The value of T1ρ mapping in preoperatively predicting the status of ER, PR, HER-2 and Ki-67 in breast cancer

Purpose

to explore the value of T1ρ mapping in preoperatively predicting the status of ER, PR, HER-2 and Ki-67 in patients with breast cancer

Method

26 biopsy proved breast cancer patients were prospectively enrolled in this study. They all received preoperative clinical routine breast MRI and T1 ρ mapping sequence. Patients were grouped into ER, PR, Her-2 and Ki-67 negative (n=5, 5, 20, 13, respectively) and positive groups (n=21, 21, 6, 13, respectively) with reference to pathological results. ROIs were drawn by two radiologists along the edge of the tumor at three largest slices on T1ρ mapping images, and avoiding artifacts, blood vessels, necrosis, etc. Calculate the average value of two measurements as a final absolute T1ρ value of the lesion. Independent t test, ROC curves, analysis were used for statistical analyses.

Results

Patients with ER positive status had significantly lower T1ρ value than negative group (P<0.01). ROC curve showed that T1p presented AUCs of 0.867 in predicting ER status. Patients with PR positive status also had significantly lower T1ρ value than negative group (P=0.01). ROC curve showed that T1p presented AUCs of 0.79 in predicting PR status. Patients with Her-2 positive status had significantly higher T1ρ value than negative group (P=0.04). ROC curve showed that T1p presented AUCs of 0.77 in predicting Her-2 status. Patients with Ki-67 positive status showed significantly higher T1ρ value than negative group (P=0.02). ROC curve showed that T1p presented AUCs of 0.75 in predicting Ki-67 status.

Conclusion

T1ρ Mapping has the potential for preoperative evaluation of ER, PR, HER-2, and Ki-67 status, which may give additional information to guide individualized therapeutic strategy in breast cancer.