• Home
• Preliminary Program

14:00   Breast / Oncology Chair: Harald Groen 14:00 15 mins Feasibility of Image-guided Navigation with Electromagnetic Tracking During Robot-assisted Sentinel Node Biopsy: A Prospective Study L. Aguilera Saiz, W.J. Heerink, H.C. Groen, M.A.J. Hiep, H.G. van der Poel, E.M.K. Wit, J.A. Nieuwenhuijzen, T.A. Roeleveld, A.N. Vis, M..L. Donswijk, P.J. van Leeuwen, T.J.M. Ruers Abstract: Image-guided surgical navigation (IGSN) can enhance surgical precision and safety. The expansion of minimally invasive surgery has increased the demand for integration of these navigation systems into robot-assisted surgery. Our objective was to evaluate the integration of electromagnetic tracking with IGSN in robot-assisted sentinel lymph node biopsy (SLNB). We conducted a prospective feasibility study to test the use of IGSN in SLNB. In total, 25 patients scheduled for SLNB at The Netherlands Cancer Institute were included (March 2022 to March 2023). SLNB using IGSN was performed using a standardised technique with a da Vinci robot (Intuitive Surgical, Sunnyvale, CA, USA) in four-arm configuration. Feasibility was determined as the percentage of sentinel nodes (SNs) successfully identified via IGSN. Successful SN resection was defined as SNs correctly localised via navigation and validated ex vivo with a gamma probe. Surgeon feedback on the robot-assisted IGSN workflow was evaluated using the System Usability Scale (SUS). In accordance with the protocol, the first five patients were used for workflow optimisation, and the subsequent 20 patients were included in the analysis. IGSN led to successful identification of 91% (50/55) of the SNs. There were no complications associated with navigation. The surgeon feedback (SUS) was 60.9, with lowest scores reported for the user interface and workflow integration. In conclusion, IGSN during robot-assisted surgery was feasible and safe. The technique allowed identification and removal of predefined small pelvic lymph nodes. General significance: Imaging-guided navigation in robot-assisted prostate surgery is feasible, safe, accurate and effective. 14:15 15 mins In the spotlight: 4D dynamic contrast-enhanced dedicated breast CT. A phantom study for the validation of a novel imaging technique Liselot Goris, Juan Pautasso, Mikhail Mikerov, Koen Michielsen, Ioannis Sechopoulos Abstract: Four-dimensional dynamic contrast-enhanced dedicated breast CT (4D DCE-bCT) is a novel imaging technique that aims to characterize breast tumors by monitoring the wash-in and wash-out of an iodinated contrast agent over time. This functional information could enhance tumor diagnosis and treatment. However, before clinical implementation, optimal acquisition and reconstruction protocols must be determined. Therefore, we developed a breast perfusion and tumor phantom capable of simulating clinically relevant time-intensity curves (TICs) with known ground truth for validating time-dependent iodine concentration estimates in 4D DCE-bCT. The phantom includes a 3D-printed breast, filled with olive oil to simulate fatty tissue, a fibroglandular tissue insert to mimic background parenchymal enhancement partially filled with sodium-alginate beads, and a gyroid-structured tumor phantom to simulate tumoral microvasculature. Programmable syringe pumps enable contrast and water flow, and an in-line spectroscopy system monitors iodine concentrations at the phantom’s entrance and exit. This system uses an LED light source (400-600 nm) and photodetectors to measure the transmitted light. The relationship between thirteen iodine concentrations (0-6 mg I/mL) and light transmission was tested, and the system’s repeatability and accuracy were determined. Thereafter, the entire phantom was used for 4D DCE-bCT imaging, with a programmed wash-in time of 100 s, to reach a maximum concentration of 6 mg I/mL, and wash-out over 200 s. The time-dependent iodine concentration estimates captured by the bCT were compared to those from the optical system. The optical system showed a strong correlation between iodine concentrations and light transmission with a root-mean-square error of 0.007. Repeated measurements showed a relative standard deviation of 0.1%. The accuracy measurements exhibited a mean (± std. dev.) error of 0.008 (± 0.07) mg I/mL. Optical TICs captured wash-in up to 6.08 mg I/mL in 100 s and wash-out over 200 s. In contrast, 4D DCE-bCT acquisitions of the phantom showed wash-in up to 4.2 mg I/mL and wash-out over the same time period. The discrepancy highlights potential areas for improvement in the bCT reconstruction process. Overall, our breast phantom provides a valuable platform for validating the imaging process, marking a significant step toward clinical implementation of 4D DCE-bCT. 14:30 15 mins A Preliminary Study of the Pulse Oximetry for Early Breast Cancer Detection Bangyu Lan, Ellen Juffermans, Izad Tamadon, Kenan Niu Abstract: Breast cancer is a critical health issue globally, with a high incidence rate especially in the Netherlands, where around one of eight women develop the disease during the lifetime. Early detection could enhance the survival rate. However, current methodologies like the mammography have the problems of low accessibility, high cost, and less reliability. This study proposed a novel screening method using an array of pulse oximeters, a potentially low-cost but highly accessible strategy, to detect the early signs of breast cancer through the hypoxia measurement. This approach used the phenomenon that the early-stage breast cancer cells consume increased amounts of oxygen for growth, thereby changing the oxygen levels in the blood. In this study, a simple setup including six pulse oximetry sensors was developed. It was compared with a commercial finger pulse oximeter on the wrist for basic operational verification. Next, a phantom model was created to simulate breast tissues. This was used to test whether the pulse oximetry sensors could detect the low oxygen levels caused by breast cancer. The experimental design tested various sensor configurations and performed comparative analyses to establish a baseline of the accuracy and reliability for the sensors under different oxygen-level conditions. The results showed that the pulse oximetry setup could detect variations of oxygen saturation, which might correlate with the hypoxic conditions from the breast tumours. However, effectively using it for breast screening is still challenging due to the deep location and specific nature of low oxygen levels of breast cancer, which differ from the surface-level measurements typically using this technology. Future research will adapt the proposed design to directly measure the oxygen level from the breast tissues. In addition, the next step will also focus on enhancing sensor sensitivity and specificity for the breast tissue hypoxia and validating in a clinical setting. This study explored an innovative use of pulse oximetry for early breast cancer detection. It paved the way for developing more accessible and less invasive breast cancer screening methods, potentially increasing the early detection rates and survival rates. 14:45 15 mins Phantom Studies for Photoacoustic Imaging for Thyroid Nodule Diagnosis Nan Lubbers, Veltman Jeroen, Manohar Srirang Abstract: Background: The increased use of imaging techniques has led to increased detection of (incidental) thyroid nodules. Thyroid nodules require risk assessment since 10-15% are malignant [1]. In current clinical practice, ultrasound (US) imaging is the first step in the diagnostic process [2]. A main limitation is that nodules might show non-definitive radiographic features, necessitating invasive diagnostic procedures to rule out cancer, despite a low risk of malignancy [1,3]. Photoacoustic imaging (PAI) takes advantage of the contrast of optical imaging and the resolution of US imaging, and excels at visualising tissue vasculature [4]. By leveraging the different vascular architecture of malignant tissue as a biomarker [5], PAI could complement US and play an important role in risk assessment, improving the detection and diagnosis of malignant thyroid nodules [2]. Aim: Various studies towards thyroid imaging with PAI have already been performed [6–8]. However, due to current challenges such as reflection artefacts, limited imaging depth and spectral colouring, more research is needed to advance PAI for the thyroid towards clinical practice. This research aims to investigate which and how metrics obtained from PAI can be included in the US-based thyroid risk stratification system to improve the diagnostic process. A vital step towards this goal is the performance of phantom and in vivo studies to address the mentioned challenges. Methods & Results: Early versions of two test objects have been developed to evaluate the resolution of the Imagio Breast Imaging System (Seno Medical Instruments, San Antonio, TX, USA) and its ability to detect and visualise (micro)vasculature. One test object is a phantom with a leaf skeleton embedded in a tissue-mimicking material, based on a phantom from Jose et al. [9]. Furthermore, a channel phantom has been developed with channels of different diameters, positioned at various depths. The channels can be filled with a blood-mimicking fluid to mimic simplified vessels of different diameters. Significance: The experimental results will be essential in improving and advancing the reconstruction methods of the system. Furthermore, the experience gained regarding the phantoms can be used to improve the two test objects and develop more advanced thyroid phantoms. References 1. Uppal N, Collins R, James B. Thyroid nodules: Global, economic, and personal burdens. Front Endocrinol (Lausanne). 2023;14. 2. Wang Z, Yang F, Zhang W, Xiong K, Yang S. Towards in vivo photoacoustic human imaging: Shining a new light on clinical diagnostics. Fundamental Research. 2023; 3. Mavromati M, Saiji E, Demarchi MS, Lenoir V, Seipel A, Kuczma P, et al. Unnecessary thyroid surgery rate for suspicious nodule in the absence of molecular testing. Eur Thyroid J. 2023;12(6). 4. Yang X, Xiang L. Photoacoustic imaging of prostate cancer. J Innov Opt Health Sci. 2017 Jun 13;10(04):1730008. 5. Yaseen MA, Ermilov SA, Brecht HP, Su R, Conjusteau A, Fronheiser M, et al. Optoacoustic imaging of the prostate: development toward image-guided biopsy. J Biomed Opt. 2010;15(2):21310. 6. Noltes ME, Bader M, Metman MJH, Vonk J, Steinkamp PJ, Kukačka J, et al. Towards in vivo characterization of thyroid nodules suspicious for malignancy using multispectral optoacoustic tomography. Eur J Nucl Med Mol Imaging. 2023 Jul 1;50(9):2736–50. 7. Kim J, Park B, Ha J, Steinberg I, Hooper SM, Jeong C, et al. Multiparametric Photoacoustic Analysis of Human Thyroid Cancers In Vivo. Cancer Res. 2021 Sep 15;81(18):4849–60. 8. Roll W, Markwardt NA, Masthoff M, Helfen A, Claussen J, Eisenblätter M, et al. Multispectral Optoacoustic Tomography of Benign and Malignant Thyroid Disorders: A Pilot Study. J Nucl Med. 2019;60(10):1461–6. 9. Jose J, Willemink RGH, Steenbergen W, Slump CH, van Leeuwen TG, Manohar S. Speed-of-sound compensated photoacoustic tomography for accurate imaging. Med Phys. 2012 Dec 1;39(12):7262–71. 15:00 15 mins Virtual surgical planning in DIEP flap breast reconstructions: How to plan DIEP flap volume? Eline Karstanje, Judith Waldner - Troost, Ruud Verdaasdonk, Hinne Rakhorst, Rob van Doremalen Abstract: Background: One in three women with breast cancer is treated with a mastectomy. A mastectomy can lead to a lowered quality of life, mostly related to a lower body image, for which asymmetry is an important factor. After a mastectomy, preferred treatment is reconstruction with autologous tissue, specifically the deep inferior epigastric perforator (DIEP) flap. The challenge is to obtain symmetry. Reducing asymmetry after DIEP flap breast reconstruction can lead to a reduction of revisions, an improved body image and quality of life. Using pre-operative virtual surgical planning to determine the volume of the DIEP flap, could aid in improving the symmetry. This study focusses on a virtual surgical planning for DIEP flap volume using CTA scans and a desired volume. Methods: A semi-automatic algorithm has been developed that computes the delineation for the abdominal incision based on landmarks. The algorithm iteratively attempts to reach the desired volume. We aim to validate he computed volume through a prospective feasibility study (n=14), with the aim of a maximum deviation of 10% compared to weight of the extracted tissue. The computed delineation is transferred to the patient using a 3D-printed patient-specific guide. Results: The first four cases showed a difference in weight of less than 10% for all patients. The computed delineation was adjusted in two cases. Conclusion: Preliminary data indicates that virtual surgical planning for DIEP flap volume transferred using a 3D-printed guide could predict the volume within a 10% deviation. After the prospective study is finished we hope to present significant evidence.

end %-->