The study of diagnostic efficacy of MR spectroscopy in prostate cancer

Objective: To evaluate the diagnostic efficacy of MRS in prostate cancer based on sextant localization. Methods: There were 110 patients, 54 patients with pathologically confirmed prostate cancer and 56 patients confirmed non-prostate cancer proved by ultrasound guided systemic biopsy. The (choline + creatine) / citrate (CC/C) value in each voxel and ratio of positive voxel (PVR) in sextant localization were measured. The ROC analysis was used to evaluate the diagnostic efficacy of CC/C in single voxel and PVR in sextant localization. Results: There are 1673 and 2426 voxel in prostate cancer and non-prostate cancer respectively. The median of CC/C in cancer sextants was 2.137; the median of CC/C in noncancer sextants was 0.600. The difference of these two groups was statistically significant (Z = -41.7, P < 0.01). The diagnostic sensitivity was 81.4% (1362/1673), the specificity was 83.1% (2018/2426), and the accuracy was 82.4% [(1362 + 2018)/4099] for prostatic cancer with the cutoff point 0.911 of the CC/C value. The median of PVR in cancer sextants and noncancer sextants were 1 and 0 respectively, the difference of PVR was statistically significant ( Z =-11.7, P < 0.01). The diagnostic sensitivity was 77.5% (148/191), the specificity was 76.9% (247/321), and the accuracy was 77.1%[(148 + 247)/512] for prostatic cancer with the cutoff point 0.519 of the PVR. Conclusion: Detecting the cutoff point of the CC/C value in single voxel and the PVR in sextant localization may be valuable in the diagnosis of prostate cancer. (authors)