Sentinel node detection and definition may depend on the imaging agent and timing.

PURPOSE: Two cases of sentinel lymph node imaging are presented in which the results are exceptions to what the literature generally defines as sentinel lymph nodes. In one case, Tc-99m antimony trisulfide colloid produced significantly different results than did Tc-99m tin colloid. In the second case, the results bring into question the definition of a sentinel node as the first in a lymphatic drainage pathway. MATERIALS AND METHODS: In one patient, lymphoscintigraphy was performed initially using Tc-99m antimony trisulfide colloid injected intradermally around a melanoma excision site. Repeated lymphoscintigraphy 1 month later, 1 hour before sentinel node excision, was done using Tc-99m tin colloid, a larger particle than antimony trisulfide colloid. The second patient, with a melanoma biopsied only, had sentinel node imaging performed using Tc-99m sulfide colloid, a particulate also larger than antimony trisulfide colloid and also 1 hour before sentinel node excision. RESULTS: In the first patient, imaging with the smaller antimony trisulfide colloid showed more lymphatic pathways and more sentinel nodes than with tin colloid. In the second patient, the first focus of retention of the imaging agent in the lymphatic pathway seen showed less intense accumulation than the next focus in the pathway, contrary to published reports that the sentinel node shows more intense accumulation than do nodes further downstream in a lymphatic pathway. CONCLUSIONS: There are exceptions to published characteristics of sentinel node lymphoscintigraphy, so care must be exercised in localizing sentinel nodes.     

Multimodal fusion imaging ensemble for targeted sentinel lymph node management: initial results of an innovative promising approach for anatomically difficult lymphatic drainage in different tumour entities

Purpose There are situations where exact identification and localisation of sentinel lymph nodes (SLNs) are very difficult using lymphoscintigraphy, a hand-held gamma probe and vital dye, either a priori or a posteriori. We developed a new method using a simultaneous injection of two lymphotropic agents for exact topographical tomographic localisation and biopsy of draining SLNs. The purpose of this prospective pilot study was to investigate the feasibility and efficacy of this method ensemble. Methods Fourteen patients with different tumour entities were enrolled. A mixture of ^99mTc-nanocolloid and a dissolved superparamagnetic iron oxide was injected interstitially. Dynamic, sequential static lymphoscintigraphy and SPECT served as pathfinders. MR imaging was performed 2 h after injection. SPECT, contrast MRI and, if necessary, CT scan data sets were fused and evaluated with special regard to the topographical location of SLNs. The day after injection, nine patients underwent SLN biopsy and, in the presence of SLN metastasis, an elective lymph node dissection. Results Twenty-five SLNs were localised in the 14 patients examined. A 100% fusion correlation was achieved in all patients. The anatomical sites of SLNs detected during surgery showed 100% agreement with those localised on the multimodal fusion images. SLNs could be excised in 11/14 patients, six of whom had nodal metastasis. Conclusion Our novel approach of multimodal fusion imaging for targeted SLN management in primary tumours with lymphatic drainage to anatomically difficult regions enables SLN biopsy even in patients with lymphatic drainage to obscure regions. Currently, we are testing its validity in larger patient groups and other tumour entities.     

Identification of sentinel lymph node in stage I-II breast cancer with lymphoscintigraphy and surgical gamma probe: comparison of Tc-99m MIBI and Tc-99m sulfur colloid

AIM: To evaluate the efficacy of the surgical gamma probe (SGP) after peritumoral injection of Tc-99m MIBI and filtered Tc-99m sulfur colloid (SC) in sentinel lymph node (SLN) detection in stage I and II breast cancer for deciding on the need for axillary dissection. MATERIALS AND METHODS: Thirty patients with stage I-II breast cancer had peritumoral injection of Tc-99m MIBI (74 MBq/0.2 mL [2 mCi/0.2 mL] at 4 different locations) and 42 different patients had peritumoral injection of filtered Tc-99m sulfur colloid (50 MBq/0.2 mL [1.3 mCi/0.2 mL] at 4 different locations). Anterior, lateral, and anterolateral spot images were acquired at 10, 30, 45, 60, and 120 minutes and 24 hours are injection in 5 patients. During surgery, counts were obtained from the injection site, affected breast tissue, internal mammary, axillary, and supraclavicular regions and the contralateral side using the gamma probe. Peritumoral blue dye was also injected during surgery. The first lymph nodes with counts at least twice the background tissue and/or with blue dye uptake were surgically isolated. Modified radical mastectomy and axillary dissection were performed. RESULTS: Histopathologic evaluation was made on SLN and other excised tissues. In the Tc-99m sulfur colloid group, lymphatic drainage and lymph nodes were demonstrated with lymphoscintigraphy in 31 of 42 patients. SLN was detected by SGP in 35 of 42 patients. In the Tc-99m MIBI group, lymphatic drainage and lymph nodes were visualized with lymphoscintigraphy in 23 of 30 patients. SLN was detected in 25 of 30 patients with SGP in this group. CONCLUSION: In patients with stage I-II breast cancer, SLN could be successfully demonstrated with lymphoscintigraphy and SGP by the peritumoral injection of filtered Tc-99m sulfur colloid and Tc-99m MIBI.     

An original approach in the diagnosis of early breast cancer: use of the same radiopharmaceutical for both non-palpable lesions and sentinel node localisation.

A modern approach to the surgical treatment of early breast carcinoma requires intraoperative localisation of non-palpable lesions and assessment of the lymph node status. Localisation of breast lesions can be achieved by intratumoural injection of a small amount of radiotracer and intraoperative use of a gamma probe (i.e. radioguided occult lesion localisation, or ROLL). Assessment of the lymph node status is possible by means of the sentinel node approach. To date, two different radiopharmaceuticals have been used for localisation of tumour and sentinel node. We now propose the use of a single nanocolloidal tracer (Nanocoll, with a particle size of less than 80 nm) which is labelled with technetium-99m for simultaneous performance of ROLL and sentinel node identification. The aim of this study was to evaluate the feasibility of this approach, which should be easier and more practical than the dual-tracer injection method. We have employed this new technique in 73 patients with non-palpable, cytologically diagnosed breast cancer and non-palpable axillary lymph nodes. In all patients the radiocolloid, in a total volume of 0.3-0.4 cc, was injected under sonographic or stereotactic guidance. Half of the dose was injected intratumourally and half superficially, but very close to the tumour. Because of the slow lymphatic flow in the breast, Nanocoll must be injected some time before surgery in order to enable adequate migration to the axilla. We injected colloid in the afternoon before surgery (16-23 h before the start of the operation, with an average interval of 18 h). An average dose of 130 MBq (range 110-150) was injected in order to have about 10 MBq of radioactivity when surgery commenced. Lymphoscintigraphy was performed after 15-19 h, with an average interval of 17 h. The procedure was always successful in permitting the localisation of occult breast lesions. Lesions were always localised at the first attempt, and were always contained within the surgical margins. Histological examination revealed all 73 resected lesions to be malignant: there were 64 cases of infiltrating carcinoma and nine of intraductal carcinoma. All breast lesions were therefore confirmed to be early breast cancer. We achieved sentinel node localisation in 71 out of 73, either at scintigraphy or with the intraoperative probe; in two patients, radiopharmaceutical migration was absent. Lymphoscintigraphy showed only axillary drainage in 52 cases, only internal mammary chain (IMC) drainage in nine cases, and combined axillary and IMC drainage in eight cases. In two cases, lymphoscintigraphy suggested the sentinel node was located inside the same breast (intramammary lymph node). All the visualised sentinel nodes were biopsied except for four that were localised in the IMC. Histological examination of the nodes showed metastases in 20 cases: in 15 cases there were micrometastases, and in five, macrometastases. In conclusion, this study has demonstrated the feasibility of the proposed procedure. Simultaneous performance of ROLL and sentinel node localisation using a single tracer represents a useful and practicable choice in the management of early breast cancer.     

Lymphoscintigraphic studies of lymphatic drainage from the testes

Two colloidal radiopharmaceuticals, Au-198 and Tc-99m antimony, were used to evaluate the lymphatic drainage of the testis in experimental animals and humans. One to 24 hours after direct intratesticular injection of Au-198 colloid in dogs and 4-6 hours after injection of Tc-99m antimony colloid in men, distribution within retroperitoneal lymph nodes was demonstrated. Uptake within the para-aortic lymph nodes primarily draining the testis was decreased following proximal ligation of the spermatic vessels in dogs. Testicular lymphoscintigraphy successfully demonstrated an intact spermatic cord lymphatic communication to the para-aortic nodes in five of six patients with chronic lower-extremity lymphedema. When the intact testicle and spermatic cord were transposed to the thigh in a patient with chronic lymphedema of the lower extremity, percutaneous pedal lymphoscintigraphy successfully demonstrated uptake within the para-aortic lymph nodes draining the ipsilateral testis.     

An original approach in the diagnosis of early breast cancer: use of the same radiopharmaceutical for both non-palpable lesions and sentinel node localisation

A modern approach to the surgical treatment of early breast carcinoma requires intraoperative localisation of non-palpable lesions and assessment of the lymph node status. Localisation of breast lesions can be achieved by intratumoural injection of a small amount of radiotracer and intraoperative use of a gamma probe (i.e. radioguided occult lesion localisation, or ROLL). Assessment of the lymph node status is possible by means of the sentinel node approach. To date, two different radiopharmaceuticals have been used for localisation of tumour and sentinel node. We now propose the use of a single nanocolloidal tracer (Nanocoll, with a particle size of less than 80 nm) which is labelled with technetium-99m for simultaneous performance of ROLL and sentinel node identification. The aim of this study was to evaluate the feasibility of this approach, which should be easier and more practical than the dual-tracer injection method. We have employed this new technique in 73 patients with non-palpable, cytologically diagnosed breast cancer and non-palpable axillary lymph nodes. In all patients the radiocolloid, in a total volume of 0.3-0.4 cc, was injected under sonographic or stereotactic guidance. Half of the dose was injected intratumourally and half superficially, but very close to the tumour. Because of the slow lymphatic flow in the breast, Nanocoll must be injected some time before surgery in order to enable adequate migration to the axilla. We injected colloid in the afternoon before surgery (16-23 h before the start of the operation, with an average interval of 18 h). An average dose of 130 MBq (range 110-150) was injected in order to have about 10 MBq of radioactivity when surgery commenced. Lymphoscintigraphy was performed after 15-19 h, with an average interval of 17 h. The procedure was always successful in permitting the localisation of occult breast lesions. Lesions were always localised at the first attempt, and were always contained within the surgical margins. Histological examination revealed all 73 resected lesions to be malignant: there were 64 cases of infiltrating carcinoma and nine of intraductal carcinoma. All breast lesions were therefore confirmed to be early breast cancer. We achieved sentinel node localisation in 71 out of 73, either at scintigraphy or with the intraoperative probe; in two patients, radiopharmaceutical migration was absent. Lymphoscintigraphy showed only axillary drainage in 52 cases, only internal mammary chain (IMC) drainage in nine cases, and combined axillary and IMC drainage in eight cases. In two cases, lymphoscintigraphy suggested the sentinel node was located inside the same breast (intramammary lymph node). All the visualised sentinel nodes were biopsied except for four that were localised in the IMC. Histological examination of the nodes showed metastases in 20 cases: in 15 cases there were micrometastases, and in five, macrometastases. In conclusion, this study has demonstrated the feasibility of the proposed procedure. Simultaneous performance of ROLL and sentinel node localisation using a single tracer represents a useful and practicable choice in the management of early breast cancer.     

Influence of fast lymphatic drainage on metastatic spread in cutaneous malignant melanoma: a prospective feasibility study

The concept of sentinel lymph node biopsy in cutaneous malignant melanoma is widely established. Preoperative cutaneous lymphoscintigraphic mapping is a reliable method for identifying the nodal basins at risk of metastases in melanomas. In this prospective study we investigated the correlation between the scintigraphic appearance time and the metastatic involvement of sentinel lymph nodes. In 276 malignant melanoma patients (137 women, 139 men; age 16-93 years), dynamic and static lymphoscintigraphy was performed after strict intracutaneous application of technetium-99m nanocolloid (40-150 MBq; 0.05 ml/deposit) around the tumour or biopsy scar. Analysis of dynamic scans primarily focussed on the appearance time of sentinel lymph nodes. Sentinel lymph node visualisation 20 min as slow drainage. Fast lymphatic drainage was found in 236 patients, of whom 34 (14.4%) had sentinel lymph node metastases. Twenty-two patients showed hybrid (fast and slow) lymphatic drainage, and eight (36.4%) of them had sentinel lymph node metastases. Seven of the latter demonstrated fast lymphatic drainage, while one showed one positive sentinel lymph node with fast and another with slow drainage. The melanomas of 18 patients demonstrated exclusively slow lymphatic drainage, in all cases without sentinel lymph node metastases. This prospective study indicates that the scintigraphic appearance time of sentinel lymph nodes seems to be a clinically relevant factor for prediction of metastatic spread of cutaneous malignant melanoma. Larger numbers of patients need to be examined to truly assess the benefit of the scintigraphic appearance time compared with other predictors of sentinel lymph node tumour positivity.     

A preliminary study on sentinel lymph node biopsy: feasibility and predictive ability in oral cavity cancer

The main factor that affects the prognosis of patients with head and neck cancer (HNC) is regional lymph node metastases. For this reason, the accurate evaluation of neck metastases is required for neck management. This study investigates the sentinel lymph node identification and the accuracy of the histopathology of the sentinel lymph node in patients with HNC. Eleven patients with histologically proven oral squamous cell carcinoma accessible to radiocolloid injection were enrolled in this study. Using both lymphoscintigraphy and a handheld gamma probe, the sentinel lymph node could be identified in all 11 patients. Subsequently, the sentinel lymph nodes and the neck dissection specimen were examined for lymph node involvement due to tumor. The histopathology of sentinel lymph nodes was consistent with the pathological N classification in all 11 patients. Furthermore, the histopathology of sentinel lymph nodes was superior to physical examination, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) scan. The results of this study indicate that sentinel lymph node identification is technically feasible and predicts cervical metastases in patients with oral cavity cancer. This may be a useful diagnostic technique for identifying lymph node disease in staging lymph node dissection.     

Temporary shielding of hot spots in the drainage areas of cutaneous melanoma improves accuracy of lymphoscintigraphic sentinel lymph node diagnostics

Detection of the "true" sentinel lymph nodes, permitting correct staging of regional lymph nodes, is essential for management and prognostic assessment in malignant melanoma. In this study, it was prospectively evaluated whether simple temporary shielding of hot spots in lymphatic drainage areas could improve the accuracy of sentinel lymph node diagnostics. In 100 consecutive malignant melanoma patients (45 women, 55 men; age 11-91 years), dynamic and static lymphoscintigraphy in various views was performed after strict intracutaneous application of technetium-99m nanocolloid (40-150 MBq; 0.05 ml/deposit) around the tumour (31 patients) or the biopsy scar (69 patients, safety distance 1 cm). The images were acquired with and without temporary lead shielding of the most prominent hot spots in the drainage area. In 33/100 patients, one or two additional sentinel lymph nodes that showed less tracer accumulation or were smaller (<1.5 cm) were detected after shielding. Four of these patients had metastases in the sentinel lymph nodes; the non-sentinel lymph nodes were tumour negative. In 3/100 patients, hot spots in the drainage area proved to be lymph vessels, lymph vessel intersections or lymph vessel ectasias after temporary shielding; hence, a node interpreted as a non-sentinel lymph node at first glance proved to be the real sentinel lymph node. In two of these patients, lymph node metastasis was histologically confirmed; the non-sentinel lymph nodes were tumour free. In 7/100 patients the exact course of lymph vessels could be mapped after shielding. In one of these patients, two additional sentinel lymph nodes (with metastasis) were detected. Overall, in 43/100 patients the temporary shielding yielded additional information, with sentinel lymph node metastases in 7%. In conclusion, when used in combination with dynamic acquisition in various views, temporary shielding of prominent hot spots in the drainage area of a malignant melanoma of the skin leads to an improvement in the accuracy of identification and localisation of sentinel lymph nodes by lymphoscintigraphy.     

Evaluation and localization of lymphatic drainage and sentinel lymph nodes in patients with head and neck melanomas by hybrid SPECT/CT lymphoscintigraphic imaging

In patients with head and neck tumors, preoperative lymphoscintigraphy can be used to map lymphatic drainage patterns and identify sentinel lymph nodes. However, it is very difficult to determine the exact locations of head and neck sentinel nodes on preoperative lymphoscintigraphy without the use of anatomic landmarks. Lymph nodes in the head and neck are grouped into 7 regions, or levels, on the basis of anatomic landmarks. In patients undergoing standard lymphoscintigraphy, obtaining lateral marker images that show important anatomic landmarks can help with the localization of sentinel nodes. However, technical problems often render marker images of little or no use. Hybrid SPECT/CT lymphoscintigraphic imaging facilitates the localization of sentinel nodes by reliably showing the relationships between sentinel nodes and important anatomic structures. After reading this article, the reader should understand the lymph node level classification system for head and neck melanomas, be able to describe the technique used for the imaging of sentinel nodes in the head and neck region, and be able to demonstrate how SPECT/CT lymphoscintigraphic imaging can enable precise sentinel node localization and thus help to ensure minimal dissection.     

Subareolar injection of technetium-99m nanocolloid yields reliable data on the axillary lymph node tumour status in breast cancer patients with previous manipulations on the primary tumour: a prospective study of 117 patients

According to recently published guidelines, histological clarification by interventional techniques should be undertaken before planning the surgical management of patients with breast carcinoma. In patients with previous manipulations on the primary tumour, peritumoural injection in the context of preoperative scintigraphic detection of the sentinel lymph nodes is not possible. The aim of this prospective study was to clarify whether subareolar injection of nanocolloid can yield reliable data on the axillary lymph node tumour status in breast cancer patients with previous manipulations on the primary tumour. To date, 117 women (age 31–80 years) with breast carcinoma have been enrolled. All of these patients had undergone a biopsy (n=88) or surgery on the primary tumour (n=29) and were without clinical suspicion of lymph node metastases. Subareolar injection of 40 MBq technetium-99m nanocolloid was carried out in at least eight deposits around the areolar margin [one deposit in the middle of each quadrant and one deposit at each quadrant intersection (0.05 ml/deposit)]. Immediately after injection, dynamic and static lymphoscintigraphy of the axillary, thoracic and cervical areas was performed in various views with a gamma camera (LEAP collimator, 256×256 matrix). Lymphatic drainage was directed exclusively to the ipsilateral axilla. Sentinel lymph node biopsy and elective dissection of axillary lymph nodes were performed in all patients. All lymph nodes removed were examined by histology and immunohistochemistry. In 26 patients, lymph node metastases were found in the sentinel lymph nodes. In six of them, non-sentinel lymph nodes also showed tumour involvement. In the remaining 91 patients, lymph node metastases could be found neither in sentinel lymph nodes nor in non-sentinel lymph nodes. In conclusion, subareolar nanocolloid injection can yield reliable information on the axillary lymph node tumour status in patients with previous manipulations on the primary tumour in the breast.     

Evaluation of the sentinel lymph node combining SPECT/CT with the planar image and its importance for the surgical act

The sentinel node biopsy procedure is based on the hypothesis of the existence of an orderly and predictable pattern of lymphatic drainage to a regional lymph node basin. This results in the consideration of all lymph nodes with direct drainage from the primary tumor as sentinel nodes. The sentinel node is not necessarily the hottest or the most nearby node, although this is often the case. Lymphoscintigraphy has been an essential component for preoperative sentinel node identification. With the new generation of multimodality gamma cameras, SPECT/CT has been incorporated into the sentinel node procedure. The resulting SPECT/CT fused images depict sentinel nodes in an anatomical landscape providing a helpful roadmap for surgeons. Therefore, it is necessary to define the role of SPECT/CT in relation to the classical planar lymphoscintigraphy for the identification of sentinel nodes. To understand the combined use of lymphoscintigraphy and SPECT/CT, the criteria for sentinel node identification on preoperative images must be specified. The authors, based on their experience in this field, present tentative criteria to identify lymph nodes as sentinel nodes both in planar and SPECT/CT images and classify them into different categories. The use of these scintigraphic categories to characterize radioactive lymph nodes is also helpful for surgical decision making.     

Lymphatic drainage patterns on early versus delayed breast lymphoscintigraphy performed after injection of filtered Tc-99m sulfur colloid in breast cancer patients undergoing sentinel lymph node biopsy

The axillary lymph node status is the most important predictor of prognosis and aids in breast cancer treatment planning. Patients with breast cancer now frequently undergo sentinel lymph node (SLN) biopsy rather than axillary lymph node dissection to determine the status of the regional lymph nodes. However, the optimal timing of radionuclide injection relative to the timing of SLN biopsy remains controversial. The objective of this study was to compare the lymphatic drainage patterns on lymphoscintigraphy performed at 15 minutes to 4 hours and at 18 to 24 hours after injection of filtered Tc-99m sulfur colloid, and to determine whether, over time, radiocolloid migrates to second-echelon nodes that are not the SLNs. Fifteen women with breast cancer (mean age, 55 years; range, 38-78 years) were scheduled to undergo SLN biopsy after each received an injection of 18.5 MBq (0.5 mCi) filtered Tc-99m sulfur colloid into the breast parenchyma surrounding the tumor or biopsy cavity. Both early (15 minutes to 4 hours after radionuclide injection) and delayed (18-24 hours after radionuclide injection) lymphoscintigraphy was performed in each patient. SLN biopsy was performed, followed by completion axillary lymph node dissection and planned breast surgery. In each patient the patterns of distribution of the radionuclide in the lymph nodes were the same on early and delayed lymphoscintigrams. These findings, that the distributions of radionuclide in lymph nodes are identical on early and delayed images obtained after injection of filtered Tc-99m sulfur colloid, suggest that performing SLN biopsy on the day after injection does not diminish the accuracy of the technique in predicting the potential site of metastasis in the regional lymph nodes in patients undergoing this procedure for breast cancer.     

The value of combined peritumoral and subdermal injection techniques for lymphoscintigraphy in detection of sentinel lymph node in breast cancer

PURPOSE: The aim of this study was to evaluate the success rate of combined peritumoral and subdermal injection techniques based on our previous experience on different injection techniques for lymphoscintigraphy. PATIENTS AND METHODS: Fifty-nine women with early breast cancer (mean tumor size, 20.5 mm) were prospectively studied. On the morning of the operation, each patient had 2 injections, one peritumoral (PT) medial to the lesion and one subdermal (SD) into the skin over the tumor quadrant. Each injection consisted of 20 MBq (540 mCi) Tc-99m rhenium sulfide colloid. Early dynamic and delayed static images were obtained up to 4 hours after injections. An intraoperative gamma probe was used to explore the axillary sentinel lymph nodes (SLN). All surgical specimens were evaluated histopathologically. RESULTS: Forty patients had breast-preserving surgery and 19 had modified radical mastectomy. Thirty-eight patients had axillary dissection. All but 4 patients showed axillary lymphatic drainage. Twelve of 59 patients (20%) showed extraaxillary drainage with lymphoscintigraphy. Combined injection technique yielded a 93.2% success rate in detecting axillary SLN. In 2 of 4 patients with no drainage on lymphoscintigraphy, intraoperative gamma probe revealed SLN during the surgery. Twenty patients (33%) had positive axillary lymph nodes. In 14 of them, the SLN was the only positive node. A false-negative rate was found 1.6% (one of 59 patients). CONCLUSION: This results suggest that a combination of both PT and SD techniques increases the success rate of visualization SLN and enhances the visualization of extraaxillary nodes for further treatment planning.     

The hidden sentinel node and SPECT/CT in breast cancer patients

Purpose  In a minority of breast cancer patients, lymphoscintigraphy shows no lymphatic drainage and ‘hidden’ sentinel nodes may remain undiscovered. The purpose of this study was to explore the additional value of the recently introduced hybrid SPECT/CT in breast cancer patients with axillary non-visualisation on planar images. The role of blue dye and careful palpation of the axilla was evaluated in patients in whom axillary sentinel nodes remained hidden after SPECT/CT. Methods  Fifteen breast cancer patients with non-visualisation on planar lymphoscintigraphy and 13 women with only extra-axillary sentinel nodes underwent SPECT/CT following late planar imaging without re-injection of the radiopharmaceutical. Results  SPECT/CT visualised lymphatic drainage in eight of the 15 patients (53%) with non-visualisation on planar imaging, depicted nine of the 14 harvested sentinel nodes (64%) and three of five tumour-positive sentinel nodes. In two of the 13 patients (15%) with only extra-axillary sentinel nodes on their planar lymphoscintigram, SPECT/CT showed an axillary sentinel node that appeared to be uninvolved. Careful exploration of the axilla with the combined use of blue dye, a gamma probe and intra-operative palpation revealed an axillary sentinel node in the remaining 18 patients. SPECT/CT showed the exact anatomical location of all visualised sentinel nodes. Conclusion  SPECT/CT discovered ‘hidden’ sentinel nodes in the majority of patients with non-visualisation, but was less valuable in patients with only extra-axillary lymphatic drainage on the planar images. Exploration of the axilla in patients with persistent non-visualisation improved the identification of axillary (involved) sentinel nodes.     

Lymphatic mapping in patients with breast carcinoma: reproducibility of lymphoscintigraphic results

PURPOSE: To evaluate the reproducibility of lymphoscintigraphic results in assessment of the location and number of sentinel nodes in patients with breast cancer. MATERIALS AND METHODS: Twenty-five patients with breast cancer were prospectively enrolled in this study. Lymphoscintigraphy was performed after intratumoral injection of about 130 MBq of technetium 99m nanocolloid. Anterior and lateral images were obtained 20 minutes and 2 and 4 hours after injection. The following day, scintigraphy was repeated after a second injection of the radiolabeled colloid in an identical fashion and was preceded by acquisition of a starting image. Two observers evaluated the paired images independently, and count rates were calculated from the images. Correlation coefficient and Bland-Altman methods were used to analyze the paired count rates. RESULTS: At least one sentinel node was visualized at lymphoscintigraphy in all 25 patients. Drainage to the axilla was observed in 17 patients; drainage to the axilla and extraaxillary basins, in seven patients; and drainage exclusively to extraaxillary sentinel nodes, in one patient. The second scintigraphic study revealed the same drainage pattern in all 25 patients (reproducibility, 100%; 95% CI: 86%, 100%). The Pearson correlation coefficient of the paired count rates was 0.54 (P <.001). Count rates at repeat scintigraphy were 23%-417% of the count rates at first scintigraphy in 95% of cases. CONCLUSION: Results of lymphoscintigraphy for lymphatic mapping in breast cancer are highly reproducible for assessment of the number of sentinel nodes.     

Lymphatic mapping to tailor selective lymphadenectomy in cN0 tongue carcinoma: beyond the sentinel node concept

Purpose Cervical lymph node status is the most important pathological determinant of prognosis and decision making in head and neck squamous cell carcinoma (SCC). The aim of this study was to demonstrate that lymphoscintigraphy (LS) can supply a complete map of the lymphatic drainage before surgery, allowing planning of the type of intervention and serving to guide lymphadenectomy.Methods The study population comprised 14 patients with T2–4 SCCs of the tongue and clinically negative lymph nodes in the neck (cN0) who were scheduled to undergo tumour resection and selective level I–IV neck dissection extended to level V. LS was performed in all patients following the injection of ^99mTc-colloidal sulphide in three aliquots around the primary lesion. Dynamic, static and tomographic images of the head and neck were acquired. The operative specimens were subjected to lymphoscintigraphic evaluation. Preoperative and postoperative imaging results were compared with the pathological findings. All nodes were examined using haematoxylin-eosin staining.Results Preoperative LS was successful in all patients. Preferential pathways of lymphatic drainage were identified: level II of the neck was the most common lymphatic drainage pattern, followed by levels IV and III. Contralateral drainage occurred in 11 patients and in two of them metastatic nodes were found on the contralateral side. Metastases were observed only in radioactive lymph nodes.Conclusion LS is able to supply a complete map of the lymphatic drainage before surgery, making it possible to tailor selective neck dissection to each individual patient based on the results of preoperative mapping, thereby sparing healthy lymphatic tissue and reducing surgery-related morbidity.     

Single-photon emission computed tomography/computed tomographyfor sentinel node mapping in breast cancer

Accurate lymph node staging is essential for the prognosis and treatment in patients with cancer. The sentinel lymph node is the first node to which lymphatic drainage and metastasis from the primary tumor occurs. In malignant melanoma and breast cancer, the sentinel lymph node detection and biopsy already have been implemented into clinical practice. Currently, 2 techniques are used to identify the sentinel lymph nodes: technetium-99m-labeled colloid and blue dye. After peritumoral injection, the material migrates through the lymphatics to the first lymph nodes draining the tumor. The precise anatomic localization of the sentinel lymph nodes is important for minimal invasive surgery and to avoid incomplete removal of the sentinel lymph nodes. All sentinel lymph nodes should be resected to achieve a complete nodal staging. In the inguinal or low-axillary nodal stations, planar scintigraphic images mostly are adequate for the localization of the sentinel lymph nodes. However, in the regions of the head and neck, the chest, and the pelvis, an imaging method for the more precise anatomic localization of the sentinel lymph nodes preoperatively is highly desired. Recently, integrated single-photon emission computed tomography and computed tomography (SPECT/CT) scanners have become available. Initial reports suggest that integrated SPECT/CT might have an additional value in sentinel lymph node scintigraphy in head and neck tumors and tumors draining to the pelvic lymph nodes. We evaluated the clinical use of integrated SPECT/CT in the identification of the sentinel lymph nodes in patients with operable breast cancer. In our experience, localization and identification of sentinel lymph nodes was more accurate by integrated SPECT/CT imaging in comparison with planar images and SPECT images, respectively. In this report, the experiences of sentinel lymph node imaging with SPECT/CT are summarized.     

Clinically node-negative breast cancer, internal mammary lymph nodes, and sentinel lymph node biopsy

We report 2 cases demonstrating that localization of internal mammary (IM) sentinel lymph nodes with lymphoscintigraphy using peritumoral injection of Tc-99m antimony sulfide colloid, followed by resection using minimal access surgery, can reveal nodal metastatic disease in patients with clinically node-negative breast cancer when axillary sentinel nodes are not affected by metastatic disease. When this is found, it changes staging and can affect prognosis and treatment. These cases confirm that the technique used is sampling true sentinel IM nodes, that is nodes that receive direct lymph flow from the breast cancer, and confirm the importance of sampling IM sentinel lymph nodes. Unless techniques are used that are specifically designed to identify IM node drainage from the breast cancer site itself, with subsequent directed surgical removal of sentinel IM nodes, some patients with breast cancer will not be staged correctly.     

Sentinel lymph node biopsy in oral cancer: validation of technique and clinical implications of added oblique planar lymphoscintigraphy and/or tomography

Purpose: To validate lymphatic mapping combined with sentinel lymph node biopsy as a staging procedure, and to evaluate the possible clinical implications of added oblique lymphoscintigraphy and/or tomography and test the intra- and interobserver reproducibility of lymphoscintigraphy.

Material and Methods: Forty patients (17 F and 23 M, aged 32-90) with 24 T1 and 16 T2 squamous cell carcinoma of the oral cavity. Planar lymphoscintigraphy, emission and transmission tomography were performed. Detection and excision of the sentinel nodes were guided by a gamma probe. The sentinel nodes were step-sectioning and stained with hematoxylin and eosin and cytokeratin (CK 1). Histology and follow-up were used as “gold standard”. Tumor location, number of sentinel lymph nodes, metastasis, and recurrences were registered. Two observers evaluated the lymphoscintigraphic images to assess the inter-rater agreement.

Results: Eleven (28%) patients were upstaged. The sentinel lymph node identification rate was 97.5%. Sentinel lymph node biopsy significantly differentiated between patients with or without lymph node metastasis (P = 0.001). Lymphatic mapping revealed 124 hotspots and 144 hot lymph nodes were removed by sentinel lymph node biopsy. Three patients developed a lymph node recurrence close to the primary tumor site during follow-up. Added oblique lymphoscintigraphic images and/or tomography revealed extra hotspots in 15/40 (38%) patients. In 4/40 (10%), extra contralateral hotspots were detected.

Conclusion: Sentinel lymph node biopsy upstaged 28% of the patients. Sentinel lymph nodes close to the primary tumor were difficult to find. Added oblique planar images and/or tomographic images revealed extra clinical relevant hotspots in 38% of patients. Reproducibility proved excellent.