Feasibility of Robotic Partial Prostatectomy for Isolated Anterior Prostate Cancer

Introduction: Ablative focal therapy for localized prostate cancer (PCa) is becoming more prevalent. In 2017, Villers et al reported 17 partial prostatectomies for low- and intermediate-risk PCa. They had excellent postoperative continence and potency, but their positive surgical margin (PSM) rate was 53%.1 In 2021, Sood et al described their “precision prostatectomy” in 88 patients, which involves surgical excision of the PCa lesion and >90% of the surrounding prostatic tissue. The prostatic capsule and contralateral seminal vesicle/vas deferens are left intact. They showed great urinary and sexual functional outcomes. Overall PSM rate was 42%, of which the majority were focal (<3 mm) and Gleason 3 + 3 = 6. In their series, biochemical recurrence was rare and there were no patients with metastasis at mean 36-month follow-up.2,3 To our knowledge, these are the only two clinical studies examining focal therapy through surgical excision (i.e., partial prostatectomy) for PCa. In this study, we describe our initial experience with robot-assisted partial prostatectomy (RAPP) for isolated anterior PCa lesions with an associated video. Materials and Methods: We identified five patients with isolated anterior low- to intermediate-risk PCa. None of these patients had baseline erectile dysfunction or incontinence. All cases selected for RAPP underwent MRI with a systematic and targeted biopsy, revealing PCa isolated to the anterior MRI lesion. The pathology report of the preoperative targeted biopsies was Gleason 3 + 3 = 6 PCa in one patient and Gleason 3 + 4 = 7 PCa in four patients. Patient consent was obtained. During surgery, the PCa lesion was marked by ultrasound-guided transperineal needle placement. Robotically, we developed the space of Retzius, opened endopelvic fascia, ligated the dorsal venous complex, and excised the lesion with electrocautery. We used the needles as boundary guides and our knowledge of the MRI to excise the lesion. In four cases, extravesical fat was sutured over the defect. In one case, entry into the urethra could not be avoided, so the bladder neck was closed over this area. Results: Mean patient age was 72.6 years. Mean preoperative prostate specific antigen (PSA) was 4.4 ng/mL. Mean lesion size was 2.0 cm. Mean operative time was 129.2 minutes. Mean follow-up was 9.4 (standard deviation 7.9) months. Final pathology report demonstrated Gleason 3 + 4 PCa in three patients and Gleason 4 + 3 in two. A positive margin was noted in three cases (60%), and two of these were focal (<3 mm). No patients have reported changes from preoperative urinary and sexual function. Mean postoperative PSA was 1.2 ng/mL (73% reduction) at first follow-up. There were no intra- or postoperative complications. Conclusions: For patients who desire preservation of functional outcomes and who understand the oncologic trade-offs associated with focal therapy, RAPP is a technically feasible intervention for isolated anterior PCa. More patients and longer follow-up are needed to establish the oncologic efficacy of RAPP, specifically the long-term impact of microscopic PSM after RAPP on residual and/or recurrent clinically significant PCa. Improved intraoperative margin localization will help to improve the adoption of RAPP as a viable alternative to ablative focal therapy. Patient Consent Statement: Authors have received and archived patient consent for video recording/publication in advance of video recording of procedure. No competing financial interests exist. Runtime of video: 7 mins 7 secs