Neuroendocrine tumours (NETs) arise from secondary epithelial cell lines in the gastrointestinal or respiratory system organs. The rate of development of these tumours varies from an indolent to an aggressive course, typically being initially asymptomatic. The identification of these tumours is difficult, particularly because the primary tumour is often small and undetectable by conventional anatomical imaging. Consequently, diagnosis of NETs is complicated and has been a significant challenge until recently. In the last 30 years, the advent of novel nuclear medicine diagnostic procedures has led to a substantial increase in NET detection. Great varieties of exclusive single photon emission computed tomography (SPECT) and positron emission tomography (PET) radiopharmaceuticals for detecting NETs are being applied successfully in clinical settings, including [¹¹¹In]In-pentetreotide, [^99mTc]Tc-HYNIC-TOC/TATE, [⁶⁸Ga]Ga-DOTA-TATE, and [⁶⁴Cu]Cu-DOTA-TOC/TATE. Among these tracers for functional imaging, PET radiopharmaceuticals are clearly and substantially superior to planar or SPECT imaging radiopharmaceuticals. The main advantages include higher resolution, better sensitivity and increased lesion-to-background uptake. An advantage of diagnosis with a radiopharmaceutical is the capacity of theranostics to provide concomitant diagnosis and treatment with particulate radionuclides, such as beta and alpha emitters including Lutetium-177 (¹⁷⁷Lu) and Actinium-225 (²²⁵Ac). Due to these unique challenges involved with diagnosing NETs, various PET tracers have been developed. This review compares the clinical characteristics of radiolabelled somatostatin analogues for NET diagnosis, focusing on the most recently FDA-approved [⁶⁴Cu]Cu-DOTA-TATE as a state-of-the art NET-PET/CT radiopharmaceutical.

Nuclear medicine is defined as the diagnosis and the treatment of disease using radiolabeled compounds known as radiopharmaceuticals. Single-photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/computer tomography (PET/CT) based radiopharmaceuticals have proven reliable in diagnostic imaging in nuclear medicine and cancer treatment. One of the most critical cancers that also relies on an early diagnosis is gynecological cancer. Given that approximately 25% of all cancers in developing countries are a subset of gynecological cancer, investigating this cancer subtype is of significant clinical worth, particularly in light of its high rate of mortality. With accurate identification of high grade distant abdominal endometrial cancer as well as extra abdominal metastases, 18F-Fluorodeoxyglucose ([¹⁸F]FDG) PET/CT imaging is considered a valuable step forward in the investigation of gynecological cancer. Considering these factors, [¹⁸F]FDG PET/CT imaging can assist in making management of patient therapy more feasible. In this literature review, we will provide a short overview of the role of nuclear medicine in the diagnosis of obstetric and gynecological cancers.

Despite the revolutionized diagnostic effect of fluorine-18 -fludeoxyglucose ([18F]-FDG) as a positron emission tomography (PET) radiotracer in oncological divisions, lack of specificity and sensitivity in discovery of some tumor subtypes was inevitable. Fibroblast activation protein (FAP) is overexpressed in a vast majority of neoplasms, particularly in more than 90% of epithelial tumors which could be an appropriate target for evaluation of tumor’s molecular and metabolic functions by FAP inhibitor (FAPI) ligands. Considerably extensive radiolabeled FAPIs have been investigated during clinical trials for diagnostic as well as theranostic applications with encouraging outcomes. In the same cancers, PET/CT imaging by FAPIs are demonstrating to be valuable alternative to [18F]-FDG in assessment of cancers in which [18F]-FDG PET performance is suboptimal due to [18F]-FDG high background uptake or relatively low avidity. Furthermore, the propensity to specifically target FAP expression through FAP-targeted medications or radiotracer therapy creates prospects for image-guided treatment in both cancer and non-cancer indications. FAPI PET will remain a fascinating field of study in the future years.