Sentinel lymph node biopsy in patients with multifocal breast cancer.

BACKGROUND: Multifocal or multicentric breast cancer has been suggested as a contraindication for sentinel node biopsy (SNB). However, recent studies have demonstrated that all quadrants of the breast drain through common afferent channels to a common axillary sentinel node. This should mean that the presence of multifocal tumour should not affect the lymphatic drainage. The purpose of this study was to evaluate the feasibility and accuracy of SNB in patients with multifocal breast cancer using a peritumoural injection technique for sentinel lymph node (SN) mapping. METHODS: In the ALMANAC multicentre trial validation phase, we took SNB samples from 842 patients with node negative, invasive breast cancer with use of a blue dye and radiolabelled colloid mapping technique at the peritumoural injection site. All patients underwent standard axillary treatment after SNB. Seventy-five of the 842 patients had multifocal lesions on final histopathologic examination. The following analysis is focused on patients with multifocal lesions. RESULTS: A mean number of 2.4 SNs were identified in 71 of 75 patients (identification rate: 94.7%). Thirty-one patients had a positive SN, 40 a negative SN. Standard axillary treatment confirmed the SN to be negative in 37 of 40 patients, whereas three patients revealed positive non-sentinel lymph nodes (false-negative rate: 8.8%). Overall SN biopsy accurately predicted axillary lymph node status in 68 of 71 patients (95.8%). CONCLUSION: SNB accurately staged the axilla in multifocal breast cancer and may become an alternative to complete axillary lymph node dissection in node negative patients with multifocal breast cancer.     

Symmetrization reduction mammaplasty combined with sentinel node biopsy in patients operated for contralateral breast cancer

BACKGROUND AND OBJECTIVES: Occult invasive cancer found in reduction mammaplasty specimen in the contralateral breast in breast cancer patients requires axillary lymph node dissection (ALND) to assess the lymph node status. Routine Sentinel node (SN) biopsy in these patients may avoid secondary ALND when an occult cancer is found and the SN is negative in the permanent histological examination. METHODS: One hundred sixty-nine breast cancer patients underwent contralateral reduction mammaplasty for symmetrization and with SN biopsy of the non-cancer breast. SN mapping was done using a vital blue dye alone (n = 136) or in combination with a radiocolloid (n = 33). RESULTS: A mean number of 1.4 SNs (range 1-3 SNs) was identified in 158 of 169 patients (identification rate 93.5%). One of 158 patients revealed a positive SN but no tumor was found in the reduction mammaplasty/mastectomy specimen, whereas the SN was negative in 157 patients. Histological examination of the 169 reduction mammaplasty specimen revealed 5 occult invasive cancers and 4 patients with high grade DCIS but due to a negative SN biopsy the patients were spared a secondary ALND. CONCLUSION: The small number of patients with occult contralateral cancers may not warrant routine SN mapping in patients scheduled for contralateral reduction mammaplasty.     

Blue dye versus combined blue dye-radioactive tracer technique in detection of sentinel lymph node in breast cancer.

BACKGROUND: Sentinel lymph node biopsy in breast cancer can be used to select patients in which axillary lymph node dissection could be avoided. In this study we compared the value of two methods for identification of sentinel node (SN) using either only blue dye or combination of blue dye and radioactive tracer. MATERIAL AND METHODS: All patients were women with clinically T(1-2)N(0)M(0) breast cancer. They were randomized into two groups. In Group A (50 patients) SN marking was performed only with blue dye and in Group B (100 patients) combined SN marking with blue dye and radiotracer was done. We used 2 ml of blue dye Patentblau V (Byk Gulden). Radiotracer was Antimony sulfide marked with Tc 99m and of 0.3 mCy (11.1 MBq) activity. Application method of both contrasts was peritumoral. After SN biopsy all patients underwent mastectomy or conservative surgery with axillary lymph node dissection of levels I and II. RESULTS: In Group A mean of 1.7 SNs were identified (median 1, range 1-4). False-negative rate in this group was 3/17 (17.6%) with negative-predictive value 20/23 (86.9%), sensitivity 14/17 (82%), specificity 20/33 (60%) and accuracy 34/50 (68%). In Group B mean number of SNs excised per case was 1.6 (median 1, range 1-5). False-negative rate was 2/44 (4.5%), negative-predictive value 41/43 (95.3%), sensitivity 42/44 (95%), specificity 41/56 (73%) and accuracy 83/100 (83%). The combination technique was significantly superior to blue-dye alone technique for negative-predictive value (p=0.033) and overall accuracy (p=0.048). CONCLUSIONS: The prediction of axillary lymph node status in breast cancer patients using combined technique has significantly higher accuracy than marking of SN with blue dye alone and therefore should be preferred.     

美蓝法乳腺癌前哨淋巴结活检的手术配合

目的：探讨美蓝法乳腺癌前哨淋巴结活检技术（Sentinel lymph node biopsy，SLNB）的可行性及其与手术的配合。方法：本组32例T1、T2患者均先行乳腺区段切除，送快速冰冻病理活检，回报确诊为乳腺癌后于术中应用美蓝行前哨淋巴结活检，同时进行腋淋巴结清扫（Axillary lymph node dissection．ALND）。术后对全部前哨淋巴结（SLN）和腋淋巴结（ALN）行常规病理检查。结果：32例中检出SLN者29例，检出率为90．63％（29／32），本组准确率为84．38％（27／32）；灵敏度为91．67％（11／12），即预测符合率；假阴性率为16．67％（2／12）；假阳性率为0。结论：应用美蓝示踪定位SLNB，能准确预测T1、T2乳腺癌患者的腋淋巴结转移状况，与手术配合易于控制活检的时间，成功率较高。     

Follow-up of sentinel node negative breast cancer patients without axillary lymph node dissection.

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the feasibility of sentinel lymph node biopsy in breast cancer patients at our institution and to report the follow-up status of node-negative patients with removal of only the sentinel node. METHODS: A total of 247 breast cancer patients underwent sentinel node (SN) mapping between June of 1996 and September of 2000. The SN was identified by using a combination of vital blue dye and a radiolabeled colloid. RESULTS: A SN was identified in 227 of 247 patients (91.9%). One hundred forty-five were SN negative, 82 were SN positive. All SN-positive patients underwent axillary dissection of level I and II, whereas 83 patients with a negative SN had SN biopsy only. Median follow-up of these patients at 22 months revealed no axillary recurrence; the morbidity resulting from SN biopsy was negligible. CONCLUSIONS: Although the follow-up is very short, SN biopsy only in node-negative breast cancer patients had no negative impact on the axillary failure rate and resulted in negligible morbidity.     

Different sites and modes of tracer injection for mapping the sentinel lymph node in patients with breast cancer

Several studies have been published describing the techniques of identification of the "sentinel lymph node" (SN). There are marked differences in the techniques used by different investigators. Although agreement exists about the tracer particle size and the volume of injection, it is unknown what is the best site where to inject the tracer or the vital dye. The aim of the present study was to define the influence of different sites of injection on imaging of the lymphatic ducts and their SNs. We performed a pilot study in 30 consecutive patients with breast cancer who underwent SN biopsy by means of radioguided surgery and vital blue dye mapping. The patients were divided into six groups of five patients each; each patient was given a subdermal (ID) or peritumoral (IP) injection of radiotracer (300 microCi in 150 mL of 99mTc-HSA microcolloids; Albures, Amersham Sorin) above the tumor site in order to localize the SN. After the identification of the SN, a second injection of radiotracer was performed, which was different in each patient subset. In some cases more than one lymph node appeared on the lymphoscintigraphic scans after the second injection of radiotracer. When the peritumoral route was used it took longer to visualize the lymphatic pathways. For the ID route, injection at the exact skin projection over the tumor is optimal. Internal mammary lymph nodes were identified by both IP (2) and ID (1) injection, irrespective of the quadrant in which the tracer was injected. Our findings support the hypothesis of a precise topographic correspondence between the primary tumor and its specific SN. The subdermal route is more accurate than the intraparenchymal route, as it allows faster identification of the lymphatic vessels and SN. We believe these observations should be taken into account for the proper selection of the injection site of either vital dye or radiopharmaceuticals.     

Intradermal radioisotope injection optimises sentinel lymph node identification in breast cancer

AIM: Currently there is no consensus on the optimal technique for sentinel lymph node (SLN) identification in patients with breast cancer. The aim was to compare the efficacy of intraparenchymal and intradermal isotope injection in sentinel lymph node mapping for breast cancer. METHODS: One hundred and twenty-five patients with histologically confirmed invasive breast cancer underwent SLN mapping using radioisotope and isosulphan blue dye followed by a back-up axillary dissection. The first 80 patients had intraparenchymal (IP) injection of radioisotope given in four portions around the tumor. The remaining 45 patients had an intradermal (ID) injection given at a single site over the tumour. Both groups had isosulphan blue dye injected around the tumour. Sentinel node(s) were identified using a combination of lymphoscintigraphy, blue dye and an intra-operative hand held gamma probe. RESULTS: The preoperative lymphoscintigram (LSG) demonstrated a SLN significantly more often in the ID isotope group compared to the IP isotope group (P=0.002). A combination of blue dye and isotope successfully located the SLN in 96% of the intraparenchymal group and 100% of the intradermal group. CONCLUSION: Our results suggest that intradermal isotope injection in combination with intraparenchymal blue dye optimises the localization of the sentinel lymph node in breast cancer.     

Lymphatic mapping and sentinel node harvesting in patients with recurrent breast cancer

AIMS: To evaluate the feasibility and consequences of lymphatic mapping and a ("repeat") sentinel lymph node (SLN) procedure in patients with breast cancer relapse after previous breast and axillary surgery. METHODS: Review and presentation of a patient cohort. All SLN procedures included lymphoscintigraphy and blue dye injection technique. RESULTS: Twelve cases are described: two patients after a previous SLN procedure and ten after a previous complete axillary lymph node dissection (ALND). Ten patients (83%) had a successful repeat SLN biopsy. After previous ALND, lymphoscintigraphy revealed drainage towards the internal mammary chain in three patients, and contralateral axillary drainage in four. Based on the information from the "repeat" SLN biopsy further treatment strategy was altered in seven of the 12 patients. CONCLUSION: Lymphatic mapping and (repeat) SLN biopsy is possible and can be informative in patients who present with a relapse of breast cancer after previous surgery for primary breast cancer.     

乳腺癌前哨淋巴结活检的可行性及临床应用价值

目的 探讨前哨淋巴结(sentinel Iymph node,SLN)定位和活检(SLNB)的可行性及其对预测乳腺癌腋窝淋巴结(axillary lymph node,ALN)转移的准确性。方法 对52例临床查体及B超检测ALN阴性的乳腺癌患者,术中在肿瘤周围注射亚甲蓝进行SLN定位和活检。对常规病理检查阴性的SLN再行免疫组化检测。结果 SLNB的检出成功率为92.3％(48/52),准确率为97.9％,假阴性率为4.8％,敏感度为95.2％,特异度为100％。SLN是惟一被证实有肿瘤转移的淋巴结者占66.7％(14/21)。免疫组化检测使SLN肿瘤转移的阳性率提高了4.1％。结论乳腺癌SLNB技术是可行的,应用亚甲蓝淋巴定位方法进行的SLNB可以准确预测临床及B超检查ALN阴性的乳腺癌患者的ALN转     

Sentinel lymph node mapping in colorectal cancer: a feasibility study

AIMS AND BACKGROUND: Sentinel lymph node (SLN) biopsy is currently used and investigated in melanoma and in breast cancer. Its utility in gastrointestinal malignancies is still under debate. The prognosis of colorectal cancer patients is strongly related to the lymphatic involvement. The aim of this study was to evaluate the feasibility of SLN mapping in colorectal cancer and to assess its impact on pathological staging and treatment. METHODS AND STUDY DESIGN: We injected blue dye in 11 colorectal cancer patients during surgery. After resection the tumor specimen was examined to identify blue-stained lymph nodes and these lymph nodes were sent separately to the pathologist. Routine hematoxylin-eosin examination was performed on all nodes (including blue ones). No other techniques (eg immunohistochemistry or PCR) were performed. RESULTS: Sentinel lymph nodes were successfully identified in 10 of the 11 patients. We observed only one false negative result (10%) and the agreement between SLN and other lymph node status was 80% (8/10). One patient was upstaged: SLN was positive for metastases while the other lymph nodes were negative. CONCLUSIONS: Lymphatic mapping using patent blue dye is feasible in colorectal cancer. The identification of lymph nodal metastases by this technique led to upstaging of one patient, who may benefit from adjuvant therapy. These initial results prompt further investigation of this procedure as an accurate, minimally invasive staging approach in early colorectal cancer. We proceed with our study to evaluate the role of SLN mapping in colorectal cancer management.     

Sentinel lymph-node biopsy compared to axillary lymph-node dissection for axillary staging in breast cancer patients.

AIMS: The purpose of this study was to evaluate the feasibility of sentinel lymph-node biopsy in breast cancer patients at our institution and to compare the results of sentinel node (SN) biopsy to standard axillary lymph-node dissection (ALND). METHODS: In a retrospective study the percentage of lymph-node positive patients and the number of micrometastases in 165 breast cancer patients following SN biopsy was compared to 195 patients who underwent ALND of level I and II without SN biopsy. The SN was identified using a combination of vital blue dye and a radiolabelled colloid. RESULTS: Patients and tumour characteristics were comparable between both groups. SN biopsy found no significant difference in the number of node positive T1 cancer patients (SN group: 31/108 (28.7%) -- ALND group: 21/92 (22.8%)) and T2 tumours (SN group: 27/57 (47.4%) -- ALND group: 49/103 (47.6%)) between both groups. Micrometastases were more frequently found in the SN group when compared to the ALND group (six of 70 positive nodes) (P=0.04). CONCLUSION: SN biopsy may be as accurate as standard axillary lymph-node dissection for the evaluation of the axillary lymph-node status in breast cancer patients. Copyright Harcourt Publishers Limited.     

Sentinel lymph node biopsy is feasible for breast cancer patients after neoadjuvant chemotherapy

BACKGROUND: Despite the increasing use of both sentinel lymph node (SLN) biopsy and neoadjuvant chemotherapy (NAC) in patients with operable breast cancer, information on the feasibility and accuracy of sentinel node biopsy following neoadjuvant chemotherapy is still quite limited. Therefore, we investigated the feasibility and accuracy of sentinel lymph node biopsy for breast cancer patients after NAC. METHODS: A total of 104 patients with Stage II and III breast cancers, previously treated by NAC, were enrolled in the study. All patients were clinically node-negative after NAC. The patients underwent SLN biopsy, which involved a combination of an intradermal injection of radiocolloid and a subareolar injection of blue dye over the tumor. This was followed by completion axillary lymph node dissection (ALND). RESULTS: SLN could be identified in 97 of 104 patients (identification rate, 93.3%). In 93 of the 97 patients (95.9%), the SLN accurately predicted the axillary status. Four patients' SLN biopsies were false negative, resulting in a false-negative rate of 10.0%. The SLN identification rate tended to be lower among patients with T4 primary tumors prior to NAC (62.5%). CONCLUSION: The SLN identification and false-negative rates were similar to rates in non-neoadjuvant studies. The SLN accurately predicted metastatic disease in the axilla of patients with tumor response following NAC.     

Initial experience with sentinel node biopsy in breast cancer at the National Cancer Center Hospital East

BACKGROUND: Axillary lymph node dissection is an important procedure in the surgical treatment of breast cancer. Axillary lymph node dissection is still performed in over half of breast cancer patients having histologically negative nodes, regardless of the morbidity in terms of axillary pain, numbness and lymphedema. The first regional lymph nodes draining a primary tumor are the sentinel lymph nodes. Sentinel node biopsy is a promising surgical technique for predicting histological findings in the remaining axillary lymph nodes, especially in patients with clinically node-negative breast cancer, and a worldwide feasibility study is currently in progress. METHODS: Intraoperative lymphatic mapping and sentinel node biopsy were performed in the axilla by subcutaneous injection of blue dye (indigocarmine) in 88 cases of stage 0-IIIB breast cancer. Sentinel lymph nodes were identified by detecting blue-staining lymph nodes or dye-filled lymphatic tracts after total or partial mastectomy. Finally, axillary lymph node dissection was performed up to Levels I and II or more. RESULTS: Sentinel lymph nodes were successfully identified in 65 of the 88 cases (74%). In the final histological examination, the sentinel lymph nodes in 40 cases were negative, including four cases with non-sentinel-node-positive breast cancer (specificity, 100%; sensitivity, 86%). In nine (31%) of the 29 cases with histologically node-positive breast cancer, the sentinel lymph nodes were the only lymph nodes affected. Axillary lymph node status was accurately predicted in 61 (94%) of the 65 cases. CONCLUSIONS: Although it was the initial experience at the National Cancer Center Hospital East, sentinel node biopsy proved feasible and successful. This method may be a reasonable alternative to the standard axillary lymph node dissection in patients with early breast cancer.     

乳腺癌前哨淋巴结定位和活检

目的：难证乳腺癌前哨淋巴结定位和活检技术的可行性和前哨淋巴结的组织状况能否准确预告腋淋巴结的状况。方法：本研究使用专利蓝,对３３例乳腺癌患者进行了术中及术后前哨淋巴结定位和活检术。结果：３０例（９１％）找到前哨淋巴结,前哨淋巴结预告腋淋巴结的准确率为９６．７％,假阴性１例。结论：本研究结果证实,乳腺癌前哨淋巴结定位和活检技术是可行的,前哨淋巴结的组织学特征能够准确反映腑淋巴结的状况。我们相信在将来     

Lymphatic mapping and sentinel lymph node biopsy in the patients with breast cancer

Axillary lymph node dissection (ALND) is always standard part for a variety of surgical treatments of breast cancer. Knowledge of the status of axillary nodes presents important information for staging and prognosis, but it remains controversial that ALND provides local control of disease and offer survivalbenefit. Some authors have questioned the wisdom of continuing to do ALND, when the risk of axillary metastasis in the early case is small, and the postoperative complications are usuall…     

Sentinel lymph node biopsy in patients with breast cancer using superparamagnetic iron oxide and a magnetometer

Background

Some hospitals lack facilities for radioisotopes in sentinel node biopsy. A novel method is used with a superparamagnetic tracer and a magnetometer instead of a radioisotope.

Methods

Thirty patients were included in the study after obtaining IRB approval. Superparamagnetic iron oxide and patent blue dye were injected in the subareolar breast tissue. Following a few minutes of massage to promote migration of the iron tracer and blue dye throughout the lymphatic vessels, the axillary lymph nodes were detected transdermally using a handheld magnetometer and followed by standard axillary dissection in all patients.

Results

Of 30 patients evaluated, sentinel lymph nodes were identified in 90% (27/30) using both blue dye and magnetic tracer. Sentinel lymph nodes were identified using the magnetic method in 23/30 (77%) and blue dye in 24/30 (80%). There was one false-negative sentinel node, resulting in an overall sensitivity of 6/7 (86%).

Conclusions

This is the first study to use a magnetic tracer to identify sentinel lymph nodes in patients with breast cancer. This new technique may alter the role of radioisotopes with further refinement and experience.     

Lymphatic mapping and lymphatic endothelial cell isolation in colorectal cancer patients

Background: Sentinel lymph node (SLN) biopsy has already been established as a common procedure with malignant lymphoma and breast cancer. In colorectal cancer, however, the application of the SLN theory remains uncommon and its clinical significance is also unclear. In addition, the characteristics of the lymphatic vessels that connect SLNs or the lymphatic endothelial cells have been unclear. Our purpose is to determine the feasibility and accuracy of SLN mapping by intraoperative subserosal dye injection and to develop a novel method for the isolation of anatomically defined lymphatic endothelial cells. Methods: SLN biopsy by the subserous dye injection method (patent blue) was conducted in 36 patients with colorectal cancer for which curative resection was possible (stage 0: two cases, stage I: 18 cases, stage II: four cases, stage III: 12 cases), with additional systematic lymph node dissection. Endothelial cells were isolated from lymphatic vessels identified at the time of the SLN biopsy by the collagenase II perfusion method, and we tried to transfer them into a culture system with an endothelial cell‐specific medium. Results: SLNs could be identified in 34 cases, providing a 94.4% detection rate. The total number of resected lymph nodes was 705 and 72 of those nodes were confirmed as SLNs (10.2%). Ten metastasis‐positive nodes were found in SLNs (13.9%), and the mean number of identified SLNs per case was 2.0. No complications or toxicity associated with the dye injection were observed. In addition, cells isolated from the lymphatic vessels removed formed some colonies and the expression of lymphatic endothelial cell‐specific VEGFR‐3 was observed. Conclusion: SLNs mapping using subserosal dye injection is a feasible technique that would make the range of lymph node dissection appropriate for colorectal cancer, which is applicable to cases with advanced cancer. This new method was established to isolate lymphatic endothelial cells from resected lymphatic vessels and to culture them, which may contribute to further study of the molecular mechanisms of lymphangiogenesis.     

Sentinel node study in early breast cancer

Since October 1997 60 patients with early breast cancer (T <3 cm) were studied. All patients underwent lymphoscintigraphy with two types of colloid: the first (17 pts) with a particle size <1,000 nm; the second (43 pts) with a particle size <80 nm. The standard procedure consists of injection, on the day before surgery, of 70 MBq of the smaller nanocolloid in 0.4 cc saline divided over four sites, around the lesion or subdermally around the surgical scar. We utilize a low-energy, high-resolution LFOV camera for scintigraphy and a probe specific for the sentinel node during surgery. In 56/60 patients (93.3%) lymphoscintigraphy showed the sentinel node (SN). In two cases the SN was not detected presumably because of lymphatic interruption by an old surgical scar; in the other two cases the sites of injection were too close to the SN, thus masking it. In five cases (9%) the SN was not visualized with the surgical probe but in two of these drainage to the internal mammary chain was observed. The apparently lower sensitivity of intraoperative localization was due to the extra-axillary lymphatic drainage or to the vicinity of the SN to the primary lesion. The SN proved to be metastatic in 12 cases. No false-negative SNs were found. In five cases (10%) the radiolabeled lymph node was the only node containing tumor cells (micrometastases): this result depends on the combined use of hematoxylin-eosin and rapid cytokeratin staining. The application of blue dye was useful for easier identification of the SN but did not allow detection of more SNs. Our preliminary results are extremely encouraging. Considering that at the early stages of breast cancer the likelihood of lymph node metastases is low (20% in our series) and no false negative were reported in this study, we conclude that with SN biopsy axillary lymph node dissection can be avoided, making surgery less aggressive but maintaining accuracy.     

Identification of sentinel lymph node in breast cancer: experience from the Institut Curie]

Sentinel lymph node (SN) biopsy is a recently developed, minimally invasive technique for staging the axilla in breast cancer. This new procedure of selective lymphadenectomy has been the subject of several studies, but there is not currently a consensus of opinion to define which is the best method of identification. At the Institut Curie since 1996, we have been using the Patent blue dye. The current series present the result of 122 patients with T1, T2, N0 or N1a breast cancer consecutively operated between december 1997 and august 1998. Sentinel nodes were identified in 107 out of 122 (87.7%) and accurately predicted axillary nodal status in 104 out of 107 (97.1%) cases. Three out of 35 node positive patients would have been missed with sentinel node biopsy alone, for a false negative rate of 8.5%. In all 3 cases, one lymph node presented with a micrometastases. In 15 cases out of 35 with metastatic axillary nodes, the only positive node was the SN (43%). The encouraging results of this study shows that it is possible to identify, in a large number of cases, the sentinel node by means of Patent blue dye only. This article detailed the technique used and reviews the literature concerning other methods of identification.     

Preoperative lymphoscintigraphy and sentinel lymph node biopsy in papillary thyroid cancer. A pilot study

BACKGROUND AND OBJECTIVES: Lymphadenectomy for papillary thyroid cancer is a matter of debate. After showing its usefulness as a prognostic factor in both melanoma and breast cancer, the concept of sentinel lymph node biopsy was also recently applied to differentiated thyroid cancer. To date, all attempts to locate and remove the sentinel node were based on the intraoperative injection of a vital dye. The feasibility and the technical details of using preoperative lymphoscintigraphy coupled with intraoperative vital dye and gamma probe scanning were investigated and discussed. METHODS: Six patients diagnosed with papillary thyroid cancer were submitted to preoperative lymphoscintigraphy with (99m)Tc-labelled colloidal albumin at different dosages. The operation consisted in a total thyroidectomy with sentinel lymph node biopsy guided by intraoperative injection of a vital dye (Blu Patent V, 2.5%) and scanning with a hand-held gamma probe. Lymph node dissection was completed in the area in which the sentinel node was located. RESULTS: The sentinel node was identified using all the three methods in all cases (100%). Considering one of the methods alone, identification rates were 66, 50, and 83% for preoperative lymphoscintigraphy, vital dye, and probe scanning, respectively. One sentinel node was identified in four cases and two in the other two cases. The optimal dosage of the tracer appeared to be at 22 MBq. CONCLUSIONS: These results underline the necessity to use the combination of nuclear medicine imaging and lymphatic vital dye in order to enhance the identification rate of sentinel node also in thyroid cancer. It is now necessary to check the diagnostic accuracy of this procedure through a controlled trial involving a more extended lymph node dissection in the neck.