When it comes to molecular imaging in pediatrics, one must remember that
children are not simply small adults. Rigshospitalet in Denmark uses a PET/CT
scanner that provides ultra-fast scan times and low-dose accommodations
for young patients, often eliminating the need for sedation.
Data courtesy of Rigshospitalet, Copenhagen, Denmark
The impact of molecular imaging on modern healthcare has been nothing short of revolutionary. Techniques such as PET/CT,
PET/MRI, and SPECT/CT have ushered in an era where clinicians can delve deeper into the human body, providing a clearer understanding of diseases and offering more precise methods for diagnosis and treatment. These technologies have drastically improved patient care by enabling clinicians to visualize diseases at a molecular level. However, when it comes to molecular imaging in pediatrics, one must remember that children are not simply small adults. Their unique needs and vulnerabilities necessitate a tailored approach.
At Rigshospitalet in Denmark, a
medical institution renowned for its
commitment to excellence in pediatric
care, Dr. Lise Borgwardt and the team
have been at the forefront of the
evolving journey of molecular imaging
in pediatrics since its introduction in
2000.1 As Chief Physician in the Department of Clinical Physiology and Nuclear Medicine, subspecialized in pediatric nuclear medicine and PET, Dr. Borgwardt’s dedicated efforts have been pivotal in advancing patient care and diagnostics at this facility. This is only possible thanks to a close collaboration between dedicated technicians, doctors, physicists, and parents. Rigshospitalet is a crucial healthcare hub in Denmark and serves a vast pediatric patient community, providing care through 170,000 annual outpatient visits, 70,000 virtual patient visits, 13,000 surgeries, and 21,000 pediatric hospital admissions per year. Specifically, within molecular imaging, the Pediatric Nuclear Medicine and PET team conducts almost 2,500 pediatric exams per year.
Moreover, Rigshospitalet is currently
in the process of constructing a
new cutting-edge pediatric facility,
Copenhagen Children’s Hospital (Mary
Elizabeth’s Hospital—Rigshospitalet
for Children, Teens and Expecting
Families), set to open its doors in
2026. This children’s hospital,
with a large, dedicated children’s
diagnostic unit, underscores its
commitment to continuing to provide
state-of-the-art care and treatments
for pediatric patients.
“…the short acquisition time of only a few minutes helps us to get young patients through scans without general anesthesia or sedation.”
The role of PET/CT in pediatric patient care
In pediatric oncology and beyond,
PET/CT has become a cornerstone of
diagnostic and treatment strategies.
Clinicians in the pediatric team at the
Department of Clinical Physiology and
Nuclear Medicine at Rigshospitalet,
led by Chief Physician and team leader
of pediatric PET Kim Francis Andersen,
MD, together with Dr. Borgwardt,
encounter many oncology cases
ranging from malignant lymphomas,
soft tissue, and bone sarcomas to
neuroblastomas and brain tumors.
Beyond oncology, PET/CT also plays a
pivotal role in multiple clinical areas,
aiding in the precise diagnosis and
monitoring of various conditions.
To serve these patients, Rigshospitalet has implemented advanced technology to optimize PET/CT scanning for pediatric patients. The majority of all pediatric patients are now scanned with Siemens Healthineers Biograph
Vision Quadra™ PET/CT scanner.
Recognized for its long axial field
of view that allows ultra-fast scan
times and the ability to realize
low-dose accommodations for young
patients, it was the right scanner
for pediatric patients.2,3 Together with Dr. Flemming L. Andersen and Professor Malene Fischer, MD, the team has developed dedicated protocols tailored to the specific challenges associated with pediatric PET/CT imaging.
“With 106-cm axial field of view,” said
Dr. Borgwardt, “we can see all the
patient’s organs in the same field of
view. Biograph Vision Quadra gives
us the ability to customize scans for
each individual child. We can turn the
scan time up and down, adjust
injected tracer activity, and improve
image quality to get an optimized
scan for each child. And the short
acquisition time of only a few
minutes helps us to get young
patients through scans without
general anesthesia or sedation.”
“If we have a two-year-old patient
with suspicion of a cancer diagnosis,”
continued Dr. Borgwardt, “we try to
optimize acquisition time and
administered radiotracer activity,
where we still have a chance to avoid
anesthesia. Whereas if we have a
13-year-old patient, we can keep
radiotracer activity very low because
they can lay still for a longer period of
time. This is how we maximize the
new possibilities.”
Prioritizing scheduling and comfort for the best imaging outcome
As Dr. Borgwardt implied, using
PET/CT in pediatric imaging is not
without its challenges. Pediatric
patients differ from adult patients in
their psychology, normal physiology,
and pathophysiology, factors that
require additional consideration when planning scans.1 Younger pediatric patients, often restless and unable to remain still for extended periods, have traditionally required general anesthesia or sedation during PET/CT scans.4 This practice not only poses potential risks but can also extend the duration of the procedure.
The team, with Dr. Borgwardt in the
lead, has developed scheduling
meta-[18F]fluorobenzylguanidine ([18F]
mFBG) PET/CT protocols for different
age groups, such as newborn to one
year, one year to three years, and four
years and older. To date, they have
successfully performed 50 MFBG
PET/CT scans of children using these
protocols without any need for
sedation or general anesthesia.
This is only possible thanks to a close
collaboration between dedicated
technologists, radiographers,
doctors, physicists, and parents.
Dr. Borgwardt and the team have
published research showcasing
their ability to refrain from sedating
young patients for PET/CT scans,
a significant departure from common
practice.3 Their success in this
endeavor has been attributed to the
ultra-fast scan times, long axial field
of view, and high sensitivity on the
Biograph Vision Quadra system,
coupled with a comprehensive
protocol for scheduling pediatric
patients. By working closely with
families to schedule scans around
nap times and feedings, the team
can minimize patient radiation, avoid
the need for anesthesia, and improve
comfort and cooperation, all while
maintaining image quality.
Attention to details
“Parents are contacted in advance, so we understand the child’s normal routines, and then we plan very specifically,” explained Dr. Borgwardt. “We try to maximize the schedule for our Biograph Vision Quadra, but if you want to scan children without sedation or general anesthesia in this very fragile group of youngsters, we book half an hour in advance on the scanner because the parents need to have time in the scanner room to help prepare their child. We schedule the scanner so the child can be fed in the scanner room. After feeding, the child is then wrapped, and the light is dimmed so the child can fall asleep. It can be complex, but it’s ultimately to get the best image that will provide the best diagnostics and thereby the best outcome for that patient.”
“There can also be some other factors
depending on the tracer you use,”
added Andersen. “Some tracers
require fasting prior to injection,
whereas others don’t need that. There
are a lot of issues that we have to take
into consideration when planning a
scan. For many years, we’ve provided
parents with a phone number to our
specialist technicians, who are trained
in pediatric exams. The parents
always get written information, but if
they feel the need for more
information or to ask specific
questions about how to prepare their
child for the scan, they can call.
Parents are also offered to visit the
department and see the scanner
beforehand if the child is still anxious.
The child can try lying on the scanner
bed and be driven in the scanner
gantry, if necessary. If there is
something that’s causing anxiety, we
always want to address those issues
and allay those fears, even if it takes
up scan time.”
“[Pediatric patients have] gone from a two-and-a-half-hour scan to a five-minute scan, where it’s only one hour between radiotracer injection and scan.”
Striving for safety in pediatric PET/CT imaging
A paramount concern for pediatric patients undergoing multiple scans over time is the cumulative radiation exposure since the survival of children with cancer has increased over the last two decades.
“Today, the majority of pediatric
patients with cancer are surviving,”
Borgwardt explained, “but the
radiation used to diagnose and cure a
child can also cause secondary
malignancies—cancers developed
due to the radiation exposure—so
minimizing the radiation for all our
examinations is therefore very
important in order to give the children with cancer the
best opportunity to become
long-term survivors.”
Andersen continued, “and therefore, we have reduced injected tracer activity for all pediatric fludeoxyglucose
injection F 18 (FDG) PET/CT-scans to a standard of 1.5 MBq/kg on the Biograph Vision Quadra PET/CT, still scanning for only five minutes. This change in procedure plays a significant role in minimizing the cumulative injected radiotracer activity for our pediatric patients.”
In children with neuroblastoma, the
most common type of extracranial
cancer in children, most children get
the disease before the age of five.5 “Follow-up protocols are dependent on the disease, and for neuroblastoma, patients are typically scanned five times or more,” said Dr. Borgwardt. “These scans are the standard diagnostic work-up performed with SPECT/CT using [123I]-meta-Iodobenzylguanidine [123I]mIBG tracer,
but now we are also scanning with
PET/CT using 18F-mFBG in a current
clinical study in order to compare."
“Patients who have experienced both
are very excited about the Biograph
Vision Quadra,” added Andersen.
“They’ve gone from a two-and-a-half hour
scan to a five-minute scan,
where it’s only one hour between
radiotracer injection and scan.”
By having an onsite radiopharmacy,
the Rigshospitalet team is able to
produce many imaging agents, such as
FDG, which is standard for oncology
imaging, as well as newer agents, such
as [18F]mFBG for neuroblastoma
imaging research.
“[18F]mFBG is an extremely promising
tracer for neuroblastoma patients,
and it’s not standard of care yet,”
explained Dr. Borgwardt. “The
resolution is three times better, going
from SPECT to PET due to the change
in imaging modality, but then
increased twenty-fold from our
previous PET studies because of the
technology behind Biograph Vision
Quadra. We really see an enormous
increase in the resolution, and we
know it will be a game changer.”
PET/CT’s potential to change outcomes
Biograph Vision Quadra’s potential to
change patient outcomes was readily
apparent when a pediatric patient with
neuroblastoma was initially scanned
with [123I]mIBG at diagnosis and, due
to the team’s prospective clinical study,
also scanned with [18F]mFBG on
Biograph Vision Quadra PET/CT.
“The standard scan [123I]mIBG SPECT/
CT had shown a thoracal tumor with
no additional lesions,” explained
Dr. Borgwardt. “This is typically the
scan used to inform the patient’s
treatment. However, on Biograph
Vision Quadra, the images showed
additional lesions that had spread to
the bone marrow. This significant
discovery resulted in the patient
receiving different treatment.
Without Biograph Vision Quadra’s
images, the patient would have
received less and most likely
insufficient treatment with an
increased risk of relapse.”
In all pediatric cases, scan procedures
are individually optimized for the best
outcome and image quality.
Rigshospitalet also addresses radiation
concerns by utilizing proprietary
research artificial intelligence-software
to generate a synthetic CT, which can
be used exclusively for PET attenuation
correction.a This innovative approach
and sophisticated software were
developed at the department
at Rigshospitalet and enable the
team to minimize radiation
exposure without compromising
diagnostic accuracy.
Paving the way for precision medicine
As molecular imaging continues to
evolve, the role of precision medicine
in pediatric patient care becomes
increasingly prominent. Imaging
techniques like PET/CT are instrumental in providing invaluable
insights into the diagnosis, treatment,
and follow-up of pediatric diseases.
The optimization of these imaging
methods, as demonstrated by
Rigshospitalet’s pioneering efforts,
ensures each young patient receives
tailored, safe, and effective care.
The dedication of the clinical team
in pediatric molecular imaging at
Rigshospitalet is a testament to
the unwavering commitment of
healthcare professionals to advance
patient care. With cutting-edge
technology and a patient-centric
approach, Dr. Borgwardt, Dr. Andersen,
and their team have set a new
standard for pediatric PET/CT
imaging, and their work serves
as a beacon, illuminating the
path toward better outcomes
and improved quality of life
for pediatric patients.
About the author
Claudette Lew is a freelance medical writer and editor and writes frequently for Nuclear Medicine News & Stories.
Fludeoxyglucose F 18
Please see Indications and Important Safety Information for Fludeoxyglucose F 18 (18F FDG) Injection.