Modern radionuclide methods in diagnosing orbital masses

Abstract

Anatomic and topographic features of orbit structure and similar clinical symptoms in many diseases of different etiologies explain the complicated early diagnosis of orbital diseases. Therefore, the diagnostic algorithm for orbital masses is mainly based on instrumental diagnostic methods, especially radiology. Over the past 20-30 years, radiologic diagnosis of orbital tumors took a step forward thanks to the introducing such methods as computer tomography, magnetic resonance imaging and ultrasound into clinical practice. However, these methods of investigation, despite their great diagnostic possibilities, not always allow to obtain objective information on the tumor biology, tumor malignancy grade and characteristics of their metabolism. A significant step forward in this direction was the development and introduction of modern nuclear medicine techniques such as single photon emission computed tomography and positron emission (two-photon) tomography into clinical practice. These methods allow to visualize the functional processes in normal conditions and to perform a kind of non-invasive biopsy in case of neoplastic disorders. The use of nuclear medicine in oncology is based on hyperfixation of some radiopharmaceuticals in malignant tumors that provides important data for diagnosis and differential diagnosis based on the study of physiological and biological tumor features. The review highlights brief historical facts, as well as the results of using the most informative and safe radiopharmaceuticals. Literature analysis concludes that radionuclide tests at some point might be a method of choice for differential diagnosis of orbital masses.