COVID-19 Vaccine and PET Scans

Transcript

00:00 --> 00:01Funding for Yale Cancer Answers
00:01 --> 00:03is provided by Smilow Cancer
00:04 --> 00:05Hospital and AstraZeneca.
00:07 --> 00:10Welcome to Yale Cancer Answers with
00:10 --> 00:12your host doctor Anees Chagpar.
00:12 --> 00:14Yale Cancer Answers features the
00:14 --> 00:16latest information on cancer care by
00:16 --> 00:18welcoming oncologists and specialists
00:18 --> 00:20who are on the forefront of the
00:20 --> 00:22battle to fight cancer. This week,
00:22 --> 00:24it's a conversation about nuclear
00:24 --> 00:26medicine and cancer management with
00:26 --> 00:27Doctor Darko Pucar. Dr. Pucar is
00:27 --> 00:29an associate professor
00:29 --> 00:31of radiology and biomedical imaging
00:31 --> 00:34at the Yale School of Medicine,
00:34 --> 00:37where Dr. Chagpar is a professor
00:37 --> 00:39of surgical oncology.
00:39 --> 00:41Darko, maybe we can start off by you
00:41 --> 00:43telling us a little bit about
00:43 --> 00:44yourself and about what you do.
00:45 --> 00:48I am a nuclear radiologist.
00:48 --> 00:50That means I have received training in
00:50 --> 00:53general radiology and nuclear medicine.
00:53 --> 00:54In my case I did that
00:54 --> 00:56at Cornell and Sloan
00:56 --> 00:58Kettering and I'm certified by the
00:58 --> 01:00American Board of Radiology and
01:00 --> 01:02the Board of Nuclear Medicine.
01:02 --> 01:05I also have a science degree from
01:05 --> 01:08Mayo Clinic and I provide clinical
01:08 --> 01:10service and I conduct research
01:10 --> 01:12in general nuclear medicine.
01:12 --> 01:15and nuclear medicine therapy,
01:15 --> 01:16and aeronautics,
01:16 --> 01:18which I will explain in a minute.
01:18 --> 01:20Let's breakdown
01:20 --> 01:24some of those things,
01:24 --> 01:27tell our audience a little bit more about
01:27 --> 01:30what exactly is nuclear medicine.
01:30 --> 01:33We do use radioactive
01:33 --> 01:36tracers to detect cancer,
01:36 --> 01:39monitor cancer, and treat cancer.
01:39 --> 01:41So radioactive tracers are a chemical
01:41 --> 01:44compound in which one or more
01:44 --> 01:47atoms have been replaced by radioisotope
01:47 --> 01:49in the process that we call labeling.
01:49 --> 01:51So these chemical compounds are
01:51 --> 01:54participants in body functions that
01:54 --> 01:56are usually altered by cancer,
01:56 --> 02:00and we have two options.
02:00 --> 02:03One is to label the
02:03 --> 02:04radioisotope with the gamma rays,
02:04 --> 02:06in which case we can
02:06 --> 02:09produce images or we can
02:09 --> 02:10use radioisotopes that
02:10 --> 02:12emit the high energy particles,
02:12 --> 02:15in which case we can kill the cancer.
02:15 --> 02:17It sounds like nuclear
02:17 --> 02:20medicine has a role to play both in
02:20 --> 02:22diagnostics as well as in therapeutics.
02:22 --> 02:25So let's look at the diagnostics.
02:25 --> 02:27To begin with, many of
02:27 --> 02:29us have heard about PET scans.
02:29 --> 02:31Is that really the main modality
02:31 --> 02:33that's used in nuclear medicine
02:33 --> 02:35for cancer and tell us a little
02:35 --> 02:37bit more about how that works?
02:37 --> 02:39Yeah, you are absolutely right.
02:39 --> 02:42PET scans really are the main modality
02:42 --> 02:45used for cancer diagnostics,
02:45 --> 02:48and it's basically a hybrid machine
02:48 --> 02:50or hybrid scanner that consists of
02:50 --> 02:53the CT scanner which is X ray
02:53 --> 02:55machine that produced 3D map of body
02:55 --> 02:58density and of the PET scanner,
02:58 --> 03:00which is basically a gamma ray
03:00 --> 03:02detector machine that again gives
03:02 --> 03:05us 3D map of tracer distribution
03:05 --> 03:07in the body and then at the end
03:07 --> 03:11you fuse CT and PET images to get images
03:11 --> 03:14that show both anatomy and function in
03:14 --> 03:18the normal tissue and in the cancer.
03:18 --> 03:21Do all cancer patients get a pet CT?
03:21 --> 03:24Or is this only for particular patients?
03:25 --> 03:28Well, it would depend from cancer to cancer,
03:28 --> 03:30but usually PET scans in most
03:30 --> 03:33cancers but not in all I use for
03:33 --> 03:36more advance patients with cancer.
03:36 --> 03:38So those are the patients where
03:38 --> 03:41the cancer is either very large locally,
03:41 --> 03:44it is spread to the nodes nearby
03:44 --> 03:46to the cancer site or has
03:46 --> 03:48metastasized to distant body sites.
03:49 --> 03:51And so the pet scan really gives
03:51 --> 03:54us an idea of how far the cancer
03:54 --> 03:55has spread. Is that right?
03:56 --> 03:57Absolutely, and the
03:57 --> 04:00main advantage of the PET scan is that it
04:00 --> 04:02can detect very small lesions that
04:02 --> 04:04are not visible on the conventional
04:04 --> 04:06imaging like a CAT scan or MRI.
04:07 --> 04:10But then you also mentioned that the
04:10 --> 04:12same nuclear medicine technologies
04:12 --> 04:15can be used in the therapeutic arena.
04:15 --> 04:17So tell us more about that.
04:17 --> 04:20Yeah, so this is very exciting development.
04:20 --> 04:24I mean for years we have treated cancers,
04:24 --> 04:26but it was mostly limited to the
04:26 --> 04:29iodine treatment for thyroid cancer.
04:29 --> 04:32But now we are getting many new exciting
04:32 --> 04:34compounds for prostate cancer for
04:34 --> 04:36the new rendering tumors and probably
04:37 --> 04:39would spread to other cancers as well.
04:39 --> 04:42There are two types of
04:42 --> 04:45therapies that we conduct.
04:45 --> 04:48One is if we use chemical
04:48 --> 04:51compounds that image
04:51 --> 04:53these high energy particles
04:53 --> 04:55to kill the cancer,
04:55 --> 04:58but we do imaging still with a
04:58 --> 05:00conventional PET scan which
05:00 --> 05:01usually maps the glucose.
05:01 --> 05:03It's called fluorodeoxyglucose and
05:03 --> 05:05then there is a new exciting process
05:05 --> 05:07which is called theranostics in which
05:07 --> 05:10we can use the same chemical compound
05:10 --> 05:12which is important to the function of
05:12 --> 05:15cancer which are labeled either
05:15 --> 05:18with the isotopes that can be detected
05:18 --> 05:21by gamma ray detectors and give us
05:21 --> 05:24imagine or it can be labeled with a high
05:24 --> 05:26energy particles and kill the cancer.
05:26 --> 05:28So probably the most common
05:28 --> 05:31examples that are probably even
05:31 --> 05:33known to our audience is dotatate
05:36 --> 05:38and is the treatment for neuroendocrine cancer.
05:38 --> 05:40So if we label them with
05:40 --> 05:42some isotopes like gallium 68
05:42 --> 05:44we will get images but we can label
05:44 --> 05:47with other allies like lutetium,
05:47 --> 05:49in which case we can kill the cancer
05:49 --> 05:52and what is up and coming and many
05:52 --> 05:54prostate cancer patients are
05:54 --> 05:57waiting for that eagerly is to get
05:57 --> 05:59both imaging and treatment with
05:59 --> 06:01prostate specific membrane antigen.
06:01 --> 06:05It sounds like these
06:05 --> 06:07technologies, if you're able
06:07 --> 06:09to identify a specific antigen,
06:09 --> 06:13a specific protein on a particular cancer,
06:13 --> 06:17and target that with a particle that
06:17 --> 06:19can kill it, it would seem to me
06:19 --> 06:21that this would be a very specific
06:21 --> 06:23way to kill cancer cells.
06:24 --> 06:26You are correct. So in most cases
06:26 --> 06:29our therapy has produced results that
06:29 --> 06:32are comparable to other systemic
06:32 --> 06:35therapy like chemotherapy but with
06:35 --> 06:37substantially lower adverse effects.
06:37 --> 06:41So we kind of achieve similar results
06:41 --> 06:44but with less morbidity to our patients.
06:44 --> 06:46Is this widely available or is
06:46 --> 06:49this still in the research arena
06:49 --> 06:51and undergoing clinical trials?
06:54 --> 06:56As I mentioned before,
06:56 --> 06:58we had iodine for treatment
06:58 --> 07:01of thyroid cancer for decades,
07:01 --> 07:04and more recently we have an already
07:04 --> 07:06clinically approved drug,
07:06 --> 07:08which is called Xofigo,
07:08 --> 07:09which is actually labeled
07:09 --> 07:10radioactive labeled radium,
07:10 --> 07:13that can kill metastatic disease
07:13 --> 07:16from prostate cancer in the bone,
07:16 --> 07:17and most recently
07:17 --> 07:19and obviously they've got a lot
07:19 --> 07:21of press attention is lutera,
07:21 --> 07:23which is again labeled
07:23 --> 07:25dotatate that can kill
07:25 --> 07:27advanced neuroendocrine tumors.
07:28 --> 07:32And for those that are approved
07:32 --> 07:35are those now taking over instead
07:35 --> 07:37of being treated with chemotherapy,
07:37 --> 07:40or are these now being treated
07:40 --> 07:41with these theranostics?
07:44 --> 07:48It's more like they're
07:48 --> 07:51getting incorporated in the treatment
07:51 --> 07:54algorithms, our patients might have heard
07:54 --> 07:56there is something called the
07:56 --> 07:58National Comprehensive Network which
07:58 --> 08:00is a body that provides all these
08:00 --> 08:03guidelines how the cancers are treated and
08:03 --> 08:06slowly the radionuclide therapies are
08:06 --> 08:09getting incorporated in those guidelines
08:09 --> 08:12and are used when appropriate
08:12 --> 08:15to treat advanced or metastatic cancer.
08:15 --> 08:17Help me to understand
08:17 --> 08:18that a bit better.
08:18 --> 08:20I mean because on the one hand it
08:20 --> 08:23sounds like this is so exciting, right?
08:23 --> 08:25That these theranostics,
08:25 --> 08:29if they can truly target
08:29 --> 08:32these cancers and kill them,
08:32 --> 08:34and they're specific enough in the
08:34 --> 08:37sense that you know this is how
08:37 --> 08:39we look for cancers on imaging,
08:39 --> 08:42and so we know that
08:42 --> 08:44they're very specific and don't have all
08:44 --> 08:47of the side effects of chemotherapy.
08:47 --> 08:51Why haven't they been widely adopted yet?
08:51 --> 08:52What's the downside?
08:52 --> 08:56Well, each cancer and each
08:56 --> 09:00cancer stage is kind of different, so
09:00 --> 09:03for example, in thyroid cancer it is
09:03 --> 09:07generally given after a thyroidectomy,
09:07 --> 09:08which is removal of the thyroid
09:10 --> 09:12and after radioactive iodine
09:12 --> 09:14is given most patients get cured,
09:14 --> 09:17so thyroid cancer is a relatively
09:17 --> 09:18well behaving cancer.
09:18 --> 09:21So in this particular cancer we can actually
09:21 --> 09:24achieve cure. In some other cancers,
09:24 --> 09:26for example metastatic prostate cancer,
09:26 --> 09:29when we are going to use
09:29 --> 09:32radioactive isotopes we will have actually
09:32 --> 09:35to prove that they have advantages
09:35 --> 09:38versus other chemotherapy options,
09:38 --> 09:39which requires large trials and
09:41 --> 09:44I don't know if our patients have
09:44 --> 09:46heard of different lines of chemotherapy,
09:46 --> 09:48usually there is a first line and
09:48 --> 09:49then if there is a progression
09:49 --> 09:51second and third line and so on.
09:51 --> 09:53So you not only have to prove
09:53 --> 09:54that they generally work,
09:54 --> 09:57but you have to find appropriate lines
09:57 --> 09:59of the therapy for those tracers.
09:59 --> 10:00So this is now in the
10:00 --> 10:02process of active research.
10:02 --> 10:06So basically they have in a way
10:06 --> 10:09similar limitations as a chemotherapy,
10:09 --> 10:12despite much lower side effects.
10:12 --> 10:14If that cancer is very bad,
10:14 --> 10:17like advanced castrate
10:17 --> 10:18resistant prostate cancer,
10:18 --> 10:20they will have less impact because
10:20 --> 10:22the cancer is already so aggressive.
10:23 --> 10:24But if thyroid cancer,
10:24 --> 10:25for example,
10:25 --> 10:27that cancer is relatively
10:27 --> 10:28well behaving,
10:28 --> 10:30then we actually can achieve cure.
10:30 --> 10:31So basically,
10:31 --> 10:33in the first situation we will
10:33 --> 10:36buy time for the patients to
10:36 --> 10:38give them longer survival.
10:38 --> 10:40While in this version of thyroid
10:40 --> 10:42cancer will actually achieve the cure.
10:43 --> 10:45It sounds like there's
10:45 --> 10:47still clinical trials ongoing
10:47 --> 10:49to kind of evaluate the optimal
10:49 --> 10:52situation in which these theranostics
10:52 --> 10:54should be used. Is that right?
10:54 --> 10:56Yeah, that's absolutely correct.
10:56 --> 10:58So for the neuroendocrine tumors
10:58 --> 11:00and prostate we'll actually be
11:00 --> 11:02evaluating what are the optimal
11:02 --> 11:04situations to be used. In the other cancer there
11:05 --> 11:08are still not agents that
11:08 --> 11:10are either approved clinically
11:10 --> 11:13or approved for trials.
11:13 --> 11:15There will be a so-called early
11:15 --> 11:17phase one and phase two studies
11:17 --> 11:19to see whether they work at all.
11:19 --> 11:21So at the moment again, thyroid,
11:21 --> 11:23prostate and NETs are where
11:25 --> 11:26Radionuclide therapies
11:26 --> 11:27have advanced the most.
11:28 --> 11:29Are there other cancers
11:29 --> 11:31that are on the horizon?
11:31 --> 11:34Are there other advances that you're
11:34 --> 11:35particularly excited about?
11:35 --> 11:38I just laughed a little bit about
11:38 --> 11:40this because we're getting so many
11:40 --> 11:42contacts from the pharmaceutical
11:42 --> 11:44companies there are almost tracers
11:44 --> 11:46for every cancer that you can imagine,
11:46 --> 11:49but they will have to pass through
11:49 --> 11:52phase one and phase two trials to see
11:52 --> 11:54which of these tracers would make
11:54 --> 11:56sense to develop as clinical agents.
11:57 --> 12:00And tell us a little bit more about the
12:00 --> 12:02side effects of these theranostics because
12:02 --> 12:05it sounds like with them being so targeted,
12:05 --> 12:08granted you know it makes a
12:08 --> 12:09difference how aggressive the cancer
12:09 --> 12:11is and how far gone it is,
12:11 --> 12:14but do they have a lot of side effects?
12:14 --> 12:16Because it seems to me that when
12:16 --> 12:19we talk on the show about chemotherapy,
12:19 --> 12:22chemotherapy really targets many cells.
12:22 --> 12:24Any rapidly dividing cell,
12:24 --> 12:27which is why they cause
12:27 --> 12:30things like hair loss and bone
12:30 --> 12:31marrow suppression and so on,
12:31 --> 12:34because these are rapidly dividing cells.
12:34 --> 12:37But in the situation where
12:37 --> 12:41a protein that is very specific to a
12:41 --> 12:44cancer can be targeted and almost like
12:44 --> 12:47a laser killed by these theranostics.
12:47 --> 12:50One would imagine that the side
12:50 --> 12:51effects are different,
12:51 --> 12:52perhaps more local.
12:52 --> 12:55Tell us about the side effects that
12:55 --> 12:57patients who are undergoing therapies
12:57 --> 12:59with these agents might face?
13:00 --> 13:02That's a little bit surprising,
13:02 --> 13:05but you have to remember before
13:05 --> 13:07the tracer gets localized
13:07 --> 13:09to the tissue of interest,
13:09 --> 13:12it still stays for awhile in the blood and
13:12 --> 13:15to some extent goes to the bone marrow.
13:15 --> 13:18So unfortunately, even through the radio tracers,
13:18 --> 13:20although we have less
13:20 --> 13:23toxicity to the bone marrow,
13:23 --> 13:26patient still can get bone marrow toxicity,
13:26 --> 13:28which can drop their blood counts,
13:28 --> 13:29although this is very,
13:29 --> 13:31very less pronounced with
13:31 --> 13:34radionuclide tracers than with the
13:34 --> 13:36conventional chemotherapy and then
13:36 --> 13:38other side effects are
13:38 --> 13:40more dependent on how they
13:40 --> 13:43are eliminated from the body.
13:43 --> 13:44So for example,
13:44 --> 13:47for NETs we worry about
13:47 --> 13:49kidneys because that's where they
13:49 --> 13:52accumulate a lot when we get they get
13:52 --> 13:55eliminated or in let's say
13:55 --> 13:58prostate cancer, we worry about
13:58 --> 14:00GI tract because patients sometimes
14:00 --> 14:03get GI side effects.
14:03 --> 14:06So again, it's a degree of toxicity,
14:06 --> 14:08but unfortunately pretty much
14:08 --> 14:10every systemic treatment would,
14:10 --> 14:12to some extent have a bone
14:12 --> 14:13marrow side effect.
14:13 --> 14:15Well we're going to take
14:15 --> 14:17a short break for medical minute,
14:17 --> 14:19and when we come back we'll talk a
14:19 --> 14:22little bit more about some of your work
14:22 --> 14:24looking at COVID-19 vaccine and its
14:24 --> 14:26effect on PET scans. Please stay
14:26 --> 14:29tuned to learn more with my guest
14:29 --> 14:30Doctor Darko Pucar.
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14:45 --> 14:48The American Cancer Society estimates that
14:48 --> 14:50over 200,000 cases of Melanoma will be
14:50 --> 14:53diagnosed in the United States this year,
14:53 --> 14:56with over 1000 patients in Connecticut alone.
14:56 --> 14:58While Melanoma accounts for only
14:58 --> 15:01about 1% of skin cancer cases,
15:01 --> 15:04it causes the most skin cancer deaths,
15:04 --> 15:05but when detected early,
15:05 --> 15:08it is easily treated and highly curable.
15:08 --> 15:10Clinical trials are currently underway
15:10 --> 15:12at federally designated Comprehensive
15:12 --> 15:14cancer centers such as Yale Cancer
15:14 --> 15:17Center and at Smilow Cancer Hospital
15:17 --> 15:19to test innovative new treatments
15:19 --> 15:20for Melanoma.
15:20 --> 15:22The goal of the specialized programs
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15:29 --> 15:32targets that will lead to improved
15:32 --> 15:33diagnosis and treatment.
15:33 --> 15:36More information is available at
15:36 --> 15:38yalecancercenter.org. You're listening
15:38 --> 15:41to Connecticut Public Radio.
15:41 --> 15:41Welcome
15:42 --> 15:44back to Yale Cancer Answers.
15:44 --> 15:45This is doctor Anees Chagpar
15:45 --> 15:46and I'm joined
15:46 --> 15:48tonight by my guest Doctor
15:48 --> 15:50Darko Pucar and we're talking
15:50 --> 15:52about nuclear medicine and before
15:52 --> 15:55the break we spent some time
15:55 --> 15:57talking about the role that nuclear
15:57 --> 15:59medicine plays both in diagnosis
15:59 --> 16:02as well as potentially in the
16:02 --> 16:04therapeutic management of cancer.
16:04 --> 16:06But Doctor Pucar has
16:06 --> 16:08done some interesting work
16:08 --> 16:12looking at the impact of COVID-19
16:12 --> 16:13Vaccine on PET scans.
16:13 --> 16:16Darko, tell us a little bit
16:16 --> 16:17more about that.
16:17 --> 16:18Thank you for this question.
16:18 --> 16:20This is actually something very
16:20 --> 16:24exciting to myself and my team members
16:24 --> 16:27because we kind of anticipated once
16:27 --> 16:29the vaccine started rolling out that
16:29 --> 16:32we're going to see some active lymph
16:32 --> 16:35nodes at the site of vaccine injection.
16:35 --> 16:38So if, let's say you would get
16:38 --> 16:41injection in the left deltoid muscle,
16:41 --> 16:43you are expected to get
16:43 --> 16:44activity in the left armpit.
16:44 --> 16:47We kinda knew that was going to
16:47 --> 16:48happen because that was happening
16:48 --> 16:52with influenza and since last fall
16:52 --> 16:55influenza was given relatively rapidly
16:55 --> 16:58because we are actually seeing
16:58 --> 17:01for like a week or several weeks
17:01 --> 17:04actually influenza active lymph nodes.
17:04 --> 17:09So we were already prepared as soon as
17:09 --> 17:11COVID vaccine rollout is expected to
17:11 --> 17:13start collecting the data immediately.
17:13 --> 17:15So we were collecting actually
17:15 --> 17:18the data for all the patients that
17:18 --> 17:21had a pet scan at Yale will first
17:21 --> 17:23try to determine whether they had
17:23 --> 17:24COVID vaccine or not,
17:24 --> 17:26and then we'll assess whether
17:26 --> 17:28they have active nodes or not.
17:28 --> 17:31And in the beginning the collection
17:31 --> 17:33was relatively easy because all
17:33 --> 17:34the vaccines were administered at
17:34 --> 17:37Yale so we could get a very precise
17:37 --> 17:38understanding who had vaccine,
17:38 --> 17:40who didn't and
17:40 --> 17:42which type of the vaccine.
17:43 --> 17:46So we have collected those data as
17:46 --> 17:49quickly as possible and we published
17:49 --> 17:52the JAMA article on 68
17:52 --> 17:55patients that actually had vaccine,
17:55 --> 17:57listing the frequency of positivity in
17:57 --> 18:00Pfizer and Moderna vaccines,
18:00 --> 18:03which is kind of useful to the
18:03 --> 18:04practitioner as we'll discuss.
18:04 --> 18:06So tell me more. What did
18:06 --> 18:08you find and what happened?
18:09 --> 18:12So basically the reason why we
18:12 --> 18:15really wanted to know this is because
18:15 --> 18:17these lymph nodes theoretically
18:17 --> 18:19can mimic cancer, which would be
18:19 --> 18:20like a false positive finding.
18:20 --> 18:22Or they can mask cancer.
18:22 --> 18:24If we think that these nodes from
18:24 --> 18:27the vaccine but actually turn out
18:27 --> 18:30to be nodes from the cancer.
18:30 --> 18:33So in order to avoid the errors,
18:33 --> 18:35we kind of need everyone to participate.
18:35 --> 18:38Both the patients, the providers
18:38 --> 18:41that are administering the vaccines,
18:41 --> 18:43the oncologists and us in
18:43 --> 18:45the nuclear medicine. So it
18:45 --> 18:47is very important to know the date,
18:47 --> 18:50the type and the dose and the
18:50 --> 18:52site of vaccine administration.
18:52 --> 18:56Also, it is very important to
18:56 --> 18:58avoid administering the vaccine
18:58 --> 19:01on the side where cancer might be.
19:01 --> 19:02So, for example,
19:02 --> 19:05if you have a right breast cancer,
19:05 --> 19:06you shouldn't be getting vaccine
19:06 --> 19:08in the right arm.
19:08 --> 19:09You should be getting the vaccine
19:09 --> 19:10in the left arm.
19:10 --> 19:12Similarly for other cancers that
19:12 --> 19:16will go to the axilla like Melanoma,
19:16 --> 19:17for other cancers like lymphoma,
19:17 --> 19:20it gets more complicated because
19:20 --> 19:23they can go to different nodes,
19:23 --> 19:25but it's important to see whether,
19:25 --> 19:27for example, they had nodes
19:27 --> 19:30in one versus the other armpit,
19:30 --> 19:32to determine which arm,
19:32 --> 19:34which side would be more safe
19:34 --> 19:36to inject and for patients
19:36 --> 19:39it is extremely important to tell
19:39 --> 19:42their oncologist that they will be
19:42 --> 19:45getting the vaccine if they have some
19:45 --> 19:47of those cancers that I mentioned
19:47 --> 19:49to tell the person who is giving
19:49 --> 19:51the vaccine to avoid the side,
19:51 --> 19:54which can be confusing.
19:54 --> 19:57And when they get their PET questionnaire,
19:57 --> 19:59which is like a survey that we
19:59 --> 20:01administer prior to PET scan,
20:01 --> 20:02and that's a good idea
20:02 --> 20:05even if they didn't get the vaccine,
20:08 --> 20:10they should ask to see the chart or in epic,
20:10 --> 20:12but they should actually list if
20:12 --> 20:14they have any acute symptoms.
20:15 --> 20:16Especially something that
20:16 --> 20:17looks like inflammation,
20:18 --> 20:20and they also should provide information as to
20:20 --> 20:22when did they get vaccine?
20:22 --> 20:24What kind of vaccine,
20:24 --> 20:26and in which side of the arm
20:26 --> 20:29in left or the right?
20:30 --> 20:33For example, our data have demonstrated that
20:33 --> 20:36those reactive nodes that can either
20:36 --> 20:39mimic or mask cancer and more commonly
20:39 --> 20:42after second dose of the vaccine,
20:42 --> 20:44then after the first dose of vaccine
20:44 --> 20:46which you would kind of expect based
20:46 --> 20:48on immunologic phenomenons
20:48 --> 20:50that come with the vaccines.
20:50 --> 20:52And we also found that they are a
20:52 --> 20:53little bit more common with
20:53 --> 20:55Moderna than with Pfizer vaccine.
20:56 --> 20:59So how long does the
20:59 --> 21:02effect last on the PET scan?
21:02 --> 21:03So for example,
21:03 --> 21:07let's say you got the vaccine today.
21:07 --> 21:10How long after that would you
21:10 --> 21:12anticipate that you would still
21:12 --> 21:14be able to see those enlarged
21:14 --> 21:17lymph nodes by pet after today?
21:17 --> 21:20That's a great question. And actually,
21:20 --> 21:22when we did our original article,
21:22 --> 21:24we couldn't answer that question
21:24 --> 21:27because we had relatively few patients.
21:27 --> 21:28I cannot discuss
21:28 --> 21:30too much because we have to finish
21:30 --> 21:33the analysis, so I don't want to be giving
21:33 --> 21:36statements ahead of the statistician,
21:36 --> 21:38but based on our preliminary data
21:38 --> 21:41now of several hundred patients,
21:41 --> 21:45it seems that probably it would take
21:45 --> 21:49at least several weeks
21:49 --> 21:52for the vaccine effect to disappear,
21:52 --> 21:53and it seems again,
21:53 --> 21:55this is probably too early,
21:57 --> 21:59the final word is that it lasts
21:59 --> 22:01a little bit longer with Moderna than
22:01 --> 22:01Pfizer.
22:03 --> 22:06I think that some of the things that
22:06 --> 22:08you're saying make intuitive sense, right?
22:08 --> 22:12If you have a known right breast cancer
22:12 --> 22:16or known right arm Melanoma there,
22:16 --> 22:18getting an injection on that right
22:18 --> 22:20side can certainly be confusing
22:20 --> 22:23to a radiologist who's trying to
22:23 --> 22:25interpret whether the lymph nodes
22:25 --> 22:27look ugly because of the cancer
22:27 --> 22:30or look ugly because of the vaccine.
22:30 --> 22:31But the
22:31 --> 22:32other point though,
22:32 --> 22:35is that you may have gotten the
22:35 --> 22:38shot without knowing that you also
22:38 --> 22:40were going to develop a cancer
22:40 --> 22:43and then find the cancer later,
22:43 --> 22:46and so that's where things get a
22:46 --> 22:49little bit tricky when one didn't
22:49 --> 22:52know about the other diagnosis.
22:53 --> 22:56That's absolutely right.
22:56 --> 22:59However, most of the time when
22:59 --> 23:02we do PET scans prior to actual
23:02 --> 23:06diagnosis of cancer is for lung
23:06 --> 23:09nodules and fortunately lung cancer
23:09 --> 23:12very, very rarely goes to the armpit,
23:12 --> 23:15so in that situation we'll know based on
23:15 --> 23:18the expected distribution.
23:18 --> 23:21It will be obviously more difficult
23:21 --> 23:23if a patient eventually gets
23:23 --> 23:25diagnosed with lymphoma.
23:25 --> 23:28And then it could in some time
23:28 --> 23:31there are unfortunately few cases
23:31 --> 23:33that we couldn't really tell,
23:33 --> 23:37but although it looks really ominous,
23:37 --> 23:40it is a relatively small number of cases
23:40 --> 23:43that after careful analysis that we
23:43 --> 23:45cannot determine what's going on and
23:45 --> 23:48those we'll have to closely follow up,
23:48 --> 23:49obviously.
23:49 --> 23:52So you know getting to the point of
23:52 --> 23:54the people with lymphoma, for example,
23:54 --> 23:56where you know it would be expected
23:56 --> 23:59that you would have many enlarged lymph
23:59 --> 24:03nodes trying to distinguish that versus
24:03 --> 24:04response to a COVID
24:04 --> 24:06vaccine must be pretty difficult.
24:06 --> 24:08What kind of tools do you
24:08 --> 24:10use as a nuclear medicine physician
24:10 --> 24:13who interprets these scans to tell
24:13 --> 24:15the difference one to the other?
24:15 --> 24:18Or is this something that relies on a biopsy?
24:19 --> 24:22I'm hoping that in most cases we
24:22 --> 24:24really do not need the biopsy and
24:24 --> 24:26we actually didn't comment on the result to
24:26 --> 24:29biopsy
24:29 --> 24:31because, for example,
24:31 --> 24:34the activity after vaccine
24:34 --> 24:37is usually not very, very high.
24:37 --> 24:40So if patients have a disease like
24:40 --> 24:43a diffuse large B cell lymphoma,
24:43 --> 24:45those have very higher activity
24:45 --> 24:48than it would be with the vaccine.
24:51 --> 24:53The other thing is patients,
24:53 --> 24:54for example,
24:54 --> 24:56has disseminated disease.
24:58 --> 25:00At that point, it may not be necessary
25:00 --> 25:03to make a distinction for the axilla,
25:03 --> 25:05because if they are in all
25:05 --> 25:07other locations on the body,
25:07 --> 25:09it won't change the management
25:09 --> 25:11where I kind of see this could be
25:11 --> 25:14really a problem if a patient has a
25:14 --> 25:16so-called low grade lymphoma which
25:16 --> 25:19do not have very high activity and
25:19 --> 25:23we find isolated nodes in
25:23 --> 25:26let's say bilateral axilla.
25:26 --> 25:29So then it would be great,
25:29 --> 25:30then we'll presume, I guess,
25:30 --> 25:33in one axilla that is probably
25:33 --> 25:34due to lymphoma,
25:34 --> 25:35the one which is not injected.
25:35 --> 25:38But the injected axilla
25:38 --> 25:40probably won't know unless we
25:40 --> 25:41as you said we do the biopsy
25:42 --> 25:45and presumably you can tell
25:45 --> 25:47the difference between enlarged
25:47 --> 25:50lymph nodes that are due to benign
25:50 --> 25:53conditions like sarcoid or other
25:53 --> 25:55things versus the COVID vaccine on
25:55 --> 25:57these PET scans. Is that right?
25:59 --> 26:01In principle yes,
26:01 --> 26:05because sarcoid would tend to be in the
26:05 --> 26:08nodes around the heart industry.
26:08 --> 26:11In the area that we call media Steinem.
26:11 --> 26:12While the vaccine nodes
26:12 --> 26:14would tend to be in armpit,
26:14 --> 26:16although this differentiation
26:16 --> 26:18again is not absolute.
26:18 --> 26:24But since we still rarely image circulated,
26:24 --> 26:27let's say independently from the cancer,
26:27 --> 26:30that's way less common situation.
26:30 --> 26:32That would happen really
26:32 --> 26:34to be a diagnostic dilemma,
26:35 --> 26:38and so now that we're kind of in the
26:38 --> 26:41the scenario where you know people
26:41 --> 26:44are now thinking about booster shots,
26:44 --> 26:46do you think that that's going to
26:46 --> 26:48cause even more of a conundrum?
26:48 --> 26:51You saw that the lymph
26:51 --> 26:54nodes were more reactive on pet after
26:54 --> 26:57the second dose of the COVID vaccine.
26:57 --> 26:59Do you think that's going to be
26:59 --> 27:00the case after the third dose?
27:01 --> 27:03Well, that's a very interesting question
27:03 --> 27:06so far I have seen only two cases
27:06 --> 27:09after the booster and one was active.
27:09 --> 27:11The other was not active,
27:11 --> 27:13but I didn't have dilemma because based on
27:13 --> 27:15the other characteristics or cancers
27:16 --> 27:17and knowing where the vaccine was,
27:17 --> 27:20I was able to confidently say.
27:20 --> 27:22But I would also want to bring
27:22 --> 27:24another interesting point which we
27:24 --> 27:26are actually going to investigate.
27:28 --> 27:31We can view those nodes after
27:31 --> 27:33vaccine as negative because it can
27:33 --> 27:35create a diagnostic confusion,
27:35 --> 27:38but we are also hoping to investigate
27:38 --> 27:41whether activity of these nodes actually
27:41 --> 27:44can predict the efficacy of the vaccines.
27:44 --> 27:48And this is for example,
27:48 --> 27:51there is an Israeli study
27:51 --> 27:53and they showed that
27:53 --> 27:56the activity in the nodes
27:56 --> 27:58correlate with the level of anti
27:58 --> 28:01spike which is that protein that is
28:01 --> 28:04very important in COVID antibodies.
28:04 --> 28:07So basically there was a correlation
28:07 --> 28:09between activity in these nodes
28:09 --> 28:13and antibody levels which in a way
28:13 --> 28:15would reflect the potential level of
28:15 --> 28:17protection that people would have.
28:17 --> 28:20So maybe in the future we can not
28:20 --> 28:24only be threatened by this phenomena,
28:24 --> 28:25but maybe we can
28:25 --> 28:27even use iy to predict what level of
28:27 --> 28:29immunity cancer patients would achieve.
28:30 --> 28:33Doctor Darko Pucar is an associate
28:33 --> 28:35professor of radiology and biomedical
28:35 --> 28:37imaging at the Yale School of Medicine.
28:37 --> 28:39If you have questions,
28:39 --> 28:41the addresses cancer answers at
28:41 --> 28:43yale.edu and past editions of the
28:43 --> 28:45program are available in audio and
28:45 --> 28:48written form at Yale Cancer Center Org.
28:48 --> 28:50We hope you'll join us next week to
28:50 --> 28:52learn more about the fight against
28:52 --> 28:53cancer here on Connecticut Public
28:53 --> 28:55radio funding for Yale Cancer
28:55 --> 28:57Answers is provided by Smilow
28:57 --> 28:59Cancer Hospital and AstraZeneca.

Information

COVID-19 Vaccine and PET Scans with guest Dr. Darko Pucar October 17, 2021 Yale Cancer Center visit: http://www.yalecancercenter.org email: canceranswers@yale.edu call: 203-785-4095