TY - JOUR
T1 - Peripheral zone prostate cancer
T2 - Accuracy of different interpretative approaches with MR and MR spectroscopic imaging
AU - Westphalen, Antonio C.
AU - Coakley, Fergus V.
AU - Qayyum, Aliya
AU - Swanson, Mark
AU - Simko, Jeffry P.
AU - Lu, Ying
AU - Zhao, Shoujun
AU - Carroll, Peter R.
AU - Yeh, Benjamin M.
AU - Kurhanewicz, John
PY - 2008/1
Y1 - 2008/1
N2 - Purpose: To retrospectively compare relative accuracy of different interpretative approaches to magnetic resonance (MR) and MR spectroscopic imaging of peripheral zone prostate cancer, by using histologic examination results as the reference standard. Materials and Methods: This HIPAA-compliant study had institutional Committee on Human Research approval, with waiver of written consent requirement. Spectroscopic voxels of unequivocally benign (n = 66) or malignant (n = 77) peripheral zone tissue were identified by using step-section histopathologic tumor maps created for 28 men (mean age, 60 years; range, 46-71 years) who underwent endorectal MR and MR spectroscopic imaging before radical prostatectomy. Two readers (9 and 8 years of experience) independendy scored the selected voxels on a scale from 1 (likely benign) to 5 (likely malignant) at randomized review of the corresponding tissue outlined on a transverse T2-weighted MR image (T2 approach), the MR spectrum from the selected voxel only (single-voxel approach), the MR spectra from all voxels at the same axial level (multivoxel approach), and both the corresponding tissue outlined on a transverse T2-weighted image and the MR spectra from all voxels at the same axial level (integrated approach). Readers were aware that spectra were derived in patients with biopsy-proved diagnoses of prostate cancer and represented either benign or malignant tissue but were unaware of which voxels had been labeled benign or malignant and of all other clinical, histopathologic, and MR imaging findings. Receiver operating characteristic (ROC) curve analysis was performed. Generalized estimating equation method was used to estimate sensitivity and specificity for specific cutoff values. Results: Mean areas under the ROC curve (AUCs) for the T2, single-voxel, multivoxel, and integrated approaches were 0.69, 0.72, 0.72, and 0.76, respectively. AUC of the integrated approach was significantly higher than those of the other three approaches (F < .001). κ Values for assessment of interobserver variability for the T2, single-voxel, multivoxel, and integrated approaches were 0.39, 0.39, 0.34, and 0.48, respectively. Conclusion: Addition of MR spectroscopic imaging to MR imaging significantly improves characterization of peripheral zone prostate tissue as benign or malignant; improved performance is obtained when both data sets are interpreted in an integrated fashion.
AB - Purpose: To retrospectively compare relative accuracy of different interpretative approaches to magnetic resonance (MR) and MR spectroscopic imaging of peripheral zone prostate cancer, by using histologic examination results as the reference standard. Materials and Methods: This HIPAA-compliant study had institutional Committee on Human Research approval, with waiver of written consent requirement. Spectroscopic voxels of unequivocally benign (n = 66) or malignant (n = 77) peripheral zone tissue were identified by using step-section histopathologic tumor maps created for 28 men (mean age, 60 years; range, 46-71 years) who underwent endorectal MR and MR spectroscopic imaging before radical prostatectomy. Two readers (9 and 8 years of experience) independendy scored the selected voxels on a scale from 1 (likely benign) to 5 (likely malignant) at randomized review of the corresponding tissue outlined on a transverse T2-weighted MR image (T2 approach), the MR spectrum from the selected voxel only (single-voxel approach), the MR spectra from all voxels at the same axial level (multivoxel approach), and both the corresponding tissue outlined on a transverse T2-weighted image and the MR spectra from all voxels at the same axial level (integrated approach). Readers were aware that spectra were derived in patients with biopsy-proved diagnoses of prostate cancer and represented either benign or malignant tissue but were unaware of which voxels had been labeled benign or malignant and of all other clinical, histopathologic, and MR imaging findings. Receiver operating characteristic (ROC) curve analysis was performed. Generalized estimating equation method was used to estimate sensitivity and specificity for specific cutoff values. Results: Mean areas under the ROC curve (AUCs) for the T2, single-voxel, multivoxel, and integrated approaches were 0.69, 0.72, 0.72, and 0.76, respectively. AUC of the integrated approach was significantly higher than those of the other three approaches (F < .001). κ Values for assessment of interobserver variability for the T2, single-voxel, multivoxel, and integrated approaches were 0.39, 0.39, 0.34, and 0.48, respectively. Conclusion: Addition of MR spectroscopic imaging to MR imaging significantly improves characterization of peripheral zone prostate tissue as benign or malignant; improved performance is obtained when both data sets are interpreted in an integrated fashion.
UR - http://www.scopus.com/inward/record.url?scp=37349024297&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=37349024297&partnerID=8YFLogxK
U2 - 10.1148/radiol.2453062042
DO - 10.1148/radiol.2453062042
M3 - Article
C2 - 18024434
AN - SCOPUS:37349024297
SN - 0033-8419
VL - 246
SP - 177
EP - 184
JO - RADIOLOGY
JF - RADIOLOGY
IS - 1
ER -