Far beyond its consecrated role in cancer diagnosis and treatment, nuclear medicine also occupies a prominent position in the assessment of heart and neurological diseases – two of the main causes of morbidity and mortality in Brazil – with direct reflexes in patient survival and health system sustainability.
Impact on public health and costs
It is a medical specialty that combines molecular biology, cutting-edge technology and personalized medicine, offering functional examinations that reveal processes that occur within the organs-often before structural changes are visible.
Cardiovascular diseases (DCV) are the leading cause of death in the country, representing about 21% of all deaths, totaling approximately 382,500 deaths in 2021. DAC prevalence (coronary artery disease) among adults reached about 4.2%, and the highest risk in elderly, hypertensive, obese and sedentary. In addition, only in SUS, the costs related to myocardial infarction reached R $ 22.4 billion.
Neurological diseases – such as dementia and Alzheimer’s – impose globally an economic impact of $ 600 billion per year. In Brazil, it is estimated that dementia affects about 21.9% of the elderly over 65 years, although there is a strong underdiagnosis.
Heart: an exam that sees beyond anatomy
Myocardial perfusion scintigraphy, performed with SPECT (single photon emission tomography), is one of the most robust tools in nuclear medicine. Used since the 1970s, this technique has been continually validated by large international studies and clinical guidelines as an effective method in the evaluation of myocardial ischemia. Although traditional, it is far from being considered outdated. New generations of hybrid equipment – which combine SPECT with computed tomography (CT) – enable, in a single examination, not only to evaluate myocardial perfusion, but also calculate coronary calcium score, estimating the patient’s “arterial age” and refining cardiovascular risk.
An important technological innovation is the use of gamma cameras with solid detectors of cadmium-zinc-lutereal (CZT), which enable, through Spect, the measurement of the coronary flow reserve (RFC)-traditionally domain of PET-with greater resolution and accuracy, dispensing with the costly radiotracers of the PET. Studies show that this technology offers results comparable to PET methods, presenting greater accessibility to the national reality.
Scintigraphy-based strategies-especially when well indicated-have proven cost-effectiveness by avoiding unnecessary invasive procedures such as catheterization, and directing more appropriate treatments for each case.
In Brazil, the cardiac pet is still little widespread, although it is an internationally consolidated technique. 18F-FDG PET/CT has indication in specific cases, such as investigation of heart inflammation and the evaluation of myocardial viability, supported by clinical guidelines.
Brain: Molecular image at the service of diagnostic accuracy
In the field of neurological diseases, nuclear medicine tests provide the doctor with a unique perspective of the brain in operation. With the PET and the cerebral spect, it is possible to identify metabolism patterns and perfusion typical of diseases such as Alzheimer’s, Parkinson and other dementia, often even before symptoms are clearly installed.
The use of molecular biomarkers has revolutionized the early diagnosis of neurodegenerative diseases, allowing more early and more effective therapies. In Brazil, PET radiopharmaceuticals are now available, such as 18F-FDG, used to evaluate brain metabolism, and beta-amyloid-specific tracers such as 18F-Florbetaben, which assist early detection of Alzheimer’s disease. Although these tracers are not yet widely available in the country, they represent a promising diagnostic evolution in developing.
In Parkinson’s disease and other movement disorders, 99MTC-Todat, used in SPECT exams, allows the evaluation of the dopaminergic system and assists in the differential diagnosis of parkinsonian syndromes. New molecules are under development, with the ability to track neuroinflammatory processes and synaptic changes, expanding the possibilities for understanding and treating complex neurological conditions.
Challenges and perspectives in Brazil
Nuclear medicine combines decades of tradition with state -of -the -art technological innovations, demonstrating significant clinical and economic impacts. Although Brazil has centers of excellence in the area, access to advanced technology is still unequal. The implementation of hybrid appliances and the incentive for national production of innovative radiopharmaceuticals are fundamental steps to democratize access and track international advances.
Expanding access, stimulating national research and integrating these technologies into care practice can reduce hospital costs, allow more accurate treatments and improve patients’ quality of life – especially in a country marked by a high incidence of cardiovascular and neurological diseases.
Felipe Hemerly Villela Pedras (CRM / RQE: 52.77681-5 / 16177)
Specialist in Nuclear Medicine and Medical Director at Villelas Pedras Clinic
