In Vivo Magnetic Resonance Imaging Of Orthotopic Prostate Cancer

Methods for imaging orthotopic prostate tumors within the prostate or small tumors with extension outside the prostate are needed to more closely model human prostate tumors, which are most commonly located within the gland or may extend just through the gland. By comparing MR sequences, we found that the T2-based Dixon 'water only' sequence best visualized tumors within the prostate of mouse models in both young and old mice and that tumor weight derived from this sequence correlated highly with ex vivo tumor weight (r(2) = 0.98, p < 0.001, n = 12). This should aid tumor detection, margin delineation and evaluation of tumor burden to enable studies including, but not limited to, evaluating the natural history of the disease, the mechanisms of action and the efficacy of therapeutic interventions.METHOD SUMMARY The method utilizes a T2-based Dixon 'water only' sequence to image orthotopic prostate tumors. The sequence results in high signal of the prostate, making it the most prominent object in the image; intermediate signal of the tumor; and low signal in the surrounding fat and other structures except the easily recognizable bladder. This enables visualization and margin delineation of the orthotopic prostate tumor. Region of interest analysis can be performed to calculate tumor volume and derive tumor weight.