D. I. Maher1, E. Williams1, S. Grodski1,2, J. W. Serpell1,2, J. C. Lee1,2 1Alfred Hospital,Monash University Endocrine Surgery Unit,Melbourne, VIC, Australia 2Monash University,Department Of Surgery,Melbourne, VIC, Australia
Introduction: The majority of adrenal incidentalomas (AI) are benign, although some are large, functional or malignant, and may require surgery. Therefore, all require follow-up. This case-control study aims to determine the pattern of AI follow-up in a level 1 trauma centre in Melbourne Australia, focussing on the factors that influence whether follow-up is facilitated.
Methods: Patients with CT-detected AIs between January 2010 and September 2015 at The Alfred Hospital were included. Case files were identified using a key word search of electronic CT reports. Patients were excluded if the primary purpose of the CT was to investigate adrenal disease, or if the patient had a history of known adrenal mass. Cases were assessed by two authors and reviewed for demographics, managing unit, CT indication and findings, and follow-up arrangements. To consistently determine if “follow-up” occurred, a strict definition of the term was applied. Statistical analysis using t-test, Chi-squared test and logistic regression was performed using Stata SE v14, with a p-value of < 0.05 set as significant.
Results: A total of 38 848 chest and abdominal CTs were performed in the study period, yielding 804 patients with AIs who met inclusion criteria (mean age 65, 58 % male). The mean size of AI was 23 mm. Univariate analysis demonstrated that follow-up was more likely to occur in younger patients (mean age 62 vs 66, p < 0.001); in larger lesions (mean size 26 mm vs 21 mm, p < 0.001); if the CT suggested follow-up (p < 0.001); or if the CT report suggested a diagnosis (p < 0.001). Follow-up arrangements were most likely to be made by the trauma unit (39 %, p = 0.01).
A multivariable analysis supported the significance of these findings and indicated that the CT report and managing unit strongly influence follow-up rates. When a diagnosis was suggested by the CT report, follow-up was more likely to be facilitated (odds ratio 0.63, 95 % CI 0.45 – 0.88; p < 0.01). Additionally, more cases in the follow-up group had a follow-up recommendation in the CT report (2.88, 1.95 – 4.26; p < 0.01). A large difference in the frequency of follow-up was noted between the Trauma Unit compared to other units (1.77, 1.09 – 2.89; p < 0.02). This variance is possibly due to the introduction of a dedicated adrenal lesion protocol.
Follow-up arrangements were made for 245 cases (30 %). In 36 % of these cases (N = 88) follow-up occurred at The Alfred Hospital. Seven cases (8 %) required surgical intervention. Histopathology confirmed four adrenal cortical tumours, two metastatic melanomas and one phaeochromocytoma.
Conclusions: This study highlights that AI follow-up is often overlooked, and that approaches need to be developed to ensure that all cases receive the review they require. This study demonstrates that follow-up is influenced by patient, radiological and medical provider factors. An adrenal lesion follow-up protocol may improve follow-up rates, but requires further research.