Sentinel Lymph Node Localization Research Articles

Bi-modal near-infrared fluorescence and ultrasound imaging via a transparent ultrasound transducer for sentinel lymph node localization.

Sentinel lymph node biopsy with an indocyanine green-based near-infrared fluorescence imaging system avoids the shortcomings of using a radioisotope or a combination of a blue dye and a radioactive tracer. To improve surgical precision, recent research has provided a depth profile of the sentinel lymph node by fusing fluorescence and ultrasound imaging. Here, we present a combined near-infrared fluorescence and ultrasound imaging system based on a transparent ultrasound transducer. The transparent ultrasound transducer enables seamless coaxial alignment of the fluorescence and ultrasound beam paths, allowing bi-modal observation of a single region of interest. Further, we demonstrate that the sentinel lymph node of mice injected with indocyanine green can be successfully localized and dissected based on information from the bi-modal imaging system.

Phantom study of SPECT/CT augmented reality for intraoperative localization of sentinel lymph nodes in head and neck melanoma

ObjectiveTo show that augmented reality (AR) visualization of single-photon emission computed tomography (SPECT)/computed tomography (CT) data in 3D can be used to accurately localize targets in the head and neck region. Materials and methodsEight head and neck styrofoam phantoms were painted with a mixture of radioactive solution (Tc-99m) detectable with a handheld gamma probe and fluorescent ink visible only under ultraviolet (UV) light to create 10–20 simulated lymph nodes on their surface. After obtaining SPECT/CT images of these phantoms, virtual renderings of the nodes were generated from the SPECT/CT data and displayed using a commercially available AR headset. For each of three physician evaluators, the time required to localize lymph node targets was recorded (1) using the gamma probe alone and (2) using the gamma probe while wearing the AR headset. In addition, the surface localization accuracy when using the AR headset was evaluated by measuring the misalignment between the locations visually marked by the evaluators and the ground truth locations identified using UV stimulation of the ink at the site of the nodes. ResultsFor all three evaluators, using the AR headset significantly reduced the time to detect targets (P = 0.012, respectively) compared to using the gamma probe alone. The average misalignment between the location marked by the evaluators and the ground truth location was 8.6 mm. ConclusionAR visualization of SPECT/CT data in 3D allows for accurate localization of targets in the head and neck region, and may reduce the localization time of targets.

Study on intraoperative localization of sentinel lymph nodes using freehand SPECT in breast cancer patients.

The diagnostic and therapeutic approach to axillary lymph nodes is considered indispensable in the treatment of breast cancer patients. To investigate the effectiveness of 3D freehand SPECT (fhSPECT) in sentinel lymph node (SLN) mapping in breast cancer, compared with the use of a conventional gamma probe. We retrospectively compared the fhSPECT lymph node mapping modality, with gamma probe detection in early-stage, clinically node-negative breast cancer patients, with biopsy-confirmed malignancy. The two techniques were compared based on the average number of LNs excised per axilla. The duration of SLN mapping was also compared between the two groups. The performance of the two methods on obese and post-systemic therapy patients was evaluated. FhSPECT was used in 150 cases, while the gamma probe was employed in 50 cases. FhSPECT detected at least 3 nodes in 83.3% of the patients vs. 72.0% with the γ-probe (p = 0.107). The mean number of SLNs excised per axilla was 3.66 using the γ-probe and 4.18 with fhSPECT (p = 0.03). The average surgical time was 39 ±7 min with the γ-probe and 37.54 ±17 min with fhSPECT (p = 0.228). Sentinel lymph node biopsy (SLNB) mean surgical time evolved from 40.2 ±20.77 min to 32.35 ±10.46 min (p = 0.033). In obese patients, a reduction in surgical times was noted from 45.5 ±3.09 min to 44.04 ±20.9 (p = 0.27), in addition to a significant increase in average LN detection in the fhSPECT group (4.26 ±1.44) compared to the γ-probe group (3.2 ±1.65) (p = 0.043). The use of the fhSPECT modality is effective and safe, and, when compared to the γ-probe, has significant advantages in SLN mapping.

Sentinel lymph node localization and staging with a low-dose of superparamagnetic iron oxide (SPIO) enhanced MRI and magnetometer in patients with cutaneous melanoma of the extremity - The MAGMEN feasibility study

BackgroundIn patients with melanoma, sentinel lymph node (SLN) status is pivotal for treatment decisions. Current routine for SLN detection combines Technetium99m (Tc99) lymphoscintigraphy and blue dye (BD). The primary aim of this study was to examine the feasibility of using a low dose of superparamagnetic iron oxide (SPIO) injected intracutaneously to detect and identify the SLN, and the secondary aim was to investigate if a low dose of SPIO would enable a preoperative MRI-evaluation of SLN status. MethodsPatients with melanoma of the extremities were eligible. Before surgery, a baseline MRI of the nodal basin was followed by an injection of a low dose (0.02–0.5 mL) of SPIO and then a second MRI (SPIO-MRI). Tc99 and BD was used in parallel and all nodes with a superparamagnetic and/or radioactive signal were harvested and analyzed. ResultsFifteen patients were included and the SLNB procedure was successful in all patients (27 SLNs removed). All superparamagnetic SLNs were visualized by MRI corresponding to the same nodes on scintigraphy. Micrometastatic deposits were identified in four SLNs taken from three patients, and SPIO-MRI correctly predicted two of the metastases. There was an association between MRI artefacts in the lymph node and the dose SPIO given. DiscussionIt is feasible to detect SLN in patients with melanoma using a low dose of SPIO injected intracutaneously compared with the standard dual technique. A low dose of SPIO reduces the lymph node MRI artefacts, opening up for a non-invasive assessment of SLN status in patients with cancer.

Percutaneous contrast-enhanced ultrasound for localization and qualitative diagnosis of sentinel lymph nodes in cutaneous malignant melanoma of lower extremities: a preliminary study.

To explore the feasibility of sentinel lymph node (SLN) tracing by percutaneous contrast-enhanced ultrasound (pCEUS) in patients with cutaneous malignant melanoma (CMM) and the ability to enhance patterns of SLNs in diagnosing lymph nodes (LNs) metastases. Fifty-three patients with CMM of the lower extremities treated at our hospital were included in the study. All the participants received pCEUS preoperatively. The enhanced lymphatic channels (LCs) and associated SLNs were observed and tracked in real-time. The number of enhanced LCs and enhancing patterns of SLNs were recorded. Subsequently, SLNs localized by pCEUS were pathologically examined. Of the 53 cases, SLNs were successfully localized by pCEUS in 48 cases. In total, there were 59 detected SLNs averaging 1.23±0.42 SLNs per case. The main lymphatic drainage patterns (LDPs) were the following: one enhanced LC pointed to one or more than one SLN, and multiple enhanced LCs pointed to one or multiple SLNs. There were four enhancing patterns of SLNs (uniform, annular, uneven, and no enhancement), among which the first two were considered benign nodes, while the latter two were considered metastatic nodes. With pathological results as the gold standard, the diagnostic sensitivity and specificity by pCEUS were 90.9% and 75.0%, respectively. Contrast-enhanced ultrasound (US) is a feasible approach for SLN identification in patients with CMM of the lower extremities. Enhancing patterns of SLNs may help predict metastasizing SLNs. This novel method may be a promising technique for clinical application.

Assessment of sentinel lymph node detection by radioisotope scan and methylene blue alone in operable oral cavity cancer to assess its accuracy for metastasis

Background: Squamous cell carcinoma (SCC) is the most common malignancy affecting the oral cavity. It typically metastasizes into the regional cervical lymph nodes before spreading to distant organs.Methods: A prospective study on sentinel lymph node biopsy (SLNB) in early oral cancers using methylene blue dye and sentinel node localisation using pre-operative lymphoscintigraphy and intraoperative gamma probe in early oral cavity cancer.Results: Present study had a male to female ratio of 1.9:1, with (65.5%) male and (34.5%) female patients. Present study had a side distribution of disease more on left side with 138 patients (62.7%) and ratio of left to right was approximately 1.7:1. In present study most predominating gross morphological pattern of growth was ulcerative (35%) followed by ulcero-infilterative (25%). Buccal mucosa was the most common sub-site of origin of carcinoma in oral cavity, followed by tongue, with 83 (37.7%) and 64 (29.1%) patients. Identification rate of methylene blue dye was 91.7% (100 out of 109 patient). Identification rate of radionuclide tracer was 94.6% (105 out of 111 patient). In methylene blue dye group out of 103 metastatic sentinel lymph nodes, 9 metastatic sentinel lymph nodes were detected on IHC.Conclusions: With the above results it can be concluded the SLNB study is liable in detection of actual positive node and can avoid unnecessary neck dissections in patients with SCC with negative sentinel lymph node, as having very low risk of occult lymphatic metastases in the remaining lymphatic drainage.

Within-patient comparison between [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy and [99mTc]Tc-tilmanocept lymphoscintigraphy for sentinel lymph node detection in oral cancer: a pilot study

To compare sentinel lymph node (SLN) identification using [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy to [99mTc]Tc-tilmanocept lymphoscintigraphy (including SPECT/CT) in early-stage oral cancer. Furthermore, to assess whether reliable intraoperative SLN localization can be performed with a conventional portable gamma-probe using [99mTc]Tc-tilmanocept without the interference of [68Ga]Ga-tilmanocept in these patients. This prospective within-patient comparison pilot study evaluated SLN identification by [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy compared to conventional lymphoscintigraphy using [99mTc]Tc-tilmanocept (~ 74MBq) in 10 early-stage oral cancer patients scheduled for SLN biopsy. After conventional [99mTc]Tc-tilmanocept lymphoscintigraphy, patients underwent peritumoral administration of [68Ga]Ga-tilmanocept (~ 10MBq) followed by PET/CT acquisition initiated 15min after injection. Intraoperative SLN localization was performed under conventional portable gamma-probe guidance the next day; the location of harvested SLNs was correlated to both lymphoscintigraphic images in each patient. A total of 24 SLNs were identified by [99mTc]Tc-tilmanocept lymphoscintigraphy, all except one were also identified by [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy. [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy identified 4 additional SLNs near the injection site, of which two harbored metastases. Lymphatic vessels transporting [68Ga]Ga-tilmanocept were identified by PET/CT lymphoscintigraphy in 80% of patients, while draining lymphatic vessels were visualized by [99mTc]Tc-tilmanocept lymphoscintigraphy in 20% of patients. Of the 33 SLNs identified by [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy, 30 (91%) were intraoperatively localized under conventional gamma-probe guidance. [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy provided more accurate identification of SLNs and improved visualization of lymphatic vessels compared to [99mTc]Tc-tilmanocept lymphoscintigraphy. When combined with peritumoral administration of [99mTc]Tc-tilmanocept, SLNs detected by [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy can be reliably localized during surgery under conventional gamma-probe guidance.

Predictors of uncommon location of sentinel nodes in endometrial and cervical cancers

ObjectiveSentinel node mapping is widely used in the treatment of gynecologic cancers. The current study aimed to identify predictors of uncommon sentinel lymph node (SLN) locations. MethodsThe current study included women who were operated for endometrial or cervical cancer with attempted sentinel lymph node mapping during surgical staging. Data were collected from electronic charts. The pelvis and the external ilia and obturator basins were common node locations. Para-aortic, pre-sacral, common iliac, internal iliac, and parametrial nodes were considered uncommon locations. We conducted analyses stratified according to common, uncommon, and very uncommon (para-aortic, pre-sacral, parametrial) node location sites. ResultsA total of 304 women were enrolled in the current study; 15.8% had SLN in uncommon locations and 4.3% had very uncommon node locations. Body mass index (BMI) was a negative predictor for uncommon SLN locations (OR 0.88, p = 0.03). The use of either indocyanine green (ICG) or Tc99 & blue dye was an independent predictor for uncommon SLN locations (OR 8.24, p = 0.006). More recent surgeries and the presence of positive nodes were independent predictors for very uncommon node locations (OR 2.13, p = 0.011, and OR 9.3, p = 0.002, respectively). ConclusionsBMI, tracer type, surgical year, and positive nodes were independent predictors for uncommon SLN locations. These findings suggest that surgical effort, technique and experience may result in better identification of uncommon SLN locations.

Methods of Sentinel Lymph Node Identification in Auricular Melanoma.

Background:Sentinel lymph node biopsy is used to evaluate for micrometastasis in auricular melanoma. However, lymphatic drainage patterns of the ear are not well defined and predicting the location of sentinel nodes can be difficult. The goal of this study was to define the lymphatic drainage patterns of the ear and to compare multiple modalities of sentinel node identification.Methods:A retrospective review of a prospectively maintained database evaluated 80 patients with auricular melanoma who underwent sentinel lymph node biopsy by comparing preoperative imaging with intraoperative identification of sentinel nodes. Patients were placed into two cohorts, based on the modality of preoperative imaging: (1) planar lymphoscintigraphy only (n = 63) and (2) single-photon emission computerized tomography combined with computerized tomography (SPECT-CT) only (n = 17). Sites of preoperative mapping and sites of intraoperative identification were recorded as parotid/preauricular, mastoid/postauricular, and/or cervical.Results:In patients that underwent planar lymphoscintigraphy preoperatively (n = 63), significantly more sentinel nodes were identified intraoperatively than were mapped preoperatively in both the parotid/preauricular (P = 0.0017) and mastoid/postauricular (P = 0.0047) regions. Thirty-two nodes were identified intraoperatively that were not mapped preoperatively in the planar lymphoscintigraphy group (n = 63), two of which were positive for micrometastatic disease. In contrast, there were no discrepancies between preoperative mapping and intraoperative identification of sentinel nodes in the SPECT-CT group (n = 17).Conclusions:SPECT-CT is more accurate than planar lymphoscintigraphy for the preoperative identification of draining sentinel lymph nodes in auricular melanoma. If SPECT-CT is not available, planar lymphoscintigraphy can also be used safely, but careful intraoperative evaluation, even in basins not mapped by lymphoscintigraphy, must be performed to avoid missed sentinel nodes.

Analysis of the Different Lymphatic Drainage Patterns during Sentinel Lymph Node Biopsy for Skin Melanoma

In the last two decades, studies of lymphoscintigraphy imaging in lymphatic mapping reported an extreme heterogeneity of skin lymphatic drainage of some skin area, in contrast with the previous scientific literature. The aim of this study was to investigate the presence of any correlations between the topographical location of cutaneous melanoma and the topographical location of sentinel lymph nodes. Data from 165 patients undergoing sentinel lymph node biopsy between January 2013 and May 2021 were analyzed, demonstrating that melanomas in the Lumbar region presented a significant more heterogeneous drainage by site than those in the Scapular region (p < 0.01) and that melanomas in the Subscapular region were significantly more heterogeneous by laterality (unilateral vs. bilateral) than those in the Scapular region (p < 0.05). Results of this study supported the evidence of multiple lymphatic drainage as regards the sentinel node biopsy performed in skin melanoma located on the dorsal subscapular region and lumbar region. For this reason, the association of preoperative lymphoscintigraphy with another imaging evaluation is needed in these critical cutaneous areas. Recent technical developments enabling fluorescence lymphography together with indocyanine green have significantly improved the visualization of lymphatic drainage patterns at a microscopic level. In the preoperative phase, any doubt can be resolved by associating the SPET-CT scan to lymphoscintigraphy, while during the intraoperative phase, an additional evaluation with indocyanine green can be performed in doubtful cases. The aim of the duplex lymphatic mapping (pre and/or intraoperative) is an accurate search of sentinel nodes, in order to reduce the rate of false negatives.

Efficacy of sentinel lymph node mapping in endometrial cancer with low‐ or high‐intermediate risk

This study was aimed to evaluate the efficacy of sentinel lymph node (SLN) mapping using indocyanine green (ICG) in Chinese women with endometrial cancer (EC). Consecutive EC patients undergoing SLN mapping at Obstetrics and Gynecology Hospital of Fudan University were retrospectively reviewed. Overall and bilateral SLN detection rates and SLN locations were presented. Sensitivity, negative predictive value (NPV), and agreement rate were calculated and were compared between patients with low-intermediate (LIR) or high-intermediate risk (HIR). There were 454 patients screened, with SLN mapping with ICG performed in 428 patients and systematic lymphadenectomy performed in 159 patients. Overall and bilateral SLN detection rates were 96.50% and 82.71%, respectively. The sensitivity of SLN mapping was 80.00%, and the NPV was 97.76%. SLNs were most commonly located in obturator and external iliac regions. Efficacy of SLN mapping was higher in LIR patients than in HIR patients, with sensitivities of 100.00% and 75.00% (p > 0.05), NPVs of 100.00% and 90.00% (p = 0.002), and agreement rates of 100.00% and 92.31% (p = 0.007), respectively. SLN mapping with ICG had acceptable diagnostic efficacy in Chinese women with EC, but may cause more missed diagnoses in patients with HIR due to relatively low NPV and agreement rate.

Single photon emission computed tomography-computed tomography visualization of sentinel lymph nodes for lymph flow guided nodal irradiation in oral tongue cancer.

PurposeTo evaluate correlation of single photon emission computed tomography-computed tomography (SPECT-CT) data on lymph flow (LF) from oral tongue cancer (OC) and the topography of lymph nodes (LN) metastases; to determine the clinical value of lymph flow guided radiotherapy (LFGRT).Materials and methodsSPECT-CT visualization of LF from the OC lesions was performed after peritumoral injection of 99mTc-phytate in 26 primary patients with clinical stage cT1-2N0M0 disease. We determined the individual drainage (unilateral/bilateral) from the tumor, and localization of sentinel LNs according to the neck levels. Metastases in LNs were verified with histology and a 2-year follow-up.ResultsSPECT-CT detected bilateral LF in 10 (38.5%) of 26 patients; in 16 (61.5%) cases the drainage was unilateral. Histology revealed LNs metastases in three cases; regional recurrences were diagnosed in other four patients. In all seven observations metastases were located at the same site and level as the sentinel LNs. In eight (30.8%) of 26 patients sentinel LNs were visualized unilaterally at levels Ib–IIa; in five cases, unilaterally at levels I–IIa–III. In these patients, LFGRT demonstrated 59%–70% reduction of irradiated volume, and 26%–42% and 51%–70% decrease of the mean dose to the spinal cord and the contralateral parotid gland. In patients with a bilateral drainage the reduction of doses absorbed by the spinal cord and contralateral parotid gland was 19% and 6%, respectively.ConclusionLocalization of sentinel LNs determined by SPECT-CT corresponds to the localization of metastatic LNs in terms of side and levels.

A Study on the Detection Rates and Location of Sentinel Lymph Node in Patients with Gynecologic Cancers.

Sentinel lymph node mapping is emerging as an accurate technique to assess the lymph nodal status while reducing surgical and postoperative morbidity. Present study looks into the detection rates and location of sentinel nodes during Sentinel node mapping when Indocyanine green dye was used as a tracer. This is a single institutional study with details retrieved from a prospectively maintained database. All patients who underwent sentinel node mapping using ICG dye for atypical hyperplasia, endometrial and cervical cancers from February 2015 to April 2020 were included. Location of the sentinel node was taken from the graphical record maintained during surgery. The data obtained are expressed as number and percentage and/or mean and standard deviation for continuous variables. Chi-square test was performed to compare categorical variables. Two hundred and seventy-nine patients underwent sentinel node mapping with ICG dye during this period. Mapping was successful in 270 patients (96.8%) with 85% having successful bilateral mapping. Obturator was the most common location (52%) followed by external iliac (34%). There was no significant difference in detection among patients with BMI less than 30 or more than 30. The detection rate across various histologies of endometrial cancer was also similar. Sentinel node mapping using ICG dye has got excellent overall and bilateral detection rates making it a valuable tool. Obturator was found to be the most common location for the sentinel node. Mapping using ICG dye yield good detection rates in all histologies of endometrial cancer and in patients with high BMI.

Sentinel lymph node biopsy in upper tract urothelial cancers: an experience with intraoperative radiotracer injection.

The feasibility of the sentinel node mapping in upper tract urothelial cancers (UTUC) was evaluated, using a radiotracer as the mapping material. To identify the sentinel lymph nodes, 37 MBq of [99mTc] phytate was injected in five patients with the renal pelvis or ureter cancer, who were candidates for ureterectomy and lymphadenectomy. The radiotracer was injected in a peritumoral fashion following the surgical exposure of the tumour. The sentinel lymph nodes were detected using a handheld gamma probe. By intraoperatively injecting the radiotracer immediately after surgical exposure of the tumour, at least one sentinel lymph node could be detected in each patient, and the detection rate was 100%. The location of sentinel nodes was in the paracaval, renal hill, retro-aortic, para-aortic, common iliac, and external iliac areas, which was dependent on the tumour location. No false-negative case was identified. Sentinel node mapping is feasible in UTUC. Injection technique (intra-vesical approach vs peri-tumoral injection after exposure of the tumour) and location of the tumour (proximal vs distal) may affect the technique's feasibility.

Feasibility of Sentinel Lymph Node Sampling in Early-Stage Carcinoma Endometrium: Single-Institution Experience.

Accurate surgical staging is an essential component in the management of carcinoma endometrium to assess the stage of disease and to tailor adjuvant treatment. Sentinel node technique was introduced as an alternative for extensive lymphadenectomy in early stages to avoid complications associated with lymphadenectomy. To assess the detection rate and diagnostic accuracy of SLN mapping in patients with early-stage carcinoma endometrium. Prospective validation study involving 30 patients diagnosed to have early-stage carcinoma endometrium. Sentinel nodes were detected by combined methods of radio colloid dye and isosulphan blue dye injection. Sentinel lymph node was detected in 19 patients (63.4%). 11 patients had no sentinel nodes. Total number of sentinel nodes isolated was 68 with a mean of 2.26 per patient (range 0-4). Ten (33.33%) patients had single sentinel node location, while 9 (30%) had more than 1 sentinel lymph nodes. Twelve patients had bilateral sentinel nodes, and the most frequent location of sentinel node was obturator, 19 (63.3%) especially on right hemi-pelvis. One patient had a hot para-aortic node, while none had blue para-aortic sentinel node. Average number of lymph nodes obtained by lymphadenectomy was 13 per patient (range 7-22). All patients with sentinel node had negative frozen report as well as in histopathology. Two patients in whom no sentinel nodes were detected by either techniques had metastatic nodes in histopathology report. Detection rate was maximum with radiocolloid dye, and it is better to utilize the technique for less graded tumours and endometrioid variants.

Introducing SentiMag in a rural setting: a 5-year experience.

The Sentimag device is a probe that contains a sensitive magnetometer which detects either an implantable magnetic marker (MagSeed) or an infectable superparamagnetic ironoxide nanoparticle tracer (MagTrace). MagSeed is used to localise impalpable breast lesions; MagTrace is used to identify sentinel lymph nodes. In Australasia, Sentinel lymph node (SLN) biopsy, using radioactive colloid injection, is a mainstay of prognostication in breast surgery in patients with a clinically negative axilla. In addition, radioactive seeds or hookwires have been used to detect impalpable breast lesions. Gisborne Hospital has been using the SentiMag device since June 2016 to both identify sentinel lymph nodes (Magtrace) and impalpable tumours (Magseed). This study gives perspective over more than 5 years on how this new technology can benefit patients and clinicians in the rural setting. Patient data had been collected by the operative surgeon prospectively and corroborated with the coding department. Consecutive cases performed by a single surgeon were included in this study. Inclusion criteria were: (1) any patient who needed localisation of an impalpable breast lesion; (2) any patient who needed a sentinel lymph node biopsy; (3) cases were collected from January 2013 with the large majority of cases were collected between January 2015 and Jan 2020. Comparisons were made between patients with different localisation methods. Basic demographics were collected at the time of the surgery and outcomes then recorded. Staging, lymph node status, lymph node detection rates and complications were collected. Mode of tumour and sentinel node location was recorded. Financial data was collected from administrative staff via receipts and invoices of purchases to the hospital. Of the 125 patients included in this study: 23 underwent magnetic seed insertion; 15 underwent a hookwire insertion; 45 cases used MagTrace injection; 71 cases used radioactive colloid injection. There was a significantly higher detection rate of two or more sentinel nodes in the SentiMag group. (91% vs. 71.8%, p=0.01). Neither complication rates, nor cancer detection rates were significantly different. Eighty-four (67.2%) cases did not require tumour location. SentiMag is safe to use in a rural setting. Using the SentiMag system can simplify care for patients and surgeons and was shown to be cost effective in our hospital.

Introducing the GammaPen: All-in-One Gamma Probe for Sentinel Lymph Node Biopsy

Purpose: Using an itra-operative gamma probe after injection of radiotracer during surgery helps the surgeon to identify the sentinel lymph node of regional metastasis through the detection of radiation. This work reports the design and specification of an integrated gamma probe (GammaPen), developed by our company. Materials and Methods: GammaPen is a compact and fully integrated gamma probe. The detector module consists of a thallium-activated Cesium Iodide (CsI (Tl)) scintillator, and a Silicon Photo Multiplier (SiPM), shielded using Tungsten housing. Probe sensitivity, spatial resolution and angular resolution in air and water, and side and back shielding effectiveness were measured to evaluate the performance of the probe based on NEMA NU3 standard. Results: The sensitivity of the probe in the air/water at distances of 10, 30, and 50 mm is 18784/176800, 3500/3050, and 1575/1104 cps/MBq. The spatial and angular resolutions in the air/scattering medium are 40/47 mm and 77/87 degrees at a 30 mm distance from the probe. The detector shielding effectiveness and leakage sensitivity are 99.91% and 0.09%, respectively. Conclusion: The results and surgeon experience in the operating room showed that GammaPen can be effectively used for sentinel lymph node localization.

Real-Time In Situ Navigation System With Indocyanine Green Fluorescence for Sentinel Lymph Node Biopsy in Patients With Breast Cancer.

BackgroundThe naked-eye invisibility of indocyanine green fluorescence limits the application of near-infrared fluorescence imaging (NIR) systems for real-time navigation during sentinel lymph node biopsy (SLNB) in patients with breast cancer undergoing surgery. This study aims to evaluate the effectiveness and safety of a novel NIR system in visualizing indocyanine green fluorescence images in the surgical field and the application value of combined methylene blue (MB) and the novel NIR system in SLNB.MethodsSixty patients with clinical node-negative breast cancer received indocyanine green (ICG) and MB as tracers. Two NIR system instruments, namely, lymphatic fluorescence imaging system (LFIS) designed by the University of Science and Technology of China and vascular imager by Langfang Mingde Medical Biotechnology Co., Ltd. (Langfang vascular imager), were used as navigation assistance to locate sentinel lymph nodes (SLNs). Excising the lymph nodes developed by both MB and ICG by two NIR systems or palpably suspicious as SLNs and undergoing rapid pathological examination.ResultsBoth instruments exhibited 95% (57/60) success for real-time lymphatic fluorescent images. A total of 186 SLNs were identified, of which two were pathologically confirmed as lacking any lymph node tissue. SLN identification rate was 100% (184/184) for MB plus LFIS and 86.96% (160/184) for MB alone. The median number of SLNs identified by LFIS combined with MB was 3 (range of 1–8), which was significantly higher than that by MB alone at 2 (range 1–7) (P<0.05).ConclusionLFIS effectively detects SLNs in breast cancer, projects the fluorescence signals during surgery, and provides a continuous surgical navigation system without the need for a remote monitor. The ICG method navigated by combined LFIS and MB may be a promising alternative tracer for radioisotope in SLN mapping.Clinical Trial RegistrationThis clinical trial was registered with the China Clinical Trial Center, registration number ChiCTR2000039542.

Comparative study of two contrast agents for intraoperative identification of sentinel lymph nodes in patients with early breast cancer.

The use of contrast-enhanced ultrasound (CEUS) to locate sentinel lymph nodes (SLNs) in breast cancer has been studied more and more in recent years. This prospective study aimed to compare periareolar injection of two different contrast agents, SonoVue® (SNV) and Sonazoid® (SNZ), followed by CEUS to identify SLNs in breast cancer patients with clinically negative nodes. A total of 205 patients with T1-2N0M0 breast cancer were divided into the SNV group and SNZ group. All were administered a periareolar injection of SNV or SNZ and underwent US to identify contrast-enhanced SLNs. Each contrast-enhanced SLN underwent a biopsy with blue dye and examined again by CEUS in vitro. In all cases, contrast-enhanced lymphatic vessels were clearly visualized using US soon after the periareolar injection of SNZ, and the SLNs were easily identified. The SLN identification rates were 75.27% (210/279) for SNV and 93.58% (102/109) for SNZ. Although the accuracy of detecting SLN metastasis was slightly different between the two groups, there was no statistically significant difference between those groups (P=0.615). Moreover, it was possible to identify SLNs in vitro in the SNZ group, and these could be compared with the lymph nodes (LNs) located using SNZ during the preoperative stage and with blue dye during the procedure. This helped in determining the resection requirements. When comparing the subdermal use of SNV and SNZ, no significant differences in the number of detected SLNs and the diagnosis of metastatic LNs were observed. Because SLNs can be detected for a longer time in living tissues with SNZ, this contrast agent may provide more intraoperative information for complete resection of all preoperative localization of SLN.

Sentinel lymph node biopsy in breast cancer guided by CT lymphography; History, evolution and current applications.

Sentinel lymph node biopsy (SLNB) has efficiently replaced axillary lymph node dissection (ALND) in axillary staging in node-negative breast cancer patients. Dual sentinel lymph node (SLN) localization using radioisotopes and blue dye is the standard technique for SLN mapping. Yet, nuclear medicine facilities are not widely available worldwide. In Japan, Computed tomography lymphography (CTLG) is presented as an SLN mapping technique which was first suggested in 2003 by Suga etal. Multiple subsequent studies confirmed the efficacy of CTLG in SLN mapping in breast cancer. Further applications of the technique followed; such as prediction of SLN metastasis using CTLG, the use of CTLG guided SLN biopsy after neoadjuvant therapy, video-assisted CTLG guided SLN biopsy, the use of real-time virtual sonography with 3-D CTLG, and preoperative localization of the CTLG mapped SLN using either real-time virtual sonography (RVS) guided Indocyanine green (ICG) injection or its marking using liquid charcoal and silver wire and the use of SPIO enhanced magnetic resonance imaging (MRI) for prediction of metastasis in SLNs detected by CTLG. This efficacy and variable applications open the door for conducting wide-scale randomized controlled trials to suggest using CTLG as an efficient alternative for the use of radioisotopes in SLN mapping in breast cancer patients, especially in low and middle-income countries.