Background: It has been proven that intraoperative prostate-specific membrane antigen (PSMA)-targeted radioguidance is valuable for the detection of prostate cancer (PCa) lesions during open... Show moreBackground: It has been proven that intraoperative prostate-specific membrane antigen (PSMA)-targeted radioguidance is valuable for the detection of prostate cancer (PCa) lesions during open surgery. Rapid extension of robot-assisted, minimally invasive surgery has increased the need to make PSMA-radioguided surgery (RGS) robot-compliant.Objective: To evaluate whether the miniaturized DROP-IN gamma probe facilitates translation of PSMA-RGS to robotic surgery in men with recurrent PCa.Design, setting, and participants: This prospective feasibility study included 20 patients with up to three pelvic PCa recurrences (nodal or local) on staging PSMA positron emission tomography (PET) after previous curative-intent therapy.Surgical procedure: Robot-assisted PSMA-RGS using the DROP-IN gamma probe was carried out 19-23 h after intravenous injection of (99m)technetium PSMA-Investigation & Surgery (Tc-99m-PSMA-I&S).Measurements: The primary endpoint was the feasibility of robot-assisted PSMA-RGS. Secondary endpoints were a comparison of the radioactive status (positive or negative) of resected specimens and final histopathology results, prostate-specific antigen (PSA) response following PSMA-RGS, and complications according to the Clavien-Dindo classification.Results and limitations: Using the DROP-IN probe, 19/21 (90%) PSMA-avid lesions could be resected robotically. On a per-lesion basis, the sensitivity and specificity of robot-assisted PSMA-RGS was 86% and 100%, respectively. A prostate-specific antigen (PSA) reduction of >50% and a complete biochemical response (PSA <0.2 ng/ml) were seen in 12/18 (67%) and 4/18 (22%) patients, respectively. During follow-up of up to 15 mo,* Corresponding author. Department of Urology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, Amsterdam 1066 CX, The Netherlands. Tel. +31 205126988. E-mail address: h.d.barros@nki.nl (H.A. de Barros) Show less
Background: With the rise of prostate-specific membrane antigen (PSMA) radioguided surgery, which is performed using a microdosing regime, demand for visual target confirmation via fluorescence... Show moreBackground: With the rise of prostate-specific membrane antigen (PSMA) radioguided surgery, which is performed using a microdosing regime, demand for visual target confirmation via fluorescence guidance is growing. While proven very effective for radiotracers, microdosing approaches the detection limit for fluorescence imaging. Thus, utility will be highly dependent on the tracer performance, the sensitivity of the fluorescence camera used, and the degree of background signal. Using a porcine model the ability to perform robot-assisted radical prostatectomy under fluorescence guidance using the bimodal or rather hybrid PSMA tracer (Tc-99m-EuK-(SO3)Cy5-mas(3)) was studied, while employing the tracer in a microdosing regime. This was followed by ex vivo evaluation in surgical specimens obtained from prostate cancer patients. Results: T-50% blood and T-50% urine were reached at 85 min and 390 min, in, respectively, blood and urine. Surgical fluorescence imaging allowed visualization of the prostate gland based on the basal PSMA-expression in porcine prostate. Together, in vivo visualization of the prostate and urinary excretion suggests at least an interval of > 7 h between tracer administration and surgery. Confocal microscopy of excised tissues confirmed tracer uptake in kidney and prostate, which was confirmed with PSMA IHC. No fluorescence was detected in other excised tissues. Tumor identification based on ex vivo fluorescence imaging of human prostate cancer specimens correlated with PSMA IHC. Conclusion: Intraoperative PSMA-mediated fluorescence imaging with a microdosing approach was shown to be feasible. Furthermore, EuK-(SO3)Cy5-mas(3) allowed tumor identification in human prostate samples, underlining the translational potential of this novel tracer. Trial registration Approval for use of biological material for research purposes was provided by the Translational Research Board of the Netherlands Cancer Institute-Antoni van Leeuwenhoek hospital (NKI-AvL) under reference IRBm19-273 (22/10/2019). Show less
Background: Since the introduction of prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging, isolated local recurrence after radical prostatectomy (RP) can be... Show moreBackground: Since the introduction of prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging, isolated local recurrence after radical prostatectomy (RP) can be delineated accurately.Objective: To describe and evaluate surgical technique, biochemical response, and therapy-free survival (TFS) after salvage surgery in patients with local recurrence in the seminal vesicle bed.Design, setting, and participants: We retrospectively assessed 40 patients treated with open salvage surgery in two centres (11/2014-02/2020). All patients presented with biochemical recurrence (BCR) after RP with a singular local recurrence at PSMA PET imaging. Thirty-three (82.5%) patients received previous salvage radiation therapy.Surgical procedure: Open salvage surgery with PSMA radioguidance.Measurements: Prostate-specific antigen (PSA) nadir and percentage of patients with complete biochemical response (cBR) without further treatment (PSA < 0.2 ng/ml) after 6-16 wk were assessed. BCR-free survival and TFS were calculated using Kaplan-Meier estimates. Clavien-Dindo complications were evaluated.Results and limitations: Prior to salvage surgery, median PSA was 0.9 ng/ml (interquartile range [IQR]: 0.5-1.7 ng/ml). Postoperatively, median PSA nadir was 0.1 ng/ml (IQR: 0-0.4 ng/ml). In 31 (77.5%) patients, cBR was observed. During the median follow-up of 24.4 months, 22 (55.0%) patients experienced BCR and 12 (30.0%) received further therapy. At 1 yr of follow-up, BCR-free survival rate was 62.2% and TFS rate was 88.3%. Three (7.5%) Clavien-Dindo grade III complications were observed. The main limitations are the retrospective design, short follow-up, and lack of a control group.Conclusions: Salvage surgery of local recurrence within the seminal vesicle bed is feasible. It may present an opportunity in selected, locally recurrent patients to prolong BCR-free survival and increase TFS. Further studies are needed to confirm our findings.Patient summary: We looked at the outcomes from prostate cancer patients with locally recurrent disease after radical prostatectomy and radiotherapy. We found that surgery in well-selected patients may be an opportunity to prolong treatment-free survival. (C) 2020 European Association of Urology. Published by Elsevier B.V. All rights reserved. Show less
Background: The DROP-IN gamma probe was introduced to overcome the restricted manoeuvrability of traditional laparoscopic gamma probes. Through enhanced manoeuvrability and surgical autonomy, the... Show moreBackground: The DROP-IN gamma probe was introduced to overcome the restricted manoeuvrability of traditional laparoscopic gamma probes. Through enhanced manoeuvrability and surgical autonomy, the DROP-IN promotes the implementation of radioguided surgery in the robotic setting.Objective: To confirm the utility and safety profile of the DROP-IN gamma probe and to perform a comparison with the traditional laparoscopic gamma probe and fluorescence guidance.Design, setting, and participants: Twenty-five prostate cancer patients were scheduled for a robot-assisted sentinel lymph node (SN) procedure, extended pelvic lymph node dissection, and prostatectomy at a single European centre.Surgical procedure: After intraprostatic injection of indocyanine green (ICG)-Tc-99m-nanocolloid (n = 12) or Tc-99m-nanocolloid + ICG (n = 13), SN locations were defined using preoperative imaging. Surgical excision of SNs was performed under image guidance using the DROP-IN gamma probe, the traditional laparoscopic gamma probe, and fluorescence imaging.Measurements: Intraoperative SN detection was assessed for the different modalities and related to anatomical locations. Patient follow-up was included (a median of 18 mo).Results and limitations: Overall, 47 SNs were pursued in vivo by the DROP-IN gamma probe, of which 100% were identified. No adverse events related to its use were observed. In vivo fluorescence imaging identified 91% of these SNs. The laparoscopic gamma probe identified only 76% of these SNs, where the detection inaccuracies appeared to be related to specific anatomical regions.Conclusions: Owing to improved manoeuvrability, the DROP-IN probe yielded improved SN detection rates compared with the traditional gamma probe and fluorescence imaging. These findings underline that the DROP-IN technology provides a valuable tool for radioguided surgery in the robotic setting.Patient summary: Radioguided robot-assisted surgery with the novel DROP-IN gamma probe is feasible and safe. It enables more efficient intraoperative identification of sentinel lymph nodes than can be achieved with a traditional laparoscopic gamma probe. The use of the DROP-IN probe in combination with fluorescence imaging allows for a complementary optical confirmation of node localisations. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of European Association of Urology. Show less
Maurer, T.; Robu, S.; Schottelius, M.; Schwamborn, K.; Rauscher, I.; Bereg, N.S. van den; ... ; Eibere, M. 2019
Background: Prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) can visualize metastatic lesions in recurrent prostate cancer (PC). However, reliable... Show moreBackground: Prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) can visualize metastatic lesions in recurrent prostate cancer (PC). However, reliable identification of small and/or atypically localized lesions during salvage surgery procedures is challenging.Objective: To describe the technique, feasibility, and short-term outcomes of (99m)Technetium (Tc-99m)-based PSMA-radioguided surgery (Tc-99m-PSMA-RGS) for removal of recurrent PC lesions.Design, setting, and participants: Thirty-one consecutive patients with evidence of recurrent PC on Ga-68-PSMA N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl] ethylenediamine-N,N'-diacetic acid (Ga-68-PSMA-11) PET after radical prostatectomy undergoing Tc-99m-PSMA-RGS were retrospectively analyzed.Surgical procedure: Salvage surgery with intraoperative radioguidance using a gamma probe was performed after intravenous application of Tc-99m-PSMA investigation and surgery (mean activity 571 MBq, mean time to surgery 19.7 h).Measurements: Radioactive rating (positive vs negative) of resected tissue was compared with the findings of postoperative histopathological analysis. Best prostate-specific antigen (PSA) response without additional treatment was determined after 8-16 wk postoperatively. Biochemical recurrence- and treatment-free survival was evaluated.Results and limitations: In total,132 tissue specimens were removed, of which 58 showed metastatic involvement on histological analysis. On a specimen basis, radioactive rating yielded a sensitivity of 83.6% (confidence interval [CI]: 70.9-91.5%), a specificity of 100%, and an accuracy of 93.0% (CI: 85.5-96.7%). With Tc-99m-PSMA-RGS, all lesions visualized on preoperative Ga-68-PSMA-11 PET could be removed. Moreover, Tc-99m-PSMA-RGS detected additional metastases as small as 3 mm in two patients. Thirteen patients suffered from complications related to surgery (Clavien-Dindo grade 1: 12 patients; grade 3a: one patient). A PSA reduction below 0.2 ng/ml was observed in 20 patients. Thirteen patients remained biochemical recurrence free after a median follow-up of 13.8 (range: 4.6-18.3) mo. Twenty patients continued to be treatment free after a median follow-up of 12.2 (range: 5.5-18.3) mo.Conclusions: As a new technique for surgical guidance, Tc-99m-PSMA-RGS is feasible, and has been proved to be of high value for successful intraoperative detection and removal of metastatic lesions in PC patients scheduled for salvage surgery. Its long-term impact on outcome has to be evaluated.Patient summary: In this report, we evaluated a novel technique to identify metastatic lesions intraoperatively in patients with recurrent prostate cancer to facilitate surgical removal. After intravenous injection of radioactive molecules that specifically bind to prostate cancer cells that show increased expression of the prostate-specific membrane antigen, we were able to detect and remove these metastatic lesions during surgery. Following salvage surgery, 41.9% of patients remained biochemical recurrence free (median follow-up of 13.8 mo) and 64.5% continued to be treatment free (median follow-up of 12.2 mo). (C) 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved. Show less
