Cancer de la prostate : les aspects cliniques, biologiques et histopathologiques utiles au radiologue

[MR spectroscopy of the prostate with external surface coils: clinical feasibility]

PURPOSE

To determine the clinical feasibility of MR spectroscopy (MRS) of prostate cancer using external multi-channel surface coils at 1.5T. Materials and methods. Retrospective study of 31 patients with prostate cancer who underwent MRS as part of the staging work-up prior to radical prostatectomy. The ratio of the three main metabolites ([choline + creatine]/citrate) were measured along with spectral analysis of different regions of interest (ROI) placed in areas of normal tissue and cancer using the surgical specimen as the standard of reference.

RESULTS

One hundred and eighty-three voxels were analyzed. Qualitative visual analysis identified pathological spectra in 88.5% of cancer ROI, 11.7% of normal transitional zone ROI and 1.6% of normal peripheral zone ROI. The ratios of normal prostate tissue were significantly more elevated (p<0.0001) in the transition zone (0.41 +/- 0.24) than in the peripheral zone (0.22 +/- 0.36). Tumor containing voxels had significantly higher ratios (2.84 +/- 2.74) than normal tissue containing voxels of the transition zone (p<0.0001) and peripheral zone (p<0.0001).

CONCLUSION

Prostate MRS using external surface coils appears routinely feasible at 1.5T, even though it presents some limitations.

Prostate cancer computer-assisted diagnosis software using dynamic contrast-enhanced MRI

ProCAD is a computer assisted diagnosis (CAD) software dedicated to prostate DCE-MRI analysis.

METHODS

In addition to standard visualization features, 2D and multislice 2D contouring tools based on a seeded growing region algorithm were included in the software. Tumor volume assessment and semiquantitative analysis of suspicious lesions can be performed. A 5-levels cancer suspicion score (ranging from "probably benign" to "Highly suspicious" is calculated on the basis of adjusted parameters extracted from the data of 121 suspicious benign or tumoral lesions.

RESULTS

Using a simple scoring algorithm based the median w.i and w.o values of TZK, TZB, PZK and PZB and designed to provide the highest sensitivity we had respective Se/Sp of 100/49% for peripheral zone cancers, and 100/40% for transition zone cancers characterization.

CONCLUSION

This software provides useful data for an unbiased an reproducible assessment of hypervascularized prostatic areas in routine practice.