The result is significant, as the PET scan allows doctors to determine if the therapy regimen is working very early in the treatment process, providing information that will allow physicians and patients to decide as soon as possible whether to continue treatment with imatinib mesylate or try a different therapy.
The study, which was conducted by researchers at the University of Texas M.D. Anderson Cancer Center in Houston, Texas, was published in the January 2004 edition of The Journal of Nuclear Medicine. They conducted the retrospective analysis by examining the sensitivity and predictive values of PET and CT scans taken prior to therapy and then again two months after imatinib mesylate treatment had begun. While there was no significant statistical difference between the pretreatment accuracy of the two different types of scans, PET was more effective in early assessment of the patients' responses to the drug.
"In our judgment," the researchers stated, "18F-FDG PET is an excellent prognostic tool for early assessment of response to imatinib mesylate therapy." The researchers further concluded that there is not significant value in the use of CT to monitor early response to this treatment.