Changes of T2 Relaxation Time From Neoadjuvant Chemotherapy in Breast Cancer Lesions

Abstract

BackgroundNeoadjuvant chemotherapy (NAC) is generally an effective method of reducing locally advanced malignant breast lesions before surgery; assessing the tumor response to NAC is crucial for patient management. T2 relaxation times can reflect biological state of lesions, may prove useful to assess the response to NAC.ObjectivesTo investigate the lesion T2 relaxation times change in breast cancer neoadjuvant chemotherapy (NAC).Patients and MethodsIn total, 26 patients underwent NAC. Magnetic resonance imaging (MRI) T2 mapping was performed before and after NAC. The T2 relaxation times were obtained by using Functool software on an AW 43 workstation. The treatment response was assessed according to the pathological response classification. We aimed to analyze the changes in the T2 relaxation times before and after NAC as well as to study the relationship between the response and the lesion T2 relaxation times after NAC.ResultsIn 26 cases with NAC, the mean lesion T2 relaxation time before NAC was 81.34 ± 13.68 ms, compared with 64.50 ± 8.71 ms after NAC. Significant differences in the lesion T2 relaxation times existed between the pre- and post-NAC (P < 0.001) ; based on the pathology results, the mean lesion T2 relaxation times in 23 of the 26 responders (63.18 ± 8.37 ms) was shorter than in 3 of the 26 nonresponders (74.62 ± 2.32 ms) after NAC (P = 0.029).ConclusionIn breast cancer after NAC, the lesion T2 relaxation time was reduced in the responders, and this finding is potentially useful to assess the response to NAC.

Repeatability and reproducibility of 3D MR fingerprinting relaxometry measurements in normal breast tissue

“…Previous studies on breast relaxometry have observed significant differences in T 1 and T 2 relaxation times between normal fibroglandular breast tissue and benign and malignant breast tumors . Changes in T 2 relaxation time has also been used to characterize response to chemotherapy in breast cancers . However, the T 1 and T 2 values reported for normal breast tissue show a wide variation due to the differences in mapping techniques and field strengths .…”

“…However, the T 1 and T 2 values reported for normal breast tissue show a wide variation due to the differences in mapping techniques and field strengths . Similarly, studies on response assessment to treatment used different T 2 mapping techniques, which affects comparability of these results . For quantitative imaging techniques to be successfully used in practice, assessment of measurement variability and repeatability are crucial to interpret results.…”

“…5,6 Changes in T 2 relaxation time has also been used to characterize response to chemotherapy in breast cancers. [7][8][9] However, the T 1 and T 2 values reported for normal breast tissue show a wide variation due to the differences in mapping techniques and field strengths. 5,10,11 Similarly, studies on response assessment to treatment used different T 2 mapping techniques, which affects comparability of these results.…”

Variation of T2 relaxation times in pediatric brain tumors and their effect on metabolite quantification

“…An additional multi‐TE acquisition to measure the T 2 of water can be implemented with a scan time of less than a minute, and is recommended to improve the accuracy of metabolite quantification. This may be particularly pertinent if using quantitative MRS to assess treatment response, as tumor water T 2 is known to reduce following treatment . However, if water T 2 values for individual cases are not available, then the mean values for the relevant tissue type would be preferable to default values.…”

“…This may be particularly pertinent if using quantitative MRS to assess treatment response, as tumor water T 2 is known to reduce following treatment. [27][28][29] However, if water T 2 values for individual cases are not available, then the mean values for the relevant tissue type would be preferable to default values.…”