At the end of 2025, Latvian researchers conducted a unique experiment demonstrating the development of a new radiopharmaceutical agent for early cancer diagnosis and therapy, which will help patients receive more precise treatment and reduce side effects.
In the spring 2026 issue of the University of Latvia (UL) magazine "Alma Mater", Elīna Pajuste, Director of the Institute of Chemical Physics (ICP) at the Faculty of Exact Sciences and Technologies (FEST), head of the Radiochemistry Group and lead researcher of the experiment, describes the laboratory work and the experiment’s course.
From Idea to Radiopharmaceutical Agent
Under Elīna Pajuste’s leadership, the team included researchers Anete Stīne Teimane, Vanda Voikiva, and Līga Avotiņa, lead researcher Artūrs Zariņš, and scientific assistants Rūdolfs Jānis Zabolockis and Laura Dace Pakalniete.
The project also involved the European Organization for Nuclear Research (CERN) and the Latvian company Nucleo. At CERN, LU researcher Patrīcija Kalniņa and LU alumnus and current postdoctoral researcher Edgars Mamis prepared the target material for irradiation and arranged its shipment to Latvia.
The experiment’s most significant achievement was completing the entire process cycle necessary for developing targeted radiopharmaceuticals. LU scientists, together with partners, developed the target material, irradiated it using CERN infrastructure, transported it to Latvia, purified it, synthesized it, and demonstrated that the developed materials and methods functioned as intended.
“Many teams worldwide work only on separate stages. What makes our work unique is that we completed the entire cycle,” Pajuste explains to Alma Mater. “Moreover, Latvia has had virtually no experience across this full spectrum. Previously, our radiation laboratory mainly focused on energy-related studies, investigating radionuclides linked to nuclear synthesis and other processes. Over the past five years, we have deliberately expanded our expertise and increasingly focused on medical applications.”
Latvian Science Shows It Can Compete Globally
This experiment demonstrates that Latvian science, international partners, and a local company can implement projects previously thought possible only in large countries with established radiopharmaceutical industries.
“This is a signal for both researchers and industry: Latvia can become a notable player in developing theranostic radiopharmaceuticals, offering expertise, technology, and a flexible collaborative ecosystem,” says Elīna Pajuste.
Cancer Diagnosis and Therapy in a Single Molecule
The experiment is based on a theranostic approach, which combines cancer diagnosis and therapy in one solution. A single pharmaceutical molecule can be used in two ways, depending on the attached radioactive isotope: either to precisely visualize disease sites in the body or to target and treat them.
“One molecule, one element, but with different isotopes,” explains Pajuste. “One isotope emits radiation for imaging, while another has a very short range to selectively destroy cancer cells.”
One precise diagnostic method is positron emission tomography (PET), which detects the radiation emitted from the molecule. The result is a high-resolution map of disease sites down to the cellular level.
“Patients are administered a radiopharmaceutical — a molecule that accumulates in specific areas. For example, a commonly used radiolabeled sugar concentrates in tumor cells because they consume more energy and grow faster than healthy cells. Other radiopharmaceuticals target receptors on the cell surface, highlight actively dividing cells, or accumulate in areas with altered blood flow. The tomograph detects the isotope’s radiation, producing a detailed map of disease locations at the cellular level,” she explains.
Unlike traditional external radiation therapy, where surrounding healthy tissue is also exposed, the therapeutic isotope in theranostics acts locally, minimizing side effects.
“This means the radiation hits only the disease site. We do not irradiate the entire body. The substance is delivered exactly where needed, and the radiation works locally,” Pajuste emphasizes.
The Path to Patients
The experiment does not yet mean a ready-made drug. Such radiopharmaceuticals reach patients only after preclinical and clinical studies, conducted later by pharmacists and medical professionals. This process can take several years, as safety is the top priority.
However, completing the full-cycle demonstration is a crucial prerequisite for further development. “We are chemists — our job is to prepare the foundation. After repeated experiments, other specialists will take over. The benefit is already clear: it lays the groundwork for more precise, personalized cancer treatment. Ultimately, the main beneficiary will be the patient, with earlier diagnosis, targeted therapy, and fewer side effects.”
From CERN Bunkers to Latvia’s Only Radiation Laboratory
Collaboration with CERN is often associated with fundamental physics and the Large Hadron Collider, but the organization is also active in medical applications. The CERN-MEDICIS program focuses specifically on producing medical radionuclides.
The radioactive materials for this experiment were produced at CERN-MEDICIS in Switzerland, where particle accelerators irradiate specially prepared target materials. Afterwards, they were transported to Latvia under strict safety protocols.
Working with radioactive substances requires very strict safety measures. Experiments take place in specialized rooms and bunkers, using so-called hot cells (lead boxes) for handling through leaded glass. Some processes are robotized, while others are performed manually with specialized protective equipment.
Every step is coordinated with the Radiation Safety Center of the State Environmental Service, alongside meticulous documentation and safety procedures. “It’s a big responsibility but an essential part of this type of research,” Pajuste notes. “Radiation is relatively easy to measure, so each stage — production, purification, synthesis — is precisely controlled.”
Science as a Journey
Elīna Pajuste’s 24-year scientific career shows that specialization does not mean being stuck in one area. From nuclear synthesis and energy studies, she has recently expanded into medical research, leveraging her existing expertise.
“I want to encourage scientists, even in mid-career, not to be afraid to explore a slightly different direction. Science allows experimentation, and even a failed result is still a result,” Pajuste says.
She advises aspiring students to choose STEM fields, as science is not just laboratory work: “It’s like a journey — it allows you to see the world, work internationally, and create solutions with real impact.”
And as she jokingly adds, science is not everything: her own family includes three children, a dog, a cat, and a garden, with plenty of time for hobbies and everyday joys.
