Fig. 10
From: Imaging biomarkers for evaluating tumor response: RECIST and beyond
![Fig. 10](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40364-021-00306-8/MediaObjects/40364_2021_306_Fig10_HTML.png)
Proton magnetic resonance spectroscopy (MRS) can early predict chemotherapy response. A A woman with 34 mm breast cancer in the left breast (white arrow). B The pretreatment MRS shows a choline peak of 2.33 mmol/kg. C After one cycle of Adriamycin and Cyclophosphamide, the tumor was 26 mm (white arrow), showing a 24 % reduction in size. According to the RECIST 1.1, this is a non-responder. D However, posttreatment MRS shows much more sensitive evidence of tumor response with a 51 % reduction of total choline level (from 2.33 mmol/kg to 1.15 mmol/kg) (black arrow)