Comparison of Micro-US and Multiparametric MRI for Prostate Cancer Detection in Biopsy-Naive Men.

Background Multiparametric MRI has led to increased detection of clinically significant prostate cancer (csPCa). Micro-US is being investigated for csPCa detection. Purpose To compare multiparametric MRI and micro-US in detecting csPCa (grade group ≥2) and to determine the proportion of MRI nodules visible at micro-US for real-time targeted biopsy. Materials and methods This prospective, single-center trial enrolled biopsy-naive men with suspected prostate cancer (PCa) between May 2019 and September 2020. All patients underwent multiparametric MRI followed by micro-US; findings at both were interpreted in a blinded fashion, followed by targeted biopsy and nontargeted systematic biopsy using micro-US. Proportions were compared using the exact McNemar test. The differences in proportions were calculated. Results Ninety-four men (median age, 61 years; IQR, 57-68 years) were included. MRI- and micro-US-targeted biopsy depicted csPCa in 37 (39%) and 33 (35%) of the 94 men, respectively (P = .22); clinically insignificant PCa in 14 (15%) and 15 (16%) (P > .99); and cribriform and/or intraductal PCa in 14 (15%) and 13 (14%) (P > .99). The MRI- plus micro-US-targeted biopsy pathway depicted csPCa in 38 of the 94 (40%) men. The addition of nontargeted systematic biopsy to MRI- plus micro-US-targeted biopsy did not enable identification of any additional men with csPCa but did help identify nine additional men with clinically insignificant PCa (P = .04). Biopsy was avoided in 32 of the 94 men (34%) with MRI and nine of the 94 men (10%) with micro-US (P < .001). Among 93 MRI targets, 62 (67%) were prospectively visible at micro-US. Conclusion MRI and micro-US showed similar rates of prostate cancer detection, but more biopsies were avoided with the MRI pathway than with micro-US, with no benefit of adding nontargeted systematic biopsy to the MRI- plus micro-US-targeted biopsy pathway. Most MRI lesions were prospectively visible at micro-US, allowing real-time targeted biopsy. ClinicalTrials.gov registration no.: NCT03938376 © RSNA, 2022 Online supplemental material is available for this article.

MRI-guided Focused Ultrasound Ablation for Localized Intermediate-Risk Prostate Cancer: Early Results of a Phase II Trial.

Background To reduce adverse effects of whole-gland therapy, participants with localized clinically significant prostate cancer can undergo MRI-guided focal therapy. Purpose To explore safety and early oncologic and functional outcomes of targeted focal high-intensity focused ultrasound performed under MRI-guided focused ultrasound for intermediate-risk clinically significant prostate cancer. Materials and Methods In this prospective phase II trial, between February 2016 and July 2019, men with unifocal clinically significant prostate cancer visible at MRI were treated with transrectal MRI-guided focused ultrasound. The primary end point was the 5-month biopsy (last recorded in December 2019) with continuation to the 24-month follow-up projected to December 2021. Real-time ablation monitoring was performed with MR thermography. Nonperfused volume was measured at treatment completion. Periprocedural complications were recorded. Follow-up included International Prostate Symptom Score (IPSS) and International Index of Erectile Function-15 (IIEF-15) score at 6 weeks and 5 months, and multiparametric MRI and targeted biopsy of the treated area at 5 months. The generalized estimating equation model was used for statistical analysis, and the Holm method was used to adjust P value. Results Treatment was successfully completed in all 44 men, 36 with grade group (GG) 2 and eight with GG 3 disease (median age, 67 years; interquartile range [IQR], 62-70 years). No major treatment-related adverse events occurred. Forty-one of 44 participants (93%; 95% CI: 82, 98) were free of clinically significant prostate cancer (≥6 mm GG 1 disease or any volume ≥GG 2 disease) at the treatment site at 5-month biopsy (median, seven cores). Median IIEF-15 and IPSS scores were similar at baseline and at 5 months (IIEF-15 score at baseline, 61 [IQR, 34-67] and at 5 months, 53 [IQR, 24-65.5], P = .18; IPSS score at baseline, 3.5 [IQR, 1.8-7] and at 5 months, 6 [IQR, 2-7.3], P = .43). Larger ablations (≥15 cm3) compared with smaller ones were associated with a decline in IIEF-15 scores at 6 weeks (adjusted P < .01) and at 5 months (adjusted P = .07). Conclusion Targeted focal therapy of intermediate-risk prostate cancer performed with MRI-guided focused ultrasound ablation was safe and had encouraging early oncologic and functional outcomes. © RSNA, 2021 Online supplemental material is available for this article See also the editorial by Tempany-Afdhal in this issue.

Salvage interstitial laser thermal therapy under MRI guidance (MRgFLA) for high-intensity focal ultrasound (HIFU) recurrences: feasibility study.

While focal therapy (FT) is increasingly endorsed for treating localized prostate cancer in the appropriately selected patient, management of recurrences following FT is not well-established in the literature. This case series describes three patients who received high-intensity focal ultrasound (HIFU) for primary treatment followed by focal laser interstitial thermal therapy (FLTT) for salvage therapy treated in the context of an ongoing clinical trial. Evaluation of these reported patients demonstrates that FLTT is feasible in the salvage setting with promising short-term oncologic outcomes and with the potential to preserve functional outcomes. Repeat focal therapy for previous failures is feasible however, it requires sophisticated imaging modalities for the accurate identification of recurrence and treatment of the tumor.