Clinical Significance And Prognostic Value Of The Imaging Infiltrative Feature Of Renal Masses: A Large Sample Sized Retrospective Study

Objective: The preoperative diagnosis and treatment of imaging indeterminate renal masses are still faced with many challenges.This study aims to clarify the clinical significance and prognostic value of the imaging infiltrative feature of renal masses and explore its guiding significance for preoperative diagnosis and treatment selection.Methods: The study included 1174 patients who underwent high-quality abdominal or renal plain and contrast-enhanced CT/MRI scans at two participating institutions between 2012 and 2016.Cases with bilateral renal masses,blurred CT/MR images,and imaging highly considered as benign lesions were excluded.The imaging findings of all patients were reviewed retrospectively.Subsequently,the demographic information,clinicopathological features,treatment,perioperative conditions,and follow-up results of 916 patients who continued to be treated in our centers after the discovery of renal mass were collected.The relationship between the infiltrative feature and other imaging manifestations,clinicopathological features,choice of treatment,perioperative condition,and prognosis were compared and analyzed.Finally,univariate and multivariate regression analyses were used to confirm the independent predictors of overall survival and disease-free survival of patients with renal masses,and then Nomogram predictive models were established to predict the prognosis of patients with malignant renal masses.Results: 210 cases(17.9%)of imaging indeterminate renal masses had infiltrative characteristics.The comparison of imaging findings showed that more than half of the infiltrative renal masses(IRMs)retained renal contours.Necrosis within the mass,perirenal/renal sinus fat invasion,collecting system involvement,renal vein/vena cava tumor thrombus,regional lymph node enlargement,and distant metastasis were more common in IRMs.Clinical data analysis showed that patients with IRMs had more symptoms,with a significant increase in tumor size and tumor complexity,and more frequent locally advanced and advanced diseases.The pathological results revealed that there were 896 cases(97.8%)of malignant tumors and 20 cases(2.2%)of benign lesions.The benign renal masses were mainly inflammatory lesions,followed by fat-poor renal angiomyolipoma,oncocytoma,and metanephric adenoma.Renal cell carcinoma played a dominant role in malignant tumors,followed by urothelial carcinoma,sarcoma,metastasis,and lymphoma.High-grade(Fuhrman/ISUP III-IV)renal cell carcinoma,collecting duct carcinoma,urothelial carcinoma and other poorly differentiated or highly malignant tumors are more common in IRMs.Patients with IRMs had markedly increased operative time,intraoperative bleeding,positive rate of incisal margin,postoperative recurrence and metastasis rate,and mortality.The results of survival analysis showed that the overall survival rate and disease-free survival rate of patients with malignant IRMs were significantly decreased.Finally,univariate and multivariate regression analysis confirmed that infiltrative characteristics were an independent predictor of both overall survival and disease-free survival in patients with malignant renal masses.Nomogram predictive models of overall survival and disease-free survival in patients with malignant renal masses were constructed by using several independent prognostic factors including the infiltrative feature.Conclusion: Renal masses with the imaging infiltrative feature include inflammatory lesions and tumors.Although inflammatory lesions are rare,the combination of specific medical history,clinical data,and imaging findings will contribute to suspect some inflammatory lesions and guide biopsies if necessary.Most of the infiltrative renal masses are malignant tumors.The infiltrative feature is a non-invasive preoperative parameter that can be used to evaluate the malignant potential of tumors and predict prognosis.Routine identification of the infiltrative feature will be helpful for risk assessment and individualized treatment of renal masses with unclear imaging diagnosis.