The imaging technique, called a functional diffusion map, uses a magnetic resonance imaging scan (MRI) and special software to track the diffusion, or movement, of water through the cells. Researchers mapped the changes in diffusion over the course of treatment. The tumour cells slow the movement of water, so as those cells die, water diffusion increases.
Researchers studied metastatic prostate cancer in mice; half the mice were given chemotherapy to treat the cancer, which was in the bones, while the remaining mice served as an untreated control group. Researchers performed an MRI of bone tumours to collect diffusion data.
A functional diffusion map analysis found the mice that did not receive treatment had little or no change in water diffusion, while the treated mice had progressively increasing changes in the functional diffusion map over the three weeks of treatment. Researchers could identify a statistically significant change in diffusion as early as seven days after treatment began.
At the end of the study, the researchers removed the tumours and found the functional diffusion map predicted the tumours’ response to treatment. Tumours or portions of a tumour that had appeared not to change on the functional diffusion map had not responded to treatment. At the same time, the map accurately predicted which cells were responsive to the chemotherapy.
"The functional diffusion map could serve as an early biomarker indicating that a tumour is responding to treatment. This could allow patients to switch to an alternative therapy without wasting time on a treatment that is not working," says study author Kenneth Pienta, M.D., professor of internal medicine and urology and director of the Urologic Oncology Program at the University of Michigan Comprehensive Cancer Center.
MEDICA.de; Source: University of Michigan Health System