Cancer cell size may serve as a unique biomarker for tumor progression and response to treatment. Currently, however, information about cell size can only be obtained by pathological evaluation of invasive biopsy samples. Efforts to use noninvasive diffusion-weighted MRI have been limited to animal MRI scanners or have required long acquisition times.
Now, Junzhong Xu, PhD, and colleagues have modified an approach called IMPULSED (imaging microstructural parameters using limited spectrally edited diffusion) to assess cell size using a clinical MRI.
In Magnetic Resonance in Medicine, they report a practical imaging protocol and new analytical equations that link diffusion-weighted MRI signals to specific microstructural parameters including cell size. They validated the approach using computer simulations and measurements of cells in vitro and animal models in vivo.
They also used IMPULSED to assess tumor cell size in breast cancer patients, and they suggest that the method may have potential for evaluating early response to neoadjuvant therapy.
This research was supported by the National Institutes of Health (grants CA168936, CA109106, CA173593, TR002243, OD021771, CA142565, CA216942, TR000445, CA068485) and the American Cancer Society.
