The medical imagistic in diagnosis and evaluation of the local spreading degree of breast cancer
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StatusThe thesis was presented on the 7 April, 2006Approved by NCAA on the 29 June, 2006 Abstract – 0.69 Mb / in romanianThesisCZU 618.19-006-07 R82
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Keywords
cancer, breast, imaging, MRI, mammography, ultrasonography, axillary node, neoadjuvant chemotherapy, local relapseSummary
The aim of the study is to appreciate with the help of the imagistic methods the diagnosis and the degree of local spreading of the breast cancer if order to stabilize optimal treatment tactics.
Objectives: 1. The appreciation of the dimensions and localization of the multicentricity of neoplastic affection and tumor bed with the application of bilateral simultaneous breast MRI. 2. The morphological and dynamic study of the breast tumoral forms with the application of diverse MRI techniques with the aim of tissular characteristics evaluation. 3. The evaluation of residual mass after the preoperative neoadjuvant chemotherapy treatment application and the determination of the signs of local relapse. 4. The elaboration of discriminating criteria that will allow the identification of axillary lymph node and their number, their differenciation etween benign and malignant. 5. The comparative study of different groups of contrast media used in the MRI lymphography in vivo and ex-vivo. 6. The comparative study of breast cancer imaging methods in correlation with the sensitivity and specificity of each method with respect to the staging process of the neoplasm.
From 2001 to 2004, 395 patients underwent clinical, mammographic, and/or USG and/or MRI in Henri Mondor and Saint Louis (France), Oncology Institute from Moldova (respectively 245 in France and 150 in Moldova). 75% from cases are patients with T in situ and T1 breast cancer according to TNM classification. The study was done with the help of a device of 1,5T.
Mammorgraphic USG and MRI evaluation criteria were based on the Breast Imaging Reporting and Data System (BI-RADS). Only enhancing lesions which underwent histological verification were included in this study to evaluate discriminated criteria in order to achieve reliable data.
MRI sensibility is directly proportional with the tumor histological form and through this allows the characteristic of discriminating signs of MRI. The best technique for diagnosis issue solving is the 3D gradient Echo, contrast material-enhanced, dynamic imaging, subtraction technique in fine cups of 1,25-2-3mm. Kinetic criteria for malignancy were strong signal enhancement within the first 90s after bolus injection followed by subsequent signal plateau level or decrease of wash-out phenomenon. Defined diagnosis criteria combining morphologic and kinetic enhancement patterns.
Because of the overlapping enhancement characteristics of benign and malignant lesions, research efforts on defining more specific diagnostic criteria for lesion characterization.
The done study revealed the discriminated signs were judged as indicators of malignancy: Dynamic criteria (fast initial wash-in, plateau phenomenon, wash-out phenomenon, blooming sign, inhomogenous enhancement, centripetal enhancement); morphological criteria (unsharp borders if a lesion on T1- weighted images, iso- or hypointensity T1-weighted images, adjacent vessel leading to the lesion cutaneous thickening, - or hypointensity T2-weighted images, edema, perifocal, diffuse, unilateral, bilateral, connection of the lesion with the pectoral muscle, lymph nodes larger than 1 cm). The blooming sign describes a fast enhancing lesion with initially sharply shaped borders 1 minute after bolus injection becoming unsharp 7 min after bolus injection including lesions showing partially shaped borders in the beginning. Hydrostatic microvascular pressure mainly causing an interstitial hypertension in solid tumors differs between the tumor and the surrounding tissue eventually causing a dilution of contrast agents on the periphery. The calculated values of specificity regarding the occurrence of blooming sign in MRI turns out to be fairly high (94,34%) as well as its PPV (95,16%) and accuracy (81,34%) whereas sensitivity (72,84%) and NPV (64,94%) are low.
At the
beginning of the neoadjuvant preoperative chemotherapy treatment wash-out was registered in 89%
of cases and a progressive curve in 11% of cases. At the end of the treatment the wash out aspect
was detected in 53% of cases. The plateau -7% of cases and the progressive in 40% of cases. The
medium percentage of residual cells in the group of kinetic curve without aspect modifications and
in the group of modifications was different. In the group “without answer” the percentage of
tumoral cells varied between 50 to 100%, the kinetic curve modified after chemotherapy and
correspond to a delayed answer to treatment. In the group “with answer” the percentage of tumoral
cells was from 0% till 45% being considered as a major histological answer. The study proved the
existence of correlation between the kinetic modification of the tumoral signal in MRI and the
percentage of residual cells appreciated within the histological exam. Was established that the
considerable diminishing (with 20%) of the contrast enhancement percentage afte 2 treatment
courses is favorable for an adequate answer to the treatment. MRI allows to diagnose an eventual
relapse from 3 mm. In the study was proved that the method sensibility is of 91,1%, specificity
92,3%, NPV=100%. Were studied 26 women undergoing axillary lymph node dissection after
combined bilateral breast MRI and high resolution MRI of the axilla. Axillary MRI findings were
compared with the final pathologic results from axillary lymph node dissection in all patient. A total
of 166 lymph nodes were studied with MRI and morphopathologically. From 166 nodes – 86
metastatic and 80 normal. The study was done pre and post operatively with ex vivo and in vivo
evaluation. Were established the following discriminating signs of the malignant lymph node:
irregular contours (71%), contrast enhancement (57%), abnormal cortex (86%), and
eccentric/concentric cortex (92%), central high signal intensity on inversion recovery T2 weighed
images 71%, extracapsular invasion 85%. A hilum was identified in 84 nodes and was encountered
significantly more frequent in patients with negative pathologic findings. The methods sensibility
95,6%, specificity 92%, utilizing Superparamagnetic Iron Oxide Enhancement.
Oficial Reviewers
- Petru Pihut
doctor habilitat - Andrei Bondari
doctor în medicină, profesor universitar, UMF Craiova, România - Mihai-Romeo Găleşanu
doctor în medicină, profesor consultant, UMF Iaşi, România
Theses
