What is nuclear medicine ?

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

How does it work?

An introduction to the imaging techniques and treatment procedures of Nuclear Medicine, to help you understand therapy protocols and how they work in the body to fight off the disease.

by Stefano Buono, AAA (Advanced Accelerator Applications)

 Molecular Nuclear Diagnostics work by introducing into the patient’s body (by injection, swallowing or inhalation) targeted radiopharmaceuticals that accumulate in the organs or lesions revealing specific biochemical processes.
These radiopharmaceuticals are capable to emit, albeit only for a few hours, some radiation that can be used to create metabolic images of the lesions in a camera around the patient. 

 In PET (Positron Emission Tomography), the emitted radiation is a positron (the anti-particle of the electron) which, when interacting with the tissues around the radiopharmaceutical, creates 2 rays, one opposite the other. The rays hit a camera and the two signals taken in coincidence allow a precise localization of the emission point (see picture).

    In SPECT (Single Photon Emission Tomography), the emitted radiation already is a ray, which is then directly used to create the camera images. SPECT cameras use collimators to help localizing with precision the direction of the incoming ray. 

When two detectors see the photon pair from an annihilation event, we know he event occurred on the line between them. After many events are detected, the intersection of the lines between detector pairs tells us where the activity is.

Molecular Nuclear Medicine is a medical specialty which uses trace amounts of active substances (called radiopharmaceuticals) to create organs and lesions images, and treat
various diseases such as cancer. The technique works by injecting into the patient’s body targeted radiopharmaceuticals that accumulate within the organs or lesions to reveal specific biochemical processes.

Molecular Nuclear Diagnostics use a variety of imaging devices and radiopharmaceuticals. PET (Positron Emission Tomography) and SPECT (Single Photon Emission Tomography) are highly sensitive imaging technologies that enable physicians to diagnose different types of cancer, cardiovascular diseases, neurological disorders and other diseases in their early stages.

Molecular Nuclear Therapy uses radiopharmaceuticals that emit electrons, the same particles used in Radio Therapy (treating cancers using particle accelerators). By targeting special radiopharmaceuticals specifically to the tumors, these electrons are only emitted locally over a certain time, and cure by destroying unhealthy tissues; this allows for an efficient treatment and avoids surrounding healthy tissues. For the analogy to Radio Therapy, this technique is also called Radio Metabolic Therapy (RMT).