Improved prostate cancer imaging with SPECT/CT and MRI/MRSI

We present a combined imaging technique for prostate cancer using /sup 111/In-ProstaScint/spl reg/ SPECT/CT and MRI/MRSI. When used alone, either SPECT/CT or MRI/MRSI has limitations in assessing the patient undergoing clinical prostate cancer management. However, combined imaging can use MRI/MRSI to assess the prostate gland while SPECT/CT /sup 111/In-ProstaScint/spl reg/ imaging can evaluate nearby and distant lymph nodes for metastases. The combined imaging study thereby provides complementary information useful for the cancer management. /sup 111/In-ProstaScint/spl reg/ SPECT data are reconstructed using an iterative algorithm that includes CT-derived attenuation correction and depth-dependent collimator blurring compensation. 3D MR spectra are overlaid on the T2-weighted MR image. Images from a patient who sequentially received /sup 111/In-ProstaScint/spl reg/ SPECT/CT and MRI/MRSI in one and half months suggest that the findings from both studies are correlative and complementary to each other in that MRI/MRSI generally provides better specificity for the cancer detection in the prostate bed, and better anatomic details of the prostate than /sup 111/In-ProstaScint/spl reg/ SPECT/CT. Yet, /sup 111/In-ProstaScint/spl reg/ SPECT/CT improves sensitivity for detection of distant lymph node metastases, and also is more sensitive when the patient is undergoing androgen deprivation therapy and thereby provides useful diagnostic information that is not readily available from the MRI/MRSI study alone.