RESUMEN

BACKGROUND: The prognosis for women with locally advanced breast cancer (LABC) is poor and there is a need for better treatment stratification. Gray-level co-occurrence matrix (GLCM) texture analysis of magnetic resonance (MR) images has been shown to predict pathological response and could become useful in stratifying patients to more targeted treatments. PURPOSE: To evaluate the ability of GLCM textural features obtained before neoadjuvant chemotherapy to predict overall survival (OS) seven years after diagnosis of patients with LABC. MATERIAL AND METHODS: This retrospective study includes data from 55 patients with LABC. GLCM textural features were extracted from segmented tumors in pre-treatment dynamic contrast-enhanced 3-T MR images. Prediction of OS by GLCM textural features was assessed and compared to predictions using traditional clinical variables. RESULTS: Linear mixed-effect models showed significant differences in five GLCM features (f1, f2, f5, f10, f11) between survivors and non-survivors. Using discriminant analysis for prediction of survival, GLCM features from 2 min post-contrast images achieved a classification accuracy of 73% (P < 0.001), whereas traditional prognostic factors resulted in a classification accuracy of 67% (P = 0.005). Using a combination of both yielded the highest classification accuracy (78%, P < 0.001). Median values for features f1, f2, f10, and f11 provided significantly different survival curves in Kaplan-Meier analysis. CONCLUSION: This study shows a clear association between textural features from post-contrast images obtained before neoadjuvant chemotherapy and OS seven years after diagnosis. Further studies in larger cohorts should be undertaken to investigate how this prognostic information can be used to benefit treatment stratification.

Asunto(s)

Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/mortalidad , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Medios de Contraste , Estudios de Factibilidad , Femenino , Gadolinio DTPA , Humanos , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Noruega , Valor Predictivo de las Pruebas , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia

RESUMEN

Purpose To report the feasibility, accuracy and initial clinical experience of the use of real-time magnetic resonance navigated ultrasound (rtMRnUS) in the surgical planning of breast-conserving surgery (BCS) via guide wire insertion. Materials and Methods 29 participants were recruited into this prospective ethics committee approved study. The first 4 cases were utilized as a training set. Participants underwent a supine contrast-enhanced breast MR examination with external fiducials and corresponding ink marks placed on the skin of the affected breast to act as co-registration pairs. MR examinations included both functional and morphological images. A LOGIQ E9 ultrasound system (GE Healthcare, Milwaukee, WI, USA) equipped with a 6 - 15 MHz transducer was utilized for rtMRnUS. To facilitate point co-registration of the previously acquired MR dataset with the real-time ultrasound, co-registration pairs were identified on both imaging modalities. The following co-registration quality metrics were recorded: root mean square deviation (RMSD), lesion and global accuracies. Post co-registration guide wire insertion was performed. Results Co-registration was successfully undertaken in all participants. Results from 25 participants are presented. The median (min, max) RMSD was 3.3 mm (0.6 mm, 8.8 mm). The global accuracy was assessed as very good (8), good (12), moderate (3) and poor (2) while the median (min, max) lesion accuracy was recorded at 8.9 mm (2.1 mm, 33.2 mm). Conclusion The use of rtMRnUS to facilitate guide wire insertion is a feasible technique. Generally, very good or good global registration can be expected. Lesion accuracy results indicate that a median difference, in 3 D space, of 9 mm can be expected between imaging modalities.

Asunto(s)

Neoplasias de la Mama , Imagen por Resonancia Magnética , Mamografía , Mastectomía Segmentaria , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/cirugía , Estudios de Factibilidad , Femenino , Humanos , Estudios Prospectivos

RESUMEN

BACKGROUND: This work aims to see whether Minkowski Functionals can be used to distinguish between cancer types before chemotherapy treatment has begun, and whether a response to treatment can be predicted by an initial scan alone. METHODS: Fat-nulled T1w 3T DCE-MRI scans were taken of 100 cases of biopsy confirmed breast cancer and a series of binary images created on lesion containing slices. Minkowski Functionals were calculated for each binary image and the change in these values as the binary threshold was raised was described using 6(th) order polynomials. These polynomials were used to compare between patient subgroups, for triple negative breast cancer (TNBC) status, chemotherapy response, biopsy grade, nodal status, and lymphovascular invasion status. RESULTS: When using Minkowski Functionals statistically significant (P < 0.05) differences were found between TNBC status, biopsy grade, and lymphovascular invasion status subgroups for all methodologies. The analysis performance did not appear to be affected by the number of threshold steps used. Most notably, very strong differences (P ≤ 0.01) were found between TNBC and other intrinsic subtype patients. When analyzed with a binary logistic regression model, an area under the curve value of 0.917 (0.846-0.987, 95% confidence interval) for TNBC classification was found. CONCLUSION: The method of texture analysis presented here provides a novel way to characterize tumors, and demonstrates clear differences between cancer groups which are detectable before treatment begins, and can help with treatment planning as a valuable prognosis tool.

Asunto(s)

Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética , Neoplasias de la Mama Triple Negativas/diagnóstico por imagen , Neoplasias de la Mama Triple Negativas/patología , Adulto , Anciano , Algoritmos , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Área Bajo la Curva , Biopsia , Neoplasias de la Mama/tratamiento farmacológico , Ciclofosfamida/administración & dosificación , Docetaxel , Quimioterapia/métodos , Epirrubicina/administración & dosificación , Femenino , Humanos , Metástasis Linfática , Persona de Mediana Edad , Pronóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Programas Informáticos , Estadísticas no Paramétricas , Taxoides/administración & dosificación , Resultado del Tratamiento , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico

RESUMEN

OBJECTIVES: The aim of this study was to determine if associations exist between pretreatment dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI)-based metrics (vascular kinetics, texture, shape, size) and survival intervals. Furthermore, the aim of this study was to compare the prognostic value of DCE-MRI parameters against traditional pretreatment survival indicators. MATERIALS AND METHODS: A retrospective study was undertaken. Approval had previously been granted for the retrospective use of such data, and the need for informed consent was waived. Prognostic value of pretreatment DCE-MRI parameters and clinical data was assessed via Cox proportional hazards models. The variables retained by the final overall survival Cox proportional hazards model were utilized to stratify risk of death within 5 years. RESULTS: One hundred twelve subjects were entered into the analysis. Regarding disease-free survival-negative estrogen receptor status, T3 or higher clinical tumor stage, large (>9.8 cm) MR tumor volume, higher 95th percentile (>79%) percentage enhancement, and reduced (>0.22) circularity represented the retained model variables. Similar results were noted for the overall survival with negative estrogen receptor status, T3 or higher clinical tumor stage, and large (>9.8 cm) MR tumor volume, again all been retained by the model in addition to higher (>0.71) 25th percentile area under the enhancement curve.Accuracy of risk stratification based on either traditional (59%) or DCE-MRI (65%) survival indicators performed to a similar level. However, combined traditional and MR risk stratification resulted in the highest accuracy (86%). CONCLUSIONS: Multivariate survival analysis has revealed that model-retained DCE-MRI variables provide independent prognostic information complementing traditional survival indicators and as such could help to appropriately stratify treatment.

Asunto(s)

Neoplasias de la Mama/patología , Imagen por Resonancia Magnética/métodos , Biopsia , Neoplasias de la Mama/irrigación sanguínea , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/terapia , Medios de Contraste , Femenino , Gadolinio DTPA , Humanos , Meglumina , Estadificación de Neoplasias , Compuestos Organometálicos , Pronóstico , Estudios Retrospectivos , Medición de Riesgo , Análisis de Supervivencia , Carga Tumoral

RESUMEN

PURPOSE: To evaluate diffusion weighted MRI (DW-MR) as a response metric for assessment of neoadjuvant chemotherapy (NAC) in patients with primary breast cancer using prospective multi-center trials which provided MR scans along with clinical outcome information. MATERIALS AND METHODS: A total of 39 patients with locally advanced breast cancer accrued from three different prospective clinical trials underwent DW-MR examination prior to and at 3-7 days (Hull University), 8-11 days (University of Michigan) and 35 days (NeoCOMICE) post-treatment initiation. Thirteen patients, 12 of which participated in treatment response study, from UM underwent short interval (<1hr) MRI examinations, referred to as "test-retest" for examination of repeatability. To further evaluate stability in ADC measurements, a thermally controlled diffusion phantom was used to assess repeatability of diffusion measurements. MRI sequences included contrast-enhanced T1-weighted, when appropriate, and DW images acquired at b-values of 0 and 800 s/mm2. Histogram analysis and a voxel-based analytical technique, the Parametric Response Map (PRM), were used to derive diffusion response metrics for assessment of treatment response prediction. RESULTS: Mean tumor apparent diffusion coefficient (ADC) values generated from patient test-retest examinations were found to be very reproducible (|ΔADC|<0.1x10-3mm2/s). This data was used to calculate the 95% CI from the linear fit of tumor voxel ADC pairs of co-registered examinations (±0.45x10-3mm2/s) for PRM analysis of treatment response. Receiver operating characteristic analysis identified the PRM metric to be predictive of outcome at the 8-11 (AUC = 0.964, p = 0.01) and 35 day (AUC = 0.770, p = 0.05) time points (p<.05) while whole-tumor ADC changes where significant at the later 35 day time interval (AUC = 0.825, p = 0.02). CONCLUSION: This study demonstrates the feasibility of performing a prospective analysis of DW-MRI as a predictive biomarker of NAC in breast cancer patients. In addition, we provide experimental evidence supporting the use of sensitive analytical tools, such as PRM, for evaluating ADC measurements.

Asunto(s)

Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Imagen de Difusión por Resonancia Magnética/métodos , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Quimioterapia Adyuvante , Estudios de Factibilidad , Femenino , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento

RESUMEN

PURPOSE: To determine if MRI data obtained at 3.0 T can more accurately report the size of DCIS as compared to radiographic mammography, as a whole cohort and when subdivided by lesion characteristics. METHODS: Thirty-nine participants underwent X-ray mammography and MRI prior to breast surgery for DCIS. Longest diameter (LD) measurements were recorded for each imaging modality and compared to histopathological LD via a logarithmic transformed Bland-Altman agreement plot methodology resulting in dimensionless mean difference and 95% limits of agreement (LoA). RESULTS: Data from 39 patients with a median age of 55 years (range 38-78 years) underwent analysis. Mastectomy was undertaken in 21 cases, while breast conserving surgery was performed in 18 subjects. Histopathological analysis revealed one low grade, nine intermediate grade, and 21 high grade lesions. The mean±standard deviation LD measurements for histopathology, X-ray mammography and MRI were 50.6±34.2 mm, 30.7±23.1 mm and 49.6±26.8 mm respectively. Bland-Altman agreement plot analysis for the whole cohort revealed not only a smaller logarithmic mean difference between MRI and histopathology (0.086), but also narrower 95% LoA (-0.941 to 1.113) compared with X-ray mammography and histopathology (mean difference -0.658, 95% LoA -3.503 to 2.187). When the level of agreement was assessed between clinically relevant subgroups additional significant differences were noted based on grade, hormonal receptor status, invasion, necrosis, mircocalcifications and growth pattern. CONCLUSION: MRI provides a more accurate estimation of DCIS size than X-ray mammography. MRI's superior ability was not only noted in general, but also for clinical relevant subdivisions such as grade and the presence or absence of necrosis.

Asunto(s)

Neoplasias de la Mama/diagnóstico , Carcinoma Intraductal no Infiltrante/diagnóstico , Imagen por Resonancia Magnética , Mamografía , Mastectomía Segmentaria , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Carcinoma Intraductal no Infiltrante/patología , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Mamografía/métodos , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Sensibilidad y Especificidad

RESUMEN

OBJECTIVES: To determine associations between dynamic contrast-enhanced MR imaging (DCE-MRI) parameters and survival intervals in patients with locally advanced breast cancer treated with neoadjuvant chemotherapy (NAC), surgery, and adjuvant therapies. Further, to compare the prognostic value of DCE-MRI parameters against traditional survival indicators. METHODS: DCE-MRI and MR tumour volume measures were obtained prior to treatment and post 2nd NAC cycle. To demonstrate which parameters were associated with survival, Cox's proportional hazards models (CPHM) were employed. To avoid over-parameterisation, only those MR parameters with at least a borderline significant result were entered into the final CPHM. RESULTS: When considering disease-free survival positive axillary nodal status (hazard ratio [HR] 6.79), younger age (HR 3.37), negative oestrogen receptor status (HR 3.24), pre-treatment Maximum Enhancement Index (MaxEI) (HR 6.51), and percentage change in MaxEI (HR 1.02) represented the retained CPHM covariates. Similarly, positive axillary nodal status (HR 11.47), negative progesterone receptor status (HR 4.37) and percentage change in AUC90 (HR 1.01) represented the retained predictive variables for overall survival. CONCLUSIONS: Multivariate survival analysis has demonstrated that DCE-MRI parameters obtained prior to NAC and/or post 2nd cycle can provide independent prognostic information that can complement traditional prognostic indicators available prior to treatment. KEY POINTS: • MR-derived DCE-MRI parameters obtained prior to treatment have prognostic value. • Early treatment-induced reductions in DCE-MRI parameters represents a positive prognostic indicator. • DCE-MRI parameters provide independent prognostic information that can complement traditional prognostic indicators.

Asunto(s)

Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/tratamiento farmacológico , Medios de Contraste , Imagen por Resonancia Magnética , Terapia Neoadyuvante , Adulto , Factores de Edad , Mama/patología , Neoplasias de la Mama/cirugía , Terapia Combinada , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Gadolinio DTPA , Humanos , Aumento de la Imagen , Persona de Mediana Edad , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Resultado del Tratamiento , Carga Tumoral

RESUMEN

Imaging biomarkers capable of early quantification of tumor response to therapy would provide an opportunity to individualize patient care. Image registration of longitudinal scans provides a method of detecting treatment associated changes within heterogeneous tumors by monitoring alterations in the quantitative value of individual voxels over time, which is unattainable by traditional volumetric-based histogram methods. The concepts involved in the use of image registration for tracking and quantifying breast cancer treatment response using parametric response mapping (PRM), a voxel-based analysis of diffusion-weighted magnetic resonance imaging (DW-MRI) scans, are presented. Application of PRM to breast tumor response detection is described, wherein robust registration solutions for tracking small changes in water diffusivity in breast tumors during therapy are required. Methodologies that employ simulations are presented for measuring expected statistical accuracy of PRM for response assessment. Test-retest clinical scans are used to yield estimates of system noise to indicate significant changes in voxel-based changes in water diffusivity. Overall, registration-based PRM image analysis provides significant opportunities for voxel-based image analysis to provide the required accuracy for early assessment of response to treatment in breast cancer patients receiving neoadjuvant chemotherapy.

RESUMEN

OBJECTIVES: The ability to detect and identify malignant lesions within the prostate with conventional T2-weighted imaging is still limited. Although lesion conspicuity is improved with dynamic contrast-enhanced imaging there still remains some ambiguity as all tissues within the prostate may enhance. The aim of the current study was to take advantage of the improved signal-to-noise ratio at 3 T and assess the ability of 2 alternative pharmacokinetic models to clearly identify malignant areas within the prostate. We also aspire to assess the impact of tissue heterogeneity on variation in estimated pharmacokinetic parameters. MATERIALS AND METHODS: Quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of the prostate was implemented using multiple flip angles for T1 determination, and a rapid dynamic 3D T1-weighted acquisition with parallel imaging and a temporal resolution of 6.7 s. Pharmacokinetic analysis was performed for regions of tumor, normal-appearing peripheral zone (PZ), and central gland (CG) using fast exchange limit (FXL) or fast exchange regimen (FXR) models. Cell density was obtained from hematoxylin and eosin stained whole mount radical prostatectomy specimens. RESULTS: Native tissue T1 was significantly lower in tumor and PZ tissue than in CG. The FXL model revealed increased mean K(trans), k(ep), and v(e) in tumor and CG compared with PZ. With the FXR model, fitting was improved and all parameters were significantly increased, however, there were no longer significant differences between regions for v(e). The additional parameter of the FXR model, tau(i), nominally representing mean lifetime of intracellular water, was significantly decreased in tumor compared with both PZ and CG. Rate constants for CG were significantly lower than those of tumor for both models. In addition, for all tissues, K(trans) and v(e) were positively correlated with cell density. CONCLUSIONS: Accounting for a finite water exchange rate between cells and their environment improves the discrimination of malignant from benign tissues within the prostate and may aid staging accuracy and ability to monitor response to treatment.

Asunto(s)

Imagen de Difusión por Resonancia Magnética/métodos , Gadolinio DTPA/farmacocinética , Modelos Biológicos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/metabolismo , Adulto , Medios de Contraste/farmacocinética , Diagnóstico Diferencial , Humanos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Próstata/metabolismo , Próstata/patología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad

RESUMEN

OBJECTIVES: To assess the relationship between MRI derived parameters (apparent diffusion coefficient (ADC) and T2 relaxation time) and tumor cellularity as determined from whole mounted radical prostatectomy specimens, for both prostatic carcinoma and normal peripheral zone tissue. MATERIALS AND METHODS: Over a 16-month period, 20 patients (mean age: 61 years, range: 42-70 years) were prospectively recruited. Diffusion and T2 imaging were performed on a 3.0 Tesla scanner to enable subsequent ADC and T2 calculation. After radical retropubic prostatectomy specimens were whole-mounted and regions of interest (ROIs) drawn in areas of prostatic carcinoma and normal peripheral zone. Cell density was then determined using an adaptive histogram thresholding technique. Differences in tissue type were explored using the unpaired t test while the relationship between parameters was assessed using scatter-plots and the Pearson correlation coefficient. RESULTS: Significant differences (P < 0.0001 in all cases) were noted between peripheral zone tissue and prostatic carcinoma in terms of ADC (1.88 +/- 0.22 vs. 1.43 +/- 0.19 x 10(-3) mm2/s), T2 (142 +/- 24 vs. 109 +/- 20 milliseconds), and cell density (9.4% +/- 3.0% vs. 19.8% +/- 5.3%). A significant negative correlation with cell density was noted for both ADC (R = -0.695, P < 0.0001) and T2 (R = -0.505, P = 0.001). Trends for increased cell density, decreased ADC, and decreased T2 with increasing Gleason score were also noted. CONCLUSIONS: ADC and to a lesser extent T2 are good indicators of cell density. Because of the potential link with Gleason score, MRI derived parameters may have a prognostic role with regard to potential metastatic activity and tumor aggressiveness.

Asunto(s)

Imagen de Difusión por Resonancia Magnética/métodos , Interpretación de Imagen Asistida por Computador/métodos , Próstata/patología , Neoplasias de la Próstata/patología , Adulto , Anciano , Recuento de Células , Humanos , Aumento de la Imagen/métodos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estadística como Asunto

RESUMEN

Quantitative isotropic diffusion MRI and voxel-based analysis of the apparent diffusion coefficient (ADC) changes have been demonstrated to be able to accurately predict early response of brain tumors to therapy. The ADC value changes measured during pre- and posttherapy interval are closely correlated to treatment response. This work was demonstrated using a voxel-based analysis of ADC change during therapy in the brains of both rats and humans, following rigidly registering pre- and post-therapeutic ADC MRI exams. The primary goal of this paper is to extend this voxel-by-voxel analysis to assess therapeutic response in breast cancer. Nonlinear registration (with higher degrees of freedom) between the pre- and post-treatment exams is needed to ensure that the corresponding voxels actually contain similar cellular partial contributions due to soft tissue deformations in the breast and compartmental tumor changes during treatment as well. With limited data sets, we have observed the correlation between changes of ADC values and treatment response also exists in breast cancers. With diffusion scans acquired at three different timepoints (pre-treatment, early post-treatment and late post-treatment), we have also shown that ADC changes across responders within 5 weeks are a function of time interval after the initiation of treatment. Comparison of the experimental results with pathology shows that ADC changes can be used to evaluate early response of breast cancer treatment.

Asunto(s)

Antineoplásicos/administración & dosificación , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/tratamiento farmacológico , Imagen de Difusión por Resonancia Magnética/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Algoritmos , Inteligencia Artificial , Femenino , Humanos , Aumento de la Imagen/métodos , Pronóstico , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Resultado del Tratamiento

RESUMEN

The purpose of this study was to investigate whether dynamic contrast enhanced MRI (DCE-MRI) data, both pharmacokinetic and empirical, can predict, prior to neoadjuvant chemotherapy, which patients are likely to have a shorter disease free survival (DFS) and overall survival (OS) interval following surgery. Traditional prognostic parameters were also included in the survival analysis. Consequently, a comparison of the prognostic value could be made between all the parameters studied. MR examinations were conducted on a 1.5 T system in 68 patients prior to the initiation of neoadjuvant chemotherapy. DCE-MRI consisted of a fast spoiled gradient echo sequence acquired over 35 phases with a mean temporal resolution of 11.3s. Both pharmacokinetic and empirical parameters were derived from the DCE-MRI data. Kaplan-Meier survival plots were generated for each parameter and group comparisons were made utilising logrank tests. The results from the 54 patients entered into the univariate survival analysis demonstrated that traditional prognostic parameters (tumour grade, hormonal status and size), empirical parameters (maximum enhancement index, enhancement index at 30s, area under the curve and initial slope) and adjuvant therapies demonstrated significant differences in survival intervals. Further multivariate Cox regression survival analysis revealed that empirical enhancement parameters contributed the greatest prediction of both DFS and OS in the resulting models. In conclusion, this study has demonstrated that in patients who exhibit high levels of perfusion and vessel permeability pre-treatment, evidenced by elevated empirical DCE-MRI parameters, a significantly lower disease free survival and overall survival can be expected.

Asunto(s)

Antineoplásicos/uso terapéutico , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/tratamiento farmacológico , Imagen por Resonancia Magnética/métodos , Terapia Neoadyuvante/mortalidad , Neoplasias de la Mama/mortalidad , Quimioterapia Adyuvante/mortalidad , Medios de Contraste , Supervivencia sin Enfermedad , Femenino , Humanos , Selección de Paciente , Pronóstico , Medición de Riesgo , Factores de Riesgo , Análisis de Supervivencia , Tasa de Supervivencia , Resultado del Tratamiento , Reino Unido

RESUMEN

The aim of this study was to investigate the utility of the water T(2) values of malignant breast lesions in predicting response after the first and second cycles of neoadjuvant chemotherapy (NAC), both alone and in combination with lesion volumes. Thirty-five patients were scanned before the commencement of chemotherapy and again after the first, second and final treatment cycles. Two methods of obtaining lesion T(2) were used: imaging, where a series of T(2)-weighted images was acquired (T(R)/T(E)=1000/30, 60, 90 and 120 ms), and spectroscopy, where the T(2) value of unsuppressed water signal was determined with a multiecho sequence (T(R)=1.5 s; initial T(E)=35 ms; 64 steps of 2.5 ms; 2 unsuppressed acquisitions per T(E)). Lesion volumes were computed from contrast-enhanced 3D fat-suppressed images. The study found that, using the imaging method of obtaining T(2), the ratio of the product of lesion T(2) and volume after the second cycle of NAC to pretreatment value is a good predictor of ultimate lesion response, defined as a > or =65% reduction in tumor volume after the final treatment cycle, with positive and negative predictive values of 95.5% and 84.6%, respectively.

Asunto(s)

Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Terapia Neoadyuvante , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Curva ROC , Resultado del Tratamiento

RESUMEN

Echo-planar-based diffusion-weighted imaging (DWI) of the prostate is increasingly being suggested as a viable technique, complementing information derived from conventional magnetic resonance imaging methods for use in tissue discrimination. DWI has also been suggested as a potentially useful tool in the assessment of tumor response to treatment. In this study, the repeatability of apparent diffusion coefficient (ADC) values obtained from both DWI and diffusion tensor imaging (DTI) has been assessed as a precursor to determining the magnitude of treatment-induced changes required for reliable detection. The repeatability values of DWI and DTI were found to be similar, with ADC values repeatable to within 35% or less over a short time period of a few minutes and a longer time period of a month. Fractional anisotropy measurements were found to be less repeatable (between 26% and 71%), and any changes duly recorded in longitudinal studies must therefore be treated with a degree of caution.

Asunto(s)

Algoritmos , Imagen de Difusión por Resonancia Magnética/métodos , Imagen Eco-Planar/métodos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Próstata/anatomía & histología , Adulto , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad

RESUMEN

Traditionally, tumor response has been assessed via tumor size measurements during the course of a treatment. However, changes in these morphologically based measures occur relatively late in the course of a treatment. Alternative biomarkers are currently being evaluated to enable an earlier assessment of treatment to facilitate early cessation and cost savings. Diffusion-weighted imaging (DWI) has been identified by preclinical studies to be a likely alternative to tumor size measurements. In this study, 10 patients were examined prior to and after the first and second chemotherapy cycle time points. Longest diameter tumor measurements and apparent diffusion coefficients (ADCs) were recorded at each exam. An increase in the mean (normalized) ADC was noted as early as the first cycle time point. However, a reduction in the mean (normalized) longest diameter was only noted at the second cycle time point. Significant alterations from the baseline value were noted for ADC at the first (P=.005) and second cycle time points (P=.004). Longest diameter measurements only achieved a borderline significance at the second time point (P=.057). These results indicate that DWI may provide a suitable biomarker capable of providing an indication of response to treatment prior to tumor size measurements.

Asunto(s)

Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Imagen de Difusión por Resonancia Magnética , Quimioterapia Adyuvante , Ciclofosfamida/administración & dosificación , Epirrubicina/administración & dosificación , Femenino , Humanos , Terapia Neoadyuvante , Estadísticas no Paramétricas , Resultado del Tratamiento

RESUMEN

OBJECTIVES: We sought to assess the efficacy of diffusion imaging in the differential diagnosis of prostatic carcinoma using a 3.0 T scanner and parallel imaging technology. MATERIALS AND METHODS: Diffusion-weighted images were acquired using a single shot echo-planar imaging sequence with b = 0 and 500 seconds/mm. Apparent diffusion coefficient (ADCy) values were calculated in tumor and healthy-appearing peripheral zone for 62 patients. Diffusion tensor images were also acquired in 25 patients and mean diffusivity and fractional anisotropy determined. RESULTS: Significant differences were noted between prostatic carcinoma (1.33 +/- 0.32 x 10(-3) mm2/s) and peripheral zone (1.86 +/- 0.47 x 10(-3) mm2/s) for ADCy. Significant differences between the 2 tissue types were also noted for mean diffusivity and fractional anisotropy. Utilizing a cut-off of 1.45 x 10(-3) mm/s for mean diffusivity, a sensitivity of 84% and a specificity of 80% were obtained. CONCLUSIONS: Diffusion imaging of the prostate was implemented at high magnetic field strength. Reduced ADC and increased fractional anisotropy values were noted in prostatic carcinoma.

Asunto(s)

Imagen de Difusión por Resonancia Magnética , Próstata/patología , Neoplasias de la Próstata/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Imagen Eco-Planar , Humanos , Masculino , Persona de Mediana Edad , Curva ROC

RESUMEN

PURPOSE: To measure the apparent diffusion coefficient (ADC) of normal and malignant prostate tissue at 3.0T using a phased-array coil and parallel imaging, and determine the utility of ADC values in differentiating tumor from normal peripheral zone (PZ). MATERIALS AND METHODS: ADC values were calculated for 49 patients (tumor and PZ) with evidence of prostate cancer. Additionally, for nine asymptomatic volunteers, ADC values were determined for apparently normal central gland and PZ. A single-shot EPI diffusion-weighted imaging (DWI) technique with b = 0 and 500 seconds/mm2 was employed. RESULTS: ADC values were significantly lower for tumor (1.38 +/- 0.32 x 10(-3) mm2/second) than for patient PZ (1.95 +/- 0.50 x 10(-3) mm2/second, P < 0.001) and volunteer PZ (1.60 +/- 0.25 x 10(-3) mm2/second, P = 0.031). A considerable overlap of ADC values was noted between patient tissue types. CONCLUSION: DWI of the prostate at 3.0T in conjunction with a phased-array coil and parallel imaging allows ADC calculation of the prostate. ADC values were lower for tumors compared to normal-appearing PZ; however, there was considerable intersubject variability.

Asunto(s)

Imagen de Difusión por Resonancia Magnética , Procesamiento de Imagen Asistido por Computador , Neoplasias de la Próstata/patología , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Diagnóstico Diferencial , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Factores de Riesgo , Muestreo , Sensibilidad y Especificidad , Estadísticas no Paramétricas , Técnicas de Cultivo de Tejidos

RESUMEN

Neoadjuvant chemotherapy has become the standard treatment for patients with locally advanced breast cancer; however a technique that can accurately differentiate responders from non-responders at an early time point during treatment has still to be identified. The purpose of this work was to evaluate the ability of pharmacokinetically modelled dynamic contrast-enhanced MRI data to predict and monitor response of patients diagnosed with locally advanced breast cancer to neoadjuvant chemotherapy, at an early time point during treatment. Sixty-eight patients with histology proven breast cancer underwent MRI examination prior to treatment, early during treatment and following the final cycle of chemotherapy. A two compartment pharmacokinetic model provided the kinetic parameters transfer constant (Ktrans), rate constant (Kep) and extracellular extravascular space (Ve) for a region of interest encompassing the whole lesion (ROIwhole) and a 3x3 pixel 'hot-spot' showing the greatest mean maximum percentage enhancement from within that region (ROIhs). Following treatment 48 patients were classified as responders and 20 as non-responders based on total tumour volume reduction. Tumour volume changes between the pre-treatment and early treatment time points demonstrated differences between responders and non-responders with percentage change revealing the most significant result (p<0.001). Analysis based on ROIhs provided more statistically significant differences between responders and non-responders then ROIwhole analysis. ROIhs analysis demonstrated differences between responders and non-responders both prior to and early during treatment. A highly significant reduction in both Ktrans and Kep (p<0.001) was noted for responders between the pre-treatment and early treatment time points, while Ve significantly increased during the same time period for non-responders (p<0.001). Quantification of dynamic contrast enhancement parameters provides a potential means for differentiating responders from non-responders early during their treatment, thereby allowing a prompt change in treatment if necessary.

Asunto(s)

Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Quimioterapia Adyuvante , Medios de Contraste/administración & dosificación , Ciclofosfamida/administración & dosificación , Epirrubicina/administración & dosificación , Femenino , Fluorouracilo/administración & dosificación , Humanos , Persona de Mediana Edad , Terapia Neoadyuvante , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Resultado del Tratamiento