[Adrenal incidentaloma: management approaches: CT - MRI]

Dual-layer dual-energy CT for characterization of adrenal nodules: can virtual unenhanced images replace true unenhanced acquisitions?

PURPOSE

To investigate the diagnostic performance of dual-layer dual-energy CT (dlDECT) in the evaluation of adrenal nodules.

METHODS

In this retrospective study, 66 patients with triphasic dlDECT (unenhanced, venous phase (VP), delayed phase (DP)) for suspected adrenal lesions were included. Virtual unenhanced images (VUE) were derived from VP acquisitions. Reference diagnoses were established with true unenhanced (TUE) attenuation, absolute washout, follow-up imaging and pathological data. Attenuation for adrenal lesions and abdominal tissues was acquired on TUE, VUE, VP and DP images. VUE and TUE attenuation were compared in all included tissues. Characterization of adrenal nodules based on TUE and VUE attenuation was investigated. ROC analysis was used to determine an adjusted threshold for diagnosing lipid-rich adenomas.

RESULTS

Seventy-three adrenal nodules (mean size: 18.9 ± 8.9 mm) were identified in 66 patients (38 females, 28 males; age: 61 ± 13 years) including adenoma (n = 65), metastases (n = 2), pheochromocytoma (n = 3), adrenocortical carcinoma (n = 1) and myelolipoma (n = 2). Mean attenuation of all included tissues except for the abdominal aorta (p = 0.11) was significantly higher in VUE compared to TUE images, including the attenuation of adrenal nodules (20.0 ± 17.2 vs. 7.1 ± 19.8; p < 0.05). Classification of adrenal adenomas as lipid-rich based on VUE attenuation ≤ 10 HU yielded a sensitivity/specificity of 0.2/1.0, while an adjusted threshold of ≤ 22 HU yielded a sensitivity/specificity of 0.82/0.85.

CONCLUSION

dlDECT-derived VUE images overestimated attenuation in adrenal nodules, resulting in low sensitivity for diagnosis of lipid-rich adenomas using the established 10 HU threshold. Based on an adjusted threshold (≤ 22 HU) a higher sensitivity was attained, yet at the expense of a lower specificity, warranting further validation.

A clinical audit: diagnostic and epidemiological evaluation of the adrenal incidentaloma

BACKGROUND

Audit is a clinical instrument of government characterized by a whole process of evaluation inter pares to improve medical behaviors in the clinical practice. Different endocrinopathies are underestimated in the clinical and diagnostics practice but they can be a real problem in patients admitted in the departments of Internal Medicine. The adrenal incidentaloma is an accidental discovery with an incidence equal to 4% in radiologic studies but it's rarely considereted in the internal disorders. In the departments of Internal Medicine are hospitalized each year approximately 1450,000 patients and 58,000 about them show a surrenalic lesion identified with CT or MRI as Adrenal Incidentaloma.

METHODS

Through a search in the radiological archives, were reviewed all abdominal CT performed in the year 2012 in 8 departments of Internal Medicine of 8 Italian public hospitals. They also examined all medical records of these patients to value clinical management of the adrenal masses and the real incidence of the adrenal incidentaloma.

RESULTS

Distribution of pathological results show an important incidence about adrenal incidentaloma in Italian patients although this pathology is represented as a rare disease and its clinical and economic burden are significant. Many questions remain unanswered as the association between duration and severity of the disease, morbidity and how the dimensions affecting it. These results need to be supported by important studies with long follow-up to realize an easy diagnosis.

CONCLUSIONS

The results of this audit confirm the real incidence of this pathology in the internistic patients and the final target is to implement changes about therapeutic diagnostic pathway of the hospital patients in the internal medicine departments.

[Hypofractionated stereotactic body radiation therapy for adrenal metastases]

Adrenal glands are a common site for metastatic spread since they represent the fourth metastatic site of solid tumors. Interest in local ablative treatments of oligometastases is growing since literature suggests better progression-free survival, quality of life and potentially overall survival in selected patients. Surgery remains the first treatment of adrenal oligometastases because results are good, with a long enough follow-up. However, stereotactic radiotherapy appears to be comparable to surgery and could be proposed to elderly, unfit, inoperable patients, or even to patients whose systemic treatment should not be suspended for too long. This article aims to present a review of published studies to date on stereotactic radiotherapy of adrenal metastases and to propose a treatment protocol.

Value of 18-F-FDG PET/CT and CT in the Diagnosis of Indeterminate Adrenal Masses

The purpose of this paper was to study the value of 18-FDG PET/CT and reassess the value of CT for the characterization of indeterminate adrenal masses. 66 patients with 67 indeterminate adrenal masses were included in our study. CT/MRI images and 18F-FDG PET/CT data were evaluated blindly for tumor morphology, enhancement features, apparent diffusion coefficient values, maximum standardized uptake values, and adrenal-to-liver maxSUV ratio. The study population comprised pathologically confirmed 16 adenomas, 19 metastases, and 32 adrenocortical carcinomas. Macroscopic fat was observed in 62.5% of the atypical adenomas at CT but not in malignant masses. On 18F-FDG PET/CT, SUVmax and adrenal-to-liver maxSUV ratio were significantly lower in adenomas than in malignant tumors. An SUVmax value of less than 3.7 or an adrenal-to-liver maxSUV ratio of less than 1.29 is highly predictive of benignity.