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INTRODUCTION: Vascular targeted photodynamic therapy (VTP) with WST11 (TOOKAD(R) Soluble; STEBA Biotech, Luxembourg) is a form of tissue ablation that may be used therapeutically for localized prostate cancer (PCa). To study dosing parameters and associated treatment effects we undertook a prospective multicenter phase I/II trial of WST11 VTP for treatment of PCa METHODS: 30 men with unilateral, low volume, Gleason 3+3 PCa were enrolled at 5 centers following local IRB approval. Light energy, fiber number, and WST11 dose were escalated to identify optimal dosing parameters for VTP hemiablation. Men were treated by VTP and evaluated by post-treatment MRI and biopsy. PSA, light dose index (LDI -defined as sum of fiber length/ desired treatment volume), toxicity, and quality of life parameters were recorded. RESULTS: Following dose escalation, 21 men received optimized dosing of 4 mg/kg WST11 200 J energy. On post-treatment biopsy, residual PCa was found in the treated lobe in 10 men, untreated lobe in 4, and both lobes in 1. When LDI>/=1, at optimal dosing, (n=15), 73.3% had a negative biopsy in the treated lobe. Six men undergoing retreatment, with optimal dose and LDI >/=1, had negative post-treatment biopsy. Minimal effects on urinary, sexual function, and overall quality of life, were observed. CONCLUSIONS: Hemiablation of the prostate with WST11 VTP was well-tolerated and resulted in negative biopsy in the treated lobe for the majority of men. Dosing parameters and LDI appear related to tissue response as determined by MRI and biopsy. These parameters may serve as the basis for further prospective studies.

PURPOSE OF REVIEW: We review recent developments in prostate MRI for prostate cancer diagnosis. RECENT FINDINGS: Large series have strengthened the case for the use of MRI prior to subsequent biopsy to maximize the detection of clinically significant disease, and reduce the detection of clinically insignificant disease. This has effectively moved the discussion on from whether MRI is useful in prostate cancer detection to how best to use it, and at which time point. The Prostate Imaging- Reporting And Data System (PIRADS) group have published a second version of the PIRADS criteria for prostate MRI, covering acquisition, interpretation, and reporting both for clinical practice and data collection for research.There is debate about the commonly used and more prescriptive PIRADS system versus the less prescriptive systems based on overall clinical impression of clinically significant disease (e.g. Likert or simplified quantum scoring). Studies suggest that the Likert or simplified quantum scoring approach may outperform PIRADSv2. Published data are conflicting on whether software-assisted fusion of MRI lesions to ultrasound used at biopsy is more effective than visual registration by a trained operator. SUMMARY: The use of prostate MRI is increasing worldwide, and the debate now focuses on how best to use it to optimize the detection of clinically significant disease.