“Prostate Cartography”: Targeted &systematic perineal stereotactic prostate biopsy using the BiopSee®platformin locating and re-locating prostate cancer foci and facilitating focal treatment

¹Schwerfeld-Bohr J; ¹Hohenhorst JL; ¹Musch, M; ¹Pailliart, A; ¹Vanberg, M; ¹Krege, S; ¹Kröpfl. D; ²Sakas, G

1 Department of Urology, Pediatric Urology and Urologic Oncology, Kliniken Essen-Mitte, Essen, Germany2 MedCom GmbH, Darmstadt, Germany

Introduction:The 2011 inaugurated novel BiopSee® prostate biopsy system integrates, by means of the fusion, the pre-interventional data based on mpMRI prostate examination with peri-interventional ultrasound. It allows precise stereotactic navigated guidance of the biopsy needle and the combination of targeted and systematic biopsies. Furthermore it provides a high tumour detection rate, the “cartographic localisation” of prostate cancer foci, the assessment of the tumour extension in the prostate, the relationship of the tumour to adjacent structures and the retrievable reproducible documentation. More than this, a focal treatment e.g. by irreversible electroporation can be navigated with this system.

Method:We regard “prostate cartography” being a combination of targeted biopsies on mpMRI suspicious locations with systematic sampling of the whole prostate (16-24 cores) as superior alternative to prostate mapping, involving 60-80 cores. The location of all needles is documented and positive cores within the prostate in transversal and longitudinal sections are marked. All cores are dyed on their proximal extension with formalin resistant day, which allows precise assessment of the relationship of the tumour found to adjacent structures. After pathology, the location and extend of CA-findings on the geographic position of the corresponding cores are marked (see Fig.1). To verify the accuracy of this procedure, we compared the tumour location in mpMRI, positive cores and final histopathology of patients who underwent radical prostatectomy. We visually distinguished good, intermediate and poor match groups, meaning good as matching in all three parameters, intermediate in 2 (final histopathology to either mpMRI or biopsy). (see Fig.2)

Results:Between 2014 and 2015 we cartographed tumour foci in 100 treated patients. 65 of those underwent radical prostatectomy; final histopathological findings of this cases could be used as references. According to the criteria mentioned above, we found 80% (n=52) as good matching, 15.4 % (n=10) as intermediate matching, and 4.6 % (n=3) as poor matching cases (see Fig.2). Of those 65 patients, 26 would have been suitable for the option of focal treatment according to criteria of the IRE-prostate study. Of those, 77 % (n=20) were good matching, 15.4 % (n=4) intermediate , and 7.6% (n=2) poor matching.

Conclusion:Due to our experiences we believe that “prostate cartography” facilitates and provides a necessary precondition for focal therapy approaches. It allows precise localisation and treatment of the diagnosed tumour and can exclude the presence of significant multi-focal disease in the rest of the gland.Furthermore, using a navigator as the Biopsee ® System, the foci can be re-localized and precisely targeted, allowing the treated area to be as small as possible without missing malignant area.

a. mpMRI indentifies and localizessuspicious lesions

b. Prostate-samples taken by biopsee© systemby targeting lesions and involving whole gland as random-biopsies

c. Cores are embedded seperately,apical end is marked with dye

d. Precise histopathological report containing tumour volume and distances to base and apex ofcancer cells within the core togehter eith the report from biopsee © procedure delivers exact information about the foci‘s localisation within the prostate=> prostate cartographye. Using this information, in case of focal treatment option

tumour foci can be re-localized accurately andneedels‘ positioning can be navigated by biopsee © platform

Fig. 1: Algorythm of prostate cartography

Fig. 2: example of poor (left) and good match (right) in all 3 parameters:mpMRI, biopsee-result and histology after prostatectomy

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Literature:1. Hadaschik et al. „A novel

stereotactic prostate biopsy system integrating pre-interventional magnetic resonance imaging and live ultrasound fusion“, Jurol Vol 186, 2214-2220, Dec. 2011

2. “A Multi-Center Randomized Single-Blind Two Arm Intervention Study Evaluating Irreversible Electroporation for the Ablation of Prostate Cancer”-study protocol, De La Rosette 2014