BackgroundIndocyanine green near-infrared fluorescence bowel perfusion assessment has shown its potential benefit in preventing anastomotic leakage. However, the surgeon's subjective visual... Show moreBackgroundIndocyanine green near-infrared fluorescence bowel perfusion assessment has shown its potential benefit in preventing anastomotic leakage. However, the surgeon's subjective visual interpretation of the fluorescence signal limits the validity and reproducibility of the technique. Therefore, this study aimed to identify objective quantified bowel perfusion patterns in patients undergoing colorectal surgery using a standardized imaging protocol.MethodA standardized fluorescence video was recorded. Postoperatively, the fluorescence videos were quantified by drawing contiguous region of interests (ROIs) on the bowel. For each ROI, a time-intensity curve was plotted from which perfusion parameters (n = 10) were derived and analyzed. Furthermore, the inter-observer agreement of the surgeon's subjective interpretation of the fluorescence signal was assessed.ResultsTwenty patients who underwent colorectal surgery were included in the study. Based on the quantified time-intensity curves, three different perfusion patterns were identified. Similar for both the ileum and colon, perfusion pattern 1 had a steep inflow that reached its peak fluorescence intensity rapidly, followed by a steep outflow. Perfusion pattern 2 had a relatively flat outflow slope immediately followed by its plateau phase. Perfusion pattern 3 only reached its peak fluorescence intensity after 3 min with a slow inflow gradient preceding it. The inter-observer agreement was poor-moderate (Intraclass Correlation Coefficient (ICC): 0.378, 95% CI 0.210-0.579).ConclusionThis study showed that quantification of bowel perfusion is a feasible method to differentiate between different perfusion patterns. In addition, the poor-moderate inter-observer agreement of the subjective interpretation of the fluorescence signal between surgeons emphasizes the need for objective quantification. Show less
Boekestijn, I.; Oosterom, M.N. van; Dell'Oglio, P.; Velden, F.H.P. van; Pool, M.; Maurer, T.; ... ; Leeuwen, F.W.B. van 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
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
Michi, Verduijn, as it either provided additional information about perfusion or confirmed the clinical assess-ment. Our pilot study showed a significant decrease of FN in patients undergoing an... Show moreMichi, Verduijn, as it either provided additional information about perfusion or confirmed the clinical assess-ment. Our pilot study showed a significant decrease of FN in patients undergoing an ABR with a DIEP when near-infrared fluorescence imaging was used to assess flap perfusion. This study provides a standardized working protocol for near-infrared fluorescence imaging. In the future, large multicenter studies should focus on the quantification of near-infrared fluorescence imaging. (c) 2021 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Else-vier Ltd. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ ) 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
A clear margin is an important prognostic factor for most solid tumours treated by surgery. Intraoperative fluorescence imaging using exogenous tumour-specific fluorescent agents has shown... Show moreA clear margin is an important prognostic factor for most solid tumours treated by surgery. Intraoperative fluorescence imaging using exogenous tumour-specific fluorescent agents has shown particular benefit in improving complete resection of tumour tissue. However, signal processing for fluorescence imaging is complex, and fluorescence signal intensity does not always perfectly correlate with tumour location. Raman spectroscopy has the capacity to accurately differentiate between malignant and healthy tissue based on their molecular composition. In Raman spectroscopy, specificity is uniquely high, but signal intensity is weak and Raman measurements are mainly performed in a point-wise manner on microscopic tissue volumes, making whole-field assessment temporally unfeasible. In this review, we describe the state-of-the-art of both optical techniques, paying special attention to the combined intraoperative application of fluorescence imaging and Raman spectroscopy in current clinical research. We demonstrate how these techniques are complementary and address the technical challenges that have traditionally led them to be considered mutually exclusive for clinical implementation. Finally, we present a novel strategy that exploits the optimal characteristics of both modalities to facilitate resection with clear surgical margins. 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
In this thesis the additional value of targeted Next-Generation Sequencing was described in order to optimize the diagnostic process of patients with a suspect pancreatic lesion. Furthermore,... Show moreIn this thesis the additional value of targeted Next-Generation Sequencing was described in order to optimize the diagnostic process of patients with a suspect pancreatic lesion. Furthermore, several imaging techniques are described to visualize pancreatic cancer or colorectal liver metastases prior to surgery and during surgery. By better visualization of the tumor extent optimal treatment plans can be proposed and radical resections can be accomplished. Show less
The aim of this thesis was to investigate the feasibility of multimodal visualization techniques to observe adult stem cells, in particular HFBSCs, in the living animal. Due to the novelty of... Show moreThe aim of this thesis was to investigate the feasibility of multimodal visualization techniques to observe adult stem cells, in particular HFBSCs, in the living animal. Due to the novelty of HFBSCs in the field of inner ear research, a series of proof-of-principle experiments have been undertaken to investigate if these cells can undergo neuronal differentiation, tolerate genetic modification with lentiviral constructs containing the genes coding for reporter proteins, and tolerate subsequent loading with nanoparticles in vitro. In addition, it was of importance to examine if HFBSCs do integrate into modiolar tissue and if they can be visualized in the cochlea of the guinea pig. Lastly, we performed in vivo studies to investigate the ototoxic effect of ouabain in guinea pigs and the behavior of HFBSCs in mice with traumatic brain injury. Show less
For years, pancreatic cancer had a dismal prognosis with a long term survival of around 5%. Since the centralization of pancreatic cancer surgery and the introduction of systemic chemotherapy... Show moreFor years, pancreatic cancer had a dismal prognosis with a long term survival of around 5%. Since the centralization of pancreatic cancer surgery and the introduction of systemic chemotherapy with FOLFIRINOX, the median overall survival increased to around 20%. Radical tumor-margin free resection provides the patient with the best potential chance for cure. However, due to late onset of symptoms, the majority of patients present with inoperable disease. These patients can benefit from neoadjuvant therapy, or palliative chemotherapy. During clinical practice, this means that decision-making before and during surgery is critical to select the most optimal primary treatment modality. Currently, conventional imaging modalities lack sensitivity to detect small metastatic lesions, and are unable to visualize treatment response on neoadjuvant therapy. Tumor-specific molecular imaging in the form of fluorescence and photoacoustic imaging aids the surgeon to accurately recognize and resect malignant tissues in real-time during surgery. This thesis focuses on the challenges a surgeon faces during pancreatic cancer treatment, and the potential improvements that could be achieved by the use of tumor-specific imaging. In addition, the regulatory aspects of clinical translation of tumor-specific optical imaging agents are addressed. Show less
KleinJan, G.H.; Werkhoven, E. van; Berg, N.S. van den; Karakullukcu, M.B.; Zijlmans, H.J.M.A.A.; Hage, J.A. van der; ... ; Leeuwen, F.W.B. van 2018
Surgery is the cornerstone of curative treatment of many malignancies. However, incomplete resections and avoidable iatrogenic damage during surgery increase morbidity and mortality rates in... Show moreSurgery is the cornerstone of curative treatment of many malignancies. However, incomplete resections and avoidable iatrogenic damage during surgery increase morbidity and mortality rates in patients. Although advances in preoperative imaging modalities have improved adequate patient selection and surgical planning, during procedures surgeons rely mainly on inspection and palpation. It is often very difficult to distinguish between fibrotic, inflamed, or malignant tissues [1]. Inspection and palpation are highly subjective and have low sensitivity for detecting cancer, especially for subcentimeter lesions [2].Near-infrared fluorescence (NIRF) imaging is a technique that enhances contrast of certain structures during surgery and thereby improves their detectability [3, 4]. It uses targeted and non-targeted fluorescent tracers in combination with dedicated NIRF imaging systems. These tracers consist of fluorophores; molecules that emit fluorescence with a certain wavelength upon excitation by an external light source. These fluorescence signals can be captured by an imaging system optimized for that specific wavelength. Especially near-infrared wavelengths (i.e. 700-900 nm) have excellent characteristics, including relatively high tissue penetration capacity and low tissue autofluorescence, and are therefore preferably used for clinical applications [5]. NIRF imaging can identify targets covered by up to 10 mm tissue.Non-targeted fluorescent tracers such as indocyanine green (ICG; emission peak 830 nm) and methylene blue (emission peak 700 nm) have been available for several decades, albeit for different indications. Their off-label use is safe and cheap, which contributed significantly to clinical experience and enabled NIRF imaging research to get momentum (chapter 2 and 3). NIRF imaging systems could be developed simultaneously with improved fluorophores. In general, NIRF-guided surgery has the potential to increase radical resection rates, while reducing avoidable iatrogenic damage. Both non-targeted as well as targeted tracers will be discussed, followed by the future perspectives of NIRF imaging.Non-specific Show less
The aim of the work included in this PhD thesis was to explore the diverse application possibility of using NIR fluorescent probes with specific properties to visualize and characterize cancer and... Show moreThe aim of the work included in this PhD thesis was to explore the diverse application possibility of using NIR fluorescent probes with specific properties to visualize and characterize cancer and cell death. In this thesis, we mainly focus on optical imaging and its application, both at microscopic and macroscopic level. Because we believe optical imaging in particular represents a technology that has unique potential to exploit further our knowledge in preclinical research. First, we imaged breast tumors and their metastases using combinations of four NIR fluorescent probes that possess different optical imaging properties. Then, we studied two different NIR fluorescent probes, PSVue and a heat shock protein-90 alkylator (NIR fluorescent conjugate of GSAO), which can be used to non-invasively imaging cell death with different optical modules in a mouse model of traumatic brain injury. Next, we employed the NIR fluorescently tagged GSAO as a biomarker for monitoring breast cancer cell death after chemotherapy. Moreover, we provides a general discussion about the advantages and the challenging that the state-of-art optical imaging is facing and shares some future prospective. This thesis ends with a summary that outlined the major findings of studies described in different chapters and explored the clinical implications. Show less
