Cancer core length from targeted biopsy: an index of prostate cancer volume and pathological stage.

OBJECTIVE: To study the relationship of maximum cancer core length (MCCL), on targeted biopsy (TB) of magnetic resonance imaging (MRI)-visible index lesions, to volume of that tumour found at radical prostatectomy (RP). PATIENTS AND METHODS: In all, 205 men undergoing fusion biopsy and RP were divided into two groups: 136 in whom the MCCL came from an index MRI-visible lesion (TB) and 69 in whom MCCL came from a non-targeted lesion (non-targeted biopsy [NTB]). MRI was 3-T multi-parametric and biopsy was via MRI-ultrasonography fusion. RESULTS: In the TB group, MCCL correlated with volume of clinically significant index tumours (ρ = 0.44-0.60, P < 0.01). The correlation was similar for first and repeat biopsy and for transition and peripheral zone lesions (ρ = 0.42-0.49, P < 0.01). No correlations were found in the NTB group. TB MCCL (6-10 and >10 mm) and MRI lesion diameter (>20 mm) were independently associated with tumour volume. TB MCCLs >10 mm and Gleason scores >7 were each associated with pathological T3 disease (odds ratios 5.73 and 5.04, respectively), but MRI lesion diameter lesion was not. CONCLUSIONS: MCCL on a TB from an MRI-visible lesion is an independent predictor of both cancer volume and pathological stage. This relationship does not exist for MCCL from a NTB core. Quantifying CCL on MRI-TBs may have a value, not previously described, to risk-stratify patients with prostate cancer before treatment.

MR-guided biopsy and focal therapy: new options for prostate cancer management.

PURPOSE OF REVIEW: Options for prostate cancer management are rapidly expanding. The recent advent of MRI technology has led to guided prostate biopsies by radiologists working in-bore or by urologists using MR/US fusion technology. The resulting tumor visualization now provides the option of focal therapy. Currently available are highly directed energies - focused ultrasound (HIFU), cryotherapy, and laser - all offering the hope of curing prostate cancer with few side effects. RECENT FINDINGS: MRI now enables visualization of many prostate cancers. MR/US fusion biopsy makes possible the targeted biopsy of suspicious lesions efficiently in the urology clinic. Several fusion devices are now commercially available. Focal therapy, a derivative of targeted biopsy, is reshaping the approach to treatment of some prostate cancers. Focal laser ablation, originally done in the MRI gantry (in-bore), promises to soon become feasible in a clinic setting (out-of-bore) under local anesthesia. Other focal therapy options, including HIFU and cryotherapy, are currently available. Herein are summarized outcomes data on focal therapy modalities. SUMMARY: MRI-guided biopsy is optimizing prostate cancer diagnosis. Focal therapy, an outgrowth of guided biopsy, promises to become a well tolerated and effective approach to treating many men with prostate cancer while minimizing the risks of incontinence and impotence from radical treatment.

Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) Magnetic Resonance Imaging Scoring to Predict Clinical Outcomes in Active Surveillance for Grade Group 1 Prostate Cancer.

OBJECTIVE: To determine whether radiological change on serial multiparametric magnetic resonance imaging scored using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) Scoring system predicts grade reclassification (GR) at surveillance biopsy in men on active surveillance (AS) with Grade Group 1 (GG1) prostate cancer (PCa). METHODS: We retrospectively reviewed records of 255 men with low-risk PCa on AS with magnetic resonance imaging (MRI)-informed diagnostic and confirmatory biopsies and studied the subset who had surveillance biopsies (n = 163) within 6months of an interval MRI. RESULTS: We studied 309 PRECISE scores in 255 men. 14% demonstrated radiological progression (PRECISE 4-5) on interval MRI performed within 24months, compared to 34% of those whose interval MRI was performed at a >3-year interval (P = .002). 28% (46/163) of men undergoing surveillance biopsy experienced GR to ≥ GG2 PCa. There was no significant increase in the rate of GR with increasing PRECISE score (PRECISE 1-2: 24%, PRECISE 3: 23%, PRECISE 4-5: 38%; P = .11). There was a significant increase in the rate of GR with increasing PI-RADS score (P < .05). On multivariable analysis, a PI-RADS score of 4-5 was significantly associated with GR compared to men who had a highest PI-RADS ≤3 (OR=1.98 [95% CI: 1.45-3.09, P = .01]). CONCLUSION: In a low-risk AS cohort with limited follow-up, a patient's highest PI-RADS rather than their PRECISE score on interval MRI was predictive of GR on surveillance biopsy.

Active Surveillance of Grade Group 1 Prostate Cancer: Long-term Outcomes from a Large Prospective Cohort.

BACKGROUND: Active surveillance (AS) is the preferred management option for most men with grade group (GG) 1 prostate cancer (PCa). Questions persist regarding long-term outcomes and the optimal approach to AS. OBJECTIVE: To determine survival and metastatic outcomes in AS patients. Secondary objectives were to measure the cumulative incidence and association of patient-level factors on biopsy grade reclassification. DESIGN, SETTING, AND PARTICIPANTS: A prospective, active, open-enrollment cohort study was conducted from 1995 through July 2018 at a tertiary-care academic institution. Patients with very-low-risk or low-risk PCa were enrolled. INTERVENTION: AS with semiannual prostate-specific antigen (PSA) and digital rectal examination, serial prostate biopsy, and multiparametric magnetic resonance imaging (mpMRI). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The 10- and 15-yr cumulative incidences of primary and secondary outcomes were determined. RESULTS AND LIMITATIONS: Overall, 1818 men were monitored on AS for a median of 5.0yr (interquartile range 2.0-9.0). There were 88 non-PCa deaths, four PCa deaths, and one additional case of metastasis. The cumulative incidence of PCa-specific mortality or metastasis was 0.1% (95% confidence interval, 0.04-0.6%) at both 10 and 15yr. The 5-, 10-, and 15-yr cumulative incidences of biopsy grade reclassification were 21%, 30%, and 32%, respectively. On multivariable analysis, biopsy grade reclassification was associated with older age, African-American race, PSA density, and increased cancer volume on biopsy, and men who underwent mpMRI prior to enrollment were less likely to undergo grade reclassification. Our selection and monitoring are more stringent than many other contemporary AS programs. CONCLUSIONS: In a large, single-institution, prospective AS cohort, the risk of cancer death or metastasis was <1% over long-term follow-up. Consistent with clinical guidelines, these data support the use of AS for the management of most men diagnosed with GG1 PCa. PATIENT SUMMARY: This study investigated long-term outcomes in patients with grade group 1 prostate cancer managed with active surveillance (AS). Ten years after enrolling in AS, the risk of metastasis or death from prostate cancer was <1%, while 48% of men switched to treatment. Patients who underwent multiparametric magnetic resonance imaging (mpMRI)/ultrasound-fusion targeted biopsy prior to enrollment were less likely to experience biopsy grade reclassification during follow-up, suggesting a role for mpMRI as part of a comprehensive risk assessment to confirm AS eligibility. These findings support the safety of AS in most men with grade group 1 prostate cancer, but specific outcomes may differ in programs with less intensive monitoring.

Use of MRI-Guided Biopsy for Selection and Follow-up of Men Undergoing Hemi-gland Cryoablation of Prostate Cancer.

OBJECTIVE: To investigate safety, efficacy, and quality of life impact of hemi-gland cryotherapy for clinically-significant prostate cancer (CaP), when patient selection and follow-up includes MRI-guided biopsy. METHODS: Twenty-nine men with unilateral CaP (all clinically significant with prostate volume <60 cc) were enrolled in a prospective observational trial of hemi-gland cryotherapy. Mean patient age was 68.7 years. Median prostate-specific antigen (PSA) was 6.6 ng/mL. MRI-guided biopsy (3T-MRI, Artemis US fusion) was used for diagnosis and repeated at 6-month follow-up in all men. Treatment was under general anesthesia using the BTG/Galil system. Validated questionnaires were used to determine effects of treatment on urinary and sexual function and quality of life. RESULTS: Cryotherapy was completed satisfactorily in all 29 cases in <60 minutes with no intraoperative complications. Significant decreases in PSA (median decrease 5.6 ng/mL) and PSA density (median decrease 0.14 ng/mL/cc) were observed (P < .01). At 6 months, 23 patients (79%) demonstrated no residual cancer on follow-up MRI-guided biopsy of the treated side. Three patients (10%) revealed micro-residual disease. Three patients (10%) had residual cancer and underwent further treatment. Ipsilateral MRI lesions were present before treatment in 26 patients and after treatment in only 2, reflecting the gross ablative effect; however, MRI showed disappearance of lesions in 4 patients with residual tumor on biopsy. The single complication was 1 case of transient urinary retention; 85% of men who were sexually active continued without change after treatment. Voiding function was unchanged. CONCLUSION: Hemi-gland cryoablation for clinically-significant CaP is well-tolerated, and when patients are selected and followed by MRI/US fusion biopsy, cancer control appears promising at 6 months.

Targeted Prostate Biopsy in the Era of Active Surveillance.

Targeted prostate biopsy using magnetic resonance imaging (MRI) guidance is improving the accuracy of prostate cancer (CaP) diagnosis. This new biopsy technology is especially important for men undergoing active surveillance, improving patient selection for enrollment and enabling precise longitudinal monitoring. Magnetic resonance imaging/ultrasound fusion biopsy allows for 3 functions not previously possible with US-guided biopsy: targeting of suspicious regions, template-mapping for systematic sampling, and tracking of cancer foci over time. This article reviews the evolving role of the new biopsy methods in active surveillance, including the UCLA Active Surveillance pathway, which has incorporated magnetic resonance imaging/ultrasound fusion biopsy from program inception as a possible model.

Targeted Prostate Biopsy Using 68Gallium PSMA-PET/CT for Image Guidance.

Prostate specific membrane antigen (PSMA) scanning is a sensitive method of prostate cancer detection. In a 71 y.o. man with a PSA of 49 (6%F), 4 negative MRI studies and 6 negative biopsies over an 8 year interval, a 68Ga-PSMA PET/CT scan showed a PSMA-avid spot in the prostate. Using image fusion technology, the lesion was target-biopsied and Gleason 3 + 4 = 7 (cancer core length of 12 mm) was identified. This case may herald a new application for PSMA scanning and prostate cancer imaging.