1H MR spectroscopy of invasive ductal carcinoma: correlations with FDG PET and histologic prognostic factors.

Objective: The purpose of this article is to assess the histologic prognostic relevance of choline levels obtained using (1)H MR spectroscopy with a 1.5-T MR unit in patients with invasive breast cancer and to compare the observed choline levels with the standardized uptake value obtained using FDG PET.

Materials And Methods: Single-voxel (1)H MR spectroscopy and PET/CT were performed for 50 patients with invasive ductal carcinoma (1.5-3 cm in size). The normalized choline signal was calculated using an external standard method.

Results: Proton MR spectroscopy detected the presence of choline in 44 cases. The average normalized choline signal was 1.1 (range, 0-3.9). The average standardized uptake value was 6.5 (range, 1.1-23). The correlation (r) between the normalized choline signal and the standardized uptake value was 0.52 (p < 0.0001). The normalized choline signal was significantly correlated with nuclear grade (p = 0.0002), triple-negative breast cancer status (p = 0.0009), and estrogen receptor negativity (p = 0.007). The standardized uptake value was significantly correlated with nuclear grade (p = 0.0002), estrogen receptor negativity (p = 0.002), and triple-negative breast cancer status (p = 0.009). No significant differences were found between the progesterone receptor-positive and negative groups or between the human epidermal growth factor receptor 2-positive and negative groups.

Conclusion: The choline levels obtained using (1)H MR spectroscopy with a 1.5-T unit were well correlated with the standardized uptake value obtained using PET/CT and with the histologic prognostic parameters (nuclear grade, estrogen receptor status, and triple-negative lesion status).