5. Radioactive Tracers in Medicine
Inject
Radioactive
Material Detect
Radioactivity
Measure function of the body
Inject nanomolar concentrations
Does not perturb the function of
the body
Can be measured noninvasively
Nuclear medicine uses radiotracers for functional
assessments of the human body
6.
7.
8.
9. What is Nuclear Medicine
Nuclear Medicine Tripod
Physician
Diagnosis (80%)
Therapy (20%)
Radiopharmacist Radiophysicist (RSO) + Nuclear Medicine
Technologists
QC of instrumentation
Radiation Dosimetry + RN
Therapy+ Imaging
Radionuclide Chemical Radiopharmaceutical
(Targeted)
Preparation of
radiopharmaceuticals
QC of chemicals
Biomedical Engineer
Design/Service/
Maintenance
13. 99mTc-MDP Bone Scanning
• To see for Bony
Metastasis in
• Breast Cancer patients
• Prostate Cancer Patients
• Osteomyelitis
• Bone inflammation
• Bone infection
25. FDG
• Most widely used PET
tracer
• Glucose utilization
• Taken up avidly by most
tumours
CH2HO
HO
HO
O
OH
18
F
CH2HO
HO
HO
O
OH
OH
glucose
2-deoxy-2-(F-18) fluro-D-glucose
26. FDG Metabolism
FDG FDG -6-P
Radio-
active
Glucose
18
F-FDG
Radioactive Glucose 18
F-FDG
X
Glucose Glucose
Glucose
Glucose-6-
Phosphate
Unlike glucose, FDG is trapped
27. PET IN TUMOR IMAGING
Lymphomas, Breast, Colorectal, Non-small cell
lung carcinoma, Head and neck, Brain, Melanomas
maximally studied and benefited
Also useful in cancer in other locations such as in
the Ovaries, Bladder, Thyroid, Pancreas, etc.
28. Lymphoma
Patient with lymphoma with infra and supra-diaphragmatic
lymph node involvement. PET allows complete staging with
just one test and serves as the basis to check treatment efficacy
31. Colon Carcinoma
Patient with colon carcinoma and multiple liver, bone and soft
tissue metastases, whose diagnosis using the usual methods
would have been much more difficult, costly and uncomfortable
for the patient. With just one PET study, complete staging is
possible.
32. Breast Cancer
Patient with breast cancer and metastatic lymph node
involvement. This involvement is often difficult
for the usual diagnosis methods to detect
34. PET Imaging – Cardiology Applications
Assess myocardial viability
Confirm myocardial ischemia
Pre-transplantation assessment
Diagnosis of cardiomyopathy
35. Myocardium perfusion and metabolism study with 13N-Amonium and
FDG respectively, with a match pattern in which it can be seen that
there is absence of both perfusion and metabolism in the antero-septal
region, indicating lack of myocardium viability, and therefore
discarding the possibility of revascularization treatment (by-pass).
Non-viable Myocardium
36. Patient with acute myocardial infarction (AMI) history and PET
mismatch pattern in which lack of perfusion can be seen laterally
with metabolism persistence, compatible with viable myocardial
tissue. After revascularization surgery, myocardium recovery is
observed, together with perfusion and metabolism normalization
Viable Myocardium
37. Nuclear Medicine in Therapy
Radio-iodine was first used in the treatment of
metastasized thyroid carcinoma in 1943.
Its success in terms of tumor response, quality of
life improvement and survival was considered a
‘miracle’, as in those days metastatic cancer was
generally fatal.
Inspired by this, many efforts have been made to
apply radioisotope therapy to other tumors.
38. One of the most important difference between targeted
radionuclide therapy and external beam irradiation is the
finite (restricted) range of ionizing particles emitted.
Targeted radionuclide therapy involves the use of
radiolabeled tumor-seeking molecules to deliver a cytotoxic
dose of radiation to tumor cells.
39. 1. Beta-particle emitters
2. Alpha-particle emitters
3. Auger electron
Radionuclides that decay by the following three general
categories of decay have been studied for therapeutic
potential :
40.
41. Advantages of Targeted Radionuclide Therapy
Tumor specific, with sparing of healthy tissue (low
toxicity).
No limit to the absorbed dose (no limit to the number of
treatment).
Radiation can be delivered to subclinical tumors and
metastases that are too small to be imaged and thereby
untreated by surgical excision and external beam
therapy.
42. Established therapies
1. Hyperthyroidism- (I-131)
2. Thyroid carcinoma (I-131-High Dose)
3. Bone metastases (32P, 89Sr, 153 Sm)
4. I-131- MIBG therapy (Neuroblastoma, Pheos)
5. Lipiodol therapy (Iodine-131-HCC)
6. Synovectomy (short range B-emitters)
Newer Therapies
1. Radio-peptide therapy (177Lu, 90Y)
2. Radio-immunotherapy of lymphoma
3. Microsphere therapy for liver cancer (90Y)
43. Nuclear Medicine (PET/SPECT) Drug Development
• Development of New Tracers for human use (Diagnostic &
Therapeutic).
• Drug Development (Pharmaceuticals)
• In clinical trials, PET Technology evaluates whether a drug
has a biological effect
• How the effect compared with other agents, whether the drug reached
the target organ
• Whether it did so at an effective concentration.
• Of particular utility in the development of new anti-cancer therapy
44.
45.
46. Nuclear Medicine
(Biomarker Imaging)
• Provides an opportunity to interrogate the target/tissue of interest – in a
temporal fashion (dynamic studies)- Proof of Target (POT)
• Answers questions around distribution (target or compound) -POT
• Structural and functional consequences of intervention with novel
therapies - POM
• These approaches –facilitate better and faster decision making-POE
• Testing of therapies in the appropriate patient population
• Provides robust endpoints for regulatory submission
49. NM – Imaging Cuts down the cost of
Drug Development
Cost involvement – around 800 $ (million)
Time line - 10-12 years
Shortening the Drug Discovery/Development process
Increasing the Efficiency of the testing methods
Facilitating the Transition between the Preclinical testing and
clinical evaluation of the drugs
NM Imaging methods are more easily applied than the traditional
methods as more realistic animal models of human disease can
be created
50. Conclusion
• Role of Imaging in drug development
is valued
• Impact of numerous Imaging
modalities including
SPECT/PET/dceMRI/CE-US is
significant
• As we head in to the era of
personalized medicines
• Imaging has role in drug
development, diagnosis, stratification
and monitoring of patients in the
treatment setting
51. Nuclear Medicine
Nuclear medicine began approximately 50 years ago and has
evolved into a major medical specialty for both diagnosis and
therapy of different disease conditions
3,900 hospital-based nuclear medicine departments in USA
alone Perform over 10 million nuclear medicine imaging and
therapeutic procedures each year.
India has close to 200 Nuclear Medicine Centers (0.5 million
NM- Procedures catering to the need of 1.2 billion population
( Look at the Scope of expansion of NM –India)
Despite its integral role in patient care, nuclear medicine is still
often confused with other imaging procedures, including general
radiology, CT, and MRI.
52. Challenges-Trained Technical Manpower ?
Interdisciplinary Groups
Radiochemists
Radiopharmacists
Biomedical Engineers
Physicists
Imaging Experts
Toxicologists
Pharmacologists
Dosimetrists
Nuclear Medicine Physicians
Molecular Biologists
Genomics/Proteomics Experts
Hybridoma Experts
•Initiation of Leaderships of Universities/academic/research
Institutes
•Technical courses to generate the technical manpower
•Inter-institutional teaching/research collaborations
•Organization of thematic Training workshops/seminars
(students/faculty participation)
•Achieving the target of Personalized Medicine
Hinweis der Redaktion
One of the first experiments was performed by Blumgard and Weiss in 1943. By injecting a small amount of radioactivity into the arm vein of a subject and monitoring the appearance of radioactive signal with a detector on the contralateral side, they were able to measure the transit time of blood from the venous to the arterial circulation.
This experiment illustrates what we call the "tracer principle"