3-T multiparametric MRI characteristics of prostate cancer patients suspicious for biochemical recurrence after primary focal cryosurgery (hemiablation).

Introduction: We aimed to report on multiparametric MRI (mpMRI) characteristics of post-primary focal cryosurgery (PFC) patients suspected of biochemical recurrence (BCR) by the Phoenix criteria.

Methods: We retrospectively reviewed all patients at our institution who had undergone PFC. Prostate-specific antigen nadir was determined using 2 or more post-PFC values. Suspicion of BCR was determined using the Phoenix criteria (nadir + 2 ng/ml). At the discretion of the physician, pre-and post-PFC 3-T mpMRIs were obtained and in a few cases biopsies were performed.

Results: Ninety (58.4%) of 154 consecutive patients who underwent PFC were included in our analysis and had a median (range) age and prostate volume of 66.5 (48-82) years and 40.5 (16-175) ml, respectively. Of those suspected of BCR (37/90, 41.1%), with a median time to BCR of 19.9 (7.0-38.5) months, 27 patients (73.0%) underwent a post-PFC mpMRI. Twenty-two (81.5%) of these mpMRIs were found with 24 suspicious lesions. A considerable number (9/24, 37.5%) of these lesions were located in the central gland of the prostate. Seven of 24 lesions exhibited adverse mpMRI characteristic; 4 (16.7%) had capsular contact, 2 (8.2%) showed frank extracapsular extension, and 1 (4.2%) showed seminal vesicle invasion. Five (45.5%) of 11 patients with positive post-PFC mpMRIs were positive on biopsy (4/5, 80% were clinically significant prostate cancer).

Conclusion: Post-PFC mpMRI, at Phoenix suspicion of BCR, may help identify a significant number of patients failing post-PFC.