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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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Signal intensity-time curve for DCE-MRI.Signal intensity-time curve for DCE-MRI showing early (PE1) and late (PE2) percent enhancement measurements. S0, S1, and S2 represent the signal intensity of images obtained at t0 (before contrast injection), t1 (2.5 minutes after contrast injection), and t2 (7.5 minutes after contrast injection), respectively. Three curves display different patterns of signal increase and washout: 1) the blue curve shows a slow gradual increase in enhancement, more characteristic of normal tissue; 2) the green curve shows an early enhancement with little washout, essentially a plateau in signal intensity; 3) the red curve shows a pattern of early enhancement with a fast washout, which is more characteristic of highly vascularized tissues.
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pone-0061969-g002: Signal intensity-time curve for DCE-MRI.Signal intensity-time curve for DCE-MRI showing early (PE1) and late (PE2) percent enhancement measurements. S0, S1, and S2 represent the signal intensity of images obtained at t0 (before contrast injection), t1 (2.5 minutes after contrast injection), and t2 (7.5 minutes after contrast injection), respectively. Three curves display different patterns of signal increase and washout: 1) the blue curve shows a slow gradual increase in enhancement, more characteristic of normal tissue; 2) the green curve shows an early enhancement with little washout, essentially a plateau in signal intensity; 3) the red curve shows a pattern of early enhancement with a fast washout, which is more characteristic of highly vascularized tissues.

Mentions: In breast DCE-MRI, physiological parameters related to tumor vascularity can be extracted from the contrast enhancement kinetics exhibited in the signal intensity-time curves (Figure 2). Malignant tissues are characterized by a rapid rise in signal intensity after contrast injection followed by a stabilized signal intensity or signal washout (Figure 2, red curve). Normal and benign tissues, by comparison, show a slower increase in enhancement with little or no washout (Figure 2, blue and green curves). In the signal intensity-time curve, S0, S1 and S2 are the signal intensity values in the pre-contrast (t0), early post-contrast (t1) and late post-contrast phases (t2), respectively (Figure 2). Percent enhancement (PE = 100*(S1-S0)/S0) is calculated for each voxel. Signal enhancement ratio (SER), defined as the ratio of early to late enhancement (SER = (S1-S0)/(S2-S0)), is a method developed to measure contrast enhancement kinetics from high spatial resolution, low temporal resolution DCE-MR images commonly used for clinical breast MRI [13]. High SER values consistently identify tissue with a strong signal washout characteristic [14].


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)

Signal intensity-time curve for DCE-MRI.Signal intensity-time curve for DCE-MRI showing early (PE1) and late (PE2) percent enhancement measurements. S0, S1, and S2 represent the signal intensity of images obtained at t0 (before contrast injection), t1 (2.5 minutes after contrast injection), and t2 (7.5 minutes after contrast injection), respectively. Three curves display different patterns of signal increase and washout: 1) the blue curve shows a slow gradual increase in enhancement, more characteristic of normal tissue; 2) the green curve shows an early enhancement with little washout, essentially a plateau in signal intensity; 3) the red curve shows a pattern of early enhancement with a fast washout, which is more characteristic of highly vascularized tissues.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0061969-g002: Signal intensity-time curve for DCE-MRI.Signal intensity-time curve for DCE-MRI showing early (PE1) and late (PE2) percent enhancement measurements. S0, S1, and S2 represent the signal intensity of images obtained at t0 (before contrast injection), t1 (2.5 minutes after contrast injection), and t2 (7.5 minutes after contrast injection), respectively. Three curves display different patterns of signal increase and washout: 1) the blue curve shows a slow gradual increase in enhancement, more characteristic of normal tissue; 2) the green curve shows an early enhancement with little washout, essentially a plateau in signal intensity; 3) the red curve shows a pattern of early enhancement with a fast washout, which is more characteristic of highly vascularized tissues.
Mentions: In breast DCE-MRI, physiological parameters related to tumor vascularity can be extracted from the contrast enhancement kinetics exhibited in the signal intensity-time curves (Figure 2). Malignant tissues are characterized by a rapid rise in signal intensity after contrast injection followed by a stabilized signal intensity or signal washout (Figure 2, red curve). Normal and benign tissues, by comparison, show a slower increase in enhancement with little or no washout (Figure 2, blue and green curves). In the signal intensity-time curve, S0, S1 and S2 are the signal intensity values in the pre-contrast (t0), early post-contrast (t1) and late post-contrast phases (t2), respectively (Figure 2). Percent enhancement (PE = 100*(S1-S0)/S0) is calculated for each voxel. Signal enhancement ratio (SER), defined as the ratio of early to late enhancement (SER = (S1-S0)/(S2-S0)), is a method developed to measure contrast enhancement kinetics from high spatial resolution, low temporal resolution DCE-MR images commonly used for clinical breast MRI [13]. High SER values consistently identify tissue with a strong signal washout characteristic [14].

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