Focal therapy for prostate cancer: revolution or evolution?

The face of prostate cancer has been dramatically changed since the late 1980s when PSA was introduced as a clinical screening tool. More men are diagnosed with small foci of cancers instead of the advanced disease evident prior to PSA screening. Treatment options for these smaller tumors consist of expectant management, radiation therapy (brachytherapy and external beam radiotherapy) and surgery (cryosurgical ablation and radical prostatectomy). In the highly select patient, cancer specific survival employing any of these treatment options is excellent, however morbidity from these interventions are significant. Thus, the idea of treating only the cancer within the prostate and sparing the non-cancerous tissue in the prostate is quite appealing, yet controversial. Moving forward if we are to embrace the focal treatment of prostate cancer we must: be able to accurately identify index lesions within the prostate, image cancers within the prostate and methodically study the litany of focal therapeutic options available

Performance of multiparametric MRI in men at risk of prostate cancer before the first biopsy: a paired validating cohort study using template prostate mapping biopsies as the reference standard.

BACKGROUND: Multiparametric magnetic resonance imaging (mpMRI) has the potential to serve as a non-invasive triage test for men at risk of prostate cancer. Our objective was to determine the performance characteristics of mpMRI in men at risk before the first biopsy using 5 mm template prostate mapping (TPM) as the reference standard. METHODS: One hundred and twenty-nine consecutive men with clinical suspicion of prostate cancer, who had no prior biopsy, underwent mpMRI (T1/T2-weighted, diffusion-weighting, dynamic contrast enhancement) followed by TPM. The primary analysis used were as follows: (a) radiological scores of suspicion of ≥3 attributed from a five-point ordinal scale, (b) a target condition on TPM of any Gleason pattern ≥4 and/or a maximum cancer core length of ≥4 mm and (c) two sectors of analysis per prostate (right and left prostate halves). Secondary analyses evaluated the impact of changing the mpMRI score threshold to ≥4 and varying the target definition for clinical significance. RESULTS: One hundred and forty-one out of 258 (55%) sectors of analysis showed 'any cancer' and 77/258 (30%) had the target histological condition for the purpose of deriving the primary outcome. Median (with range) for age, PSA, gland volume and number of biopsies taken were 62 years (41-82), 5.8 ng ml(-1) (1.2-20), 40 ml (16-137) and 41 cores (20-93), respectively. For the primary outcome sensitivity, specificity, positive and negative predictive values and area under the receiver-operating curve (with 95% confidence intervals) were 94% (88-99%), 23% (17-29%), 34% (28-40%), 89% (79-98%) and 0.72 (0.65-0.79), respectively. CONCLUSIONS: MpMRI demonstrated encouraging diagnostic performance characteristics in detecting and ruling out clinically significant prostate cancer in men at risk, who were biopsy naive