Radiopharmaceuticals in Nuclear Medicine

Sarah Benjamin
March 15, 2018

Submitted as coursework for PH241, Stanford University, Winter 2018

Introduction

Fig. 1: Packaging process of radiopharmaceuticals.(Source: Wikimedia Commons).

In the 1930s, Ernest Orlando Lawrence invented and developed the first cyclotron that would soon catalyze the emergence artificial radioactive elements. [1] Being a vehicle for the production of radiopharmaceuticals for their use in imaging systems, the cyclotron brought about a new era of enhanced diagnosis and medical techniques and remains an essential feature for further studies of the human body. As a result, radiopharmaceuticals have played an integral role in assessing bodily functions to diagnose and treat diseases through nuclear medicine. [2] In 2014, the Society of Nuclear Medicine posited there were 20 million nuclear medicine procedures using radiopharmaceuticals and imaging systems each year alone. [3] Consequently, healthcare professionals and scientists are gaining more insight into complex diseases, assessing the effects of new drugs, improving the selection of therapy, offering enhanced and non-invasive medical techniques to identity individuals at risk of disease, and providing rapid evaluations and premier care to those requiring treatment. [4]

Production

Radiopharmaceuticals can be developed by irradiating a target in nuclear reactors, or in cyclotrons. As shown in Fig. 1, before they are administered to patients, radiopharmaceuticals are carefully produced in controlled conditions and tested for quality. As a result, production requires a number of processes to ensure proper handling of large quantities of radioactive substances and chemical processing. Fig. 2 also demonstrates the attention to detail that is required for radiopharmaceutical processing and packaging.

Use in Nuclear Medicine

Fig. 2: Glass vials containing radiopharmaceuticals (Source: Wikimedia Commons)

Used in Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), two of the most widely used imaging systems, radiopharmaceuticals have inspired rapid advancement in non-invasive medical techniques that are commonplace today. [5,6] Through intravenous injection, radiopharmaceuticals have enhanced the function of these scans by improving their capability to diagnose and track the progression of heart and gall bladder disease, detect disorders in bones, and evaluate intestinal bleeding. [2] More recently, they have been utilized in diagnosing Parkinson's disease in the brain. [2] However, these scans and the use of radiopharmaceuticals have been incredibly essential to detecting cancer and monitoring its progression. [2] While there are risks of radiation exposure due to the use of radioactive tracers, the dose to patients is not greater than that received during X-rays or CT scans. [2] Consequently, the knowledge gained, and patient recovery achieved is a key aspect of nuclear medicine inspired through the use of radiopharmaceuticals today. [7]

© Sarah Benjamin. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

References

[1] S. Carlson, "A Glance at the History of Nuclear Medicine," Acta Oncol. 34, 1095 (1995).

[2] "Nuclear Medicine," U.S. National Institute of Biomedical Imaging and Bioengineering, July 2016.

[3] B. Gutfilen and G. Valentini, "Pharmaceuticals in Nuclear Medicine: Recent Developments for SPECT and PET Studies," Biomed Res. Int. 2014, 426892 (2014).

[4] "What Is Nuclear Medicine and Molecule Imaging," Society of Nuclear Medicine and Molecular Imaging, 2016.

[5] A. Rios, "Nuclear Medicine Imaging," Physics 241, Stanford University, Winter 2017.

[6] E. Pinilla, "Nuclear Medicine: Positron Emission Tomography," Physics 241, Stanford University, Winter 2018.

[7] G. Klaris, "The Future of Nuclear Medicine," Physics 241, Stanford University, Winter 2016.