Teranostics – tailor-made medicine
Theranostics, the close combination of diagnosis and therapy to select targeted treatment for a specific patient – safe and effective at the same time, is the future of medicine – including nuclear medicine. Personalized medicine, theranostics and precision medicine are currently the most repeated terms that characterize the medicine of the future. Theranostic philosophy will become increasingly common, especially in oncology, experts of the Polish Society of Nuclear Medicine predict.
Concept „theranostics” was formulated based on a combination of twooch słow: therapeutics and diagnostics. It was first applied by John Funkhouser in 2002. He proposed that before herceptin is administered to women with breast cancer, the expression of the receptor should be determined by histological examinationow for HER2 (Herceptin treatment is only justified in theowhile the comocancer cells show the presence of this receptor). Nuclear medicine has been guided by this principle from the beginning: radioactive iodine in the treatment of thyroid cancer (the first therapeutic procedure using radioisotopeo(w) is administered to patients only when a scintigraphic examination after a diagnostic dose of radioiodine shows preserved iodine uptake.
Currently, theranostics is reaching out to the latest technologies and materialow, such as nanotechnologies, nanomaterials, biomaterials and biomimetics, ktore allow simultaneous detection of the process ofoof the disease in the patient’s body and take action thatore enable delivery of the drugoin directly to the areaoin those affected by the disease process.
Such targeted intervention allows for more effective treatment. What’s more, it also makes it possible to tailor treatment methods (including the dose of the drug) to the individual needs of a particular patient. Theranostics as diagnostics and therapy at the molecular level is the basis of modern personalized precision medicine, called medicine „tailor-made”.
– The idea behind theranostics is to first see if a particular drug, whichore to our knowledge can be used in the treatment of a given condition, will actually combine with the comowith disease cells. A given drug is administered only when we find that it actually binds to the lesions and the treatment is very likely to be effective. In the context of nuclear medicine, used in oncology therapy, we check for this ro¿different radiopharmaceuticals, including peptide radiopharmaceuticals – mowi prof. Leszek Krolicki, national consultant in nuclear medicine.
The first step in the theranostic approach is the labeling of the selected drug with a radioisotope, used for diagnostic. These are radioisotopes that emit gamma (or positron) radiation. This radiation is recorded by instruments – gammacameras (SPECT or PET). – On the basis of the diagnostic test, we need to estimate what the desired range and energy of radiation should be, depending on the volume of the cancer tumor and the degree of accumulation of the radiopharmaceutical – explains prof. Leszek Krolicki.
The next step is the preparation of a radiopharmaceutical labeled with a radioisotope that emits radiation that destroys comocancerous tumors – beta or alpha radiation. – The basic condition is to carry out the labeling in such a way that the combination is very stable, while not changing the biological properties of the carrier – mowi prof. Leszek Krolicki. – Someore isotopes emit radiation, whichore would be suitable for treatment, but the stability of their binding to a specific carrier (for example, a peptide) is too low. Selector substances, whichore we apply, is therefore always well thought out – adds Prof. Leszek Krolicks.
– The range of therapeutic procedures carried out in nuclear medicine is very extensive. In the treatment of anti-bolowe metastatic lesions to the bone we use elements such as Samar or Strontium. They are calcium analogs and accumulate in tumor foci in the bones, and the beta radiation emitted destroys them, alleviating bol. Recently, roalso 223-Rad (it is also a calcium analog), whichory emits alpha radiation – with a short range, but with such high energy that it is able to effectively destroy the DNA of the comocancerous re – explains Prof. Leszek Krolicki.
– The drug targets roalso for the treatment of metastasesoin tumorsoInto the bone (now metastaticoin prostate cancer), but exhibits not only anti-bolowe, but roalso significantly prolongs the survival time of patients – adds prof. Leszek Krolicki.
A slightly different mechanism is adopted in the treatment of tumoroin neuroendocrine. These cancers are characterized by significantly increased expression of receptorow for somatostatin, a peptide hormone that blocks the secretion of growth hormone by the pituitary mozg and inhibit insulin secretion. At the first stage, a diagnostic test (scintigraphy) is performed using labeled analogues of theow somatostatin. If scintigraphy shows a very high affinity of tumor foci for this peptide, while kidney and bone marrow function is normal, treatment with the same radiopharmaceutical but labeled with a beta (or alpha) emitting radioisotope is being considered.
In prostate cancer therapy, scientists’ enthusiasmow and clinicianoin excites PSMA. This is an antigen found on the membrane of comorkowe comosteric rec. Its expression has been shown to be significantly increased on comork cancer. This observation was the basis for the search for a peptideow, combining with this antigen.
– Radioisotope-labeled peptides (68Ga, 18F) revolutionize prostate cancer diagnosis – It is now possible to evaluate even non-enlarged nodesoIn lymphatics in search of metastatic foci. What’s more, the PSMA antigen has become a therapeutic target for treating patients with disseminated metastatic cancer no longer responsive to hormone or chemotherapy. For this purpose, the radiopharmaceutical is labeled with beta-emitters (186-Lutet), or alpha-emitters (225-Actin) – explains Prof. Leszek Krolicki.
The use of a theranostic strategy makes it possible to implement an effective treatment that is appropriate for a given patient, or to modify the therapy already being used for that patient. Glohe other fields of medicine where theranostics is used are: oncology, endocrinology, process therapyoin inflammatory and autoimmune lesions.
– With the exponentially increasing number of cancer cases, dubbed an oncology tsunami, the ability to offer patients modern, targeted and effective therapies is critical. Teranostics is an interdisciplinary field, combining rodifferent branches of science. Its use in the service of fighting the most common diseases – especially oncological ones – those where therapeutic success still remains a major challenge (prostate cancer, pancreatic cancer) has great potential, so it is worth developing this field – mowi prof. Leszek Krolicki.
Sourceosource: Polish Society for Nuclear Medicine, press release