Login to Access Video or Poster Abstract: MP03-14
Sources of Funding: None

Introduction

Focal therapy of prostate cancer might be an alternative to radical prostatectomy (RP) in treating patients with low- or intermediate-risk disease. Since MRI alone might not be sufficient in tumor location, template perineal biopsy is performed. To investigate the accuracy of locating a tumor focus we compared the results of multiparametric (mp)MRI and perineal stereotactic MRI-based TRUS-guided fusion biopsy (SFB) with the histopathology of the radical prostatectomy specimen.

Methods

All patients who underwent a SFB in our hospital with positive findings of tumor that lead to a RP from 08/2012 to 07/2016 were included. MRI of the prostate was performed multiparametric and evaluated according to PI-RADS-classification. Lesions were marked 3-dimensionally by the radiologist. The SFB was performed using the BiopSee ©-platform. Lesion-targeted and random biopsies were taken. The cores’ positions in the prostate were recorded. Cores were embedded separately, the basal tips got marked with dye. In the histopathological report the location of tumor in the core in terms of apical, mid or base location was mentioned. Thereby tumor-foci location could be projected on the prostate in 3 dimensions. In the prostatectomy-specimen (whole mount step section) the tumor’s location was reported by the pathologist. A single investigator determined the conformity of all three results visually: good (all 3 results matching), intermediate (MRI or biopsy matching with prostatectomy’s result), and poor conformity (no match at all).

Results

128 patients could be included. 103 patients (79.8 %) showed good, 17 (13.2 %) intermediate, and 8 (6.2 %) poor conformity of the tumor’s location. According to oncological criteria (PSA< 15 ng/ml, Gleason max. 7a, cT1-2a, unilateral disease) 67 patients (52%) would have been suitable for focal therapy. From these 50 (75%)would have been in good conformity, 12 (18%)in intermediate and 5(7,%) in poor conformity to the prostatectomy result.

Conclusions

These results show a high accuracy in locating the tumor by SFB. This could give a good base for a precise focal therapy that is not only sufficient in terms of treating all tumor cells but also in sparing surrounding structures by avoiding over-estimation of the extensions of he foci.

Funding

None