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Simple Summary: Computer tomography (CT)-guided percutaneous core biopsies are currently the gold standard in diagnostic procedures for patients with bone lesions of unknown kind. Morphologic targeting can be challenging, especially for small and/or heterogeneous lesions. Hereby, targeting inaccuracies may lead to misdiagnosis or inconclusive histopathology. This increases the need for repeat biopsies, which is associated with an accompanying increase in healthcare costs, delay in diagnosis and treatment, and decrease in quality of life. Interventional molecular image guidance has the potential to refine lesion localization and personalize the biopsy strategy. By using 2-deoxy-2-18F-fluoro-D-glucose-positron emission tomography (18F-FDG-PET)/CT to support the identification of heterogeneous lesions or lesions without radiographic substrate, we show that molecular image guidance helps to increase the procedural success rate by 16%. Computer tomography (CT)-guided percutaneous core biopsies are currently the gold standard in diagnostic procedures for patients with bone lesions of unknown kind. CT-guided biopsies can lead to misdiagnosis or repetition of biopsies in case of small or heterogeneous lesions. We hypothesize that molecular image guidance could be used to optimize the biopsy strategy, by supporting the detection of heterogeneous lesions or lesions without radiographic substrate. To evaluate this hypothesis, we investigated if and how the addition of 2-deoxy-2-18F-fluoro-D-glucose-positron emission tomography (18F-FDG-PET)/CT could augment routine CT-guided bone biopsies. To this end, 106 patients who underwent a CT-guided bone biopsy between April 2019 and April 2020, obtained from either a vertebral or peripheral bone, were included. Patients were divided into 2 groups: 36 patients received an 18F-FDG-PET/CT scan prior to their CT-guided bone biopsy (PET group), while 70 patients only had a morphological CT scan (CT group). Histopathology was used to categorize biopsies into five subgroups (inconclusive, benign, malignant or infectious disease, or normal tissue). In the PET group, the number of conclusive biopsies was significantly higher compared to the CT group (N = 33/36 (92%) versus N = 53/70 (76%); p < 0.05). Furthermore, the number of first-try biopsies was lower in the PET group compared to the CT group (1.9 vs. 2.54, p = 0.051). In conclusion, 18F-FDG-PET/CT imaging significantly increased the success rate of first-try CT-guided bone biopsies by showing less inconclusive biopsies and misdiagnosis. [ABSTRACT FROM AUTHOR]

Background: Lymph node (LN) metastasis is a relevant predictor for survival in patients with a.o. penile cancer (PeCa), malignant melanoma. The sentinel node (SN) procedure comprises targeted resection of the first tumour-draining SNs. Here, the hybrid tracer indocyanine green (ICG)-99mTc-nanocolloid has been used for several years to combine optical and nuclear detection. Recently, the resource of the nanocolloid precursor stopped production and the precursor was replaced by a different but chemically comparable colloid, nanoscan. Our aim was to study the performance of ICG-99mTc-nanoscan compared to ICG-99mTc-nanocolloid from a nuclear and surgical perspective. Methods: Twenty-four patients with either PeCa or head-and-neck (H&N) melanoma and scheduled for a SN procedure were included. The initial group (n = 11) received ICG-99mTc-nanocolloid until no longer available; the second group (n = 13) received ICG-99mTc-nanoscan. Tracer uptake was assessed on lymphoscintigraphy and single-photon emission (SPECT). Intraoperatively, SNs were identified using gamma tracing and fluorescence imaging. Ex vivo (back-table) measurements were conducted to quantify the fluorescence emissions. Chemical analysis was performed to compare the ICG assembly on both precursors. Results: The mean tracer uptake in the SNs was similar for ICG-99mTc-nanocolloid (2.2 ± 4.3%ID) and ICG-99mTc-nanoscan (1.8 ± 2.6%ID; p = 0.68). 3 SNs (interquartile range (IQR) 3–4) were detected on lymphoscintigraphy in PeCa patients receiving ICG-99mTc-nanoscan compared to 2 SNs (IQR 2–3) in PeCa patients receiving ICG-99mTc-nanocolloid (p = 0.045), no differences were observed in H&N patients. Back-table measurements of resected SNs revealed a lower total fluorescence intensity in the ICG-99mTc-nanoscan group (24*109 arbitrary units (A.U) IQR 1.6*109–14*109 in the ICG-99mTc-nanocolloid group versus 4.6*109 A.U. IQR 2.4*109–42*109 in the ICG-99mTc-nanoscan group, p = 0.0054). This was consistent with a larger degree of "stacked" ICG observed in the nanoscan formulation. No tracer-related adverse events were reported. Conclusions: Based on this retrospective analysis, we can conclude that ICG-99mTc-nanoscan has similar capacity for SN identification as ICG-99mTc-nanocolloid and can safely be implemented in SN procedures. [ABSTRACT FROM AUTHOR]

(1) Background: Up to 50% of patients with colorectal cancer either have synchronous colorectal liver metastases (CRLM) or develop CRLM over the course of their disease. Surgery and thermal ablation are the most common local treatment options of choice. Despite development and improvement in local treatment options, (local) recurrence remains a significant clinical problem. Many different imaging modalities can be used in the follow-up after treatment of CRLM, lacking evidence-based international consensus on the modality of choice. In this systematic review, we evaluated 18F-FDG-PET-CT performance after surgical resection, thermal ablation, radioembolization, and neoadjuvant and palliative chemotherapy based on current published literature. (2) Methods: A systematic literature search was performed on the PubMed database. (3) Results: A total of 31 original articles were included in the analysis. Only one suitable study was found describing the role of 18F-FDG-PET-CT after surgery, which makes it hard to draw a firm conclusion. 18F-FDG-PET-CT showed to be of additional value in the follow-up after thermal ablation, palliative chemotherapy, and radioembolization. 18F-FDG-PET-CT was found to be a poor to moderate predictor of pathologic response after neoadjuvant chemotherapy. (4) Conclusions: 18F-FDG-PET-CT is superior to conventional morphological imaging modalities in the early detection of residual disease after thermal ablation and in the treatment evaluation and prediction of prognosis during palliative chemotherapy and after radioembolization, and 18F-FDG-PET-CT could be considered in selected cases after neoadjuvant chemotherapy and surgical resection. [ABSTRACT FROM AUTHOR]

Background *Equal contributors.Planar bone scintigraphy (PBS) is often advocated for diagnosing occult scaphoid fractures. PBS is a sensitive diagnostic modality, but lacks specificity, which may result in over-diagnosis. Purpose To examine, in a pilot study, the potential additional value of single photon emission computed tomography (SPECT) combined with low dose computed tomography (CT) for the diagnosis of an occult scaphoid fracture. Material and Methods Ten patients that underwent combined PBS and SPECT/CT for a clinically suspected scaphoid fracture, where radiographs could not detect a fracture, were included in this pilot study. The PBS and SPECT/CT results were independently and separately evaluated by a nuclear physician for scaphoid fractures and other injuries. Results PBS was positive for a scaphoid fracture in four patients and diagnosed three other fractures. SPECT/CT showed five scaphoid fractures and one other fracture. SPECT/CT – PBS had discrepant results in three patients. In two patients PBS diagnosed a trapezoid fracture where SPECT/CT showed a scaphoid fracture. The other patient was diagnosed with a scaphoid fracture on PBS, whereas SPECT/CT showed bone bruise of other carpal bones. Conclusion SPECT/CT has the potential to be more accurate than PBS as it uses anatomical information of the CT to discriminate between the scaphoid, other carpal bones, and bone bruises. Larger studies with an independent reference standard are needed for confirmation of these preliminary data. [ABSTRACT FROM AUTHOR]

Liver cancer is a leading cause of cancer deaths worldwide. Surgical resection of superficial hepatic lesions is increasingly guided by the disrupted bile excretion of the fluorescent dye indocyanine green (ICG). To extend this approach to deeper lesions, a dedicated bimodal tracer that facilitates both fluorescence guidance and radioguidance was developed. Methods: A tracer comprising a methylated cyanine-5 (Cy5) fluorescent dye and a mercaptoacetyltriserine chelate ( h HEPATO-Cy5) was synthesized and characterized. Cellular uptake and excretion were evaluated in hepatocyte cultures (2-dimensional culture and in vitro lesion model), using a fluorescent bile salt, MitoTracker dye, and methylated Cy5 as a control. After radiolabeling, the pharmacokinetics of 99m Tc- h HEPATO-Cy5 were assessed in mice over 24 h (percentage injected dose and percentage injected dose per gram of tissue, SPECT/CT imaging and fluorescence imaging). The ability to provide real-time fluorescence guidance during robot-assisted hepatobiliary surgery was evaluated in a porcine model using ICG as a reference. Results: The unique molecular signature of h HEPATO-Cy5 promotes hepatobiliary excretion. In vitro studies on hepatocytes showed that where methylated Cy5 remained internalized, h HEPATO-Cy5 showed fast clearance (10 min) similar to that of fluorescent bile salt. In vivo use of 99m Tc- h HEPATO-Cy5 in mice revealed liver accumulation and rapid biliary clearance. The effectiveness of bile clearance was best exemplified by the 2-orders-of-magnitude reduction in count rate for the gallbladder ( P = 0.008) over time. During hepatobiliary surgery in a porcine model, h HEPATO-Cy5 enabled fluorescence-based lesion identification comparable to that of ICG. Conclusion: The bimodal 99m Tc- h HEPATO-Cy5 provides an effective means to identify liver lesions. Uniquely, it helps overcome the shortcomings of fluorescence-only approaches by allowing for an extension to in-depth radioguidance., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Introduction: This study investigates the incidence of extrahepatic perfusion and incomplete hepatic perfusion at intraoperative methylene blue testing and on postoperative nuclear imaging in patients undergoing hepatic arterial infusion pump (HAIP) chemotherapy., Methods: The first 150 consecutive patients who underwent pump implantation in the Netherlands were included. All patients underwent surgical pump implantation with the catheter in the gastroduodenal artery. All patients underwent intraoperative methylene blue testing and postoperative nuclear imaging ( 99m Tc-Macroaggregated albumin SPECT/CT) to determine perfusion via the pump., Results: Patients were included between January-2018 and December-2021 across eight centers. During methylene blue testing, 29.3% had extrahepatic perfusion, all successfully managed intraoperatively. On nuclear imaging, no clinically relevant extrahepatic perfusion was detected (0%, 95%CI: 0.0-2.5%). During methylene blue testing, 2.0% had unresolved incomplete hepatic perfusion. On postoperative nuclear imaging, 8.1% had incomplete hepatic perfusion, leading to embolization in only 1.3%., Conclusion: Methylene blue testing during pump placement for intra-arterial chemotherapy identified extrahepatic perfusion in 29.3% of patients, but could be resolved intraoperatively in all patients. Postoperative nuclear imaging found no clinically relevant extrahepatic perfusion and led to embolization in only 1.3% of patients. The role of routine nuclear imaging after HAIP implantation should be studied in a larger cohort., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Surgery and biomedical imaging encompass a big share of the medical-device market. The ever-mounting demand for precision surgery has driven the integration of these two into the field of image-guided surgery. A key-question herein is how imaging modalities can guide the surgical decision-making process. Through performance-based design, chemists, engineers, and doctors need to build a bridge between imaging technologies and surgical challenges., Areas-Covered: This perspective article highlights the complementary nature between the technological design of an image-guidance modality and the type of procedure performed. The specific roles of the involved professionals, imaging technologies, and surgical indications are addressed., Expert-Opinion: Molecular-image-guided surgery has the potential to advance pre-, intra- and post-operative tissue characterization. To achieve this, surgeons need the access to well-designed indication-specific chemical-agents and detection modalities. Hereby, some technologies stimulate exploration ('go'), while others stimulate caution ('stop'). However, failing to adequately address the indication-specific needs rises the risk of incorrect tool employment and sub-optimal surgical performance. Therefore, besides the availability of new technologies, market growth is highly dependent on the practical nature and impact on real-life clinical care. While urology currently takes the lead in the widespread implementation of image-guidance technologies, the topic is generic and its popularity spreads rapidly within surgical oncology.

Prostate-specific membrane antigen (PSMA) PET is used to select patients with recurrent prostate cancer for metastasis-directed therapy. A surgical approach can be achieved through radioguided surgery (RGS), using a Drop-In γ-probe that traces lesions that accumulate the radioactive signal. With the aim of guiding patient selection for salvage surgery, we studied the correlation between the SUV max of lesions on preoperative PSMA PET/CT and their intraoperative counts/s measured using the Drop-In γ-probe. Methods: A secondary analysis based on the prospective, single-arm, and single-center feasibility study was conducted (NCT03857113). Patients ( n = 29) with biochemical recurrence after previous curative-intent therapy and a maximum of 3 suggestive lesions within the pelvis on preoperative PSMA PET/CT were included. Patients treated with androgen deprivation therapy within 6 mo before surgery were excluded. All patients received an intravenous injection of 99m Tc-PSMA-I&S 1 d before surgery. Radioguidance was achieved using a Drop-In γ-probe. Correlation was determined using the Spearman rank correlation coefficient (ρs). Subgroup analysis was based on the median SUV max Results: In total, 33 lesions were visible on the PSMA PET/CT images, with a median overall SUV max of 6.2 (interquartile range [IQR], 4.2-9.7). RGS facilitated removal of 31 lesions. The median Drop-In counts/s were 134 (IQR, 81-220) in vivo and 109 (IQR, 72-219) ex vivo. The intensity of the values correlated with SUV max (ρs = 0.728 and 0.763, respectively; P < 0.001). Subgroup analysis based on median SUV max in the group with an SUV max of less than 6 showed no statistically significant correlation with the numeric signal in vivo (ρs = 0.382; P = 0.221) or the signal-to-background-ratio (ρs = 0.245; P = 0.442), whereas the group with an SUV max of 6 or more showed respective statistically significant positive correlations (ρs = 0.774 [ P < 0.001] and ρs = 0.647 [ P = 0.007]). Conclusion: Our findings indicate that there is a direct relation between SUV max on PSMA PET/CT and the readout recorded by the surgical Drop-In probe, thereby indicating that SUV max can be used to select patients for PSMA RGS. For more definitive subgroup definitions for treatment recommendations, further studies are necessary to validate the present findings., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Introduction: In early-stage vulvar squamous cell carcinoma (VSCC) a sentinel lymph node (SLN) procedure is regarded successful if at least one SLN is removed with minimal residual radioactivity. An inguinofemoral lymphadenectomy is considered if not all SLNs visualized on lymphoscintigraphy can be found, with subsequent increased morbidity. We correlated lymphoscintigraphy findings with surgical outcome and groin recurrence with focus on number of SLNs found., Methods: This study concerns a retrospective cohort of 171 women treated for early-stage VSCC who underwent a SLN procedure between 2000 and 2020. The risk of groin recurrence was compared after either a successful or complete SLN procedure, i.e. removal of all SLNs that were visualized on lymphoscintigraphy., Results: In 13 (7.6%) groins of 171 patients SLN visualization on lymphoscintigraphy failed. In 230 of the 246 (93.5%) groins in which a SLN was visualized, at least one SLN was found during surgery. In 224 of the 246 (91.1%) groins the SLN procedure was regarded either successful (n = 14) or complete (n = 210). An isolated groin recurrence was documented in 5 out of 192 (2.6%, 95%-CI; 0.34 to 4.9) SLN-negative groins after a median follow-up of 47.0 months. All recurrences were noted in the complete SLN group (5/180 groins). The difference with the successful SLN group (0/12 groins) was not significant., Conclusion: Risk of groin recurrence was 2.6% after SLN negative biopsy in early-stage VSCC. The risk appeared not increased if at least one SLN was found with minimal residual radioactivity, in case more SLNs were visualized on lymphoscintigraphy., (© 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Positron emission tomography (PET) is an important imaging modality for personalizing clinical management of patients with lung cancer. In this regard, PET imaging is essential for adequate clinical staging and monitoring of treatment response in patients with lung cancer. The key advantage of PET over other radiological imaging modalities is its high sensitivity for the detection of pulmonary lesions, normal-sized metastatic hilar and/or mediastinal lymph nodes, and distant metastases. Furthermore, with increasing clinical evidence, the role of PET imaging for treatment selection, adaptation, early response monitoring and follow up in patients with lung cancer is being increasingly recognized. At the heart of PET imaging lies the ability to visualize and quantify numerous biological parameters that are responsible for treatment resistance. In order to ensure accurate and reproducible image quantification, harmonization of patient preparation and imaging protocols is essential. Additionally, there are several technical factors during PET scanning that have to be taken care of to safeguard image quality and quantitative accuracy. One of these factors is the occurrence of respiratory motion artifacts, which is a well-known factor that can significantly influence image quality and quantitative accuracy of PET images. If left uncorrected, respiratory motion artifacts can introduce uncertainties in diagnosis and staging, inaccuracies in definition of target volumes for radiation treatment planning, and hinder adequate monitoring of therapy response. Although many different respiratory gating techniques have been developed to correct PET images for respiratory motion artifacts, respiratory gating has traditionally not been widely adopted in clinical practice. This is due to the fact that these methods tend to be disruptive for the clinical workflow due the lengthening of image acquisition times, higher amounts of activity being administered to the patient, and the requirement to synchronize additional hardware with the scanner. Developments in respiratory gating techniques over the last years have resulted in considerable technical improvements. These newer respiratory gating techniques can operate directly on the acquired PET data without the use of additional hardware to trace respiratory motion and can be seamlessly applied into clinical routine. Furthermore, instead of only using a fraction of the acquired PET data newer methods have the ability to use all of the acquired PET data for image reconstruction, thereby improving image quality. The clinically added value of respiratory gating lies in improving image quality by reducing the amount of respiration-induced image blurring. This considerably improves the detection and characterization of small lesions, potentially improving early diagnosis and staging of patients with lung cancer. Furthermore, the incorporation of (4D) respiratory gated PET for radiotherapy purposes has shown to improve target volume definition through more accurate tracking of tumor motion. In addition, the effect of respiratory motion artifacts on widely used volumetric and uptake parameters in PET have been described. Although respiratory gating improves quantitative accuracy of PET images, the exact impact of these corrections on clinical management of patients with lung cancer often still needs to be determined., Competing Interests: Declaration of interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

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 of targeting the sentinel node (SN) for biopsy in MIBC patients using the hybrid tracer indocyanine green (ICG)- 99m Tc-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- 99m Tc-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- 99m Tc-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., Competing Interests: Conflicts of interest and sources of funding: This work was partially supported by an NWO-STW-VIDI grant (grant STW BGT11272). There are no potential conflicts of interest or payments received from a third party., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: The aim of this study was to assess the superiority of ICG- 99m Tc-nanocolloid for the intraoperative visual detection of sentinel lymph nodes (SLNs) in vulvar squamous cell carcinoma (VSCC) patients compared to standard SLN detection using 99m Tc-nanocolloid with blue dye., Methods: In this multicenter, randomized controlled trial, VSCC patients underwent either the standard SLN procedure or with the hybrid tracer ICG- 99m Tc-nanocolloid. The primary endpoint was the percentage of fluorescent SLNs compared to blue SLNs. Secondary endpoints were successful SLN procedures, surgical outcomes and postoperative complications., Results: Forty-eight patients were randomized to the standard (n = 24) or fluorescence imaging group (n = 24) using ICG- 99m Tc-nanocolloid. The percentage of blue SLNs was 65.3% compared to 92.5% fluorescent SLNs (p < 0.001). A successful SLN procedure was obtained in 92.1% of the groins in the standard group and 97.2% of the groins in the fluorescence imaging group (p = 0.33). Groups did not differ in surgical outcome, although more short-term postoperative complications were documented in the standard group (p = 0.041)., Conclusions: Intraoperative visual detection of SLNs in patients with VSCC using ICG- 99m Tc-nanocolloid was superior compared to 99m Tc-nanocolloid and blue dye. The rate of successful SLN procedures between both groups was not significantly different. Fluorescence imaging has potential to be used routinely in the SLN procedure in VSCC patients to facilitate the search by direct visualization., Clinical Trial Registration: Netherlands Trial Register (Trial ID NL7443)., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: The hybrid tracer indocyanine green (ICG)-Tc-nanocolloid has been introduced for sentinel node imaging. However, until now, a comparison of this tracer with other radiocolloids with a larger particle size has not been effectuated. Based on a head-to-head evaluation in patients with melanoma, we have compared ICG-Tc-nanocolloid (particle size 5-80 nm) with Tc-Senti-Scint (particle size 100-600 nm) to establish differences in drainage pattern and sentinel node localization using lymphoscintigraphy and single-photon emission computed tomography combined with computer tomography (SPECT-CT) in melanoma patients scheduled for sentinel node biopsy., Methods: Twenty-five patients (mean age: 56.9 years, range: 25-79 years) with a melanoma scheduled for SLN biopsy prior to (re)excision of the primary lesion (scar) were prospectively included following a two-day procedure. The first day, after Tc-Senti-Scint injection in four intradermal depots around the primary lesion or scar, early/delayed lymphoscintigraphy and SPECT-CT images were acquired. The injection sites were marked. The second day, after assessing lymph node radioactivity using planar scintigraphy, ICG-Tc-nanocolloid was injected at the previously marked skin points and imaging was performed. The paired planar and SPECT-CT images of both tracers were evaluated with respect to drainage patterns, SLN visualization and non-SLN appearing., Results: Twenty-four out of 25 patients were evaluable. SLN visualization on a patient basis was 100% for ICG-Tc-nanocolloid and 96% for Tc-Senti-Scint, whereas uptake in non-SLNs was found in, respectively, 71% (17/24) and 61% (14/23). Concordance in drainage to 45 lymph node basins was 91%. Discordant drainage was found for two melanomas in the head-and-neck and one in the clavicular area. Unique lymph node basins were seen in 44/45 (98%) for ICG-Tc-nanocolloid and 42/45 (93%) for Tc-Senti-Scint. Concerning identified SLNs, the number was similar for both tracers (n = 58); however, more non-SLNs (65 vs 50) were visualized with ICG-Tc-nanocolloid than with Tc-Senti-Scint., Conclusion: A slightly higher SLN visualization accompanied by a tendency to depict more non-SLNs was found for ICG-Tc-nanocolloid. Excepting the head and neck area, an overall high concordance in drainage was found for both radiotracers. With an additional value for the hybrid tracer due to the combination of preoperative imaging and the additional visual signal in the operation room, added by the fluorescent component of the hybrid tracer, there was a preference for ICG-Tc-nanocolloid.

Introduction : Radioguided surgery is an ever-evolving part of nuclear medicine. In fact, this nuclear medicine sub-discipline actively bridges non-invasive molecular imaging with surgical care. Next to relying on the availability of radio- and bimodal-tracers, the success of radioguided surgery is for a large part dependent on the imaging modalities and imaging concepts available for the surgical setting. With this review, we have aimed to provide a comprehensive update of the most recent advances in the field. Areas covered : We have made an attempt to cover all aspects of radioguided surgery: 1) the use of radioisotopes that emit γ, β + , and/or β - radiation, 2) hardware developments ranging from probes to 2D cameras and even the use of advanced 3D interventional imaging solutions, and 3) multiplexing solutions such as dual-isotope detection or combined radionuclear and optical detection. Expert opinion : Technical refinements in the field of radioguided surgery should continue to focus on supporting its implementation in the increasingly complex minimally invasive surgical setting, e.g. by accommodating robot-assisted laparoscopic surgery. In addition, hybrid concepts that integrate the use of radioisotopes with other image-guided surgery modalities such as fluorescence or ultrasound are likely to expand in the future.

Introduction: Cyclodextrin (CD)-based supramolecular interactions have been proposed as nanocarriers for drug delivery. We previously explored the use of these supramolecular interactions to perform targeted hepatic radioembolization. In a two-step procedure the appropriate location of the diagnostic pre-targeting vector can first be confirmed, after which the therapeutic vector will be targeted through multivalent host-guest interactions. Such a procedure would prevent therapeutic errors that come from a mismatch between diagnostic and therapeutic procedures. In the current study we explored the use of dual-isotope imaging to assess the in vivo stability of the formed complex and individual components., Methods: Dual-isotope imaging of the host and guest vectors was performed after labeling of the pre-targeted guest vector, being adamantane (Ad) functionalized macro-aggregated albumin (MAA) particles, with technetium-99 m ( 99m Tc-MAA-Ad). The host vector, Cy5 0.5 CD 9 PIBMA 39 , was labeled with indium-111 ( 111 In-Cy5 0.5 CD 9 PIBMA 39 ). The in situ stability of both the individual vectors and the resulting [MAA-Ad- 111 In-Cy5 0.5 CD 9 PIBMA 39 ] complexes was studied over 44 h at 37 °C in a serum protein-containing buffer. In vivo, the host vector 111 In-Cy5 0.5 CD 9 PIBMA 39 was administered two hours after local deposition of 99m Tc-MAA-Ad in mice. Dual-isotope SPECT imaging and quantitative biodistribution studies were performed between 2 and 44 h post intravenous host vector administration., Results: The individual vectors portrayed <5% dissociation of the radioisotope over the course of 20 h. Dissociation of [MAA-Ad- 111 In-Cy5 0.5 CD 9 PIBMA 39 ] complexes remained within a 10-20% range after incubation in serum. In vivo dual-isotope SPECT imaging of host-guest interactions revealed co-localization of the tracer components. Quantitative assessment of the biodistribution revealed that the hepatic accumulation of the host vector nearly doubled between 2 h and 44 h post-injection (from 14.9 ± 6.1%ID/g to 26.2 ± 2.1%ID/g)., Conclusions: Assessment of intra-hepatic host-guest complexation was successfully achieved using dual isotope multiplexing, underlining the complex stability that was found in situ (up to 44 h in serum). Overall, the results obtained in this study highlight the potential of supramolecular chemistry as a versatile platform that could advance the field of nanomedicine., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Summary: Fluorine-18-methyl-choline (F18-choline) PET/computed tomography (CT) is routinely performed in our hospital for patients with significantly increased or rapidly increasing prostate-specific antigen (PSA) levels to detect and localize recurrent prostate carcinoma. We observed uptake of this PET tracer in mediastinal lymph nodes in a significant number of patients. The aim of this study was to assess the frequency of this finding and to determine whether it is correlated with tumour and nontumour-related aspects., Materials and Methods: A total of 48 consecutive men (mean age: 65.6 years; range: 50-79 years, standard deviation: 7.1) with histopathologically proven prostate cancer were referred for F18-choline PET/CT imaging for restaging from March 2009 to October 2010. All patients had a suspicion of tumour recurrence because of an increased PSA or a rapidly increasing PSA. All studies were reviewed, and the results were correlated with general data such as age; smoking; chronic obstructive pulmonary disease; tumor, lymph nodes and distant metastases stage; Gleason Score and PSA level; with a maximum interval of 3 months between serum PSA and the PET/CT scan., Results: In 27 patients (56.3%), F18-choline PET/CT showed positive lymph nodes in the mediastinum (mean standardized uptake values: 3.75; range: 1.7-13.8, standard deviation: 2.4). No histological biopsy was carried out in F18-choline-positive lymph nodes, but in none of the patients was mediastinal recurrence or pulmonary infection observed during a 6-month follow-up. Only one patient had histologically proven pulmonary metastasis. No significant relationship was observed between mediastinal F18-choline lymph node uptake and serum PSA level (P=0.785), initial T stage (P=0.555), N stage (P=0.548), M stage (P=0.426), smoking (P=0.537), chronic obstructive pulmonary disease (P=0.115) or the presence of tumour recurrence on F18-choline PET/CT., Conclusion: Mediastinal lymph node uptake of F18 choline is frequently observed, without any significant relationship with tumour characteristics. Therefore, interpretation of positive mediastinal lymph node uptake should be done carefully.