Presentation Authors: Francesco Giganti*, Armando Stabile, Vasilis Stavrinides, Adam Retter, Clement Orczyk, London, United Kingdom, Valeria Panebianco, Rome, Italy, Alex Freeman, Charles Jameson, Shonit Punwani, Clare Allen, Alex Kirkham, Mark Emberton, Caroline M Moore, London, United Kingdom
Introduction: The PRECISE recommendations for MRI in men on active surveillance (AS) include repeated measurement of each lesion, and attribution of a PRECISE radiological progression score for the likelihood of clinically significant change over time. A 1-5 Likert scale is used where 1 shows regression of a previously visible lesion, 3 denotes stability and 5 is definitive radiological stage progression. We compared the PRECISE score with clinical progression in men who are managed using an MRI-led AS protocol.
Methods: Men on AS for low or intermediate risk prostate cancer who had had two or more MRI scans between April 2006 and September 2017 were included. A total of 535 scans from 150 men were re-reported by a dedicated radiologist to give a PI-RADS v2 score for each scan, measurement of all lesions and a PRECISE score for the likelihood of radiological progression. Clinical progression was defined by histological progression to â‰¥ Gleason Grade Group 3 and/or initiation of active treatment. Tumour growth rate between serial scans was calculated.
Results: Freedom from clinical progression at 12, 24 and 60 months for PRECISE 1-2 was 100% at all time points; for PRECISE 3 it was 98.4%, 96.7%, 96.7% and for PRECISE 4-5 it was 98.5%, 92.4%, 67.1%. There was a significant difference between PRECISE 1-2 vs 4-5 and PRECISE 3 vs 4-5 (p < 0.001). Fifty-six men (37%) had a visible lesion on all scans, and their tumour growth rate (%) by planimetry was higher with higher PRECISE scores (p < 0.05). Limitations include the fact that serial biopsies were not routinely performed and that the biopsy approach at baseline varied (standard vs targeted).The Kaplan-Meier curves show the rate of clinical progression stratified by PRECISE score (1-2 vs 3 vs 4-5) in the overall population (n=150).
Conclusions: Radiological stability (PRECISE 1-3) in men on AS is associated with a high rate of freedom from clinical progression. If men had clinical progression, then this was almost always detectable on MRI. Men with a stable MRI had a very low likelihood of clinical progression and many could avoid routine re-biopsy.