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MRI enhancement in stromal tissue surrounding breast tumors: association with recurrence free survival following neoadjuvant chemotherapy.

Jones EF, Sinha SP, Newitt DC, Klifa C, Kornak J, Park CC, Hylton NM - PLoS ONE (2013)

Bottom Line: Proximity-dependent PE and SER were analyzed using a linear mixed effects model and Cox proportional hazards model for recurrence-free survival.The mixed effects model displayed a decreasing radial trend in PE at both V1 and V2.Survival analysis showed that the hazard ratio estimates for each unit decrease in global SER was statistically significant at V1 [estimated hazard ratio = 0.058, 95% Wald CI (0.003, 1.01), likelihood ratio p = 0.03]; but was not so for V2.

View Article: PubMed Central - PubMed

Affiliation: Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States of America. ella.jones@ucsf.edu

ABSTRACT

Rationale and objectives: Normal-appearing stromal tissues surrounding breast tumors can harbor abnormalities that lead to increased risk of local recurrence. The objective of this study was to develop a new imaging methodology to characterize the signal patterns of stromal tissue and to investigate their association with recurrence-free survival following neoadjuvant chemotherapy.

Materials and methods: Fifty patients with locally-advanced breast cancer were imaged with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before (V1) and after one cycle (V2) of adriamycin-cytoxan therapy. Contrast enhancement in normal-appearing stroma around the tumor was characterized by the mean percent enhancement (PE) and mean signal enhancement ratio (SER) in distance bands of 5 mm from the tumor edge. Global PE and SER were calculated by averaging all stromal bands 5 to 40 mm from tumor. Proximity-dependent PE and SER were analyzed using a linear mixed effects model and Cox proportional hazards model for recurrence-free survival.

Results: The mixed effects model displayed a decreasing radial trend in PE at both V1 and V2. An increasing trend was less pronounced in SER. Survival analysis showed that the hazard ratio estimates for each unit decrease in global SER was statistically significant at V1 [estimated hazard ratio = 0.058, 95% Wald CI (0.003, 1.01), likelihood ratio p = 0.03]; but was not so for V2.

Conclusions: These findings show that stromal tissue outside the tumor can be quantitatively characterized by DCE-MRI, and suggest that stromal enhancement measurements may be further developed for use as a potential predictor of recurrence/disease-free survival following therapy.

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Related in: MedlinePlus

Proximity mapping of breast tumor.The proximity mapping method takes the difference of the segmentation of tumor (a) and fibroglandular map (b) to create a 3-dimensional stromal proximity map (c). The stromal proximity map is then applied to the functional image to calculate proximity-dependent values.
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pone-0061969-g003: Proximity mapping of breast tumor.The proximity mapping method takes the difference of the segmentation of tumor (a) and fibroglandular map (b) to create a 3-dimensional stromal proximity map (c). The stromal proximity map is then applied to the functional image to calculate proximity-dependent values.

Mentions: Tumor regions on MR images were identified using an established enhancement criteria of 70% applied to the first post-contrast image [15]. This empirical threshold was based on visual agreement with radiological assessments in clinical practice [11]. Normal-appearing stromal tissue surrounding the tumor was subsequently defined as fibroglandular tissue and was segmented from adipose tissue using a fuzzy C-means clustering method [8]. Subsequent PE and SER maps were generated using a customized software program that was previously described [15]. The tumor proximity map for normal-appearing breast stroma was generated by calculating the 3-D map of the Euclidean distance between each non-tumor voxel and the nearest tumor voxel. The proximity map was then overlaid using the segmented fibroglandular tissue mask and applied to the PE and SER maps to calculate the mean PE and SER values in 3-D distance bands of 5 mm, from 0 to 40 mm outside of tumor tissue (Figure 3). Global PE and SER values were the average of all the mean PE and SER values over 5 to 40 mm. Region closest to the tumor boundary from 0 to 5 mm was considered as tumor periphery [16]. All subsequent calculations of stromal effects on radial distance, global PE and SER were focused at regions from 5 to 40 mm.


MRI enhancement in stromal tissue surrounding breast tumors: association with recurrence free survival following neoadjuvant chemotherapy.

Jones EF, Sinha SP, Newitt DC, Klifa C, Kornak J, Park CC, Hylton NM - PLoS ONE (2013)

Proximity mapping of breast tumor.The proximity mapping method takes the difference of the segmentation of tumor (a) and fibroglandular map (b) to create a 3-dimensional stromal proximity map (c). The stromal proximity map is then applied to the functional image to calculate proximity-dependent values.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3646993&req=5

pone-0061969-g003: Proximity mapping of breast tumor.The proximity mapping method takes the difference of the segmentation of tumor (a) and fibroglandular map (b) to create a 3-dimensional stromal proximity map (c). The stromal proximity map is then applied to the functional image to calculate proximity-dependent values.
Mentions: Tumor regions on MR images were identified using an established enhancement criteria of 70% applied to the first post-contrast image [15]. This empirical threshold was based on visual agreement with radiological assessments in clinical practice [11]. Normal-appearing stromal tissue surrounding the tumor was subsequently defined as fibroglandular tissue and was segmented from adipose tissue using a fuzzy C-means clustering method [8]. Subsequent PE and SER maps were generated using a customized software program that was previously described [15]. The tumor proximity map for normal-appearing breast stroma was generated by calculating the 3-D map of the Euclidean distance between each non-tumor voxel and the nearest tumor voxel. The proximity map was then overlaid using the segmented fibroglandular tissue mask and applied to the PE and SER maps to calculate the mean PE and SER values in 3-D distance bands of 5 mm, from 0 to 40 mm outside of tumor tissue (Figure 3). Global PE and SER values were the average of all the mean PE and SER values over 5 to 40 mm. Region closest to the tumor boundary from 0 to 5 mm was considered as tumor periphery [16]. All subsequent calculations of stromal effects on radial distance, global PE and SER were focused at regions from 5 to 40 mm.

Bottom Line: Proximity-dependent PE and SER were analyzed using a linear mixed effects model and Cox proportional hazards model for recurrence-free survival.The mixed effects model displayed a decreasing radial trend in PE at both V1 and V2.Survival analysis showed that the hazard ratio estimates for each unit decrease in global SER was statistically significant at V1 [estimated hazard ratio = 0.058, 95% Wald CI (0.003, 1.01), likelihood ratio p = 0.03]; but was not so for V2.

View Article: PubMed Central - PubMed

Affiliation: Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States of America. ella.jones@ucsf.edu

ABSTRACT

Rationale and objectives: Normal-appearing stromal tissues surrounding breast tumors can harbor abnormalities that lead to increased risk of local recurrence. The objective of this study was to develop a new imaging methodology to characterize the signal patterns of stromal tissue and to investigate their association with recurrence-free survival following neoadjuvant chemotherapy.

Materials and methods: Fifty patients with locally-advanced breast cancer were imaged with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before (V1) and after one cycle (V2) of adriamycin-cytoxan therapy. Contrast enhancement in normal-appearing stroma around the tumor was characterized by the mean percent enhancement (PE) and mean signal enhancement ratio (SER) in distance bands of 5 mm from the tumor edge. Global PE and SER were calculated by averaging all stromal bands 5 to 40 mm from tumor. Proximity-dependent PE and SER were analyzed using a linear mixed effects model and Cox proportional hazards model for recurrence-free survival.

Results: The mixed effects model displayed a decreasing radial trend in PE at both V1 and V2. An increasing trend was less pronounced in SER. Survival analysis showed that the hazard ratio estimates for each unit decrease in global SER was statistically significant at V1 [estimated hazard ratio = 0.058, 95% Wald CI (0.003, 1.01), likelihood ratio p = 0.03]; but was not so for V2.

Conclusions: These findings show that stromal tissue outside the tumor can be quantitatively characterized by DCE-MRI, and suggest that stromal enhancement measurements may be further developed for use as a potential predictor of recurrence/disease-free survival following therapy.

Show MeSH
Related in: MedlinePlus