THE ROLE OF TUMOR-SEEKING RADIOPHARMACEUTICALS IN THE DIAGNOSIS AND MANAGEMENT OF ADRENAL TUMORS

The variety of tumor-seeking radiopharmaceuticals, which are currently in clinical use, may have a potential role as imaging agents for adrenal gland tumors, due to physiological characteristics of this organ.

The purpose of this study was to evaluate the diagnostic potential of ^99mTc-HYNIC-TOC, ^99mTc(V)-DMSA, and ^99mTc-MIBI in the assessment of adrenal tumors, by correlating with imaging findings and histopathologic results.

The research is designed as a cross-sectional prospective study.

The study included 50 patients with adrenal tumors (19 hormone-secreting and 31 nonfunctioning) and 23 controls without adrenal involvement. In all patients, single-photon emission computed tomography (SPECT) was performed, using qualitative and semiquantitative analysis. The tumor to non-tumor tracer uptake was conducted by using a region-of-interest technique. Adrenal to background (A/B) ratio was calculated in all cases.

^99mTc-HYNIC-TOC scintigraphy showed a high statistical significance between A/B ratios, while other two tracers resulted in a lower sensitivity, specificity and accuracy. Futhermore, ^99mTc-HYNIC-TOC could have a high diagnostic yield to detect adrenal tumors (the receiver-operating-characteristic curve analysis, A/B ratio cut-off value of 8.40).

A semiquantitative SPECT analysis showed that ^99mTc-HYNIC-TOC is a highly sensitive tumor-seeking agent for the accurate localization of adrenal tumors.