Our article emerged as a result of collaborative research between the Departments of Radiology and Urology at University of California, Irvine School of Medicine. Clinically, perinephric neovessels have been recognized by Radiologists on imaging for several years and by Urologists performing nephrectomies for patients with Renal Cell Carcinoma. Despite this, neovessels have not been a factor in any clinical or surgical assessment of Renal Cell Carcinoma.
Given the role of angiogenesis in tumor metastasis, we thought it may be fruitful to assess the correlation of these neovessels with tumor staging. Thus, we used CT imaging to create and validate an imaging scoring system for neovascularity, the Retroperitoneal Vascularity Assessment and Scoring in Carcinoma (Re-VASC), to assist in the prediction of tumor staging for RCC.
Our proposed Re-VASC score was based on both the number and size of new vessels on CT imaging. The scores were assigned using the definitions below:
0 = No visible neovascularization
1 = visualized single new vessel <3mm in diameter
2 = visualized single new vessel ≥3mm in diameter
3 = visualized multiple new vessels <3mm in diameter
4 = visualized multiple new vessels ≥3mm in diameter
(*If one vessel was greater than 3mm, a score of 4 was given, even if the other vessels were less than 3mm.)
Our results showed a significant correlation between Re-VASC score and tumor staging. These results are encouraging as our scoring system can serve as an adjunct to clinical staging of RCC. Currently, accuracy of clinical RCC staging is around 70% and roughly 9% of tumors staged as T1 by Radiology are later staged as T3 by pathology. The use of our tool as an adjunct to TNM staging may be used by Radiologists and Urologists to more accurately assess renal cancers which can impact surgical decision making.
Our objective is for our tool to raise the existing standard of care by better stratifying kidney masses such that patients could receive more targeted therapies. For our future direction, we would love to examine Re-VASC’s ability to differentiate small masses as benign or malignant. In an ideal world, benign tumors could be differentiated and actively surveilled, while malignant tumors of different levels of aggressiveness could be stratified to different treatment strategies. The results of this project has certainly shed light on the future application and research of the Re-VASC scoring system.
Written by: Cameron Fateri, Department of Radiology, School of Medicine, University of California, Irvine, Orange, California, USA.
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