 
Radiopharmaceutical medical diagnostic market
The ability to visualise organ function is the unique strength of
radiopharmaceutical imaging. While other imaging modalities will
show whether an organ is structurally normal or abnormal, radiopharmaceutical
imaging will determine if that same organ is functioning as it should.
Targeted medical diagnostic products labelled with a radioactive
marker (radiopharmaceutical) are used to visualise biological processes
and the image is obtained with the aid of a gamma camera. Radiopharmaceutical
imaging provides metabolic and functional information about diseases
such as stroke, dementia, coronary artery disease and cancer that
complements anatomical imaging such as CT or MRI.
Approximately 27 million radiopharmaceutical imaging procedures
were carried out across the world in 2001 for the diagnosis of many
of the major diseases of our time. The global nuclear imaging market
is worth around £1.1 billion and is growing at about seven per cent
per year.
Most recent innovations rely on the visualisation of precise cellular
activities. Such state of the art science is likely to result in
new products that can visualise subtle changes in organ function,
enabling early diagnosis at a stage when treatment is most beneficial
to become the norm. Indeed, it is already possible to see changes
in brain function due to Parkinsonism even before the patient has
symptoms.
PET (positron emission tomography) is an advanced molecular imaging
technique which combines computer technology with procedures using
chemicals that emit positrons (positively charged electrons). The
technique requires short-lived radioactive isotopes that are produced
in a cyclotron and attached to a biochemical molecule such as sugar,
along with a high technology scanner. PET can provide earlier diagnosis
of diseases of the brain, the heart and cancer. For cancer in particular,
PET can detect early metastases and/or recurrence of cancer before
there are changes noted on physical examination or X-rays, as well
as differentiate postoperative or post-radiation therapy changes
from recurrent cancer. In addition to its use in medical diagnostics,
PET will have an important role to play in post-genomic research,
ie. medical research to identify molecular changes linked to genetic
disease, the effect of the environment on gene expression, and drug
screening and development.
The future of molecular imaging is promising. With the advent of
new products to examine key functional changes associated with cancer,
heart disease and various neurological disorders, molecular imaging
is at the forefront of innovation in diagnosis and will benefit
even more from continued advances in instrumentation.
Ultrasound medical diagnostic market
Ultrasound is a versatile, non-invasive, low-cost, realtime technique
used extensively by both hospital and office-based physicians. There
are over 150,000 ultrasound instruments installed throughout the
world, performing around 140 million scans per annum. Currently
around 0.4 per cent of the procedures are done with contrast giving
a total market of about £10 million. The true utility of ultrasound
will be fully realised with the advent of safe and efficacious medical
diagnostic products which will pass through the vessels of the microvasculature,
persist within the blood-pool for some minutes, enhance acoustic
properties and thus produce brighter and clearer images of anatomical
structure and physiology.
The latest generation of medical diagnostic products in development
offers the potential to show perfusion of the myocardium, or how
well the heart muscle is being supplied with blood. Such utility
will significantly strengthen the role of ultrasound in the evaluation
of coronary artery disease, which is the single most important disease
entity in the industrialised world in terms of both mortality and
morbidity. During 2001 good progress was made towards the goal of
assessment of cardiac perfusion with ultrasound, but additional
work needs to be done to deliver a reliable, robust approach which
is available to cardiologists everywhere.
Contrast enhancement also has the potential to add significantly
to the clinical utility of ultrasound in the assessment and management
of patients with liver disease and prostate cancer.
The future
Demographic changes, advances in imaging instruments and software,
and increasingly sophisticated medical diagnostic products support
an upward trend in the growth of the market in the years ahead.
The ability of medical diagnostic products to provide highly detailed
and specific information on disease and its progression is vital
to quality of life, bringing benefit to society and to individuals.
Molecular diagnostics that can visualise disease-related changes
in the cells and molecules of the human body are being developed.
Advances such as these will expand the role of imaging beyond diagnosis,
and may be linked to new therapies for treating disease at the molecular
level. The rapidly growing body of knowledge about the function
of our genes and proteins may one day enable science to predict
and prevent disease, with therapies tailored to the individual’s
genetic profile. Medical diagnostics could play a key role in this
development with products for predictive screening, disease staging,
selection of the best therapy, and monitoring of therapeutic efficacy
and safety.
Radiotherapy market
In therapeutic medicine, radioisotopes are used in the treatment
of both cancerous and non-cancerous tumours, and in cases where
disease has spread from the primary site they can often provide
relief from pain. The total market value is approximately £150 million.
Currently the most significant therapeutic market for radioisotopes
is brachytherapy. Brachytherapy involves the temporary or permanent
implantation of a radioactive source into a tumour, to irradiate
and kill it. It is used in the treatment of several tumours including
breast, prostate, head and neck cancers. Prostate seed implant therapy
accounts for the majority of permanent implants. This is a minimally
invasive outpatient procedure in which radioactive iodine or palladium
seeds are implanted within the prostate gland. This year, a new
10-year study of men with prostate cancer who were treated with
iodine125 seeds demonstrated disease-free survival rates
comparable to those reported for patients undergoing other prostate
treatment methods such as a radical prostatectomy, an invasive surgical
procedure.
In the United States, around 80 per cent of prostate cancer patients
present with early stage disease. About half of these patients receive
radiation treatment (either seed implants or external beam radiation)
rather than surgery. In recent years, as the efficacy and low side-effect
profile of brachytherapy have become better known, the use of seed
therapy for treatment of early stage prostate cancer has seen solid
growth. This has prompted an increase in competition which, combined
with a slowing in the rate of growth in the market, has resulted
in significant pricing and market share pressure.
In Europe, growth for seed implant therapy is on the rise and
the market has substantial development potential. The procedure
is not as well known or widely available in Europe; and early screening
and testing are not as prevalent. As a result, less than half of
the patients have early stage prostate cancer and only a small percentage
of these receive seed implants.
Systemic radioisotope therapy involves the injection or oral administration
of an isotope that concentrates in a specific part of the body,
producing a therapeutic effect. When strontium89 is injected
into the bloodstream, it can target growing bone cancers and help
to alleviate pain. Iodine131 is used for thyroid tumours.
Radiolabelled monoclonal antibodies are novel therapeutics which
combine the targeting ability of monoclonal antibodies with the
therapeutic power of radiation, and these are being developed for
the treatment of several types of cancer. The antibodies target
specific tumour cells and then attach to them, allowing the radioactive
component to destroy them while sparing the surrounding healthy
cells.
As new therapeutic applications for radioisotopes continue to emerge,
there will be considerable opportunity to apply the advantages of
this technology and harvest economic rewards from this important
area of medicine.
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