What is nuclear medicine ?

• How does it work?
• Therapy & Diagnosis
• PET & SPECT - Oncology
• Radiopharmaceuticals

Therapy & Diagnosis

The evolution in imaging technology over the past ten years turned Nuclear Medicine into a powerful therapeutic tool for improved diagnosis and personalized treatment.

by Richard Zimmermann, IBA Molecular

The evolution of the knowledge in disease diagnosis and therapy went through drastic changes in the past ten years, as a consequence of exponential knowledge accumulation and huge technology improvements. Diagnosis is now based on both biological probe analysis and imaging technologies. The technical revolutions in computer calculation capacities as well as the improvements in detectors helped to create new generations of X-ray imaging, Magnetic Resonance Imaging (MRI) and Ultrasound (US) equipment. Although these devices are able to provide excellent images of organs, tissues, fluid movements, the so-called morphologic imaging, they are unable to precisely indicate the exact working conditions of specific cells.

Biological cell processes can be only imaged with technologies capable of measuring signals with very sensitive tools. This is functional imaging, and only radioactivity is able to show such mechanisms in real time.

Nuclear medicine uses the particular ability of radio labeled molecules (or radiopharmaceuticals – molecules labeled with a radioactive atom) to integrate themselves in the biological mechanism of a cell, tissue or organ. As such, nuclear medicine diagnostic agents can indicate if and how such a tissue works, while the other imaging technologies, much more precise in terms of image quality, are limited to providing information on morphology and major tissue/organ modifications. Of course the combination of three-dimensional morphological imaging and functional imaging with new mixed equipments takes advantage of both technologies.

In Oncology, diagnostic radiopharmaceuticals are able to indicate the number, but also the aggressiveness of tumors and metastases. Different new molecules will be able to indicate if a treatment works, or even anticipate if it may work, thus opening a complete new era in personalized medicine (the right medicine for the right patient). The same simple principles can be applied to cardiology (e.g. to differentiate normal cells from ischemic or necrotic tissue in the heart) or again to neurology (e.g. Alzheimer Disease diagnosis years before clinical signs appear). Replacing the gamma emitting isotope in a radiopharmaceutical by an alpha or beta emitter can transform a diagnostic tool into a very efficient and selective therapeutic tool. This opens another nuclear medicine area, with great potential.

Over the past 50 years, and on the basis of these principles, scientists have succeeded in developing new diagnostic agents, and also therapeutic agents, that are now entering the market for the benefit of all patients.