The Role of Nuclear Medicine in the Staging and Management of Human Immune Deficiency Virus Infection and Associated Diseases.

Human immune deficiency virus (HIV) is a leading cause of death. It attacks the immune system, thereby rendering the infected host susceptible to many HIV-associated infections, malignancies and neurocognitive disorders. The altered immune system affects the way the human host responds to disease, resulting in atypical presentation of these disorders. This presents a diagnostic challenge and the clinician must use all diagnostic avenues available to diagnose and manage these conditions. The advent of highly active antiretroviral therapy (HAART) has markedly reduced the mortality associated with HIV infection but has also brought in its wake problems associated with adverse effects or drug interaction and may even modulate some of the HIV-associated disorders to the detriment of the infected human host. Nuclear medicine techniques allow non-invasive visualisation of tissues in the body. By using this principle, pathophysiology in the body can be targeted and the treatment of diseases can be monitored. Being a functional imaging modality, it is able to detect diseases at the molecular level, and thus it has increased our understanding of the immunological changes in the infected host at different stages of the HIV infection. It also detects pathological changes much earlier than conventional imaging based on anatomical changes. This is important in the immunocompromised host as in some of the associated disorders a delay in diagnosis may have dire consequences. Nuclear medicine has played a huge role in the management of many HIV-associated disorders in the past and continues to help in the diagnosis, prognosis, staging, monitoring and assessing the response to treatment of many HIV-associated disorders. As our understanding of the molecular basis of disease increases nuclear medicine is poised to play an even greater role. In this review we highlight the functional basis of the clinicopathological correlation of HIV from a metabolic view and discuss how the use of nuclear medicine techniques, with particular emphasis of F-18 fluorodeoxyglucose, may have impact in the setting of HIV. We also provide an overview of the role of nuclear medicine techniques in the management of HIV-associated disorders.