Faculty Bibliography

PURPOSE: The aim of this study was to evaluate multisequence magnetic resonance imaging (MRI) in detecting local recurrence after transurethral resection for bladder cancer. METHODS: Thirty-six patients with bladder cancer with previous transurethral resection underwent bladder MRI incorporating T2-weighted imaging, diffusion-weighted imaging, and delayed contrast-enhanced T1-weighted imaging, followed by cystoscopy. Two radiologists (R1 and R2) evaluated examinations for suspicious findings. RESULTS: Forty-seven percent of patients had recurrent tumor at cystoscopy and biopsy. Using multisequence MRI, sensitivity and specificity were 67% and 81% for R1 and 73% and 62% for R2. Both readers missed 1 high-grade pathologic stage T1 recurrent tumor; otherwise, all missed tumors were low-grade pathologic stage Ta lesions. All false positives for R1 and 7 of 9 false positives for R2 were in patients receiving previous bacillus Calmette-Guerin therapy. Furthermore, 40% to 50% of solitary abnormalities and 83% to 100% of multifocal abnormalities were tumor recurrences; 12% to 20% of smooth wall thickening, 50% to 75% of irregular wall thickening, and 88% to 100% of papillary masses were tumor recurrences. CONCLUSIONS: Although multisequence MRI exhibited moderate performance for detecting recurrent tumor, nearly all missed tumors were low grade and noninvasive.

BACKGROUND: Increasing evidence supports the use of magnetic resonance imaging (MRI)-ultrasound fusion-targeted prostate biopsy (MRF-TB) to improve the detection of clinically significant prostate cancer (PCa) while limiting detection of indolent disease compared to systematic 12-core biopsy (SB). OBJECTIVE: To compare MRF-TB and SB results and investigate the relationship between biopsy outcomes and prebiopsy MRI. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of a prospectively acquired cohort of men presenting for prostate biopsy over a 26-mo period. A total of 601 of 803 consecutively eligible men were included. INTERVENTIONS: All men were offered prebiopsy MRI and assigned a maximum MRI suspicion score (mSS). Men with an MRI abnormality underwent combined MRF-TB and SB. OUTCOMES: Detection rates for all PCa and high-grade PCa (Gleason score [GS] >/=7) were compared using the McNemar test. RESULTS AND LIMITATIONS: MRF-TB detected fewer GS 6 PCas (75 vs 121; p<0.001) and more GS >/=7 PCas (158 vs 117; p<0.001) than SB. Higher mSS was associated with higher detection of GS >/=7 PCa (p<0.001) but was not correlated with detection of GS 6 PCa. Prediction of GS >/=7 disease by mSS varied according to biopsy history. Compared to SB, MRF-TB identified more GS >/=7 PCas in men with no prior biopsy (88 vs 72; p=0.012), in men with a prior negative biopsy (28 vs 16; p=0.010), and in men with a prior cancer diagnosis (42 vs 29; p=0.043). MRF-TB detected fewer GS 6 PCas in men with no prior biopsy (32 vs 60; p<0.001) and men with prior cancer (30 vs 46; p=0.034). Limitations include the retrospective design and the potential for selection bias given a referral population. CONCLUSIONS: MRF-TB detects more high-grade PCas than SB while limiting detection of GS 6 PCa in men presenting for prostate biopsy. These findings suggest that prebiopsy multiparametric MRI and MRF-TB should be considered for all men undergoing prostate biopsy. In addition, mSS in conjunction with biopsy indications may ultimately help in identifying men at low risk of high-grade cancer for whom prostate biopsy may not be warranted. PATIENT SUMMARY: We examined how magnetic resonance imaging (MRI)-targeted prostate biopsy compares to traditional systematic biopsy in detecting prostate cancer among men with suspicion of prostate cancer. We found that MRI-targeted biopsy detected more high-grade cancers than systematic biopsy, and that MRI performed before biopsy can predict the risk of high-grade cancer.