scholarly journals 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

Author(s):  
Aram Radnia ◽  
Hamed Abdollahzadeh ◽  
Behnoosh Teimourian ◽  
Mohammad Hossein Farahani ◽  
Mohammad Esmaeil Akbari ◽  
...  

Abstract 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.

Author(s):  
Aram Radnia ◽  
Hamed Abdollahzadeh ◽  
Behnoosh Teimourian ◽  
Mohammad Hossein Farahani ◽  
Mohammad Reza Ay

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.


2020 ◽  
Author(s):  
Annie K. Kogler ◽  
Andrew M. Polemi ◽  
Surabhi Nair ◽  
Stanislaw Majewski ◽  
Lynn E. Dengel ◽  
...  

Abstract Background Assessment of lymphatic status via sentinel lymph node (SLN) biopsy is an integral and crucial part of melanoma surgical oncology. The most common technique for sentinel node mapping is preoperative planar scintigraphy of an injected gamma-emitting lymphatic tracer followed by intraoperative node localization using a non-imaging gamma probe with auditory feedback. In recent years, intraoperative visualization of SLNs in 3-D has become possible by coupling the probe to an external system capable of tracking its location and orientation as it is read out, thereby enabling computation of the 3D distribution of the tracer (freehand SPECT). In this project, the non-imaging probe of the fhSPECT system was replaced by a unique handheld gamma camera containing an array of sodium iodide crystals optically coupled to an array of silicon photomultipliers. A feasibility study was performed in which preoperative SLN mapping was performed using camera fhSPECT and the number of detected nodes was compared to that visualized by lymphoscintigraphy, probe fhSPECT, and to the number ultimately excised under non-imaging probe guidance.Results Among five subjects, SLNs were detected in nine lymphatic basins, with one to five SLNs detected per basin. A basin-by-basin comparison showed that the number of SLNs detected using camera fhSPECT exceeded that using lymphoscintigraphy and probe fhSPECT in seven of nine basins and five of five basins, respectively (probe fhSPECT scans were not performed for four basins). It exceeded the number excised under non-imaging probe guidance for seven of nine basins. There were no basins for which the number of excised nodes exceeded the number detected by camera fhSPECT. Conclusions Freehand SPECT using a prototype silicon photomultiplier-based gamma camera demonstrates high sensitivity for detection of SLNs in a preoperative setting. Camera fhSPECT is a potential means for efficiently obtaining real-time 3D activity distribution maps in applications such as image-guided percutaneous biopsy, and surgical SLNB or radioguided tumor excision.


2000 ◽  
Vol 39 (07) ◽  
pp. 214-217 ◽  
Author(s):  
B. Konz ◽  
M. H. Schmid-Wendtner ◽  
C. Sander ◽  
S. Dresel ◽  
K. Tatsch ◽  
...  

Summary Aim: The Sentinel Lymph Node (SLN) is of considerable prognostic relevance, because extended lymph node dissection may not be performed in patients presenting with histologically negative SLN. The aim of the present study was to prove the prognostic value of the SLN-concept in these patients. Methods: So far the clinical follow-up of 162 patients with histologically proven malignant melanoma and metastatically uninvolved (negative) SLN was investigated. Histological examination included standard methods (HE-Test) and special histochemical techniques (S-100, HMB-45). All patients underwent clinical examination, ultrasonic diagnosis of the regional lymph nodes, and x-ray of the chest every 3 months. Results: Despite of negative SLN-findings in 8/162 patients metastases of the malignant melanoma were found after a time period of 5-27 months. Three patients presented with recurrence in the previously mapped (negative) SLN-basin. In another case the scintigraphically visualized SLN could not be identified intraoperativelly by means of the hand-held gamma probe. One patient showed intransit-metastases or skin-metastases, respectively; another patient recurred in the scar area. One patient showed hematogenic dissemination (liver) which is not detectable by lymphoscintigraphy; in another patient metastases were found outside the primary lymphatic basin (cervical). Conclusion: In our patient group 4,9% presented with metastases despite negative SLN while published data report up to 11% (observation period 35 months), among them only 3 patients (1,9%) being real concept failures. Our results underline that there is no evidence to change this concept in patients with clinically early stage.


Author(s):  
Azadeh Nikoogoftar ◽  
Mojtaba Shamsaie ◽  
Navid Zeraatkar ◽  
Mohammad Reza Ay

Introduction: Sentinel lymph node biopsy (SLNB) is a standard surgical technique to identify sentinel lymph node (SLN) for the staging of early breast cancer. Nowadays, two methods are used for the identification of SLN: blue dye method aiding visually and radioactive dye using gamma detector. A wide range of gamma probe systems with different design and performance are used in intra-operative surgery. The performance of the probes is evaluated by some parameters such as sensitivity, spatial resolution, angular resolution, and shielding efficiency. Methods: In this study, we simulated a gamma probe system, SURGEOGUIDE II based on CsI(Tl) scintillator, a silicon photomultiplier (SiPM), and a tungsten collimator, using the MCNP4C Monte Carlo (MC) method and comparing with experimental measurement. Finally we modeled a series of probe with various crystal material, crystal length, and collimator hole length to evaluate the sensitivity and the spatial resolution in order to propose the optimal configuration. Results: The sensitivity of the system was measured as 2040 cps/MBq in 30 mm distance from the source. The spatial resolution and angular resolution were 43 mm and 70


2004 ◽  
Vol 43 (01) ◽  
pp. 10-15 ◽  
Author(s):  
R. A. Schmid ◽  
C. Kunte ◽  
B. Konz ◽  
K. Hahn ◽  
M. Weiss

Summary Aim of this study was to localize the sentinel lymph node by lymphoscintigraphy using technetium-99m colloidal rhenium sulphide (Nanocis®), a new commercially available radiopharmaceutical. Due to the manufacturers’ instructions it is licensed for lymphoscintigraphy. Patients, methods: 35 consecutive patients with histologically proved malignant melanoma, but without clinical evidence of metastases, were preoperatively examined by injecting 20-40 MBq Nanocis® with (mean particle size: 100 nm; range: 50-200 nm) intradermally around the lesion. Additionally blue dye was injected intaoperatively. A hand-held gamma probe guided sentinel node biopsy. Results: During surgery, the preoperatively scintigraphically detected sentinel lymph nodes were identified in 34/35 (97%) patients. The number of sentinel nodes per patient ranged from one to four (mean: n = 1.8). Histologically, metastatic involvement of the sentinel lymph node was found in 12/35 (34%) patients; the sentinel lymph node positive-rate (14/63 SLN) was 22%. Thus, it is comparable to the findings of SLN-mapping using other technetium-99m-labeled nanocolloides. Conclusion: 99mTc-bound colloidal rhenium sulphide is also suitable for sentinel node mapping.


2018 ◽  
Vol 64 (3) ◽  
pp. 335-344
Author(s):  
Aleksey Karachun ◽  
Yuriy Pelipas ◽  
Oleg Tkachenko ◽  
D. Asadchaya

The concept of biopsy of sentinel lymph node as the first lymph node in the pathway of lymphogenous tumor spread has been actively discussed over the past decades and has already taken its rightful place in breast and melanoma surgery. The goal of this method is to exclude vain lymphadenectomy in patients without solid tumor metastases in regional lymph nodes. In the era of minimally invasive and organ-saving operations interventions it seems obvious an idea to introduce a biopsy of sentinel lymph node in surgery of early gastric cancer. Meanwhile the complexity of lymphatic system of the stomach and the presence of so-called skip metastases are factors limiting the introduction of a biopsy of sentinel lymph node in stomach cancer. This article presents a systematic analysis of biopsy technology of signaling lymph node as well as its safety and oncological adequacy. Based on literature data it seems to us that the special value of biopsy of sentinel lymph nodes in the future will be in the selection of personalized surgical tactics for stomach cancer.


2000 ◽  
Vol 15 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Giuliano Mariani ◽  
Giuseppe Villa ◽  
Marco Gipponi ◽  
Pietro Bianchi ◽  
Ferdinando Buffoni ◽  
...  

2018 ◽  
Vol 29 (2) ◽  
pp. 377-381 ◽  
Author(s):  
V Lago ◽  
P Bello ◽  
B Montero ◽  
L Matute ◽  
P Padilla-Iserte ◽  
...  

IntroductionThere is limited evidence favoring the use of the sentinel lymph node technique in ovarian cancer, and no standardized approach has been studied. The objective of the present pilot study is to determine the feasibility of the sentinel lymph node technique by applying a clinical algorithm.MethodsPatients with confirmed ovarian cancer were included. 99mTc and indocyanine green were injected into the ovarian and infundubulo-pelvic ligament stump. A gamma probe and near-infrared fluorescence imaging were used for sentinel lymph node detection.ResultsThe sentinel lymph node technique was performed in ten patients with a detection rate in the pelvic and/or para-aortic region of 100%. The tracer distribution rates of sentinel lymph nodes in the pelvic and para-aortic regions were 87.5% and 70%, respectively.ConclusionThe detection of sentinel lymph nodes in early-stage ovarian cancer appears to be achievable. Based on these results, a clinical trial entitled SENTOV (SENtinel lymph node Technique in OVarian cancer) will be performed.


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