Identify Sentinel Lymph Nodes Research Articles

Combination Probe and Dye-Directed Lymphatic Mapping Detects Micrometastases in Early Colorectal Cancer

Nodal metastasis is the single most important prognostic factor in early colorectal cancer (CRC). Lymphatic mapping can identify sentinel nodes for focused histopathologic examination and thereby improve the nodal staging of CRC; however, the optimal technique for identifying sentinel nodes in CRC is unclear. We hypothesized that a combination of radiotracer and blue dye would more accurately identify tumor-positive sentinel nodes than blue dye alone. Lymphatic mapping was performed in 48 consecutive patients undergoing resection for CRC and in two original patients who underwent sentinel node mapping in 1996. Prior to resection, 1% vital blue dye and radiotracer were injected around the tumor in the subserosal layer. Nodes were designated as sentinel by blue coloration and/or radioactivity. Lymphatic mapping identified at least one sentinel node in 49 patients. Focused examination of multiple sentinel node sections by means of hematoxylin and eosin and immunohistochemical analysis showed that sentinel nodes accurately predicted the status of the nodal basin in 93.8% (46 of 49) of patients. Of the 19 patients with nodal metastases, 11 had macrometastases (>.2 mm), three had micrometastases (between 2 mm and 0.2 mm), and five had isolated tumor cells or clusters (<.2 mm) identified by immunohistochemical analysis only. Patients had significantly fewer blue/radioactive (“hot”) nodes than blue-only nodes (1.38 vs. 2.48 per patient; P = 0.0001). It is important to note that nodal metastases were more common in blue/hot nodes than in blue-only nodes (27.3% [19 of 68] vs. 8.8% [11 of 124]; P = 0.005). Dual-agent lymphatic mapping more accurately identifies sentinel node metastases than blue dye alone. In addition, this technique allows a more focused histopathologic examination of these nodes, in conjunction with the revised American Joint Committee on Cancer guidelines, and thereby offers the potential for significant upstaging of CRC. ( J Gastrointest Surg 2003;7:340–346.)

Endoscopic Sentinel Node Biopsy

Purpose: Sentinel node biopsy has emerged recently as an alternative to routine axillary node dissection in predicting axillary nodal metastasis. However there have been some controversies in clinical application because of its various identification rates and false negative rates. We present the usefulness of dye-guided endoscopic sentinel node biopsy. Methods: Between October 2002 and June 2003, 30 breast cancer patients with clinically node negative results underwent endoscopic blue dye-guided sentinel node biopsy from the Department of Surgery at Kangbuk Samsung Hospital. The technique involved the injection of 5 ml of 1% isosulfan blue into subareolar plexus. The Visiport docked with Telescope was inserted through a low transverse axillary incison lateral to pectoralis major. During the dissection, we identified sentinel nodes by following bluestained lymphatics directly into blue (or nonblue) lymph nodes. The identification rate and false negative rate was evaluated. Results: The mean number of sentinel nodes was 2.2. The identification rate of th sentinel node was 93.3% (28/30). Among 22 patients with negative sentinel nodes on frozen section, 10 patients underwent axillary node dissection and the results were negative in all cases, indicating false negative rate of 0% (0/10). The overall accuracy, sensitivity and specificity were 100%. Conclusion: The endoscopic technique of sentinel node biopsy can minimize the operative bleeding by handling the knife of Visiport pallelel to exposed vessels under endoscopic monitor analysis and and keep better operative visual field and less invasiveness. With the bright illumination of the endoscopic light, blue-stained sentinel lymphatics could be identified more easily. Our technique of dye-guided endoscopic sentinel node biopsy demonstrates a high sentinel node identification rate and absent false negative rate, promising it could be an alternative to the classic sentinel node biopsy. (Journal of Korean Breast Cancer Society 2003;6:174-179) ꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏ

Clinically useful detection criteria for sentinel nodes in patients with breast cancer using a radioisotope technique.

The radioisotope technique has been used to identify sentinel nodes in patients with breast cancer. However, quantitative analysis of the radioactivity for detecting the sentinel nodes was not previously examined. In this study, we considered a clinically useful criterion for detecting sentinel nodes by a detailed analysis of 312 sentinel nodes using the radioisotope technique. Patients with T1-2, N0 breast cancer were eligible for this study. The nodes with the highest radioactivity after injection of technetium-labeled tin colloids were identified as hot nodes. The radioactivities of the hot nodes and the background counts of the axillary basin were examined in order to establish new criteria for detecting the sentinel nodes. Between May 1997 and December 2001, 312 hot nodes were detected in 183 of 186 patients (98.4%). Since the false-negative rate for metastasis in hot nodes was only 2.1% (1/48), they could serve as sentinel nodes to predict the nodal status. However, there was a wide distribution of the hot nodes and the background in terms of absolute counts and a criterion for the sentinel nodes could not be established in terms of the absolute counts. When we adopted the criterion of sentinel nodes with a >/=100 count ratio in relation to the background, only 169 hot nodes (54.3%) met our definition. When the criterion of a >or=10 count ratio was adopted, all hot nodes met our definition and all other nodes remained non-sentinel nodes. The criterion for defining sentinel nodes in our method is a node with a >or=10 count ratio with respect to the background. It is recommended that an analysis based on such objective data should be investigated in order to provide surgeons with more accurate and clinically useful criteria for detecting sentinel nodes.

New method of sentinel node identification with ultrasonography using albumin as contrast agent: a study in pigs

The purpose of our study was to verify in animals the possibility of using albumin-enhanced ultrasonography as a modality for sentinel node detection. The nine pigs were injected subcutaneously in the neck with albumin, five with 5% solution and four with 25% solution, and then the regional lymph nodes were observed over time. It was found that, where the 5% solution had been injected, the lymph nodes showed no change, but where the 25% solution had been used, a high echo 1 to 5 mm in size was seen at the hilus of the nearest lymph node. Examination of the excised pathologic specimens of lymph nodes demonstrated that this echo was due to albumin accumulated in the efferent lymphatics. This finding suggested that this technique of ultrasonography using albumin as a contrast agent was an effective new method of identifying sentinel nodes. (E-mail: kiyoka@jichi.ac.jp)

Sentinel nodal assessment in patients with carcinoma of the lung

Background. Assessment of sentinel nodes to predict metastases in a regional nodal basin is valuable for staging patients with melanoma and breast carcinoma. This study tested whether injection of isosulfan blue and technetium-99 could identify mediastinal sentinel nodes in patients with lung carcinoma and determine whether sentinel node histology predicts distal nodal metastases. Methods. Isosulfan blue and technetium-99 were injected into the tumor and pulmonary resection performed. The hilum and mediastinum were assessed visually and with the gamma probe, and a mediastinal nodal dissection was performed. Results. Thirty-one patients were evaluated. Three patients had positive sentinel nodes and positive distal mediastinal nodes. Twenty-two patients had negative sentinel nodes and negative distal nodes. No sentinel node was identified in 6 patients and 2 patients had two sentinel nodes. Conclusions. These data demonstrate that this rapid, simple technique can identify sentinel nodes in the mediastinum and that the sentinel node is an accurate predictor of distal nodal metastases in patients with lung cancer.

Section 5. Breast: Patient age affects identification rate of sentinel nodes in breast cancer

Background : The aim of this study was to investigate whether clinicopathological features affect the success rate of identifying sentinel nodes using a combination method of dye and radioisotope in breast cancer patients. Methods : Sentinel node biopsy was performed in patients ( n = 154) with stage I and II breast cancer using a combination method. The association between the clinicopathological features of breast cancer and the success rate in the identification of sentinel nodes was investigated. Results : Sentinel nodes were successfully identified in 147 (95.5%) of the 154 patients. There was a concordance between the sentinel-node and axillary-node status in 146 (99.3%) of 147 cases. The false negative rate of the sentinel node biopsy was 2.4% (1/42). The identification rate of sentinel nodes was significantly ( P = 0.005) lower in patients ≥60 years (84.4%) than in those <60 years (98.4%). The tumor size, histological node status, lympo-vascular invasion, history of previous surgical biopsy, operative procedure, tumor location, and histological type were not related with the identification rate of sentinel nodes. The mean count ratio of all hot nodes was 14.0 (range 2.0–73.6) in patients ≥60 years and 73.4 (2.0–1700.6) in patients <60 years, and this difference was statistically significant ( P < 0.0001). In addition, the mean number of sentinel nodes was significantly ( P = 0.0006) lower in patients ≥60 years (1.3; range one to four) than in patients <60 years (2.1; range one to 12). Conclusions : Patient age affects the identification rate of sentinel nodes using a combination method in breast cancer.

Reliability and accuracy of sentinel node biopsy in cutaneous malignant melanoma.

The aims of this study were 1) to investigate whether sentinel lymph node (SLN) biopsy could become the method of choice for the early detection of metastatic disease in patients with malignant melanoma and 2) to identify those patients with lymph node metastases who could benefit from regional lymphadenectomy. Our study started in March 1998 and involved 110 patients with primary cutaneous malignant melanoma stage I or II (AJCC) in whom the primary lesion had been surgically removed no more than 90 days previously. On the day of lymph node dissection patients were given an intradermal injection of colloid particles of human serum albumin labeled with technetium-99m and an injection of isosulfan blue. The surgical procedure was usually performed with local anesthesia but in some cases locoregional or general anesthesia was preferred. Contralateral and ipsilateral lymphatic areas were scanned with a hand-held gamma camera (Scintiprobe MR 100) to measure the background and identify the hot point indicating the location of the sentinel node to direct the incision. The combined use of lymphoscintigraphy, isosulfan blue and gamma probe allowed us to identify sentinel nodes in 108 of 110 patients (98.18%) while the SLN was blue in only 90 cases (81.81%). The SLN was positive for metastases in 13 of the 108 patients (12.03%) and regional and distal lymphadenectomy was performed in all of them. The distribution of positive SLNs by primary lesion thickness was as follows: 0.76-1.5 mm: one positive SLN/44 patients (2.27%); 1.51-4 mm: six positive SLNs/51 patients (11.7%); > 4 mm: six positive SLNs/15 patients (40%). Only four of 12 patients with ulcerated cutaneous melanoma had positive SLNs. The patients in our study underwent follow-up visits every four months. The median follow-up was 481 days (range, 97-1271 days). In patients with primary cutaneous melanoma the histological status of the SLN accurately reflects the presence or absence of metastatic disease in the relevant regional lymph node basin. Complete lymph node dissection should only be performed in patients with positive SLNs. Patients with lesions > 4 mm are likely to develop recurrences and to die of systemic disease, so in these patients the usefulness of SLN biopsy is questionable. In conclusion, sentinel node mapping is a rational approach for the selection of patients who might benefit from early lymph node dissection of the affected basin.

Sentinel node concept in gastric carcinoma.

To assess the applicability of the sentinel node concept to gastric carcinoma. The location of metastatic lymph nodes was analyzed retrospectively in 119 patients with gastric carcinoma in whom metastasis was limited to one or two nodes. Intraoperative lymphatic mapping was attempted in 62 patients using indocyanine green injected endoscopically into the gastric submucosa adjacent to the tumor. Metastatic lymph nodes were distributed beyond the perigastric area in 4% of patients with a single node involved. The positive node was located along the greater curvature in 21% of the patients with a tumor on the lesser curvature. Two patients had a metastatic node totally occupied by cancer tissue. In 16% of patients with two nodes involved, a positive node was located on both the lesser and greater curvatures. Lymphatic mapping was successful in all subjects. A larger number and wider distribution of green-stained nodes were observed in patients injected with 8 ml of indocyanine green solution than in those injected with 4 ml. No metastasis was observed in any nodes in 47 (96%) of the 49 patients who had no metastasis in green nodes. In one patient showing metastasis in non-green nodes without metastasis in green nodes, the positive nodes were totally occupied by cancer tissue. Our results showed the complexity of lymphatic streams within and from the stomach. Lymphatic mapping using indocyanine green can be a tool for identifying sentinel nodes in gastric carcinoma although lymph nodes occupied by cancer tissue may not be detected by this technique.

Lymphatic mapping and sentinel node identification in patients with cervix cancer undergoing radical hysterectomy and pelvic lymphadenectomy.

The purpose of this study was to determine the feasibility of sentinel node identification in patients with invasive cervix cancer undergoing radical hysterectomy and pelvic lymphadenectomy using preoperative and intraoperative lymphatic mapping. Thirty-nine patients at two institutions were enrolled onto this institutional review board-approved study. All underwent preoperative lymphoscintigraphy and intraoperative lymphatic mapping with blue dye and a handheld gamma probe. Radical hysterectomy was aborted in four patients because metastatic disease was discovered on frozen section analysis of the sentinel node. Preoperative lymphoscintigraphy revealed at least one sentinel node in 33 patients (85%), including 21 (55%) with bilateral sentinel nodes. All 39 patients had at least one sentinel node identified intraoperatively. Eighty percent of sentinel nodes were in three pelvic locations: iliac, obturator, and parametrial (in descending order of frequency). The remaining sentinel nodes were in the common iliac and para-aortic nodal basins. A total of 132 nodes were identified clinically as sentinel nodes; 65 (49%) were both blue and hot, 35 (27%) were blue only, and 32 (24%) were hot only. Eight patients (21%) had metastatic disease. In five of these patients, sentinel nodes were the only positive lymph nodes. One patient had false-negative sentinel nodes. She had four microscopically positive parametrial nodes that were resected in continuity with the uterus. The sensitivity of the sentinel node was 87.5% and the negative predictive value was 97%. Preoperative lymphoscintigraphy and intraoperative lymphatic mapping were highly successful at identifying sentinel nodes in patients undergoing radical hysterectomy.

RADIOISOTOPE GUIDED PELVIC LYMPH NODE DISSECTION FOR PROSTATE CANCER

The localization of lymph node metastases in prostate cancer varies enormously. Due to high morbidity complete pelvic lymphadenectomy is often decreased to modified staging lymphadenectomy, resulting in loss of sensitivity for detecting micrometastases. Based on the promising results of intraoperative gamma probe application for identifying sentinel lymph nodes in malignant melanoma, breast and penis cancer, we identified sentinel lymph nodes in prostate cancer using a comparable technique. In 117 patients 99mtechnetium nanocolloid was transrectally injected directly into the prostate under ultrasound guidance 1 day before pelvic lymphadenectomy. Thereafter dynamic lymphoscintigraphy was done. Initially lymph nodes identified as sentinel lymph nodes by the gamma probe were removed and subsequently modified pelvic lymphadenectomy was performed. Lymphatic metastasis was detected in 28 cases. An average of 4 sentinel lymph nodes were identified per patient in 25 of 27 patients with micrometastasis, of which those in 24 contained micrometastasis for 96% sensitivity. In contrast, sensitivity of modified pelvic lymphadenectomy was 81.5%. In 16 patients only sentinel lymph nodes were positive. An average of 21.8 lymph nodes (range 10 to 51) was dissected per patient at pelvic lymphadenectomy. Lymph node metastasis was noted in 6 of the 46 patients with a prostate specific antigen between 4 and 10 ng./ml. and in 8 of the 64 with a stage pT2 tumor. Our study shows individual variability of lymphatic drainage of the prostate and limited sensitivity for detecting positive lymph nodes when the pelvic dissection area is limited. Furthermore, our experience implies that the identification of sentinel lymph nodes is feasible, not only in breast cancer and malignant melanoma, but also in prostate cancer using a comparable technique.

Sentinel node imaging and biopsy in breast cancer patients

Background: Several techniques have been shown to be accurate in identifying axillary sentinel lymph nodes. The accuracy of subareolar blue dye injection is compared with intraparenchymal radioisotope injection. Methods: Forty-two consecutive patients with breast cancer were injected with both intraparenchymal technetium-99m and subareolar isosulfan blue dye. After sentinel lymph node identification, an axillary lymph node dissection was performed. Results: The blue dye and the technetium-99m localized to the same axillary nodes even though the injection sites were different. The sensitivity of blue dye in identifying axillary sentinel nodes was 100%. The sensitivity of radioisotope injection in identifying sentinel nodes was 97.6% Conclusions: Subareolar blue dye injection is an extremely accurate and cost-effective method of sentinel node identification in breast cancer patients.

Sentinel nodes in gynecologic malignancies.

The concept of sentinel node identification and lymphatic mapping is already established as part of standard practice in the surgical management of breast cancer and melanoma. To reduce extensive radical procedures and decrease morbidity in gynecologic malignancies, much effort is being focused on implementing less aggressive interventions. By combining the use of radioactive tracers and blue dyes, investigators are identifying sentinel nodes. In vulvar and cervical carcinomas, sentinel node identification may significantly reduce the number of patients undergoing unnecessary, extensive lymphadenectomy in the absence of disease. The addition of novel techniques, such as histopathologic ultrastaging, immunohistochemistry staining, and reverse transcriptase polymerase chain reaction assays, will help increase the accuracy and rate of detection of disease.

Failure to identify sentinel nodes at operation for screen detrected breast cancers

Failure to identify sentinel nodes at operation for screen detrected breast cancers

LYMPHATIC MAPPING AND DETECTION OF SENTINEL NODES IN PATIENTS WITH BLADDER CANCER

We examined the possibility for detecting sentinel nodes in patients with bladder cancer and whether the histopathological status of identified sentinel nodes reflected that of the lymphatic field. A total of 13 patients with bladder cancer who met the criteria qualifying them for radical cystectomy had intravesical injections of radioactive tracer and blue dye marker around the tumor followed by lymphoscintigraphy to visualize lymphatic drainage and detect sentinel nodes. Sentinel nodes were identified preoperatively by the blue color and increased radioactivity and were compared histopathologically with other routinely excised lymph nodes. Sentinel nodes were detected in 85% (11 of 13) of patients. There were 4 patients who had sentinel nodes containing tumor cells, and each metastasis was only seen in the detected sentinel node. There were no false-negative sentinel nodes. Of the metastatic sentinel nodes 3 were located outside the normally excised lymph nodes of the obturator fossa. Sentinel nodes can be detected in patients with bladder cancer. The histopathological status of the identified sentinel nodes was diagnostic for all other excised lymph nodes. Sentinel nodes often seem to be located outside the obturator lymphatic field, which is normally examined during preoperative staging of bladder cancer.

Anatomy and physiology of lymphatic drainage of the breast from the perspective of sentinel node biopsy

Knowledge of the anatomy and physiology of the lymphatic system is helpful when considering a particular sentinel node biopsy technique. The delicate balance between internal and external pressures in a lymphatic channel can be influenced by the injection volume and by massage in a negative or positive way. The narrow openings in the interendothelial junctions determine the speed of clearance of particles with a certain size, and this has implications for the timing of lymphoscintigraphy and surgery. Tracer uptake and lymph flow are highly variable and depend on a number of factors, some of which are beyond our control. The lymphatic anatomy is not completely understood despite numerous studies since the end of the 18th century. Several topics have been elucidated in more recent studies and through experience with sentinel node biopsy. First, although axillary drainage is the principal lymphatic path of the breast, any drainage pattern from any quadrant of the breast can occur. Second, most lymph from the breast flows to the nodal basins with a direct course, not passing through the subareolar plexus. Another relevant point is that gentle massage encourages lymph flow and facilitates sentinel node detection. What problems do we still face in clinical practice? The optimum size and number of labeled colloid particles remain to be established. The optimum volume of the tracer also remains to be determined. But the main controversy concerns the injection site. Although the intradermal injection technique has attractive practical features, there is currently insufficient certainty that drainage of tracer injected anywhere in or underneath the skin of the breast reflects drainage from the cancer. Connections between collecting lymphatic vessels from the tumor site and the collecting vessels from the skin and subdermal lymphatics can explain the concordance between intraparenchymal and superficial injections in most patients. To determine the technique that yields the best sentinel node identification rate with the lowest possible false-negative rate would require a large randomized trial with all patients undergoing a complete lymph node dissection and evaluation of all other axillary lymph nodes with serial sections and immunohistochemistry. Current knowledge about sensitivity is based on examination of the other axillary nodes with hematoxylin and eosin staining and not with immunohistochemistry, with the exception of two studies. (33,76) In addition, a complete level I to III dissection may not have been done in all patients, and it is not certain that pathologists removed and examined all the nodes from the specimens. The proposed study seems impossible now that routine axillary node dissection has been abandoned by the larger centers around the world. Choosing the most attractive approach requires determining the aim of lymphatic mapping. A superficial injection technique may be adequate when the purpose is to spare patients without lymph node metastases in the axilla an unnecessary axillary node dissection. An intraparenchymal injection technique should be used when the additional purpose is to determine the stage as accurately as possible and to identify sentinel nodes elsewhere.

Lymphoscintigraphy of melanoma: lymphatic channel activity guides localization of sentinel lymph nodes, and gamma camera imaging/counting confirms presence of radiotracer in excised nodes.

Lymphoscintigraphy has become a standard preoperative procedure to map the cutaneous lymphatic channel for progression of nodal metastasis of melanoma of the skin. Lymphoscintigraphy was employed to visualize lymphatic channels as a guide to identify sentinel lymph nodes (SLNs). Excised tissue was imaged with a gamma camera to verify the findings of presurgical lymphoscintigraphy. Percent counts of SLN(s) among the total counts of the excised melanoma tumor or scar tissue and SLN(s) were calculated. Eleven patients with cutaneous melanoma received four to ten intradermal injections of Tc-99m sulfur colloid at elual distances around the melanoma site. Images were made immediately after injection: 1 minute per image for 15 min; and then 5 minutes or 1,000,000 counts per image for 30 min. After surgery, the excised melanoma tumor or scar and SLN(s) were imaged/counted with a gamma camera. Percent counts of SLNs among the total counts of the excised melanoma tumor or scar tissue and SLNs were calculated. To validate the specimen count accuracy, an experimental phantom study was done. Linear lymphatic channels were identified between the injected sites and the SLNs in each patient. Gamma camera images demonstrated radioactivity in the SLNs of all patients, verifying the lymphoscintigraphy findings. Uptake in the SLNs of ten of the eleven patients ranged from 0.4 to 7.2% (mean 2.2%) of the total counts in excised tissue. We noted that a node with lower uptake should not be ignored because a lower percent of SLN activity does not necessarily rule out existing metastasis. In two of eleven patients, histopathologic showed metastases. One patient's melanoma on the middle back had lymphatic channel activity directed to both axillae. The results of the phantom study validated accuracy of our specimen counts. Because linear lymphatic channels existed between lymph nodes and the injected sites in all eleven patients, these lymphatic channels could be used as a guide for localizing SLNs. The SLNs indicated by presurgical lymphoscintigraphy were verified by postoperative gamma camera imaging, and radiotracer localization in the SLNs averaged 2.2%.

A pixellated γ-camera based on CdTe detectors clinical interests and performances

A mobile gamma camera dedicated to nuclear cardiology, based on a 15 cm×15 cm detection matrix of 2304 CdTe detector elements, 2.83 mm×2.83 mm×2 mm, has been developed with a European Community support to academic and industrial research centres. The intrinsic properties of the semiconductor crystals – low-ionisation energy, high-energy resolution, high attenuation coefficient – are potentially attractive to improve the γ-camera performances. But their use as γ detectors for medical imaging at high resolution requires production of high-grade materials and large quantities of sophisticated read-out electronics. The decision was taken to use CdTe rather than CdZnTe, because the manufacturer (Eurorad, France) has a large experience for producing high-grade materials, with a good homogeneity and stability and whose transport properties, characterised by the mobility–lifetime product, are at least 5 times greater than that of CdZnTe. The detector matrix is divided in 9 square units, each unit is composed of 256 detectors shared in 16 modules. Each module consists in a thin ceramic plate holding a line of 16 detectors, in four groups of four for an easy replacement, and holding a special 16 channels integrated circuit designed by CLRC (UK). A detection and acquisition logic based on a DSP card and a PC has been programmed by Eurorad for spectral and counting acquisition modes. Collimators LEAP and LEHR from commercial design, mobile gantry and clinical software were provided by Siemens (Germany). The γ-camera head housing, its general mounting and the electric connections were performed by Phase Laboratory (CNRS, France). The compactness of the γ-camera head, thin detectors matrix, electronic readout and collimator, facilitates the detection of close γ sources with the advantage of a high spatial resolution. Such an equipment is intended to bedside explorations. There is a growing clinical requirement in nuclear cardiology to early assess the extent of an infarct in intensive care units, as well as in neurology to detect the grade of a cerebral vascular insult, in pregnancy to detect a pulmonary capillary embolism, or in presurgical oncology to identify sentinel lymph nodes. The physical tests and the clinical imaging capabilities of the experimental device which have been performed by IPB (France) and SHC (Hungary), agree with the expected performances better than those of a cardiac conventional γ- camera except for dynamic studies.

Sentinel node staging of early breast cancer using lymphoscintigraphy and the intraoperative gamma-detecting probe

Sentinel node staging for breast cancer is increasingly used in place of axillary lymph node dissection but is not yet universally accepted. The problems of non-standardized methodologies and lack of consensus on the optimum techniques to identify sentinel nodes are being addressed. Complementary use of radionuclide imaging before surgery, intraoperative probe detection, and blue dye have yielded the best reported sensitivities for finding a sentinel node (94%). The importance of imaging is summarized as identifying sentinel node(s), distinguishing sentinel from secondary nodes, guiding surgical incision planning, and facilitating lower doses. The learning curve phenomenon, which applies to the surgeon and the nuclear medicine physician, has been recognized; measures to minimize it are being implemented. Radiation exposure to operating room and pathology personnel is very low; estimates of exposure to the surgeon's hands are 0.2% of the annual whole body dose received by every human being from natural background and cosmic sources.

Endoskopisches Sentinel-Node (ESN)-Verfahren zum laparoskopisch assistierten Staging des Endometriumkarzinoms - Endoscopic Sentinel Lymph Node Identification with Laparoscopically-assisted Surgical Staging of Endometrial Carcinoma: A Case Report -

Objective: The majority of patients undergoing lymphadenectomy for endometrial cancer do not have node involvement. We describe an endoscopic surgical approach to endometrial cancer consisting of an endoscopic sentinel lymph node procedure followed by laparoscopically-assisted surgical staging and laparoscopically-assisted vaginal hysterectomy. Case Report: A 64-year old patient was referred for treatment of early endometrial cancer. 24 hours before surgery 1 ml 99m Tc-labeled nanocolloid was injected into the endometrium and myometrium around the tumor with a 6-mm hysteroscope. Lymphoscintigraphy at 6 hours showed tracer accumulation in the regional lymph nodes. At laparoscopy a gamma probe was used endoscopically to identify and remove the nodes in the sentinel region. Endoscopic staging lymphadenectomy and laparoscopically-assisted vaginal hysterectomy were performed. Conclusion: This procedure appears feasable to identify sentinel lymph nodes in patients with endometrial cancer. It should decrease surgical morbidity and yield sufficient pathologic information. We are planning a prospective trial in patients with early endometrial cancer.

Gastric lymphography and detection of sentinel nodes.

The lymphatic drainage system of the stomach was studied using lymphography with various dyes, and several major routes have been shown. Gastric lymph channels are multidirectional and form complex networks. We conducted a retrospective study to know the first site of metastasis from small gastric cancers by examining 89 cases with only one lymph node metastasis. The perigastric nodal area close to the primary tumor was the first site of metastasis in only 62% of the cases. N2 metastasis without N1 involvement was seen in 13%. In order to identify sentinel nodes for local resection of gastric cancer, a novel method needs to be developed.