The production of PET radiopharmaceuticals
requires:
-
Ciclotrón:
instrument used for the production of radionuclides or positron
emission radioactive isotopes. Of these, the most widely used
in the PET
are fluoride-18, nitrogen-13, carbon-11 and oxygen-15. The positron
emission radionuclides are characterized by having a very short
half-life (between a few minutes and two hours). The most frequently
used is the fluoride-18 that has a half-life of 110 minutes.
-
Radiopharmaceutical
processing unit: the radionuclides produced in
the cyclotrones usually do not have the suitable chemical and
pharmaceutical form for use as biological tracers wherefore
they must be incorporated with more complex molecules within
a radiopharmacy laboratory. The radiopharmaceutical obtained
must always be subject to strict control tests prior to administration
to the patient, therefore this unit must have a quality control
laboratory. The most widely used radiopharmaceutical in the
PET is 18F-fludeoxyglucose (FDG).
The Quality Management System
and Computer System implanted by Molypharma ensure traceability
and quality of its supplies
of FDG.
FDG
18F-Fludeoxyglucose
(FDG) is a radiopharmaceutical constituted by a substance similar
to glucose 2-[18F]Fluor-2-desoxi-D-Glucose bound to the radioactive
isotope-18F. This radiopharmaceutical allows the study of cell metabolism
of glucose and is the most widely used in PET. This is due fundamentally
to the high availability as its half-life of 110 minutes allows
transportation to centers other than that of its production.
Once administered to the patient,
the FDG is incorporated to the cells by the same transport mechanism
as the normal glucose but unlike this, once inside the cell it is
not metabolized. This causes it to accumulate in the cell, allowing
PET tomographic imaging.
 The
imaging of glucose consumption by the cells is the basis of the
clinical indications of PET studies with FDG. Thus, for example,
the existence of a high consumption of glucose by the tumor cells
due to an increase in metabolic activity permits the detection of
tumor processes. Under normal conditions there is a high consumption
of glucose by the brain and heart cells therefore a reduction in
FDG captured by their cells enables diagnosis of pathologies related
with these organs. The clinical
applications of the PET studies with FDG are centered fundamentally
in the fields of Oncology,
Neurology and Cardiology.
The PET studies with FDG pose the advantage of detecting functional
cellular alterations before structural alterations occur. Therefore
the PET with FDG can reveal the presence of a tumor when other conventional
morphological diagnostic modes (for example, X-rays, TAC, RNM, ecography)
are unable to detect the lesion.
A PET exploration with FDG
requires the preparation of the patient who must have fasted for
at least 6 hours prior to intravenous administration of the FDG,
the acquisition of images between 45-60 minutes after, the processing
of said images and their analysis.
CLINICAL APPLICATION OF THE FDG
The PET with FDG has its principal
clinical indications in the field of Oncology,
Neurology and Cardiology,
especially the former.
By way of indication and with
general nature, the generic clinical circumstances in which the
PET is deemed useful are detailed below:
1.
Clinical applications in Oncology
-
Differential diagnostics
of benign and malign lesions
-
Study of the extension
of the disease (staging)
-
Study of patients with
biochemistry evidence of recurrence of the tumor (increased
tumor marker levels) but that fail to show clinical or morphological
evidence of the disease through other diagnostic imaging techniques.
-
Differential diagnostics
between recurrent or residual malign disease versus changes
induced by the treatment.
-
Study of patients with
metastasis of unknown primary tumor.
-
Diagnostics of the malignancy
level of the tumors.
-
Determination of the
most aggressive part of the tumor for planning the biopsy.
-
Monitoring of the tumor
response to chemotherapy or radiotherapy.
-
Planning of the therapeutic
or palliative radiotherapy
2. Clinical
application in cardiology
3. Clinical applications
in Neurology
-
Epilepsy: Detection
and localization of the epileptogenic focus.
-
Differential diagnosis
between recidivation or residual disease versus radionecrosis
in treated brain tumors.
-
Diagnosis of dementia:
early diagnosis of the Alzheimer’s and differential diagnosis
of other forms of dementia such as vascular dementia, Parkinson’s
disease, Huntingdon’s, etc.
AUTHORIZED CLINICAL INDICATIONS
The marketing application of new radiopharmaceuticals
as well as the new indications of radiopharmaceutical already
authorized must be authorized by the Health Authorities prior
to application in clinical practice. For this, any marketing application
of a new radiopharmaceutical is subject to a rigorous application
procedure that guarantees efficacy, safety and quality of the
product.
As the evaluation process of an application
can be lengthy and complicated and the clinical use requirements
of the FDG are increasing in Spain, the Spanish Drug Agency has
authorized those indications deemed as more justified for the
appropriate used of PET with FDG.
Said justification is detailed in the document
“Indications of the 18FDG-PET”, that is based on the
scientific knowledge existing on the matter and that was drafted
by the Agencia de Evaluación de Tecnologías Sanitarias
(AETS) (Agency of Health Technology Evaluation) of the Instituto
de Salud Carlos III, in collaboration with the AETS of Andalusia,
Catalonia and Basque country..
The authorized indications
in Spain are:
-
Malignant melanoma
-
Recurrent colon-rectal
cancer
-
Solitary pulmonary nodule
-
Non-microcytic lung cancer
-
Tumors of the Central
Nervous System, differentiation between radionecrosis and recidivation
-
Staging and re-staging
of lymphomas
-
Cancer of the head and
neck
-
Recurrent thyroid cancer
Molypharma has the Marketing
Authorization for the pharmaceutical specialty
called FLUORSCAN
® 1700 MBq/ml, injection solution ([18F]-fludeoxyglucose
(FDG))
-
To consult the technical
specifications of FLUORSCAN® follow the steps details below:
- click on the link
- accept the conditions
- type FLUORSCAN in the box "Drug Product "
- press the button "Consult"
- the information will appear in the lower part of the screen
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