Multi-parametric magnetic resonance imaging monitoring patients in active surveillance for prostate cancer: a prospective cohort study

Abstract

Objectives: To evaluate the use of multi-parametric magnetic resonance imaging (mpMRI) and mpMRI guided biopsies (MRGB) for monitoring an active surveillance (AS) prostate cancer cohort.

Materials and methods: One year after initial diagnostic TRUS guided biopsy (TRUS-bx), baseline mpMRI, and enrolment in an AS program patients underwent a one year follow-up comprising the usual TRUS-bx and an mpMRI. Prostate MRI lesions were scored on the five-point PIRADS scale version 2. In cases without TRUS-bx progression, patients with PIRADS 4 or 5 lesions were scheduled for MRGB. Progression in TRUS-bx was defined as Gleason score (Gs) up-grades, >3 tumor positive cores or a maximal cancer core length (MCCL) > 50%. In MRGB, Gs upgrade or a MCCL ≥6 mm Gs 3 + 3 lesions were considered to reflect progression. PSA increase or progression in clinical T-classification alone was not considered clinical progression.

Results: 50 patients were included in the study. In total 10 (20%) patients had per definition progression at one year follow-up. Seven patients (7/50 = 14%) had clinical progression based on TRUS-bx. mpMRI identified seven newly emerged PIRADS 4 lesions. Three patients with PIRADS 4 lesions had no sign of TRUS-bx progression, while MRGB revealed significant cancer (Gs 7 (3 + 4) and Gs 8 (3 + 5)). Consequently, seven patients underwent definitive treatment. Of these, six and four had a progression on MRI and TRUS-bx, respectively.

Conclusions: Our study suggests that mpMRI is at least equal to TRUS-bx in detecting progression at one year follow-up in prostate cancer patients undergoing active surveillance.

Keywords:

• Prostate cancer
• active surveillance
• follow-up
• multi-parametric MRI

Acknowledgements

We kindly thank the Karen Elise Jensens Fund, the Arvid Nilssons fund, the Helga and Peter Kornings Fund, the AP Moller fund for the Advancement of Medical Science, and the Danish Cancer Society for financial support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Danish Cancer Society, [10.13039/501100004622].