What is new in breast MRI spectroscopy

Autor: Michael T. Nelson, Jessica E Kuehn-Hajder, Lenore I. Everson, Patrick J. Bolan, Tim H Emory, Michael Garwood
Rok vydání: 2012
Předmět:
Zdroj: European journal of radiology. 81
ISSN: 1872-7727
Popis: A review of breast spectroscopy and its metabolite imaging – MRS is useful for clinical evaluation in neoadjuvant chemotherapy for the treatment of breast cancer. Why has it not been implemented on all clinical breast MRI scanners? Doing MRI/MRS on smaller breast cancers is difficult and cannot be done on breast cancers less than 6mm × 6mm × 6mm. High field magnets are used in single voxel spectroscopy (laser) for beast quantitative results (3T or 4T). The MRI/MRS latest results from I-SPY I (NIH/ACRIN) are not yet published for the multi-centered trial. Also having to shim the magnet and preset sequences for optimizing MRS has been an issue and requires a MRI physicist to do these studies. Choline measurements on 1.5T magnets that are shimmed well can detect choline within a large tumor (>2–3 cm). However, it is difficult to quantitate the choline with the breast cancer using 1.5T magnets. The results from the first MRS trial at the University of Minnesota Center for Magnetic Resonance Research will be published at the San Antonio Breast Meeting (December 2012). The report will be on 60 MRI/MRS cases and 5 year survival data. MRI/MRS neoadjuvant breast cancer imaging can be evaluated by three MRI methods to get to the RECIST evaluation: (1) L/D – longest diameter; (2) MRS – metabolite imaging and (3) Volume imaging of contrast (3D). All these methods have difficulty with non-mass like tumors. Making objective measurements of changes in breast tumor size can be challenging. The spectrum of breast tumor morphology and appearance on MRI creates difficulty generating accurate objective measurements which is used by oncology RECIST criteria to track tumor response in breast cancer. Depending on morphology and enhancement of an individual lesion an objective LD comparison may be problematic as seen in the following abstract. Inter-observer agreement in assessment of breast cancer response to neoadjuvant chemotherapy on MRI: Qualitative versus quantitative evaluation (11/28/11 RSNA, Chicago, IL). Volume Imaging: MRI tumor volume for predicting response to neoadjuvant chemotherapy in locally advanced breast cancer: findings from ACRIN 6657/calgb 15007 (2009 Asco) Noxla Hilton. Tumor response measured volumetrically by MRI is a stronger and earlier predictor of pathologic response after (NACT) than clinical exam or tumor diameter. Volumetric MRI imaging must use accurate volume (3D) placement of a voxel under MRI guidance. This procedure is not yet automated and must be completed by an experienced MRI radiologist. If the clinical trial shows that the pathologic response is very good (in 1–2 weeks) then this test may not be as sensitive for predicting (NACT) response. (Chemotherapy drugs work extremely well and the tumor decreases gadolinium uptake to zero.)
Databáze: OpenAIRE
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