Clinical significance of PET/CT in the diagnosis of primary adrenal malignancies

Background. According to the literature, the role of combined positron-emission and X-ray computed tomography (PET/CT) in diagnosing primary adrenal tumors (AT) remains limited due to both the frequency of these neoplasms and the availability of the method. Various research is required to assess the diagnostic resources of PET/CT with 18-fluorodeoxyglucose (18F-FDG). Aim. To evaluate the clinical role of PET/CT with 18F-FDG in the diagnosis of primary adrenal malignancies (PAM). Materials and methods. The study included 9 patients, 5 males and 4 females aged 44–76, with a median age of 59.3 years, with a morphologically confirmed diagnosis of the PAM. All patients underwent PET/CT with 18F-FDG. Visual and quantitative analysis of the obtained images was performed, including determination of the standardized maximum accumulation coefficient (SUVmax) in the tumor, liver, and spleen, the ratio of SUVmax of the primary tumor to SUVmax in the liver and spleen. Tumors were more often localized on the right (5/55.6%), and one case was bilateral. The maximum size of the adrenal mass averaged 6.8 cm (3.2–11.2) and the minimum size was 6.0 cm (2.3–9.0). The median SUVmax in AT was 10.0 (3.54–22.29), while in liver and spleen, it was 3.16 and 2.34, respectively, and the ratio of tumor SUVmax to liver and spleen SUVmax was 3.33 and 4.48, respectively. Conclusion. Hybrid PET/CT with 18F-FDG is a medical imaging method with a high diagnostic accuracy of PAM. PET/CT showed significant 18F-FDG tumor uptake, with a median SUVmax of 10.0 and a ratio of tumor SUVmax to liver and spleen SUVmax of 3.33 and 4.48, respectively. PET/CT with 18F-FDG may be a method of choice for diagnosing primary ATs.