New criteria and reconstruction algorithm in 18FDG PET-CT for сharacterization of adrenal lesions in cancer patients
A.Tzonevska, I. Kostadinova, M. Garcheva
The aim of the study is applying new PET-CT criteria and reconstruction algorithm Q.Clear for characterization of adrenal lesions in oncology patients for increasing the diagnostic accuracy and differentiation of benignant from malignant lesions. 19 cancer patients with 23 adrenal lesions are included in the study. PET-CT is performed using hybrid scanner Discovery IQ, GE Healthcare. The PET reconstruction is made using standard OSEM (Ordered Subsets Expectation Maximization) and for the first the new algorithm for reconstruction Q.Clear (Regularized Reconstruction Interactive Algorithm).The quantitative analysis of FDG uptake is performed with SUV max measurement using both reconstructed images from OSEM and Q.Clear in adrenal lesions, hepar, mediastinum. The CT images are used for density measurement in adrenal lesions in HU. We accepted the following criteria for differentiation of benignant from malignant lesions: size > 40 mm, density >10 HU, SUVmax in the lesion ≤ in the liver, SUV max in the lesion < 3.0. The adrenal lesions in 4 patients fulfill all criteria formalignancy and are defined as malignant. In 6 patientsthe adrenal lesions fulfill 3 from the criteria and only the lesion density is higher from HU10, but significantly lower than that in malignant lesions. The adrenal lesions in 9 patients are defined as benignant. The assessment of theimages, reconstructed with Q.Clear show higher quality and increased quantification accuracyApplying the accepted new PET-CT criteria for adrenallesion characterization in cancer patients and the new reconstruction algorithm increase the diagnostic capabilities for benignant from malignant lesion differentiation of adrenal glands and suggests higher study accuracy.
Key words: PET-CT. SUPRAADRENAL LESIONS.RECONSTRUCTION ALGORITH