RESUMEN
PURPOSE: The aim of this study was to evaluate whether quantitative changes in contrast enhancement (CE) after neoadjuvant chemotherapy (NC) are associated with histological signs of tumor regression and whether quantitative dynamic MRI (dMRI) is capable of accurately assessing preoperative tumor size compared to mammography (MG) and ultrasound (US). METHODS: Thirty-one patients with breast cancer underwent MRI before and after NC. Dynamic CE was measured using a turbo-FLASH sequence and quantified by a two-compartment model, where two parameters, k(ep) (distribution constant rate) and A (amplitude), were calculated and color mapped. RESULTS: When tumors had signs of histological regression in the operative specimen (n=17) decrease of the parameters A and k(ep) was significantly more marked compared to tumors without regression (n=12). The correlation between tumor size measured by dMRI and histopathology was 0.81 when areas of unspecific CE were included; when they were not included the correlation was 0.66 and tumor size was systematically underestimated. In 26 patients dMRI was retrospectively compared with MG (r=0.51; dMRI, r=0.80) and in 22 patients with US (r=0.60; dMRI, r=0.75). CONCLUSION: Changes in dynamic CE are associated with histological tumor regression. Quantitative dMRI enables a valid assessment of tumor residue and is superior to MG and US. Remaining unspecific CE within the original tumor site should be considered as potentially malignant.
Asunto(s)
Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/tratamiento farmacológico , Quimioterapia Adyuvante , Imagen por Resonancia Magnética/métodos , Terapia Neoadyuvante , Mama/patología , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Medios de Contraste , Interpretación Estadística de Datos , Femenino , Humanos , Mamografía , Persona de Mediana Edad , Estudios Retrospectivos , Ultrasonografía MamariaRESUMEN
OBJECTIVE: The evaluation of mammographies carried out by conventional technique (standard imaging and focal imaging with 1.9x magnification) should be compared with a direct magnification image (standard imaging with 1.7x magnification, focal imaging with 4x magnification and preparation imaging with 7x magnification) provided by the mammographic device DIMA Plus M11 of the company feinfocus Medizintechnik. MATERIAL AND METHODS: Out of over 1,000 mammographies (DIMA technique) 50 histologically proved cases were selected for evaluation. Within a three months period these cases underwent conventional standard mammography as well as 1.9x magnification and DIMA-mammographies. The second X-ray was carried out when it was necessary for a pre-operative marking. RESULTS: When mammographies of mammaries, which were radiologically transparent and easily compressible, where taken by DIMA-technique, they showed a distinct advantage, especially in unclear micro-calcification cases, in comparison to the mammographies carried out by the conventional standard imaging. CONCLUSIONS: Direct magnification images carried out by DIMA Plus M11 provide a better breast cancer diagnostic. This refers in particular to focal images with 4x magnification and to digital mammography, which is yet being developed.
Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Mamografía/instrumentación , Tamizaje Masivo/instrumentación , Magnificación Radiográfica/instrumentación , Calcinosis/diagnóstico por imagen , Carcinoma in Situ/diagnóstico por imagen , Carcinoma Ductal de Mama/diagnóstico por imagen , Femenino , Humanos , Vigilancia de Productos Comercializados , Sensibilidad y EspecificidadRESUMEN
The conditions of dose distribution in telecentric small-angle pendulous electron irradiation of the thoracic region are reported on the basis of isodoses experimentally found using a phantom. Electron energies from 20 to 42 MeV were used, the axial depth amounted to 20 to 30 cm, the pendulous angles to 30 degrees, 40 degrees, or 60 degrees and the field breadth was 3 or 4 cm. Irradiations were performed monaxially as well as biaxially. The influences of single variables upon the dose distribution and especially on the radiation load to skin, lung and spinal cord are discussed.