How good are we at detecting vascular invasion in adrenal tumors?

Prediction of vascular invasion using a 7-point scale computed tomography grading system in adrenal tumors in dogs

Pascaline Pey, Swan Specchi, Federica Rossi, Alessia Diana, Ignazio Drudi, Allison L. Zwingenberger, Philipp D. Mayhew, Luciano Pisoni, Daniele Mari, Federico Massari, Boris Dalpozzo, Federico Fracassi, Stefano Nicoli

Background
The study addresses the limitations of existing methods to detect vascular invasion in adrenal tumors (AT) in dogs, which often rely on binary evaluations. A 7-point computed tomography (CT) grading system was tested for its accuracy in predicting vascular invasion and tumor type. Accurate preoperative information on vascular invasion is crucial for surgical planning and prognosis.

Methods
This retrospective, observational, cross-sectional study involved 91 dogs with AT who underwent adrenalectomy and pre- and postcontrast CT imaging. Radiologists used a 7-point CT grading scale to assess vascular invasion and predict tumor types. Diagnostic performance, inter-rater agreement, and a decision tree based on CT criteria were developed to identify tumor types and invasion probability.

Results
Tumor Characteristics: The study included 45 adrenocortical carcinomas (50%), 36 pheochromocytomas (40%), and 9 adrenocortical adenomas (10%).

CT Findings: Tumor type differentiation was based on attenuation values, contralateral adrenal gland size, thrombus size, and presence of mineralization. Pheochromocytomas showed higher attenuation and longer thrombi, while carcinomas were more frequently mineralized.

Vascular Invasion: The 7-point scale demonstrated high sensitivity (91–97%) and specificity (70–86%) for caudal vena cava (CVC) invasion. Intermediate grades (3–6) showed reduced diagnostic odds ratios, indicating uncertainty in predicting invasion.

Radiologist Agreement: Agreement was excellent for CVC invasion and moderate to good for other vessels.

Limitations
The study noted challenges with intermediate CT grades, variability in image quality, and differences in CT protocols. The sample size for adrenocortical adenomas was limited, reducing the power for distinguishing these tumors. Variability in histopathological standards across institutions also posed a limitation.

Conclusions
The 7-point CT grading system provides reliable probabilities of vascular invasion and aids in tumor type differentiation. This system enhances communication among radiologists, surgeons, and internists, improving preoperative planning. Future work should address the equivocal zone in grading and include prospective validation.

Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.