Hello, and welcome to the Physics World weekly
podcast.
Our guests this week are two medical physicists
who talk about the biological
impacts of ionizing
radiation.
And they also explain how radiation can be
used to treat diseases
such as cancer.
This episode was created in collaboration
with IPEM,
the Institute of Physics and Engineering in Medicine.
IPEM owns the journal Physics in Medicine and
Biology.
Here's Physics World's Tammy Freeman in conversation
with our two guests.
Radiation is both a hazard to the human
body and a beneficial tool that can be
exploited for medical application.
Radiation therapy, for example, uses beams of photons
or charged particles such as protons to destroy
tumors.
But how exactly does the radiation kill cancer
cells?
How can we prevent normal tissue from getting
damaged during this process?
And how are medical physicists
exploiting the underlying
radio biology processes for the benefit of patients?
To discuss these questions in more depth, I'm
joined today by Ileana Silvestre
Palacio,
medical physicist working at The UK's National Physical
Laboratory,
and Ruth McLaughlin,
consultant radiotherapy
physicist
at Imperial College Healthcare NHS Trust.
Welcome to the podcast, Ruth and Ileana.
Thank you.
Hello. Thank you.
So let's start by looking at radio therapy.
This is used to treat cancers, and this
is a really important medical use of radiation.
So can you just briefly explain how this
treatment works?
We're using radiation, usually high energy x X
rays, but there's other modalities like electrons and
protons and carbon ions, basically to kill the
cancer cells so that we can shrink and
destroy the tumor.
We're aiming to cause the maximum damage to
the tumor
while minimizing
the radiation effects of the normal and the
healthy tissues.
The radiation damages the DNA of the cancer
cells causing them to stop dividing and to
die.
The cancer cells will continue to,
die for weeks or even months following the
radiotherapy treatment,
but it can also affect the healthy cells
causing temporary cell damage.
Most healthy cells, though, will recover,
and they'll go back to working normally, and
the side effects
usually improve a few weeks following completion of
treatment.
Okay. So how are the the beams of
ionizing radiation are directed onto the tumour? So
how how do they actually kill the cancer
cells?
Before commenting on how ionizing radiation
kill cancer cells,
I could be it could be worth talking
about radiobiology
in relation to the radiotherapy process.
Radiobiology
is a multidisciplinary
area of science
that involves all aspects
of biology,
physics, and medicine,
and and to study how radiation affects cells,
the tissues, and biological systems as well. It
is is
a specialty that intends to understand
how radiation induce damages,
the repair mechanisms,
and the biological response to radiation.
So what happens then when cells are exposed
to ionization
ionizing radiation?
At first, there is a physical
effect between the radiation and the atoms of
molecules
on that occurs into those cells. But as
a consequence of that, then a possible biological
damage to the cell functions will follow, and
that damage will end up in killing and
really,
causing the death of the cells,
which can could occur through a process of
apoptosis,
necrosis,
or mitosis of
the cells.
That more or less, that's what I think
how what happened. Yes.
How do we know that cells react to
radiation?
Through studying the effects on people who have
been subject to to radiation.
And a lot of the information we've got,
unfortunately, has been the result of radiation incidents
and accidents, the atomic bombs,
the Chernobyl incidents, for example.
But also
for many, many, many years, patients have received
radiation as part of their cancer treatment.
So we have large cancer registries,
so we can follow-up these patients or the
people who've been involved in these incidents
and,
look at
how their exposure to radiation,
is there any link to that, to any
side effects that we see in them in
in later life. And then scientists try to
apply models
to that,
try to relate the level of exposure, the
type of exposure with the effects that they
see, and see if they can use that
to predict
how for future
patients
or people
coming into contact with radiation
predict how they are likely to be affected
by that dose.
Okay. So
when you're delivering radiation therapy,
treatments are usually delivered using a series of
daily radiation, so a treatment every day over
several weeks.
And this is called fractionation.
So can you explain why this is used
and what are the benefits of this?
Oh, yeah. I could say a little bit
even going a little bit back, you know,
at the beginning of the twentieth century where
where some doctors were already using radiation
to treat certain
tumors.
As an interesting fact, that was the case
of the Scottish radiotherapist,
Ralston Patterson,
who who used x rays to treat patients
with primary carcinomas of the lung.
At this early period,
the pioneers of radiotherapy did not really know
what was the dose
fractionated
dose of x rays.
So the concept of fractionation of the x-ray
treatment was introduced by Claude
of the x-ray treatment was introduced by Claudius
Rigault
from the Foundation
Curie in Paris and his collaborator,
Henrik Couture.
It was introduced at the first International Congress
of Radiology,
which was held in 1925 in London.
So Regard
irradiated, previous to the conference, of course, and
through their investigation,
irradiated testicular tissues of in grams and observed
that different types of of cell had different
sensitive to radiation.
And with that result, it was then increasingly
appreciated that cells in a state of growth,
division, and reproduction
were more radiosensitive
than those in resting states
stages,
and then that began to influence
treatment decisions in terms of the overall dose
and how often or how frequent this dose
will will be delivered.
And that is the hypothesis
on in vitro study was then translated
to clinical study to the first clinical study
by Couture
who introduced protracted
fractionation radiotherapy
in human patients
so early
as in talking about the beginnings of the
twentieth century.
The the first findings became the cornerstone of
the conventional radiotherapy fractionation
as they are used up to today.
And that led to also to the understanding
of the principle of the functioning of the
four heirs in radiotherapy.
It means the
function of the repair, redistribution,
repopulation,
and oxygenation,
as well as of the understanding of the
linear quadratic model, which is the model that
is mostly used
for understanding what to be the fractionation.
So you mentioned that cells at different stages
in their cycle react differently to radiation.
Do different types of cells themselves also react
differently to radiation?
They do. Not all cells are equally sensitive
to radiation. Elian has already said about radiation
sensitivity,
and the linear quadratic model,
and parameters on that are give us our
alpha beta ratio, and the values of that
is related to how radio sensitive cells are.
Generally, it's cells that are actively dividing and
replicating that are more vulnerable
because the radiation damage to their DNA can
disrupt the cell cycle and lead to cell
death and mutations.
So lymphocytes, white blood cells, blood forming cells
like in the bone marrow are highly sensitive
due to their rapid turnover and constant regeneration.
Reproductive and gastrointestinal
cells also fall into this category.
Nerve and muscle cells are relatively resistant to
radiation damage because they divide infrequently.
And with radiotherapy treatments, we see different effects
at different time points
even during and certainly post radiotherapy treatment.
Acute early effects,
we can often see them starting actually during
treatment because we we're treating patients
daily over a number of weeks, and these
effects can actually occur while we're still delivering
the treatment. It depends on where in the
body exactly we're treating, but fatigue is a
common side effect,
skin reactions,
hair loss in the treatment area, if we're
treating the head and neck region,
dry mouth, if we're treating the pelvic region,
bladder irritation can cause frequent need to go
to the toilet.
But medications can be given to counter a
lot of these things, and improvements usually seem
within six to eight weeks
following the completion of the rate of the
treatment.
But late effects,
they can occur months or even years
after the radiotherapy treatment. And we're when we're
designing
our radiotherapy treatments, we're very aware
of potentials of these late effects and minimizing
the chances of these things happening. And things
that you can see years later can be
fibrosis of the skin,
cognitive changes to the brain if we've irradiated
the brain,
cataracts,
and heart complications.
Okay. So it's it's obviously, like, really important
to make sure that it's a little as
possible radiation to normal tissue.
So
we we can use physics techniques to protect
normal tissues by precisely shaping
and directing the radiation
beams during the treatment.
Can you can you explain how this works?
The use of highly conforming radiation techniques
reduce the area of healthy healthy tissue that
can be that
is irradiated.
That can be in the in the these
days is supported by the use of some
devices called multi leaf collimators,
but also with the use of micro leaf
collimator, which are even
devices that have thinner leaves that conform
the shape to the treatment volume and spare
the healthy tissue as most as possible.
But also with the implementation of so called
stereotactic
kind of therapeutic deliveries, which try to treat
very small
volumes, but also with very small collimators, could
be circular collimator or also conformed by different
leaves. That's one way of
supporting the
improvement of treating the tumor and not treating
the or not giving those to the health
tissue.
But also lately, we there is a path
pipeline to for the introduction of,
adaptive radiotherapy.
So maybe I will left Ruth to speak
a little bit how that adaptive radiotherapy can
help to improve the radiotherapy process in general
and the protection of the healthy tissues while
giving the dose to the tumor?
So I I've been working as a clinical
radiotherapy physicist for over twenty years now. And
in that twenty years, we've seen massive advances
in the technology and way that we can
better target
those high doses,
to the tumors. So
we've always treated with multiple beams.
That allows us to build up a high
dose by targeting it at the tumor while
distributing
the a lower dose to the surrounding tissues.
But as Ileana said, one of the big
advances was the use of the multileaf collimator.
Twenty five years ago, the majority of external
beam radiotherapy treatments, we were treating with rectangular
fields. So you can imagine there was quite
a lot of adjacent normal tissues included in
those high dose volumes.
The multi leaf collimators, which are these little
leaves of tungsten that allow us to better
shape,
the radiation field to the shape of the
of the tumor,
allowed us to better protect the normal tissues,
but also paved the way for us to
be able to deliver these treatments more dynamically.
Instead of static beams, we can now
treat where we are with the beam on,
the machine is rotating around the patient, the
multileaf collimators
are moving. We can vary the rate at
which the dose is delivered. With the modern
computational,
software and power that we've got,
we can now
tell the computer what we want the dose
distribution to look like, and it can run
its inverse planning algorithms
to calculate
how better that could be delivered. And it's
all about targeting that high dose
to to the tumor. And the advent of
image guidance as well, now we can image
the patient
on the machine
as they're in their treatment position just before
we then treat them. We we can delete
we can acquire
home beam CT,
good quality CT image that's showing us how
well the patient's set up, how the anatomy
we can compare that with the planning images
that we took,
to make sure that we are
targeting that treatment
where we intend it to be treated. And
because we're now getting this three d image
information,
we can actually see if the anatomy's changed,
if the tumor has grown, if the tumor
has shrunk, and this is paving the way
for us to be able to adapt treatment
further to respond to how those tumors are
changing while we are treating the patient.
So so this is what's known as adaptive
radiotherapy.
So for example, if,
something's changed in the patient's anatomy between the
treatments,
you can change the delivery
to match the anatomy changes and make sure
it stays accurate.
So you've got these really accurate
plans.
But how how can physicists help prevent
unintentional
over radiation
during treatments? How do they know that everything's
gonna work perfectly before they start?
Every radiotherapy equipment is under
restricted and very well
defined quality
assurance program.
So, not only the machine itself, it has
a daily QA
test,
monthly, yearly, but also the plans are specifically
tested before
giving the
radiotherapy plan to the patient. So there is
something called
a specific patient QA, which is performed
mostly before the first treatment, but perhaps sometimes
in between treatments,
halfway through at the
oh, Ruth maybe have the clinical experience of
what they probably do particularly in her center.
But quality assurance is paramount to keep
safety in the delivery of of radiotherapy treatment
plans, in my opinion.
Everything we do in radiotherapy goes through a
series of checks, and it involves a multidisciplinary
team working together to ensure we provide this
safe and effective treatment for our patients. The
patient's the center of everything we do, and
our team consists of highly trained professionals, including
radiation oncologists, medical physicists, therapeutic radiographers, and other
professionals,
each with specific expertise and responsibilities.
As physicists, we're involved in all aspects of
the radiotherapy pathway.
From creating the accurate treatment plans, implementing the
rigorous quality assurance process procedures,
meticulously calibrating our equipment, making sure that our
equipment is calibrated with a traceable calibration factor
back to Ileana's work at the NPL with
their primary standards,
monitoring the performance of the equipment with a
quality assurance program to ensure that we have
these precise and safe radiation delivery. And, of
course, we're working under legislation,
the, IRR 17, the ionizing radiation regulations,
and Irma, the ionizing radiation
for medical exposure regulations.
Actually, if there is something I can add
to it, it's also interesting.
Something that NPL is quite involved is the
development of, audits or specific audits or end
to end type of audits that actually are
a requirement for hospitals to be able to
participate in clinical trials. So at the moment
at NPL, we are delivering
a a stereotactic radiosurgery end to end audit,
and we are delivering the Spain the Spine
Saver audit, which are two type of audits
that,
verify the whole process since the acquisition of
the CT scan of the patient,
the planning process of the
volumes, and by keeping all the
constraint of the dose to the tumor, dose
to the healthy tissue up to the delivery
of the treatment. So for that, we use,
detectors,
anthropomorphic
functions, so functions that simulate
the part of the body of the patient
that is going to be treated in the
case of the stereotactic
brain surgery,
the area of the head and the neck
of the patient. And in the case of
the savior spine outdid pelvis phantom,
and we deliver that to the hospitals.
They perform
the procedure of delivery or of going through
all the process, and then they send the
fountain back to us where we analyze the
result of the detectors that are inside of
the fountains.
In this case, alanine detectors and film,
graphene detectors. And then we report back to
RTTQA,
which is the organization in The UK that
has the responsibility
to guide and control
all these clinical trials. So that that's an
important asset also also of guaranteeing the safety
and
quality of the plants that are delivered. The
and then
our hospitals are able to compare results
and value of it valuable information can be
obtained from those clinical trials.
And we've just taken part in that. Eliana,
sent us her phantom for our SRS, which
we then scanned,
planned,
delivered the treatment
to that phantom on our treatment machine, and
then we send the phantom back to Ileana.
And Ileana
analyzes that and hopefully gives us the the
green light to say that
we're in tolerance and as expected.
Excellent.
Okay. And then
researchers are also,
developing new types of radiation treatments that sort
of exploit the parameters of the beam for
for specific needs.
And one example of this is flash radiotherapy,
which is an emerging technique
in which the radiation is delivered at extremely
high dose rates in a fraction of a
second.
And this is a very new thing, but
how does this really fast treatment, how does
this help?
Everybody's talking about flash and other new modalities.
And I I think from my point of
view, it it promises
that it will reduce normal tissue toxicity.
That's one of the main uptakes of why
everybody thinking that.
From other point of view is that it
will the treatment could be delivered in a
very, very short
time, which it will help in many ways.
For instance,
problems associated to eye mobilization.
If you are delivering the treatment in a
very short period of time,
this problem with eye mobilization of the patient
or movements
during the treatment will be reduced, of course.
But
it is, in my opinion, at early stage,
it's a very complicated
technologically
and mostly
dosimetry,
establishing a transverse dosimetry
to determine that the dose you are giving
to the patient is the adequate, is proven
challenging.
And there are still physicists around the world
and other scientists and other,
members of this multidisciplinary
team trying to understand what is the best
way to,
deliver this type of treatment in a safe
safer way? Flash radiotherapy techniques are actually being
used on patients at the moment through through
some clinical trials.
So as Leanna said, there's there's been lots
and lots of interest in this. Initially,
it started using conventional linear accelerators, but they're
electron, high energy electron treatments we could deliver.
What we're talking about for dose rates for
flash? Well, our standard radiotherapy, we're typically
delivering about five gray of dose in a
minute. This is talking about delivering greater than
forty gray in a second.
But with animal studies, there was promising results.
It was showing that there was a reduction
in the normal tissue complication, the normal tissue
effects,
but no change in the tumor control.
And they did lots of experiments
with monkey, pig, and cats, And, actually, in
France in 2019, they used it to treat,
a recurrent skin lesion on a patient,
and
the result was was very good.
And proton therapy, there's lots of excitement about
potential flash with proton therapy. So one of
the vendors
has bit, got a group together working on
that. And in The United States, there are
now a couple of trials called the fast
zero one and the fast zero two trial,
which is looking at using proton,
flash radiotherapy,
on patients who have painful
bone metastases
that we know that other conventional techniques are
not so good at treating.
And there's also a trial I've just heard
about last week, LAANC. It's a randomized phase
two trial. It's going to be using, going
back to the electron
treatments, but it's going to be a randomized
trial comparing
delivering flash radiotherapy
with conventional radiotherapy
for,
BCCs and SCC
skin cancers.
Oh, it worked?
People have lots of theories.
No one's completely sure.
One theory is it's to do with the
oxygen, that this rapid delivery of the radiation
induces oxygen depletion, which protects the normal tissues,
but not the cancer cells. We know that
tissues that are hypoxic, that have,
are missing oxygen,
that this makes them more radio resistant.
So it's thought that possibly
the difference in the tissue toxicity may be
due to the level of the hypoxia that
we see at ultra high dose rates and
subsequent radioresistance.
It could be differences in the tissue response.
Maybe the normal tissues are just better at
repairing damage from a rapid burst of radiation,
while cancer cells are maybe more vulnerable.
And possibly, it could be a modified immune
response because of the shorter treatment times.
There's lots of theories out there at the
moment. We're not sure.
So lots of work to be done finding
out why it works, but but it it
sounds promising.
So there's another technique
that sort of tries to do a similar
thing, I. E. Prevent the damage to normal
tissue,
and that's the use of mini beams or
micro beams.
And here, the, treatment beam is split up
into an array of tiny, thin radiation beams
that create alternating
peaks of high dose and then low dose
valleys.
So, again, what how could this help improve
cancer treatment?
Actually, it's not so such a new thing.
Already when the kV
radiotherapy started,
right after the discovery of the X rays,
there was the use of this so called
grid therapy where radiotherapies
were trying to protect the skin
by when they needed to irradiate tumors that
were a little bit below the skin's surface,
and that created that the same type of
dose distribution. So protecting and trying to protect
the toxicity that the skin will deliver. So
it's not something so new. It's just that
now,
we are technologically
better prepared
to be more,
aware of what could be
the way of implementing
this that is safer for the patient and
more in a more controlled way.
So, and that they have been intent
to implementing this
mini wings or with protons,
with, basically at the moment with protons with
m v too, but it's a little bit
more complicated because then you have to have,
like, that sort of collimators that could be
difficult to design or difficult to use at
the moment, but it's it's it's
proven that it's something that will benefit. And
in my opinion, but I might be not
totally right, it will benefit patients that has
like huge
bulk tumor tumors
because the the,
presence of this up scope abscopal effect and
bystander effect can,
help that even though you are delivering a
dose to a gray area,
this information that is missed passed is passed
between cells that are irradiated or not irradiated
can contribute to a better
control of the tumor and also a sparing
of the healthy tissue
without affecting the dose delivered to the tumor.
So I I think it's something new as
well.
And there is not a clear
yet pipeline
of how to introduce it, although there are
being
papers published is about how could be the
way to
perform clinical trials that demonstrates the validity of
these techniques.
So it's it's that that's what my understanding
of at the moment of this technique, mini
beans. But I'm so saying actually interesting, sorry
that I extended myself a little bit, but
NPL is going to,
in in between,
at at
mid March, is going to be a workshop
on spatial fractionation radiotherapy
or mini beam radiotherapy.
Well,
physicists, mostly physicists, some clinicians as well from
Europe mostly
are going to present their results in this,
and the from the dosimetry point of view,
but also the idea will be to establish
maybe a road map on how to,
introduce this, how to get to better
organization or how to introduce this technique into
the
normal clinical environment.
Lots of results out there from our animal
experiments. That's promising
and has shown an improvement in tolerance of
normal tissues, particularly brain and skin tissue.
To withstand peak doses as high as a
hundred and a 50 gray. You know, when
conventional radiotherapy, we're only
going as high as seventy,
eighty gray.
So there's hope that this will allow us
to be safely be able to escalate the
dose that we give to these radioresistant
tumors, these tumors that we know that we
we struggle to completely control.
K. So there seems to be some various
ways to use the radiation beams in different
ways,
for different types of treatment.
Are there any medical therapies that use much
lower doses of radiation?
At Dartmouth, for many, many years, we we've
treated patients with total body irradiation and total
lymph node irradiation,
and this is, as part of the preparation
regimen for patients who are going to have
bone marrow transplant. And for these patients, because
we're irradiating
the whole of their body, we we're delivering
very low
doses in in total and low dose per
fraction.
And
the reason we're doing this is we're
patients who are going to have a stem
cell transplant and bone marrow transplant,
their own body
is immune system may say see these cells
as foreign and attack it,
and the immune system will destroy them, and
then that transplant will fail. So by having
this low dose radiation treatment before you transplant
can help keep that from happening,
and it's thought to be immune enhancement rather
than direct radiation cell killing,
that enables it to have this effect. So
we've been doing that for a long time,
but there's also growing interest in the use
of low dose radiotherapy for pain relief
for noncancerous
diseases.
So I'm sure there's probably people out there
who've seen there's been a couple of documentaries
on Usain Bolt,
the Olympic sprinter.
He had some low dose radiotherapy
treatment,
for tendonitis. I think it was in in
his ankle, and as a result of that
went on and, won more gold medals.
It's been practiced for many, many years in
Germany,
and Austria,
and it's a widely emerging treatment for inflammatory
joint diseases,
osteoarthritis,
tendonitis. It's been proposed as potential treatment for,
lung complications from COVID, potentially for Alzheimer's.
It uses very low doses of radiation, so
whereas in conventional
radiotherapy we're delivering,
fractions of about two grey
over daily, over several weeks, this is delivering
a half a grey to one grey per
fraction,
to a total dose of two or six
gray, only about six treatments,
and it's been shown to
reduce pain and the inflammation.
The therapeutic mechanism is always it's complicated, multifaceted,
not fully understood,
but it's thought it's got some immune effects
and anti inflammatory
effects,
and potentially it's leading to an enhanced
immune surveillance. So it's kind of triggering the
immune system to recognize that there's there's something
going on and getting your own immune system
to then
correct the,
the issue that you've got.
We do see in conventional radiotherapy actually as
well something called the bystander effect. So there
are reports out there in the literature of
for example, if you've got a patient,
and their primary tumor was treated previously
and has been cured, but they've come back
and they've got they may have a metastatic
tumor in the lung and a metastatic tumor
in the liver, and we can treat those
using these stereotactic
technique.
And what they've seen in some patients is
by treating the tumor in the lung,
the tumor in the liver
also
disappears. Now it hasn't been directly irradiated,
but possibly by treating that tumor in the
lung it's kind of woken up the immune
system and made it recognize that there are
these cancer cells that
need to be dealt with. Another area is
now the use of low dose in diagnostics
and nuclear medicine as part of the combined
part of first,
finding where is the
radionuclide
we which area would be targeted by radionuclide
by using lower dose and then by specifically
using larger dose to complement the treatment. So
it's it's part of the so called diagnostic,
use of
radionuclides
for molecular radiotherapy.
Finally, that's sort of looking ahead into the
future.
How do you think radiation will continue to
play a really essential role in medical treatments?
How how could you see it evolving?
I think it's still going to be with
us and needed for a long time to
come. Cancer incidence
worldwide is continuing to increase. It's expected to
be doubling by two thousand and forty.
And radiotherapy is a highly effective treatment of
cancer. It we know that it delivers long
term tumor control, and it also has
great value as palliative
as treatment as well. So worldwide, around half
of patients with cancer will receive some form
of radiotherapy.
And of those cured by cancer,
forty percent will have had radiotherapy.
Early detection is key. The smaller the tumor
is, the less likely is to have spread
and the easier it is to treat. And
radiotherapy has the capacity to treat large number
of patients, and it's very cost effective.
A linear accelerator can treat 40 or 50
patients a day.
A single course of radiotherapy treatment typically cost
between 3 to £7,000
per patient when you think that a cycle
of chemotherapy can cost 30,000.
So, yeah, I think we're gonna be around
for a long time to come. But how
we deliver it, I mean, over my twenty
plus year career, things have changed and become
far more complex.
We've got the modalities
protons.
The in The UK, we now have this
three proton facilities. We've got the long standing
low
energy proton facility for treating the tumors at
the back of the eye at the Clatterbridge,
and also the two high energy proton facilities,
the one in Manchester at the Christi and
the one at University College,
in London.
So I I think we will change. Different
tumor types will be treated with different modalities.
I think we've learned lots about,
our fractionation as well. We used to deliver
not that long ago, for example, breast cancer
treatments would be a five week course of
treatment.
Now through clinical trials, we've shown that we
can deliver as effective treatment over just five
treatments. I think those things will change,
but I certainly expect to,
be long retired and there still be radiotherapy
treatments.
Yeah. I I I think I also it
will be more personalized.
It will be include immunotherapy
associated to radiotherapy.
So finding the gene, the proper gene of
this your tumor, the
person's tumor, and then the
using radiotherapy in combination with this
immunotherapy
agent with with this,
the in in a way that I think
radiotherapy will be at at at some point
personalized
to the patient.
That will maybe increase the
cost of cryotherapy, but the benefits will be,
I think,
great for the patient
as well as all the introduction of this
flash that we talk about, the mini beams.
It would be forever there. I believe that
too, that cryotherapy is not going to as
long as there there is cancer
and cancer needs to be treated,
I think cryotherapy
will be there.
Excellent. Well, thank you very much to both
of you. Thanks for joining us today.
That was Physics World's Tammy Freeman in conversation
with NPL's
Ileana
Silvestra
Patello
and Ruth McLaughlin
who is at Imperial
College Healthcare
NHS Trust.
Thanks to all three for a fascinating
conversation,
and a special thanks to Fred Ailes, who
is our audio engineer.
This episode was created in collaboration with IPEM,
the Institute of Physics and Engineering in Medicine.
IPEM owns the journal
Physics in Medicine and Biology.
Raucous,
diverse, and loud,
That's how the philosopher and physics world columnist
Robert Kress
described the stand up for science demonstration
at Washington
Square Park in New York City on Friday,
March.
This was one of 32
similar events across The US where participants
gathered to protest
planned cuts to key
scientific
agencies
in the country.
When he was there, Bob spoke to the
organizer of the New York event and also
to several protesters.
And in an article, he shares
some of the clever slogans that were chanted
and appeared on placards
at the protest.
You can read Bob's article on the Physics
World website.
Just look for the headline,
Demonstrators
March for Science
in New York City.
I'm afraid that's all the time we have
for this week's podcast.
I'll be back next week in conversation
with the quantum cryptography
pioneer,
Arthur Eckert.