Potential of quantitative T1 mapping to serve as a novel prognostic predictor of clear cell renal cell carcinoma after nephrectomy.

Background: Accurate preoperative risk stratification methods are important for clear cell renal cell carcinoma (ccRCC) patients to enable personalized treatment. However, there are still no accurate and quantitative prognostic factors. This study aimed to investigate the effectiveness of T1 mapping in predicting the progression-free survival (PFS) of ccRCC after nephrectomy.

Methods: A retrospective cohort study was performed in a China tertiary care hospital. This study reviewed the clinical and magnetic resonance imaging (MRI) data of consecutive inpatients with pathologically confirmed ccRCCs between September 2014 and September 2021. PFS was evaluated by following patients until the first adverse event. Radiological features including T1 relaxation time of tumors were assessed by 2 radiologists. Cox regression and visual nomogram, Kaplan-Meier survival, and log-rank test were utilized for survival analysis.

Results: A total of 195 patients with pathologically confirmed ccRCCs (mean age ± standard deviation, 56.0±12.0 years; 133 men) with eligible data were included in the study. The median follow-up was 27.6 months (range, 1-88 months), and 22 (11.3%) patients experienced metastasis or recurrence. Univariate and multivariate survival analysis showed the higher post-contrasted T1 relaxation time [P=0.001; hazard ratio (HR), 2.077; 95% confidence interval (CI): 1.350-3.196] and the incomplete tumor capsule (P<0.001; HR, 7.849; CI: 2.614-23.570) were independently associated with a shorter PFS of patients. Patients with ≥222.73 ms post-contrasted T1 relaxation time ccRCCs had worse PFS than the lower post-contrasted T1 relaxation time group.

Conclusions: The T1 mapping quantitative parameters may be a new potential biomarker for predicting PFS in patients with ccRCCs.