Table 1.
Association between the preoperative and postoperative tumor characteristics on conventional diagnostic workup.
ER = Estrogen receptor.
Table 2.
Inter-observer variability between observer 1 (W.K.) and observer 2 (D.K.) for 31-phosphorus spectroscopy (31P-MRS) scoring.
Agreement is seen in 24/29 tumors (83%; kappa: 0.716). PME = Phosphomonoesters. PDE = Phosphodiesters.
Table 3.
Association between postoperative histopathology and 7T MRI characteristics.
A significant association (p<0.05*) was seen between the mean apparent diffusion coefficient (ADC) on diffusion weighted imaging and estrogen receptor (ER)-status, and also between the 31-phosphorus magnetic resonance spectroscopy (31P-MRS)-scoring and lymph node status as well as mitotic count. A trend (p<0.10 **) was seen between mean ADC and tumor grade as well as lymph node status. PME = Phosphomonoesters. PDE = Phosphodiesters.
Table 4.
Association between the preoperative and postoperative indication for systemic therapy based on conventional diagnostic workup.
Table 5.
Univariate association of 7 tesla magnetic resonance imaging (7T MRI) characteristics and postoperative indication for systemic therapy.
A significant (p<0.05*) association is seen between the postoperative indication for systemic therapy and dynamic contrast-enhanced (DCE)-MRI as well as 31-phosphorus magnetic resonance spectroscopy (31P-MRS). No association was seen between the postoperative indication and the apparent diffusions coefficient (ADC) on diffusion-weighted imaging (DWI).
Fig 1.
A decision tree was created to establish a preoperative indication for systemic therapy, taking the postoperative indication as the golden standard.
7T DCE-MRI = 7 tesla dynamic contrast-enhanced magnetic resonance imaging. 31P -MRS = 31-Phosphorus MR spectroscopy. PME = Phosphomonoesters. PDE = Phosphodiesters.
Fig 2.
Examples of 7 tesla MR imaging in three patients, showing the first post-contrast dynamic contrast-enhanced MR imaging in the (A) transverse plane and the (B) coronal plane, with (C) the corresponding apparent diffusion coefficient (ADC) map; and (D) the corresponding 31-phosphorus MR spectroscopy (31P-MRS) scoring upon the ratio of phosphomonoesters (PME) to phosphodiesters (PDE).
All three patients (left/middle/right) had a negative preoperative indication for systemic therapy based on biopsy and conventional breast imaging. On the left, imaging is shown of a 47-year old woman. The decision-tree model upstages this assessment to positive indication: DCE-MRI showed a 23-mm sized lesion, an ADC of 746 x10−6mm2/s, and a PME>PDE score. Postoperatively, a grade 2 tumor and a positive indication for systemic therapy was established. In the middle, imaging is shown of a 58-year old women. The decision-tree model again upstages this assessment to positive indication: DCE-MRI showed an 18-mm sized lesion, an ADC of 980 x10−6mm2/s. The MRS score was, however, PME>PDE. Postoperatively, a grade 2 tumor and a positive indication for systemic therapy was established. On the right, imaging is shown of a 71-year old woman. The decision-tree model confirms the negative indication: DCE-MRI showed a 16-mm sized lesion, DWI a mean ADC of 834 x10−6mm2/s, and 31P-MRS a PME<PDE score. Postoperatively, a grade2 tumor and a negative indication for systemic therapy was established. Pi = Inorganic phosphate.