About this Webinar: What is a PET scan, and why is it so crucial in detecting and understanding cancer? Join us for this informative webinar from Dr. Christopher O’Brien, a physician and leader in the nuclear medicine community, where he’ll break down the basics of PET scans in simple, clear terms. Learn how these advanced imaging tools can detect a variety of cancers, guide treatment decisions, and empower you to advocate confidently with your healthcare team. Whether you’re a patient, caregiver, or loved one, this session will leave you informed and ready to take charge of your care. About this Presenter: Dr Christopher O’ Brien is a leader in the nuclear medicine community. He was Chair of the Ontario Medical Association Section on Nuclear Medicine for over 10 years. He is also past president of the Canadian Association of Nuclear Medicine as well as the Ontario Association of Nuclear Medicine. In addition, he was a Board member of the Royal College of Physician and Surgeons for eight years. Currently Dr. O’Brien is the Medical Director and Chief of Service for Nuclear Medicine at Brantford General Hospital and Pembroke Regional Hospital as well as coordinating and leading the Division of Nuclear Medicine at Stratford General Hospital.  His focus has been ensuring a high-quality nuclear medicine program for the patients in the communities he serves for over 30 years.

1. PET Scans 101: A Guide for
Patients and Families
Presented By: Dr. Christopher O’Brien

2. OBJECTIVES
1) Brief Review of Nuclear Medicine
2) Nuclear Medicine’s role in diagnosis
3) Nuclear Medicine’s role in therapy

3. NUCLEAR MEDICINE: A BRIEF HISTORY
• Nuclear Medicine is a Royal College Specialty
• A minimum of 5 years training after medical
school
• Uses medical compounds to assess cellular
and organ function rather than structure

4. NUCLEAR MEDICINE: A BRIEF HISTORY
• These compounds attach themselves to
specific cells within the organ: thus, cellular
and organ specific
• A radioactive isotope is then attached to the
compound and the whole complex becomes a
medical isotope

5. NUCLEAR MEDICINE: A BRIEF HISTORY
• The medical isotope is administered by
injection, breathing, or swallowing
• A specialized camera either SPECT or
PET then maps out the distribution of
the medical isotope making a picture

6. NUCLEAR MEDICINE: A BRIEF HISTORY
8) To detect disease there must be a 10% change
in function
9): X-Rays need a 30% change is appearance
10) Nuclear Medicine is very good at detecting
early disease by focusing on changes in function

7. NUCLEAR MEDICINE ROLE IN DIAGNOSIS
1) Medical Isotopes are used in the assessment
of a wide range of disease: both benign and
cancerous
2) Medical isotopes are used in all ages:
newborns to any aged adult

8. USES OF MEDICAL ISOTOPES
• Neurology
• Brain Death
• Alzheimer’s disease
• Parkinson’s disease
• Psychiatry
• Heart Disease
• Chest pain assessment
• Congestive heart failure
• Effects of
chemotherapy
• Infiltrative disease:
Cardiac Amyloid

9. USES OF MEDICAL ISOTOPES
• Bones
• Sport injury
• Arthritis: facet joint disease
• Joint replacement
assessment
• Cancer spread to bone
• Liver, gallbladder , kidney
• Thyroid: diagnosis and
treatment
• Parathyroid
• Salivary glad: dry mouth
assessment
• Lung scanning for blood
clots and pre-operative
assessment

10. CANCER ASSESSMENT
• SPECT scanning
– Looks at the indirect effects of cancer spread by
assessing changes in function
– Very useful in patient management with these
types of cancer
– Breast cancer
– Prostate cancer

11. CANCER ASSESSMENT
• Lung Cancer
• Thyroid cancer
• Carcinoid cancer
• Renal cancer
• Colon cancer

12. PET SCANNING
• Different from SPECT scanning as PET uses
medical isotopes that directly assess the
tumor cells themselves
• Better resolution: around 2 mm
• A PET scan can asses spread of cancer, lymph
node spread, soft tissue involvement, and
bone involvement

13. PET SCANNING
• Cancer cell have a high demand for sugar
• The first approach was to use a sugar like
compound: FDG
• This agent was able to assess a wide Range of
cancers once the diagnosis was made
• Staging improved over routine work up

14. PET SCANNING
• The next direction was to develop compounds
which would image tumor cells directly
• Prostate Cancer: PMSA
• Carcinoid: DOTATATE
• Breast Cancer: ESTRADIOL
• On the horizon: FAPI Scan

15. PET SCANNING
• PET has been subjected to rigorous large
clinical trials before any indication would be
funded
• Thus, there is a great deal of scientific support
for each indication

16. PET SCANNING
• These clinical trials have demonstrated that
the addition of a PET scan to routine clinical
work up changes patient management in
approximately 30% of patients
• Thus, if 100 patients are being evaluated with
routine work up 30 of these patients will have
their treatment changes to more effective
therapy

17. PET SCANNING
• Because of the impact on patient care PET
scanning is becoming more and more a first
line imaging modality

18. PET SCANNING
• Does a PET scan increase survival
• NO: a diagnostic procedure does not increase
survival
• However, PET scanning changes patient
management to more effective therapy which
has the potential to increase survival and
potentially cure

19. PET SCANNING
• As mentioned before, PET scan looks at
function and not size, which CT and MRI
assesses
• A Lymph node greater than 1 cm in size is
considered abnormal
• However PET scan can detect change in
function in nodes around 0.2 to 0.5 cm in size

20. PET SCANNING
• Thus, though CT/MRI would suggest no
disease by size, PET scan will detect disease in
a normal sized node thus changing the stage
• In addition, PET scanning can detect a solitary
lesion when CT/MRI are negative, thus
changing the stage of the cancer
• As “stage” is changed different therapies come
into play

21. PET SCANNING
• Survivability is impacted by correct staging
and initiating appropriate therapy

22. NUCLEAR MEDICINE ROLE IN THERAPY
• Medical isotopes are used to treat both
benign and cancerous conditions
• A medical isotope: I-131 was first used in 1941
to treat a patient with an overactive thyroid
gland: HYPERTHYROIDISM
• I -131 is also used to treat thyroid cancer and
its spread

23. NUCLEAR MEDICINE ROLE IN THERAPY
• Medical isotopes are also used to treat
inflammatory arthritis: different isotopes are
used based on joint size
• The trend now is to use medical isotopes to
diagnose and treat cancers: THERANOSTICS
• This leads to more of a personalized treatment
• Medical isotopes are also used in palliation:
Ra-223

24. NUCLEAR MEDICINE ROLE IN THERAPY
• Theranostics:
• The same compound is used to detect and treat,
the only difference is the radioactive isotope.
• Detect uses an isotope which produces a gamma
ray
• Treat uses an isotope which produces either a
Beta or an Alpha particle
•

25. NUCLEAR MEDICINE ROLE IN THERAPY
• Thyroid:
• I-123 to detect and I-131 to treat
• Prostate:
• F-18 PMSA to detect and Lu-177 PMSA to
treat
• Carcinoid:
• Ga-68 DOTATATE to detect and Lu-177
DOTATATE to treat

26. NUCLEAR MEDICINE ROLE IN THERAPY
• Modern Medical isotopes were initially used
when everything else failed
• They are now used sooner in the therapy and
as a result there is better overall survival when
compared to traditional therapies
• THERE IS HOWEVER NO MAGIC BULLETT

27. NUCLEAR MEDICINE ROLE IN THERAPY
• We are seeing combination therapies which
specifically target specific parts of the cancer cell
• Historically there was a cocktail of chemotherapy
• Targeted therapy is more effective
• The type of targeted therapy depends on the
type of cancer and the types of cells making up
the cancer
• This is leading to personalized combination
targeted therapies

28. CONCLUSION
• Medical Isotopes play a significant role in
staging and treatment: Personalized
Theranostics
• PET scanning changes patient management in
approximately 30% of individuals
• PET accomplishes this through more accurate
staging allowing more appropriate therapy to
be started sooner

29. CONCLUSION
• Adding medical isotopes improved
survivability
• The ultimate aim is to cure the cancer, and if
this is not possible to make the cancer
become a low grade chronic condition rather
than an aggressive acute process

30. THE END!
• Questions from the audience