Acute myeloid leukemia: lack of predictive value of sequential quantitative MR imaging during treatment.

ABSTRACT

PURPOSE: To assess the use of magnetic resonance (MR) imaging in monitoring treatment response in patients with acute myeloid leukemia (AML). MATERIALS AND METHODS: Bulk T1 and T2 were determined with at least four MR imaging examinations (strictly timed) during the first 6 weeks of treatment in 29 patients with AML (age range, 16-75 years; 15 female, and 14 male). Bulk T1 and T2 in responder (n = 22) and nonresponder (n = 7) patients were compared. RESULTS: Relative to pretreatment bulk T1 values, bulk T1 had increased a mean of 11% at week 1 and had decreased a mean of 7% and 39% at weeks 2 and 6, respectively. Values in nonresponder patients were not statistically significantly different (+11%, -14%, -38%). CONCLUSION: MR imaging of lumbar bone marrow in patients with AML demonstrated statistically significant changes in bulk T1 during treatment that correlated with changes in cellularity. However, neither the early increase in bulk T1 nor the rate or magnitude of the subsequent decrease in bulk T1 were indicative of a positive response to treatment.