.
28:55 --> 28:57Funding for Yale Cancer Answers is
28:57 --> 29:00provided by Smilow Cancer Hospital.

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Breakthrough Radiotherapy Provides New Options for Patients with guest Kimberly Johung April 7, 2024