[Positron emission tomography in internal medicine]

Area of Science:

• Nuclear Medicine
• Oncology
• Internal Medicine

Background:

• Fluorodeoxyglucose-positron emission tomography (FDG-PET) is an established diagnostic tool in oncology.
• FDG-PET detects elevated glucose metabolism, not specific to malignant lesions, but also present in inflammatory and infectious conditions.
• This makes FDG-PET valuable for diagnosing fevers of unknown origin, infectious foci, vasculitis, sarcoidosis, and unknown primary tumors.

Purpose of the Study:

• To highlight the diagnostic utility of FDG-PET in internal medicine beyond oncology.
• To emphasize FDG-PET's role in ruling out focal inflammation/infection and monitoring therapeutic response.
• To identify areas for further research before routine clinical integration.

Main Methods:

• Review of FDG-PET characteristics and applications in internal medicine.
• Evaluation of its diagnostic performance, particularly its negative predictive value.
• Comparison with conventional imaging techniques for assessing therapeutic response.

Main Results:

• FDG-PET demonstrates a high negative predictive value for ruling out focal inflammation or infection.
• It serves as an early marker of therapeutic response, outperforming anatomy-based imaging.
• FDG-PET is applicable to diverse internal medicine scenarios including fevers of unknown origin and suspected infections.

Conclusions:

• FDG-PET is a valuable tool for diagnosing and monitoring various conditions in internal medicine.
• Further large-scale prospective studies are required for its routine clinical integration.
• Comparative studies and cost-effectiveness evaluations are necessary.