Yttrium-90 and Rhenium-188 Radiopharmaceuticals for Radionuclide Therapy

esearch efforts, since then. However, a few partial successes are worthy of noting.
Iodine-131 MIBG has now become established, at least as a radiopharmaceutical
with a palliative action for routine treatment of childhood neuroblastomas. RSO
can restore mobility to patients with painful joint disorders and makes the time
spent waiting for an endoprosthesis more bearable. Intolerable pain from skeletal
metastases can be relieved with β emitters, giving these patients a better quality
of life.
However, sobering realities frequently have to be faced in nuclear medicine.
Yttrium-90 Zevalin, a prize product on which great hopes were pinned, has not
fulfilled investor expectations, in Europe at least. There has been a noticeable
decline in this type of radionuclide therapy. The reasons lie in the relatively high
price of radiopharmaceuticals, which can exceed €15 000, and the associated
hesitancy of the user to undertake a somewhat complicated labelling procedure
where wasteful mistakes could be made. The fact that most therapies require the
collaboration of specialists in nuclear medicine with haemato-oncologists does
not simplify the matter. Sometimes, a treatment is thwarted when the patient
refuses consent for the procedure or the necessary blood tests involved.
The number of patients on radioiodine therapy wards has fallen in recent
times, at least for those with benign thyroid disorders. Alternative plans for
maintaining the demand for routine clinical services in the field of nuclear
medicine are urgently required. There are grounds for hope. In recent years,
impressive successes have been achieved with somatostatin analogues labelled
with 177 Lu and 90 Y [2.76]. These, and other innovative approaches that have
arisen from spectacular scientific advances in labelling technologies, genetics,
proteomics, nanotechnology, molecular imaging and indeed computer technology,
are all encouraging. Such advances were also crucial for the development of the
novel therapeutic approaches described in this publication.
The future of nuclear medicine is in personalized medicine, in which the
radionuclide used and the vehicle selected for any one pathological situation will
be specifically tailored to the individual patient.
There is certainly room for improvement in the field with regard to
translation of scientific advances to routine clinical applications (from bench to
bedside). Finding ways to meet and deal with the ever increasing demands of
pharmaceutical legislation and regulations for radiation protection so that these
do not halt progress altogether is an urgent and pressing problem. There is no
sense in dismissing these demands simply as bureaucratic obstacles and shutting
our eyes to the issue. The internationally binding standards for good laboratory
practice and good manufacturing practice are challenges that have to be faced
in radiopharmacological research for the development of radioactive vehicles,
particularly for therapeutic use. Obligatory adherence to these international
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