What is the benefit of gadolinium-chelate injection for the diagnosis of local recurrence of clear cell renal cell carcinoma after percutaneous thermal ablation with MRI?

Abstract

PurposeThe purpose of this study was to compare the diagnostic capabilities of contrast-enhanced (CE)-MRI to those of non-CE-MRI to diagnose local recurrence of clear cell renal cell carcinoma (ccRCC) after percutaneous thermal ablation (TA). Materials and methodsThis institutional, review board-approved, case-control, single-center retrospective study included all consecutive adult patients with at least two post-TA MRIs showing local recurrence of ccRCC after TA validated by multidisciplinary board. ‘Control’ patients without recurrence were randomly-selected with a case:control ratio of 2/3. Four senior radiologists reviewed in a double-blinded fashion non-CE sequences of last two consecutive MRI examinations (non-CE-MRIs), assessed the presence of recurrence of ccRCC, then reviewed the CE sequences (CE-MRI) and determined again the presence of a recurrence. Area under the receiver operating characteristic curve (AUROC), sensitivity, specificity and accuracy were compared for each reader for non-CE-MRI and CE-MRI. ResultsFifty-one patients (41 men; mean age, 77.5 years) who underwent percutaneous TA for ccRCC were included. There were a total of 21 recurrences and 35 scars. Whoever the reader, AUROC was not significantly different (mean, 0.86 with-CE-MRI vs. 0.81 with non-CE-MRI; P values ranging between 0.08 and 0.98), neither sensitivity (mean, 76.2% with CE-MRI vs. 71.4% with non-CE-MRI; P values ranging between 0.06 and >0.99), nor accuracy (85.8% with CE-MRI vs. 80.8% with non-CE-MRI; P values ranging between 0.07 and >0.99). Change in specificity depended on the reader with a significant increase for one reader (+20%; P = 0.02) and a significant decrease for another reader (-17.2%; P = 0.03). ConclusionNon-CE MRI has good diagnostic performance for the follow-up of patients with ccRCC treated using percutaneous TA, questioning the systematic use of GBCA injection.