Utility of Multiparametric MRI for Predicting Residual Clinically Significant Prostate Cancer After Focal Laser Ablation.

OBJECTIVE. The purpose of this study was to compare in a multireader manner the diagnostic accuracies of 3-T multiparametric MRI interpretation and serial prostate-specific antigen (PSA) measurement in predicting the presence of residual clinically significant prostate cancer after focal laser ablation. MATERIALS AND METHODS. Eighteen men had undergone focal laser ablation for low- or intermediate-risk prostate cancer as part of two National Cancer Institute-funded phase 1 clinical trials. Multiparametric MRI was performed immediately after and 6 and 12 months after focal laser ablation. Serial PSA measurements after focal laser ablation were recorded, and MRI-ultrasound fusion biopsy was performed 6 and 12 months after ablation and served as the reference standard. Multiparametric MRI was performed at 3 T with pelvic phased-array coils. T2-weighted, DW, and dynamic contrast-enhanced MR images were retrospectively assessed by two blinded radiologists using a 3-point Likert scale (0-2). Inter-reader agreement was assessed with the Cohen kappa statistic. The diagnostic accuracies of multiparametric MRI and PSA measurement were compared. RESULTS. Residual clinically significant prostate cancer was identified in 11 of 18 (61%) men. Logistic regression analysis of serial PSA measurements yielded a correct classification rate of 61.1% (p > 0.05). Using a multiparametric MRI threshold score of 4 or greater, both radiologists made correct classifications for 16 of 18 men (89%) at 6 months and 15 of 17 men (88%) at 12 months. Interreader agreement was substantial to excellent for T2-weighted imaging, DWI, and dynamic contrast-enhanced MRI and improved uniformly from 6 to 12 months. Logistic regression analysis of the retrospectively reviewed multiparametric MR images yielded AUCs greater than 0.90 for each radiologist 6 and 12 months after focal laser ablation (p < 0.001). CONCLUSION. Multiparametric MRI 6 and 12 months after focal laser ablation significantly outperformed serial PSA measurements for predicting the presence of residual clinically significant prostate cancer.

Differing Interpretations of Report Terminology Between Primary Care Physicians and Radiologists.

PURPOSE: The lexicons of the radiologist and the referring physician may not be synonymous, which could cause confusion with radiology reporting. To further explore this possibility, we surveyed radiologists and primary care physicians (PCPs) regarding their respective interpretations of report terminology. METHODS: A survey was distributed to radiologists and PCPs through an internal listserv. Respondents were asked to provide an interpretation of the statistical likelihood of the presence of metastatic disease based upon the terminology used within a hypothetical radiology report. Ten common modifying terms were evaluated. Potential responses for the statistical likelihoods included 0%-25%, 26%-50%, 51%-75%, 76%-99%, and 100%. Differences between the groups were evaluated using either a χ2 test or Fisher exact test, as appropriate. RESULTS: The phrases "diagnostic for metastatic disease" and "represents metastatic disease" were selected by a high percentage of both groups as conferring a 100% likelihood of "true metastatic disease." The phrases "cannot exclude metastatic disease" and "may represent metastatic disease" were selected by a high proportion of both groups as conferring a 0% likelihood of "true metastatic disease." Radiologists assigned a higher statistical likelihood to the terms "diagnostic for metastatic disease" (P = .016), "represents metastatic disease" (P = .004), "suspicious for metastatic disease" (P = .04), "consistent with metastatic disease" (P < .0001), and "compatible with metastatic disease" (P = .003). CONCLUSION: A qualitative agreement among radiologists and PCPs exists concerning the significance of the evaluated terminology, although radiologists assigned a higher statistical likelihood than PCPs for several phrases.