Despite promising results in malaria-naïve individuals, whole sporozoite (SPZ) vaccine efficacy in malaria-endemic settings has been suboptimal. Vaccine hypo-responsiveness due to previous malaria... Show moreDespite promising results in malaria-naïve individuals, whole sporozoite (SPZ) vaccine efficacy in malaria-endemic settings has been suboptimal. Vaccine hypo-responsiveness due to previous malaria exposure has been posited as responsible, indicating the need for SPZ vaccines of increased immunogenicity. To this end, we here demonstrate a proof-of-concept for altering SPZ immunogenicity, where supramolecular chemistry enables chemical augmentation of the parasite surface with a TLR7 agonist-based adjuvant (SPZ-SAS(CL307)). In vitro, SPZ-SAS(CL307) remained well recognized by immune cells and induced a 35-fold increase in the production of pro-inflammatory IL-6 (p < 0.001). More promisingly, immunization of mice with SPZ-SAS(CL307) yielded improved SPZ-specific IFN-γ production in liver-derived NK cells (percentage IFN-γ+ cells 11.1 ± 1.8 vs. 9.4 ± 1.5%, p < 0.05), CD4+ T cells (4.7 ± 4.3 vs. 1.8 ± 0.7%, p < 0.05) and CD8+ T cells (3.6 ± 1.4 vs. 2.5 ± 0.9%, p < 0.05). These findings demonstrate the potential of using chemical augmentation strategies to enhance the immunogenicity of SPZ-based malaria vaccines. Show less
The introduction of the tethered DROP-IN gamma probe has enabled targeted robot-assisted radioguided prostate cancer (PCa) resection of pelvic sentinel lymph nodes (SLNs) and prostate-specific... Show moreThe introduction of the tethered DROP-IN gamma probe has enabled targeted robot-assisted radioguided prostate cancer (PCa) resection of pelvic sentinel lymph nodes (SLNs) and prostate-specific membrane antigen (PSMA)-positive lesions. While both procedures use Tc-99m-isotopes, the two vary in signal and background intensity. To understand how the different levels of image guidance impact surgical decision-making, computer-vision algorithms are used to extract the DROP-IN probe kinematic form clinical videos. 44 PCa patients undergo SLN (25) and PSMA-targeted (19) resections. PSMA-PET/CT and SPECT/CT create preoperative roadmaps, and intraoperative probe signal intensities are recorded. Using neural network-based software, probe trajectories are extracted from videos to extract multiparametric kinematics and generate decision-making and dexterity scores. PSMA-targeted resections yield significantly lower nodal signal intensities in preoperative SPECT-CT scans (three-fold; p = 0.01), intraoperative probe readouts (eight-fold; p < 0.001), and signal-to-background ratios (SBR; two-fold; p < 0.001). Kinematics assessment reveal that the challenges encounter during PSMA-targeted procedures converted to longer target identification times and increase in probe pick-ups (both five-fold; p < 0.001). This results in a fourfold reduction in the decision-making score (p < 0.001). Reduced signal intensities and intraoperative SBR values negatively affect the impact that image-guided surgery strategies have on the surgical decision-making process. Show less
Background: The occurrence of accidental nerve damage during surgery and the increasing application of image guidance during head-and-neck surgery have highlighted the need for molecular targeted... Show moreBackground: The occurrence of accidental nerve damage during surgery and the increasing application of image guidance during head-and-neck surgery have highlighted the need for molecular targeted nerve-sparing interventions. The implementation of such interventions relies on the availability of nerve-specific tracers. In this paper, we describe the development of a truncated peptide that has an optimized affinity for protein zero (P0), the most abundant protein in myelin. Methods and Materials: Further C- and N-terminal truncation was performed on the lead peptide Cy5-P0(101-125). The resulting nine Cy5-labelled peptides were characterized based on their photophysical properties, P0 affinity, and in vitro staining. These characterizations were combined with evaluation of the crystal structure of P0, which resulted in the selection of the optimized tracer Cy5-P0(112-125). A near-infrared Cy7-functionalized derivative (Cy7-P0(112-125)) was used to perform an initial evaluation of fluorescence-guided surgery in a porcine model. Results: Methodological truncation of the 26-amino-acid lead compound Cy5-P0(101-125) resulted in a size reduction of 53.8% for the optimized peptide Cy5-P0(112-125). The peptide design and the 1.5-fold affinity gain obtained after truncation could be linked to interactions observed in the crystal structure of the extracellular portion of P0. The near-infrared analogue Cy7-P0(112-125) supported nerve illumination during fluorescence-guided surgery in the head-and-neck region in a porcine model. Conclusions: Methodological truncation yielded a second-generation P0-specific peptide. Initial surgical evaluation suggests that the peptide can support molecular targeted nerve imaging. Show less
Wit, E.M.K.; KleinJan, G.H.; Berrens, A.C.; Vliet, R. van; Leeuwen, P.J. van; Buckle, T.; ... ; Poel, H.G. van der 2023
ObjectiveTo determine the diagnostic accuracy of the hybrid tracer indocyanine green (ICG)-Technetium-99 m(Tc-99m)-nanocolloid compared to sequential tracers of Tc-99m-nanocolloid and free-ICG in... Show moreObjectiveTo determine the diagnostic accuracy of the hybrid tracer indocyanine green (ICG)-Technetium-99 m(Tc-99m)-nanocolloid compared to sequential tracers of Tc-99m-nanocolloid and free-ICG in detecting tumor-positive lymph nodes (LN) during primary surgery in prostate cancer (PCa) patients.IntroductionImage-guided surgery strategies can help visualize individual lymphatic drainage patterns and sentinel lymph nodes (SLNs) in PCa patients. For lymphatic mapping radioactive, fluorescent and hybrid tracers are being clinically exploited. In this prospective randomized phase II trial, we made a head-to-head comparison between ICG-Tc-99m-nanocolloid (hybrid group) and Tc-99m-nanocolloid and subsequent free-ICG injection (sequential group).MethodsPCa patients with a >5% risk of lymphatic involvement according to the 2012 Briganti nomogram and planned for prostatectomy were included and randomized (1:1) between ultrasound-guided intraprostatic tracer administration of ICG-Tc-99m-nanocolloid (n = 69) or Tc-99m-nanocolloid (n = 69) 5 h before surgery. Preoperative lymphoscintigraphy and SPECT/CT were performed to define the locations of the SLNs. Additionally, all participants in the sequential group received an injection of free-ICG at time of surgery. Subsequently, all (S)LNs were dissected using fluorescence guidance followed by an extended pelvic lymph node dissection (ePLND). The primary outcome was the total number of surgically removed (S)LNs and tumor-positive (S)LNs.ResultsThe total number of surgically removed (S)LN packages was 701 and 733 in the hybrid and sequential groups, respectively (p = 0.727). The total number of fluorescent LNs retrieved was 310 and 665 nodes in the hybrid and sequential groups, respectively (p < 0.001). However, no statistically significant difference was observed in the corresponding number of tumor-positive nodes among the groups (44 vs. 33; p = 0.470). Consequently, the rate of tumor-positive fluorescent LNs was higher in the hybrid group (7.4%) compared to the sequential group (2.6%; p = 0.002), indicating an enhanced positive predictive value for the hybrid approach. There was no difference in complications within 90 days after surgery (p = 0.78).ConclusionsThe hybrid tracer ICG-Tc-99m-nanocolloid improved the positive predictive value for tumor-bearing LNs while minimizing the number of fluorescent nodes compared to the sequential tracer approach. Consequently, the hybrid tracer ICG-Tc-99m-nanocolloid enables the most reliable and minimal invasive method for LN staging in PCa patients. Show less
Korne, C.M.D.; Lieshout, L. van; Leeuwen, F.W.B. van; Roestenberg, M. 2023
Imaging of parasites is central to diagnosis of many parasitic diseases and has thus far played an important role in the development of antiparasitic strategies. The development of novel imaging... Show moreImaging of parasites is central to diagnosis of many parasitic diseases and has thus far played an important role in the development of antiparasitic strategies. The development of novel imaging technologies has revolutionized medicine in fields other than parasitology and has also opened up new avenues for the visu-alization of parasites. Here we review the role imaging technology has played so far in parasitology and how it may spur further advancement. We point out possibilities to improve current microscopy-based diagnostic methods and how to extend them with radiological imaging modalities. We also highlight in vivo tracking of parasites as a readout for efficacy of new antiparasitic strate-gies and as a source of fundamental insights for rational design. Show less
Barros, H.A. de; Duin, J.J.; Mulder, D.; Noort, V. van der; Noordzij, M.A.; Wit, E.M.K.; ... ; Poel, H.G. van der 2023
Background: Accurate identification of men who harbor nodal metastases is neces-sary to select patients who most likely benefit from whole pelvis radiotherapy (WPRT). Limited sensitivity of... Show moreBackground: Accurate identification of men who harbor nodal metastases is neces-sary to select patients who most likely benefit from whole pelvis radiotherapy (WPRT). Limited sensitivity of diagnostic imaging approaches for the detection of nodal micrometastases has led to the exploration of the sentinel lymph node biopsy (SLNB). Objective: To evaluate whether SLNB can be used as a tool to select pathologically node-positive patients who likely benefit from WPRT. Design, setting, and participants: We included 528 clinically node-negative primary prostate cancer (PCa) patients with an estimated nodal risk of >5% treated between 2007 and 2018. Intervention: A total of 267 patients were directly treated with prostate-only radio-therapy (PORT; non-SLNB group), while 261 patients underwent SLNB to remove lymph nodes directly draining from the primary tumor prior to radiotherapy (SLNB group); pN0 patients were treated with PORT, while pN1 patients were offered WPRT. Outcome measurements and statistical analysis: Biochemical recurrence-free survival (BCRFS) and radiological recurrence-free survival (RRFS) were compared using propensity score weighted (PSW) Cox proportional hazard models. Results and limitations: The median follow-up was 71 mo. Occult nodal metastases were found in 97 (37%) SLNB patients (median metastasis size: 2 mm). Adjusted 7-yr BCRFS rates were 81% (95% confidence interval [CI] 77-86%) in the SLNB group and 49% (95% CI 43-56%) in the non-SLNB group. The corresponding adjusted 7-yr RRFS rates were 83% (95% CI 78-87%) and 52% (95% CI 46-59%), respectively. In the PSW multivariable Cox regression analysis, SLNB was associated with improved BCRFS (hazard ratio [HR] 0.38, 95% CI 0.25-0.59, p < 0.001) and RRFS (HR 0.44, 95% CI 0.28-0.69, p < 0.001). Limitations include the bias inherent to the study's Conclusions: SLNB-based selection of pN1 PCa patients for WPRT was associated efit from the addition of pelvis radiotherapy. This strategy results in a longer dura (c) 2023 The Author(s). Published by Elsevier B.V. on behalf of European Association of Urology. This is an open access article under the CC BY license (http://creativecommons. Show less
Aims: Arthroplasty surgery of the knee and hip is performed in two to three million patients an-nually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiot-ics, and... Show moreAims: Arthroplasty surgery of the knee and hip is performed in two to three million patients an-nually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiot-ics, and implant retention (DAIR) surgery aimed at cleaning the infected prosthesis often fails, subsequently requiring invasive revision of the complete prosthetic reconstruction. Infection-specific imaging may help to guide DAIR. In this study, we evaluated a bacteria -specific hybrid tracer (99mTc-UBI29-41-Cy5) and its ability to visualize the bacterial load on fem-oral implants using clinical -grade image guidance methods. Methods: 99mTc-UBI29-41- Cy5 specificity for Stapylococcus aureus was assessed in vitro using fluorescence confocal imaging. Topical administration was used to highlight the location of S. aureus cul-tured on femoral prostheses using fluorescence imaging and freehand single photon emis-sion CT (fhSPECT) scans. Gamma counting and fhSPECT were used to quantify the bacterial load and monitor cleaning with chlorhexidine. Microbiological culturing helped to relate the imaging findings with the number of (remaining) bacteria. Results: Bacteria could be effectively stained in vitro and on prostheses, irrespective of the presence of biofilm. Infected prostheses revealed bacterial presence on the transition zone between the head and neck, and in the screw hole. Qualitative 2D fluorescence images could be com-plemented with quantitative 3D fhSPECT scans. Despite thorough chlorhexidine treatments, 28% to 44% of the signal remained present in the locations of the infection that were iden-tified using imaging, which included 500 to 2,000 viable bacteria.Conclusion: The hybrid tracer99mTc-UBI29-41-Cy5 allowed effective bacterial staining. Qualitative real -time fluorescence guidance could be effectively combined with nuclear imaging that enables quantitative monitoring of the effectiveness of cleaning strategies. Show less
Aims Arthroplasty surgery of the knee and hip is performed in two to three million patients an-nually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiot-ics, and... Show moreAims Arthroplasty surgery of the knee and hip is performed in two to three million patients an-nually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiot-ics, and implant retention (DAIR) surgery aimed at cleaning the infected prosthesis often fails, subsequently requiring invasive revision of the complete prosthetic reconstruction. Infection-specific imaging may help to guide DAIR. In this study, we evaluated a bacteria -specific hybrid tracer (99mTc-UBI29-41-Cy5) and its ability to visualize the bacterial load on fem-oral implants using clinical -grade image guidance methods.Methods 99mTc-UBI29-41- Cy5 specificity for Stapylococcus aureus was assessed in vitro using fluorescence confocal imaging. Topical administration was used to highlight the location of S. aureus cul-tured on femoral prostheses using fluorescence imaging and freehand single photon emis-sion CT (fhSPECT) scans. Gamma counting and fhSPECT were used to quantify the bacterial load and monitor cleaning with chlorhexidine. Microbiological culturing helped to relate the imaging findings with the number of (remaining) bacteria.Results Bacteria could be effectively stained in vitro and on prostheses, irrespective of the presence of biofilm. Infected prostheses revealed bacterial presence on the transition zone between the head and neck, and in the screw hole. Qualitative 2D fluorescence images could be com-plemented with quantitative 3D fhSPECT scans. Despite thorough chlorhexidine treatments, 28% to 44% of the signal remained present in the locations of the infection that were iden-tified using imaging, which included 500 to 2,000 viable bacteria.Conclusion The hybrid tracer99mTc-UBI29-41-Cy5 allowed effective bacterial staining. Qualitative real -time fluorescence guidance could be effectively combined with nuclear imaging that enables quantitative monitoring of the effectiveness of cleaning strategies. Show less
Background: Surgically induced nerve damage is a common but debilitating side effect. By developing tracers that specifically target the most abundant protein in peripheral myelin, namely myelin... Show moreBackground: Surgically induced nerve damage is a common but debilitating side effect. By developing tracers that specifically target the most abundant protein in peripheral myelin, namely myelin protein zero (P0), we intend to support fluorescence-guided nerve-sparing surgery. To that end, we aimed to develop a dimeric tracer that shows a superior affinity for P0. Methods: Following truncation of homotypic P0 protein-based peptide sequences and fluorescence labeling, the lead compound Cy5-P0(101-125) was selected. Using a bifunctional fluorescent dye, the dimeric Cy5-(P0(101-125))(2) was created. Assessment of the performance of the mono- and bi-labeled compounds was based on (photo)physical evaluation. This was followed by in vitro assessment in P0 expressing Schwannoma cell cultures by means of fluorescence confocal imaging (specificity, location of binding) and flow cytometry (binding affinity; K-D). Results: Dimerization resulted in a 1.5-fold increase in affinity compared to the mono-labeled counterpart (70.3 +/- 10.0 nM vs. 104.9 +/- 16.7 nM; p = 0.003) which resulted in a 4-fold increase in staining efficiency in P0 expressing Schwannoma cells. Presence of two targeting vectors also improves a pharmacokinetics of labeled compounds by lowering serum binding and optical stability by preventing dye stacking. Conclusions: Dimerization of the nerve-targeting peptide P0(101-125) proves a valid strategy to improve P0 targeting. Show less
Berrens, A.C.; Oosterom, M.N. van; Slof, L.J.; Leeuwen, F.W.B. van; Poel, H.G. van der; Buckle, T. 2022
Many pathogens blunt immune responses because they lack immunogenic structural features, which typically results in disease. Here, we show evidence suggesting that pathogen immunogenicity can be... Show moreMany pathogens blunt immune responses because they lack immunogenic structural features, which typically results in disease. Here, we show evidence suggesting that pathogen immunogenicity can be chemically enhanced. Using supramolecular host-guest chemistry, we complexed onto the surface of a poorly immunogenic bacterium (Staphylococcus aureus) a TLR7 agonist-based adjuvant. "Adjuvanted" bacteria were readily recognized by macrophages and induced a more pro-inflammatory immunophenotype. Future applications of this concept could yield treatment modalities that bolster the immune system's response to pathogenic microbes. Show less
Korne, C.M. de; Schuijlenburg, R. van; Sijtsma, J.C.; Bes, H.M. de; Baalbergen, E.; Azargoshasb, S.; ... ; Roestenberg, M. 2022
Antibodies can prevent malaria by neutralizing the infectious Plasmodium falciparum sporozoites (SPZ) before they establish an infection in the liver. Circumsporozoite protein (CSP), the most... Show moreAntibodies can prevent malaria by neutralizing the infectious Plasmodium falciparum sporozoites (SPZ) before they establish an infection in the liver. Circumsporozoite protein (CSP), the most abundant surface protein of SPZ is the leading candidate for passive (and subunit) immunization approaches against malaria. Comprehensive assessment of the parasite-inhibitory capacity of anti-CSP monoclonal antibodies (mAbs) is an important step in advancing CSP-based immunization strategies. In this study, we employed a quantitative imaging-based motility assay to quantify the effect of anti-CSP mAbs on SPZ motility, both in vitro and in human skin. Our assay provided a quantitative measure of mAb parasite-inhibitory capacity through measurement of the half-maximal motility inhibitory concentration (IC50M) value for anti-CSP mAbs (IC50M 2A10: 24 nM, IC50M 3SP2: 71 nM). We found a sevenfold discrepancy between the IC50M and the binding saturation concentration measured by ELISA, possibly related to the observed shedding of CSP-mAb complexes during SPZ movement. In a subset of SPZ (5%), in vitro motility was unaffected by the presence of 2A10 while 3SP2 was able to completely block movement. In our ex vivo skin explant model, SPZ proved less susceptible to anti-CSP mAbs compared to SPZ in an in vitro environment. By quantitatively assessing motility, we created a valuable tool that can be used for comprehensive assessment of anti-CSP mAb potency. Insight that will help deepen our understanding of anti-CSP mAb potency and guide selection of the most promising anti-CSP mAbs for downstream clinical development. Show less
Image-to-patient registration in navigated mandibular surgery is complex due to the mobile nature of the mandible compared with other craniofacial bones. As a result, surgical navigation is rarely... Show moreImage-to-patient registration in navigated mandibular surgery is complex due to the mobile nature of the mandible compared with other craniofacial bones. As a result, surgical navigation is rarely employed in the mandibular region. This systematic review provides an overview of the different registration methods that are used for surgical navigation of the mandible. A systematic search was performed in the MEDLINE Ovid, Scopus, and Embase databases on March 25, 2021. Search terms included synonyms for mandibular surgery, surgical navigation, and registration methods. Articles about navigated mandibular surgery, where the registration method was explicitly mentioned, were included. The database search yielded a total of 2952 articles, from which 81 articles remained for analysis. Four main registration methods were identified: point registration, surface registration, hybrid registration, and computer vision-based registration. The mobility of the mandible is accounted for by either keeping the mandible in a fixed position during preoperative imaging and surgery, or by tracking the mandibular movements. Although different registration methods are available for navigated mandibular surgery, there is always a trade-off between accuracy, registration time, usability, and invasiveness. Future studies should focus on testing the different methods in larger patient studies and should report the registration accuracy. Show less
Background: Extended pelvic nodal dissection (ePLND) represents the gold standard for nodal staging in prostate cancer (PCa). Prostate-specific membrane antigen (PSMA) radioguided surgery (RGS)... Show moreBackground: Extended pelvic nodal dissection (ePLND) represents the gold standard for nodal staging in prostate cancer (PCa). Prostate-specific membrane antigen (PSMA) radioguided surgery (RGS) could identify lymph node invasion (LNI) during robotassisted radical prostatectomy (RARP).Objective: To report the planned interim analyses of a phase 2 prospective study (NCT04832958) aimed at describing PSMA-RGS during RARP.Design, setting, and participants: A phase 2 trial aimed at enrolling 100 patients with intermediate- or high-risk cN0cM0 PCa at conventional imaging with a risk of LNI of >5% was conducted. Overall, 18 patients were enrolled between June 2021 and March 2022. Among them, 12 patients underwent PSMA-RGS and represented the study cohort.Surgical procedure: All patients received Ga-68-PSMA positron emission tomography (PET)/magnetic resonance imaging; Tc-99m-PSMA-I&S was synthesised and administered intravenously the day before surgery, followed by single-photon emission computed tomography/computed tomography. A Drop-In gamma probe was used for in vivo measurements. All positive lesions (count rate >= 2 compared with background) were excised and ePLND was performed.Measurements: Side effects, perioperative outcomes, and performance characteristics of robot-assisted PSMA-RGS for LNI were measured.Results and limitations: Overall, four (33%), six (50%), and two (17%) patients had intermediate-risk, high-risk, and locally advanced PCa. Overall, two (17%) patients had pathologic nodal uptake at PSMA PET. The median operative time, blood loss, and length of stay were 230 min, 100 ml, and 5 d, respectively. No adverse events and intraoperative complications were recorded. One patient experienced a 30-d complication (ClavienDindo 2; 8.3%). Overall, three (25%) patients had LNI at ePLND. At per-region analyses on 96 nodal areas, sensitivity, specificity, positive predictive value, and negative predictive value of PSMA-RGS were 63%, 99%, 83%, and 96%, respectively. On a per-patient level, sensitivity, specificity, positive predictive value, and negative predictive values of PSMA-RGS were 67%, 100%, 100%, and 90%, respectively.Conclusions: Robot-assisted PSMA-RGS in primary staging is a safe and feasible procedure characterised by acceptable specificity but suboptimal sensitivity, missing micrometastatic nodal disease.Patient summary: Prostate-specific membrane antigen radioguided robot-assisted surgery is a safe and feasible procedure for the intraoperative identification of nodal metastases in cN0cM0 prostate cancer patients undergoing robot-assisted radical prostatectomy with extended pelvic lymph node dissection. However, this approach might still miss micrometastatic nodal dissemination. (c) 2022 The Author(s). Published by Elsevier B.V. on behalf of European Association of Urology. Show less
Pouget, J.P.; Konijnenberg, M.; Eberlein, U.; Glatting, G.; Gabina, P.M.; Herrmann, K.; ... ; EANM Radiobiology Working Group 2022
Molecular imaging technologies are increasingly used to diagnose, monitor, and guide treatment of i.e., cancer. In this review, the current status and future prospects of the use of molecular... Show moreMolecular imaging technologies are increasingly used to diagnose, monitor, and guide treatment of i.e., cancer. In this review, the current status and future prospects of the use of molecular imaging as an instrument to help realize precision surgery is addressed with focus on the main components that form the conceptual basis of intraoperative molecular imaging. Paramount for successful interventions is the relevance and accessibility of surgical targets. In addition, selection of the correct combination of imaging agents and modalities is critical to visualize both microscopic and bulk disease sites with high affinity and specificity. In this context developments within engineering/imaging physics continue to drive the growth of image-guided surgery. Particularly important herein is enhancement of sensitivity through improved contrast and spatial resolution, features that are critical if sites of cancer involvement are not to be overlooked during surgery. By facilitating the connection between surgical planning and surgical execution, digital surgery technologies such as computer-aided visualization nicely complement these technologies. The complexity of image guidance, combined with the plurality of technologies that are becoming available, also drives the need for evaluation mechanisms that can objectively score the impact that technologies exert on the performance of healthcare professionals and outcome improvement for patients. Show less
Rietbergen, D.D.D.; Gennep, E.J. van; KleinJan, G.H.; Donswijk, M.; Olmos, R.A.V.; Rhijn, B.W. van; ... ; Leeuwen, F.W.B. van 2022
Rationale: In muscle-invasive bladder cancer (MIBC), lymph node invasion has proven to be an independent predictor of disease recurrence and cancer-specific survival. We evaluated the feasibility... Show moreRationale: In muscle-invasive bladder cancer (MIBC), lymph node invasion has proven to be an independent predictor of disease recurrence and cancer-specific survival. We evaluated the feasibility of targeting the sentinel node (SN) for biopsy in MIBC patients using the hybrid tracer indocyanine green (ICG)-Tc-99m-nanocolloid for simultaneous radioguidance and fluorescence guidance. Methods: Twenty histologically confirmed cN0M0 MIBC patients (mean age, 63.3 years; range, 30-82 years), scheduled for radical cystectomy with SN biopsy and extended pelvic lymph node dissection (ePLND), were prospectively included. Twelve patients were operated on following neoadjuvant chemotherapy. The patients received lymphoscintigraphy as well as SPECT/CT after 4 transurethral injections of ICG-Tc-99m-nanocolloid (mean, 208 MBq; range, 172-229 MBq) around the tumor/scar in the detrusor muscle of the bladder on the day before radical cystectomy. Sentinel node resection was performed under radioguidance and fluorescence guidance. Results: Nineteen patients could be analyzed. On preoperative imaging, SNs could be identified in 10 patients (53%; mean, 1.6 SN/patient), which revealed drainage pathways outside the ePLND in 20% of the patients. Interesting to note is that 2 patients (10%) with preoperative nonvisualization displayed fluorescent and radioactive SNs during surgery. Location of the primary tumor near the left lateral side of the bladder seemed to be a factor for nonvisualization. Nodal harvesting with ePLND varied among patients (mean, 23.3). Histopathology confirmed tumor-positive nodes in 4 (21%) of all patients. In the 2 patients where an SN could be identified, the ePLND specimens were tumor-negative. All patients with tumor-positive nodes had advanced disease (stage III). Conclusion: Sentinel node biopsy in bladder cancer using the hybrid tracer ICG-Tc-99m-nanocolloid is feasible, and preoperative imaging is predictive for the ability to perform SN biopsy in 83% of the patients who displayed an SN. In patients with a successful preoperative SN mapping using lymphoscintigraphy and SPECT/CT, the intraoperative SN guidance and detection were effective, even outside the ePLND area. As such, this study underscores the critical role that preoperative imaging plays in challenging image-guided surgery applications. Show less
Purpose Navigational strategies create a scenario whereby percutaneous needle-based interventions of the liver can be guided using both pre-interventional 3D imaging datasets and dynamic... Show morePurpose Navigational strategies create a scenario whereby percutaneous needle-based interventions of the liver can be guided using both pre-interventional 3D imaging datasets and dynamic interventional ultrasound (US). To score how such technologies impact the needle placement process, we performed kinematic analysis on different user groups. Methods Using a custom biopsy phantom, three consecutive exercises were performed by both novices and experts (n = 26). The exercise came in three options: (1) US-guidance, (2) US-guidance with pre-interventional image-registration (US + Reg) and (3) US-guidance with pre-interventional image-registration and needle-navigation (US + Reg + Nav). The traveled paths of the needle were digitized in 3D. Using custom software algorithms, kinematic metrics were extracted and related to dexterity, decision making indices to obtain overall performance scores (PS). Results Kinematic analysis helped quantifying the visual assessment of the needle trajectories. Compared to US-guidance, novices yielded most improvements using Reg (PSavg(US) = 0.43 vs. PSavg(US+Reg) = 0.57 vs. PSavg(US+Reg+Nav) = 0.51). Interestingly, the expert group yielded a reversed trend (PSavg(US) = 0.71 vs PSavg(US+Reg) = 0.58 vs PSavg(US+Reg+Nav) = 0.59). Conclusion Digitizing the movement trajectory allowed us to objectively assess the impact of needle-navigation strategies on percutaneous procedures. In particular, our findings suggest that these advanced technologies have a positive impact on the kinematics derived performance of novices. Show less
Azargoshasb, S.; Boekestijn, I.; Roestenberg, M.; KleinJan, G.H.; Hage, J.A. van der; Poel, H.G. van der; ... ; Leeuwen, F.W.B. van 2022
Purpose Surgical fluorescence guidance has gained popularity in various settings, e.g., minimally invasive robot-assisted laparoscopic surgery. In pursuit of novel receptor-targeted tracers, the... Show morePurpose Surgical fluorescence guidance has gained popularity in various settings, e.g., minimally invasive robot-assisted laparoscopic surgery. In pursuit of novel receptor-targeted tracers, the field of fluorescence-guided surgery is currently moving toward increasingly lower signal intensities. This highlights the importance of understanding the impact of low fluorescence intensities on clinical decision making. This study uses kinematics to investigate the impact of signal-to-background ratios (SBR) on surgical performance.Methods Using a custom grid exercise containing hidden fluorescent targets, a da Vinci Xi robot with Firefly fluorescence endoscope and ProGrasp and Maryland forceps instruments, we studied how the participants' (N=16) actions were influenced by the fluorescent SBR. To monitor the surgeon's actions, the surgical instrument tip was tracked using a custom video-based tracking framework. The digitized instrument tracks were then subjected to multi-parametric kinematic analysis, allowing for the isolation of various metrics (e.g., velocity, jerkiness, tortuosity). These were incorporated in scores for dexterity (Dx), decision making (DM), overall performance (PS) and proficiency. All were related to the SBR values.Results Multi-parametric analysis showed that task completion time, time spent in fluorescence-imaging mode and total pathlength are metrics that are directly related to the SBR. Below SBR 1.5, these values substantially increased, and handling errors became more frequent. The difference in Dx and DM between the targets that gave SBR <1.50 and SBR> 1.50, indicates that the latter group generally yields a 2.5-fold higher Dx value and a threefold higher DM value. As these values provide the basis for the PS score, proficiency could only be achieved at SBR> 1.55.Conclusion By tracking the surgical instruments we were able to, for the first time, quantitatively and objectively assess how the instrument positioning is impacted by fluorescent SBR. Our findings suggest that in ideal situations a minimum SBR of 1.5 is required to discriminate fluorescent lesions, a substantially lower value than the SBR 2 often reported in literature. Show less
