Below excerpt from United States Patent: 10194825 (uspto.gov). If this potential doesn't get you excited, I don't know what will!
Magnetic relaxometry methods using the SQUID sensors can be employed to monitor the treatment of various different modes of therapy. Measurements of the magnetic moment of the tumor due to the magnetic nanoparticles bound to the cells can be made prior to application of therapy to determine the number of cancer cells in the tumor. During the therapy, similar measurements can be performed to determine the efficacy of the treatment and to monitor cell death. Upon successful treatment, the observed magnetic moment will be reduced to the sensitivity level of the sensor system indicating all detectable cancer cells have been destroyed. The observed trend of cell destruction as a function of time of applied therapy can be used to extend the treatment beyond the detection limit to extrapolate to zero cancer cells remaining.
United States Patent: 10194825 (uspto.gov)
