Mayo Clinic is home to the highest-volume radiopharmaceutical practice in the world. As a result, its researchers and clinicians are well versed in radioactive isotopes of all varieties for cancer imaging and care. These radioisotopes are critical for building radiopharmaceutical treatments to target specific molecular markers on cells such as those found in cancerous tumors. But these isotopes can be difficult to come by and often do not occur naturally in our environment.
Enter particle accelerators, powerful machines for generating radioactive compounds. Particle accelerators, which include machines like cyclotrons and linear accelerators, allow medical teams to produce specific radioisotopes on demand, generating opportunities for researchers to explore new radioactive compounds and providing clinicians with the building blocks of radiopharmaceutical drugs to diagnose and treat a multitude of cancers.
Mayo Clinic is ready to install the next level of high-tech equipment to drive drug discovery and cancer therapy. This new equipment will allow Mayo Clinic to double down on leading the charge to develop new, lifesaving cancer therapies, and particle accelerators are making it possible.
In cancer care, the radioactive isotopes generated by particle accelerators are used for two main purposes: diagnostics and treatment.
In cancer diagnostics, radioisotopes that emit relatively low amounts of energy can be combined with molecules like antibodies that can target specific markers on the surface of cancer cells. Once the molecules have attached to the cancer cells, clinicians can use a positron emission tomography (PET) scanner to visualize the energy released by the radioisotope, allowing them to pinpoint the location of tumors in the body.
When it comes to treating cancer, radioisotopes that emit high-energy particles are similarly combined with targeting molecules. In this case, however, instead of visualizing that signal on a PET scanner, the particles released by the radioisotope are absorbed by the cancerous cells. The energetic particles released by these radioisotopes, known as beta or alpha particles depending on the treatment, break apart the DNA of the cells to kill the cancer.
In both approaches, clinicians need ready access to the correct radioisotopes to develop and administer the right treatment.
While some of the radioisotopes used for generating these treatments can be found in nature, there are a variety of reasons that it is challenging to use naturally sourced isotopes.
First, not all radioisotopes are found in the environment. Secondly, even for those found in nature, often it is not in the amount needed to produce treatments for patients, and it can be quite difficult and costly to extract and isolate the isotopes. Finally, these radioisotopes frequently decay very rapidly, meaning they release the energetic particles that make them valuable for medical applications and become inactive. This can make it difficult to transport the material to hospitals while it is still active.
The effort, expense and logistical challenges of sourcing radioisotopes from nature have led the field of medicine to turn to particle accelerators (among other manufacturing approaches), which allow for production of these compounds on demand. These machines use particle acceleration technology to fire particle beams at stable isotopes. The interaction between the beam and the stable isotope produces short-lived radioisotopes for use in medical applications.
Because these radioisotopes are unstable and decay rapidly, the ability to produce them on-site makes it possible for medical teams to quickly generate radiopharmaceutical drugs and get them to the patients who need them. This is why Mayo Clinic has cyclotron particle accelerators on each of their three campuses in Jacksonville, Florida; Phoenix, Arizona; and Rochester, Minnesota. The goal is to ensure that the patients who need these treatments can get them as soon as they need them.
However, not all accelerators are created equal. The current cyclotrons at Mayo Clinic can produce the radioisotopes needed for various types of medical imaging, such as choline-11, fluoride-18 and nitrogen-13. These radioisotopes are comparatively light. The isotopes needed for cancer treatment, such as lutetium-177, actinium-225 and radium-223, are much heavier and can’t be produced using the existing equipment. These heavier isotopes require manufacturing processes using higher-energy particle accelerators or other powerful equipment to generate the correct radioisotopes.
Larger accelerators have other benefits too. With their greater capacity, they can more quickly produce radioisotopes, providing researchers and clinicians with more access to the elements needed for research and medical use. They are also capable of generating a wider range of radioisotopes, allowing for the creation of diagnostic, therapeutic and research particles all in the same machine.
The Mayo Clinic Comprehensive Cancer Center sees nuclear oncology and radiopharmaceutical therapies as essential elements in the array of cancer treatment options. As research breakthroughs advance the field of theranostics for cancer diagnostics and care, so too do the efforts of clinicians and investigators to translate and apply these advances.
To stay at the forefront of nuclear medicine and ensure that our patients are never left behind due to material shortages or operational challenges, the Mayo Clinic Comprehensive Cancer Center hopes to build new, larger accelerators at each of the three campuses to ensure that all sites can produce any radioisotopes needed for all possible medical and research applications.
Mayo Clinic researchers are developing the therapies of the future, licensing these new therapies to companies, and running clinical trials to validate that they are safe and effective. Larger machines capable of producing therapeutic radionuclides allow Mayo Clinic scientists and physicians to accelerate the discovery science needed to develop these new therapies and attract the best and the brightest in the field to join the Mayo team.
The generosity of benefactors plays a crucial role in allowing Mayo Clinic to invest in cutting-edge technologies like larger accelerators, which are essential for advancing patient care. These philanthropic gifts provide the financial foundation necessary to undertake ambitious projects that might otherwise be out of reach, allowing Mayo Clinic to remain at the forefront of medical innovation.
By supporting the acquisition of advanced equipment, benefactors directly contribute to improving diagnostic capabilities and treatment options for patients, ultimately helping Mayo Clinic stay true to its primary value — putting the needs of the patient first.
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