1. Adrenal wash-out CT: moderate diagnostic value in distinguishing benign from malignant adrenal masses
- Author
-
Ines Ebert, Thorsten A. Bley, Wiebke Schlötelburg, Stefan Kircher, Andreas Max Weng, Timo Deutschbein, Martin Fassnacht, Andreas K. Buck, Bernhard Petritsch, and Ulrich Dischinger
- Subjects
Adult ,Male ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Unnecessary Surgery ,Adrenal Gland Neoplasms ,Computed tomography ,Diagnostic accuracy ,Cohort Studies ,Diagnosis, Differential ,Endocrinology ,Adrenal masses ,Internal medicine ,medicine ,Humans ,Aged ,Retrospective Studies ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Washout ,General Medicine ,Middle Aged ,Adrenal Cortex Neoplasms ,Adrenocortical Adenoma ,Clinical Study ,Female ,Histopathology ,Radiology ,Tomography, X-Ray Computed ,business ,Follow-Up Studies - Abstract
Objective Reliable results of wash-out CT in the diagnostic workup of adrenal incidentalomas are scarce. Thus, we evaluated the diagnostic accuracy of delayed wash-out CT and determined thresholds to accurately differentiate adrenal masses. Design Retrospective, single-center cohort study including 216 patients with 252 adrenal lesions who underwent delayed wash-out CT. Definitive diagnoses based on histopathology (n = 92) or comprehensive follow-up. Methods Size, average attenuation values of the adrenal lesions in all CT scan phases, and absolute and relative percentage wash-out (APW/RPW) were determined by an expert radiologist blinded for clinical data. Adrenal lesions with unenhanced attenuation values >10 Hounsfield units (HU) built a subgroup (n = 142). Diagnostic accuracy was calculated. Results The study group consisted of 171 adenomas, 32 other benign tumors, 11 pheochromocytomas, 9 adrenocortical carcinomas, and 29 other malignant tumors. All (potentially) malignant and 46% of benign lesions showed unenhanced attenuation values >10 HU. In this most relevant subgroup, the established thresholds of 60% for APW and 40% for RPW misclassified 35.9 and 35.2% of the masses, respectively. When we applied optimized cutoffs (APW >83%; RPW >58%) and excluded pheochromocytomas, we missed only one malignant tumor by APW and none by RPW. However, only 11 and 15% of the benign tumors were correctly identified. Conclusions Wash-out CT with the established thresholds for APW and RPW is insufficient to reliably diagnose adrenal masses. Using the proposed cutoff of 58% for RPW, malignant tumors will be correctly identified, but the added value is limited, namely 15% of patients with benign tumors can be prevented from additional imaging or even unnecessary surgery.
- Published
- 2022