Development and characterization of an all-in-one gamma probe with auto-peak detection for sentinel lymph node biopsy based on NEMA NU3-2004 standard.

BACKGROUND: A gamma probe is a handheld device used for intraoperative interventions following interstitial injection of a radiotracer to locate regional lymph nodes through the external detection of radiation. This work reports on the design and performance evaluation of a novel fully integrated gamma probe (GammaPen), recently developed by our group. MATERIALS AND METHODS: GammaPen is an all-in-one pocket gamma probe with low weight and adequate dimensions, consisting of a detector, a control unit and output all together. The detector module consists of a cylindrical Thallium-activated Cesium Iodide [CsI (Tl)] crystal optically coupled to a Silicon photomultiplier (SiPM), shielded using Tungsten housing on side and back faces. The electronics of the probe consists of two small boards to handle signal processing and analog peak detection tasks. A number of parameters, including probe sensitivity in air/water, spatial resolution in air/water, angular resolution in air/water, and side and back shielding effectiveness, were measured to evaluate the performance of the probe based on NEMA NU3-2004 standards. RESULTS: The sensitivity of the probe in air at distances of 10, 30, and 50 mm is 18784, 3500, and 1575 cps/MBq. The sensitivity in scattering medium was also measured at distances of 10, 30, and 50 mm as 17,680, 3050, and 1104 cps/MBq. The spatial and angular resolutions in scattering medium were 47 mm and 87 degree at 30 mm distance from the probe, while they were 40 mm and 77 degree in air. The detector shielding effectiveness and leakage sensitivity are 99.91% and 0.09%, respectively. CONCLUSION: The performance characterization showed that GammaPen can be used effectively for sentinel lymph node localization. The probe was successfully used in several surgical interventions by an experienced surgeon confirming its suitability in a clinical setting.

Sentinel lymph node detection by means of indocyanine green using the Karl Storz VITOM® fluorescence camera: a comparison between primary sentinel lymph node biopsy versus sentinel lymph node biopsy after neoadjuvant chemotherapy.

PURPOSE: The usage of radioactive Technetium99m (Tc99m) colloid for the purpose of sentinel lymph node biopsy (SLNB) in early breast cancer is considered the gold standard in Germany. However, new tracers, such as near-infrared (NIR) imaging agents like indocyanine green (ICG) could offer an alternative in future, as they overcome drawbacks associated with radioactive Technetium99m (Tc99m) like limited availability, high costs and radioactivity exposure for both patients and surgeons. METHODS: In this double-arm retrospective study, we sought to establish the usefulness of indocyanine green as an alternative or an addition to the conventional Technetium99m (Tc99m) in the identification of the SLN in early breast cancer. RESULTS: Among the 161 patients who underwent primary SLNB, 34 patients had at least 1 SLN with metastasis. Among these patients with SLN metastasis, 33 had the SLN detected by ICG; while 31 had the SLN detected by Tc99m. The conventional Technetium99m radiotracer failed to detect 2 patients with metastasis in this Arm of the study. Among the 87 patients who underwent SLNB after NACT, 13 patients had at least 1 SLN with metastasis. Among these 13 patients with SLN metastasis, ICG and Tc99m had detected the SLN among 12 patients, while 1 patient had been detected by ICG alone. CONCLUSIONS: Our results show that ICG is as effective as the radioisotope for SLNB even among patients who have undergone NACT. This trial is registered with the German Clinical Trial Register, ID: DRKS00013606.

Robot-assisted Sentinel Lymph Node Mapping and Inguinal Lymph Node Dissection Using Near-infrared Fluorescence in Vulvar Cancer.

The surgical treatment of vulvar cancer has undergone many changes over the last century. The morbidity of open inguinal incisions prompts the search for a minimally invasive approach to lymph node dissection. This study reports the outcomes of 4 patients with vulvar cancer undergoing robotic sentinel lymph node (SLN) mapping and lymph node (LN) dissection with near-infrared fluorescence. From 2015 to 2017, 3 patients with squamous cell carcinoma of the vulva underwent robot-assisted SLN mapping and inguinal LN dissection. One patient with a vulvar melanoma had robotic bilateral SLN mapping only. The da Vinci Xi System with Firefly technology (Intuitive Surgical, Sunnyvale, CA) and indocyanine green radiotracer was used in all cases. Eight groins underwent robot-assisted SLN mapping, 6 of which underwent inguinal LN dissection. The average operating time was 234 minutes with vulvectomy. The mean blood loss was 124 mL. The operative time decreased, and the lymph node yield increased with each case. There were no wound separations or long-term negative outcomes, such as persistent lymphedema or recurrence. This case series of robot-assisted SLN mapping and inguinal lymph node dissection shows the safety and feasibility of this new technique in vulvar cancer. It may be a valid approach to reduce short- and long-term morbidity.

Feasibility of fine-needle aspiration for assessing responses to chemotherapy in metastatic nodes marked with clips in breast cancer: A prospective registry study.

BACKGROUND: Clips are often placed to mark axillary nodes with biopsy-confirmed metastases in patients with breast cancer. The evaluation of clipped nodes after chemotherapy can identify patients who have eradication of nodal disease. The goal of this study was to determine whether preoperative fine-needle aspiration (FNA) of clipped nodes after neoadjuvant chemotherapy (NAC) could predict the presence of residual disease. METHODS: This prospective registry study enrolled 50 patients with a clip placed to mark nodes with biopsy-confirmed metastases who had completed NAC. Participants underwent FNA of the clipped node before seed-localized lymph node excision. FNA pathology was compared with surgical pathology. RESULTS: There were 36 patients (72%) with residual disease on surgical pathology: 3 (8%) had a nondiagnostic aspirate, carcinoma was seen in 14 (39%), and 19 (53%) had a false-negative result. The sensitivity of FNA was 42.4%, its specificity was 100%, and its negative predictive value was 40.6%. In a univariate analysis, the odds of a true-positive result increased significantly with the mean initial size of the clipped node (odds ratio [OR], 4.3; P = .004) and the size of the metastatic focus after NAC (OR, 1.3; P = 0.003), whereas normalization of nodes after chemotherapy (OR, 0.1) and a lack of response on ultrasound (OR, 0.11) were associated with a false-negative result (P = .01). CONCLUSIONS: FNA of marked nodes after chemotherapy has a high false-negative rate. This highlights the need for surgical staging of the axilla after NAC to assess the response.

Is there a role for a handheld gamma camera (TReCam) in the SNOLL breast cancer procedure?

BACKGROUND: Sentinel node and occult lesion localization (SNOLL) calls for a combination of two specific procedures: intraoperative detection of sentinel lymph node (SLN) and radio-guided occult lesion localization (ROLL). The safety and benefits of radio-guided localization in the surgical treatment of non-palpable breast cancer have been confirmed. The aim of this study was to evaluate the potential role for an intra-operative handheld tumor resection gamma camera (TReCam) in SNOLL procedures. METHODS: Fifteen patients were enrolled. The SNOLL procedure was performed in all patients with conventional lymphoscintigraphy (LS). TReCam was used to obtain nuclear imaging in the operating theater. Concordance between LS and TReCam images, duration of use and assessment of difficulties in data acquisition with TReCam were reported. RESULTS: Concordance for tumor localization between single-detector gamma probe and TReCam was excellent (15/15). The number of radioactive SLNs visualized between LS and TReCam was equivalent in 53.3% of cases (8/15). TReCam was considered to be very easy-to-use (12/15) or easy-to-use (3/15). Average duration of acquisition with TReCam was 4 minutes and 45 seconds for the SLN procedure, and 2 minutes and 10 seconds for lumpectomy. CONCLUSIONS: This study suggests that TReCam is easy-to-use and does not increase operative time. Its exact role in radio-guided surgery needs to be clearly defined in a larger study. However, its usefulness and benefits in radio-guided breast surgery seem to be promising.

The Impact of Breast Lumpectomy Tray Utilization on Cost Savings.

BACKGROUND: Right-sizing instrument trays reduce processing and replacement costs, physical strain, and turnover times. Historically, a 98-instrument head and neck tray has been used for breast lumpectomy cases at our institution. Observations revealed that many instruments on the tray were not used during the breast cases. With the significant number of surgical breast lumpectomies performed annually, tray downsizing could significantly reduce costs and physical strain. METHODS: Surgical technicians identified instruments needed for a standard breast lumpectomy. Breast surgeons reviewed the list and made final recommendations. Three of 13 existing head and neck trays were converted to breast lumpectomy trays. The number of breast lumpectomies in 2017 was pulled from the institution's health information system. Instrument quantities were verified using instrument management software. Weights were taken on a digital scale, and processing cost was estimated by a consultant. RESULTS: The new breast trays included 51 instruments rather than the standard 98-instrument trays. Reprocessing cost decreased from $49.98 to $26.01. With 449 breast lumpectomies performed at the institution in 2017, the annual reprocessing savings totaled $10,763. The tray weight was reduced from 27 to 16 pounds. Setup time decreased from 7 to 4 min per use (22.5 h saved annually). CONCLUSIONS: Downsizing from a head and neck tray to a specific breast lumpectomy tray demonstrated a reduction in reprocessing cost, tray weight, and setup time. Lighter trays allow for safer handling and transport by surgical personnel. In the current health-care environment, it is important to maximize operating room efficiency and minimize cost.

Late Shoulder-Arm Morbidity Using Ultrasound Scalpel in Axillary Dissection for Breast Cancer: A Retrospective Analysis.

BACKGROUND: We aimed to assess whether the use of the harmonic scalpel (HS) in axillary dissection would reduce long-term shoulder-arm morbidity compared to traditional instruments (TIs). MATERIALS AND METHODS: A retrospective analysis on 180 patients who underwent standard axillary dissection for breast cancer between 2007 and 2015 was carried out. All patients were evaluated for postoperative pain, impairment of shoulder-arm mobility, seroma formation in axilla, frozen shoulder, and lymphedema. RESULTS: HS procedure on average was 50% shorter compared to the TI technique. HS reduced by 4.5 times the risk of axillary seroma. TIs were associated with 4 times higher risk of developing a painful frozen shoulder. CONCLUSIONS: Use of the HS was associated with reduced costs and a positive long-term effect on shoulder-arm morbidity. Axillary seromas are not the only reason of later postoperative shoulder-arm morbidity: other mechanisms are hypothesized in the onset of this very disabling disorder.

Wire localization of clip-marked axillary lymph nodes in breast cancer patients treated with primary systemic therapy.

INTRODUCTION: Clipping and selective removal of initially suspicious axillary lymph nodes in breast cancer patients who have been sonographically down-staged by primary systemic therapy improves the accuracy of surgical staging and provides the opportunity for more conservative axillary surgery. This study evaluated whether preoperative ultrasound-guided wire localization of the clipped node is useful for routine clinical practice. MATERIAL AND METHODS: This prospective, single-center feasibility trial included patients with invasive breast cancer (cT1-3N1-3M0) treated by primary systemic therapy. They underwent ultrasound-guided core needle biopsy and clip placement into the most suspicious axillary lymph node prior to chemotherapy. After primary systemic therapy the clipped lymph node was localized by a wire. All patients underwent target lymph node biopsy, completion axillary lymph node dissection and, if yiN0, axillary sentinel lymph node biopsy. The primary study endpoint was the identification rate of the target lymph node. RESULTS: All patients (n = 30) underwent successful clip insertion into the lymph node. After chemotherapy, the clipped target lymph node was visible by ultrasound in 83.3% (25/30). Wire localization was possible in 24 cases (80%), and the clipped node identification rate was 70.8% (17/24 cases). In 9/30 patients (30%) clipped node removal was not confirmed by intraoperative radiography. CONCLUSION: Ultrasound-guided wire localization of the target lymph node is not suitable for clinical practice because of limitations regarding clip visibility and selective surgical preparation of the target lymph node. Further prospective evaluation of alternative techniques is needed.

Multispectral-Fluorescence Imaging as a Tool to Separate Healthy from Disease-Related Lymphatic Anatomy During Robot-Assisted Laparoscopy.

To reduce the invasive nature of extended pelvic lymph node (LN) dissections in prostate cancer, we have developed a multispectral-fluorescence guidance approach that enables discrimination between prostate-draining LNs and lower-limb-draining LNs. Methods: In 5 pigs, multispectral-fluorescence guidance was used on da Vinci Si and da Vinci Xi robots. The animals received fluorescein into the lower limb and indocyanine green-nanocolloid into the prostate. Results: Fluorescein was detected in 29 LNs (average of 3.6 LNs/template), and indocyanine green-nanocolloid was detected in 12 LNs (average of 1.2 LNs/template). Signal intensities appeared equal for both dyes, and no visual overlap in lymphatic drainage patterns was observed. Furthermore, fluorescein supported both the identification of leakage from damaged lymphatic structures and the identification of ureters. Conclusion: We demonstrated that the differences in lymphatic flow pattern between the prostate and lower limbs could be intraoperatively distinguished using multispectral-fluorescence imaging.

Gamma probe and ultrasound-guided fine needle aspiration cytology of the sentinel node (GULF) trial.

PURPOSE: Sentinel lymph node biopsy (SLNB) was introduced as a minimally invasive technique for nodal staging. Since associated morbidity is not negligible, it is highly relevant to pursue a more minimally invasive alternative. The purpose of this study was to prospectively evaluate the sensitivity of fine needle aspiration cytology (FNAC) with combined gamma probe and ultrasound (US) guidance in comparison with the gold standard histology of the sentinel node (SN) after SLNB for detecting metastasis. METHODS: The study was designed as a prospective, multicentre, open-label, single-arm trial enrolling patients with newly diagnosed cutaneous melanoma or breast cancer between May 2015 and August 2017. Sample radioactivity was measured using a Mini 900 scintillation monitor. After FNAC, all patients underwent SLNB. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were estimated. RESULTS: Accrual was terminated early following an unplanned interim analysis indicating that a FNAC sensitivity of at least 80% could not be achieved. In total 58 patients of the originally planned 116 patients underwent FNAC with gamma probe and US guidance. There were no true-positive FNAC results, 14 false-negative results and one false-positive result, and thus the sensitivity, specificity, PPV and NPV of FNAC were 0%, 98%, 0% and 75%, respectively. At least 75% of the FNAC samples had a radioactivity signal higher than the background signal. CONCLUSION: FNAC with gamma probe and US guidance is not able to correctly detect metastases in the SN and is therefore not able to replace SLNB. Gamma probe-guided US is a highly accurate method for correctly identifying the SN, which offers possibilities for future research.

Directional probe for radio-guided surgery: A pilot study.

PURPOSE: The sentinel lymph node (SLN) biopsy technique has highly evolved during the last 20 yr. Consequently, the intraoperative use of Gamma Probes (GPs) for SLN mapping is increased. This preliminary study evaluates a novel directional GP prototype. This proof-of-concept prototype is designed to identify the direction of radiopharmaceuticals uptakes, by combining the information from multiple detectors. The purpose of this work is to develop a tool able to effectively guide the surgeon reducing the surgery time. METHODS: The proposed prototype consists of three CsI(Tl) scintillation crystals, each coupled with an S10931 silicon photomultiplier (Hamamatsu Photonics K.K., Hamamatsu, JP). The three detectors lie on the same plane with an angle of 30° between them. The central detector is placed as in a common GP, so it can be used to pinpoint the target tissue. Meanwhile, the lateral sensors provide a broader view of the surgical field. A dedicated data acquisition system digitizes and processes the signals from the front-end electronics. Finally, an embedded system, based on ARM processor, calculates and displays the acquired count rates. In order to assess the prototype behavior, the isosensitivity curves for the three detectors were measured. Meanwhile, for the central one, the main quality criteria measurements were also performed (i.e., sensitivity, radial sensitivity, and spatial resolution). RESULTS: For the central detector, the measured sensitivity at the tip of the probe is better than 5 cps/kBq. The full width at half maximum (FWHM) of the radial sensitivity is less than 30° and the FWHM of the lateral sensitivity (spatial resolution) is about 7.2 mm. The central detector measured isosensitivity distribution shows a narrow profile in agreement with the spatial resolution measured. On the contrary, the two lateral detectors exhibit widespread isosensitivity distributions that mean a larger field of view. The system had shown satisfactory performance and reliability, meeting the minimal requirements of gamma probe systems. CONCLUSIONS: The prototype presented in this paper allows a rapid localization by the use of the whole system, while the sole central detector can be used to pinpoint the target source. This device, unlike common GPs, allows localizing simultaneously different areas of radiopharmaceuticals uptake, thus precisely guiding the surgeon to the region of interest. These preliminary results encourage to develop a further prototype for intraoperative validation.

Characterization of resolution, sensitivity, and shielding of a gamma-probe for sentinel lymph node localization: an experimental study.

OBJECTIVE: The aim of this study was to evaluate angular, spatial, and energy resolution, sensitivity, and shielding of a gamma-probe. MATERIALS AND METHODS: The EUROPROBE II gamma-probe (EuroRad) with sources of technetium-99m was assessed according to NEMA NU-3-2004. Resolution tests were evaluated considering the full width at half maximum (FWHM). The following parameters were evaluated: angular resolution in air, spatial resolution with a scattering medium and in air, energy resolution, and sensitivity and shielding. The collimator was used to evaluate angular and spatial resolution, sensitivity, and shielding. Background radiation was considered and did not affect the counts. RESULTS: FWHM of angular resolution (at 3/30 cm) was 39.17°/33.13° with the collimator and 74.08°/71.51° without the collimator; FWHM of spatial resolution in air at 10 mm was 13.32 mm with the collimator and 21.23 mm without the collimator. Energy resolution (%FWHM) was 20.51%. Sensitivity at 10 mm was 4.642±5 cps/MBq without the collimator and 1.063±2 cps/MBq with the collimator; shielding effectiveness of the probe tip was 99.52%. Background was not relevant to the counts. CONCLUSION: We showed that the collimator improved angular and spatial resolution to the detriment of sensitivity. Feasible results of energy resolution, sensitivity, and shielding were achieved.

Comparing Single-Site and Multiport Robotic Hysterectomy with Sentinel Lymph Node Mapping for Endometrial Cancer: Surgical Outcomes and Cost Analysis.

STUDY OBJECTIVE: To compare operative times, surgical outcomes, and costs of robotic laparoendoscopic single-site (R-LESS) vs multiport robotic (MPR) total laparoscopic hysterectomy (TLH) with sentinel lymph node (SLN) mapping for low-risk endometrial cancer. DESIGN: Retrospective cohort study (Canadian Task Force classification II-2). SETTING: Academic university hospital. PATIENTS: Patients with a biopsy-proven diagnosis of complex atypical hyperplasia (CAH) or low-grade (1 or 2) endometrial cancer with body mass index <30 kg/m2 and undergoing robotic TLH and SLN mapping between 2012 and 2016 were included. INTERVENTIONS: Surgical outcomes and cost data were collected retrospectively and analyzed based on the surgical approach with R-LESS vs MPR assistance. MEASUREMENTS AND MAIN RESULTS: Twenty-seven patients who met the inclusion criteria were identified, including 14 patients who underwent R-LESS TLH with SLN mapping and 13 patients who underwent MPR TLH with SLN mapping. Median uterine weight was comparable in the 2 cohorts (111.3 g vs 83.8 g; p = .33). Operative and console times were equivalent with the R-LESS and MPR approaches (median, 175 minutes vs 184 minutes, p = .61 and 136 vs 140 minutes, p = .12, respectively). Median estimated blood loss was 50 mL in both cohorts. Successful bilateral SLN mapping occurred in 85.7% of the R-LESS procedures and 76.9% of MPR procedures. No intraoperative or 30-day complications were encountered, and all patients were discharged within 23 hours of surgery. MPR was associated with additional disposable instrument and drape costs of $460 to $660 compared with R-LESS, depending on the surgeon's instrument selection. Average total hospital charges were lower for R-LESS procedures ($13,410 vs $15,952; p < .05). CONCLUSION: In highly selected patients with CAH or low-grade endometrial cancer undergoing TLH and SLN mapping, R-LESS appears to result in equivalent perioperative outcomes as a MPR approach while offering a more cost-effective option. Further research is needed to determine the benefits of R-LESS procedures in the gynecologic oncology setting.

Sentinel lymph node mapping using SPECT/CT and gamma probe in endometrial cancer: an analysis of parameters affecting detection rate.

PURPOSE: SPECT/CT after pericervical injection of technetium-99 m-nanocolloid was shown to be suitable for sentinel lymph node (SLN) mapping in endometrial cancer (EC). The aim of this study was to analyze factors affecting successful SLN detection by means of SPECT/CT such as imaging findings, patient characteristics and tumor biology in a large cohort of patients. METHODS: One hundred and forty-five consecutive patients suffering from EC who received pre-surgical SLN mapping at our institution between 2011 and 2016 were included in this analysis. SPECT/CT data of abdomen and pelvis (mean 4:20 ± 1:20 h p.i.) were acquired after pericervical injection of technetium-99 m-nanocolloid (mean 230 ± 45 MBq) in all patients. Surgical staging was performed on the day after. Acquisition parameters, patient characteristics, SPECT/CT findings as well as histopathological results were collected. RESULTS: A total of 282 SLNs were identified by means of SPECT/CT. Overall, preoperative and intraoperative SLN detection rates were 86%, 76% and 74% respectively. The most important factor associated with failure to detect SLNs was the presence of high bone marrow on SPECT/CT (p = 0.005). Peritoneal/abdominal radioactivity was also associated with missed SLN detection in SPECT/CT (p = 0.02). However, the presence of liver/spleen uptake on its own was not predictive for detection failure. Low numbers of detected SLNs in SPECT/CT were slightly related with older age and lower injected activity. No significant influence was found for the parameters of tumor histology and stage, lymph node involvement and the time gap between injection and imaging. CONCLUSIONS: Venous drainage as indicated by bone marrow uptake is the most important factor associated with scintigraphic SLN detection failure. Moreover, high peritoneal and abdominal activity was also associated with detection failure. Thus, meticulous application of the radiotracer is crucial in EC.

Gamma probe and ultrasound guided fine needle aspiration cytology of the sentinel node (GULF) trial - overview of the literature, pilot and study protocol.

BACKGROUND: Sentinel node (SN) biopsy (SNB) detects clinically occult metastases of breast cancer and melanoma in 20-30%. Wound infections, seroma and lymph edema occur in up to 10%. Targeted ultrasound (US) of the SN, (with fine needle aspiration cytology (FNAC) if appropriate) has been investigated as a minimally invasive alternative, but reported sensitivity rates are too low to replace SNB. Our hypothesis is that the use of a handheld gamma probe concomitant with US may improve sensitivity. Our aim is to provide an overview of the current literature on preoperative nodal staging of clinical N0 melanoma patients, report on a pilot, and present a study protocol for a minimally invasive alternative to the SNB: Gamma probe and Ultrasound guided Fine needle aspiration cytology of the sentinel node (GULF trial). METHODS: The GULF trial is a multicenter open single arm observational trial. Newly diagnosed cT1b-4N0M0 cutaneous melanoma or cT1-3N0M0 breast cancer patients, aged >18 years, presenting for SNB are eligible. 120 patients will be included for preoperative targeted gamma probe guided US and FNAC of the SN. Afterwards all patients proceed to surgical SNB. Primary endpoint is the sensitivity of FNAC. Secondary endpoints include SN identification rate and the histopathological compatibility of Core Needle Biopsy and FNAC vs. SNB. Secondary endpoints were investigated in a pilot with 10 FNACs and marker placements, and 10 FNACs combined with Core Needle Biopsy. RESULTS: A pilot in 20 patients showed that SN identification rate was 90%, supporting the feasibility of this technique. DISCUSSION: There is broad experience with US (in combination with FNAC) prior to SNB, but sensitivity and specificity are too low to completely abandon SNB. Promising alternative techniques potentially will replace SNB in the future but more evidence is needed in the form of prospective studies. Accurate identification of the SN for US-FNAC has been proven feasible in our pilot. When adequate sensitivity can be reached, US-FNAC provides a minimally invasive alternative for the surgical SNB procedure. TRIAL REGISTRATION: The GULF trial is registered in the Netherlands Trial Registry (NTR), ID: NRT5193 . May 1st 2015.

Indocyanine green-assisted sentinel lymph node biopsy in melanoma using the "FOVIS" system.

BACKGROUND: Metastatic involvement of the sentinel lymph node (SLN) represents a key prognostic factor in melanoma. The combined use of a radiocolloid (technetium-99m) and blue dye is the gold standard in sentinel lymph node biopsy (SLNB). In this context, near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) has been suggested as an alternative. The objective of the present study was to examine the potential advantages of fluorescence-guided SLNB - compared to the conventional method - with respect to the visualization of lymphatic drainage pathways and the SLN. Particular focus was on the impact of the ICG dose used and the body mass index (BMI). PATIENTS AND METHODS: The study included ten patients who underwent the SLNB procedure using technetium-99m, blue dye, and ICG. Real-time fluorescence imaging of lymphatic drainage pathways and the SLN was done using the "FOVIS"-NIR system. Depending on the quality of the images achieved, ICG was intradermally administered at a dose ranging from 0.25 to 2.5 mg. RESULTS: Nine SLNs were identified by fluorescence (90 %); (100 %) ten, by gamma probe; eight (80 %), by ICG or blue dye. Transdermal SLN detection was possible in one case (10 %). In correlation to the BMI, higher intradermal ICG doses - up to 2.5 mg overall - proved to be advantageous in the visualization of lymphatic vessels. CONCLUSIONS: Supplementing the technetium-99m method, fluorescence SLNB using ICG and the "FOVIS"-NIR system is a safe alternative to the blue-dye technique. Further studies on the optimal ICG dose and transdermal imaging in correlation to the BMI are required.

The predictive accuracy of sentinel nodes mapping in the setting of pulmonary metastasectomy.

This is the first study to evaluate the feasibility of mediastinal lymph node dissection (MLND) based on sentinel lymph node (SLN) status during pulmonary metastasectomy. A total of 22 patients (16 men, 6 women; age 63.3 ± 7.01 years) who were candidates for metastasectomy through segmentectomy or lobectomy with MLND owing to cancers metastatic to the lung were enrolled in this study. Radiotracer was administered at the peritumoral region before surgery or soon after initiating surgery. During the operation, the radioactivity of the lymph nodes (ex vivo) was counted with a handheld gamma probe after MLND. Lobectomy was performed in 17 patients, and segmentectomy, in 5 patients. The number of dissected lymph nodes per patient was 14.4 ± 8.69 (range, 5-36). In all patients, the SLN could be detected, and the number of SLNs identified was 2.0 ± 1.15 (range, 1-5) per patient. Lymph node metastasis was identified in 3 of the 22 patients (13.6%), and none of the 3 patients with N1 or N2 disease had false-negative SLNs. SLN identification might be an indicator of whether or not MLND should be performed during pulmonary metastasectomy. However, further large-volume and multi-institutional studies are needed.

Multispectral Fluorescence Imaging During Robot-assisted Laparoscopic Sentinel Node Biopsy: A First Step Towards a Fluorescence-based Anatomic Roadmap.

BACKGROUND: During (robot-assisted) sentinel node (SN) biopsy procedures, intraoperative fluorescence imaging can be used to enhance radioguided SN excision. For this combined pre- and intraoperative SN identification was realized using the hybrid SN tracer, indocyanine green-99mTc-nanocolloid. Combining this dedicated SN tracer with a lymphangiographic tracer such as fluorescein may further enhance the accuracy of SN biopsy. OBJECTIVE: Clinical evaluation of a multispectral fluorescence guided surgery approach using the dedicated SN tracer ICG-99mTc-nanocolloid, the lymphangiographic tracer fluorescein, and a commercially available fluorescence laparoscope. DESIGN, SETTING, AND PARTICIPANTS: Pilot study in ten patients with prostate cancer. Following ICG-99mTc-nanocolloid administration and preoperative lymphoscintigraphy and single-photon emission computed tomograpy imaging, the number and location of SNs were determined. Fluorescein was injected intraprostatically immediately after the patient was anesthetized. A multispectral fluorescence laparoscope was used intraoperatively to identify both fluorescent signatures. SURGICAL PROCEDURE: Multispectral fluorescence imaging during robot-assisted radical prostatectomy with extended pelvic lymph node dissection and SN biopsy. MEASUREMENTS: (1) Number and location of preoperatively identified SNs. (2) Number and location of SNs intraoperatively identified via ICG-99mTc-nanocolloid imaging. (3) Rate of intraoperative lymphatic duct identification via fluorescein imaging. (4) Tumor status of excised (sentinel) lymph node(s). (5) Postoperative complications and follow-up. RESULTS AND LIMITATIONS: Near-infrared fluorescence imaging of ICG-99mTc-nanocolloid visualized 85.3% of the SNs. In 8/10 patients, fluorescein imaging allowed bright and accurate identification of lymphatic ducts, although higher background staining and tracer washout were observed. The main limitation is the small patient population. CONCLUSION: Our findings indicate that a lymphangiographic tracer can provide additional information during SN biopsy based on ICG-99mTc-nanocolloid. The study suggests that multispectral fluorescence image-guided surgery is clinically feasible. PATIENT SUMMARY: We evaluated the concept of surgical fluorescence guidance using differently colored dyes that visualize complementary features. In the future this concept may provide better guidance towards diseased tissue while sparing healthy tissue, and could thus improve functional and oncologic outcomes.