Lymphoscintigraphy using larger colloid particles may enhance visualization of the sentinel node in breast cancer: a case report

Lymphoscintigraphy along with a gamma-detecting probe has been applied successfully to breast cancer patients to localize the sentinel node during surgery, with a 5% false-negative rate. The authors report a case of stage II breast cancer. The sentinel node was not visualized on the initial lymphoscintigraphy with peritumoral injection of 37 MBq (1 mCi) 10 ml Tc-99m colloidal rhenium sulfide (Tc-99m ReS colloid; average particle size, 100 nm). However, the sentinel node was visualized in the left lateral view of the second lymphoscintigraphy with peritumoral injection of 37 MBq (1 mCi) 10 ml Tc-99m ReS colloid (average particle size, 500 nm). Lymphoscintigraphy using the larger colloid particles may enhance visualization of a sentinel node in breast cancer.     

Timing of sentinel lymphadenectomy in cutaneous melanoma

PURPOSE: The conduct of sentinel lymphadenectomy for cutaneous melanoma varies substantially among the medical disciplines. The authors sought to characterize the number of hot spots identified during preoperative lymphoscintigraphy for cutaneous melanoma and to determine its relation to the harvesting of sentinel lymph nodes. METHODS: Sixty-nine patients with cutaneous melanoma underwent lymphoscintigraphy with filtered Tc-99m sulfur colloid before sentinel lymphadenectomy. The lymphoscintigrams were reviewed and the number of hot spots visualized over time and the number of sentinel nodes harvested were determined. RESULTS: Lymphoscintigraphy identified 79 patients with 87 lymphatic basins at risk for metastatic disease. Lymphoscintigraphy was performed in a mean time of 30 minutes (range, 15 to 40 minutes). The mean number of hot spots increased from 0.2 to 2.0 hot spots 40 minutes after the initial static image, but the number of hot spots stabilized between 20 and 40 minutes. The same number of sentinel nodes as hot spots visualized were harvested in 58% of patients. Fewer sentinel nodes were identified at the time of surgery than were visualized by lymphoscintigrams in 39% of patients. CONCLUSIONS: More hot spots were identified up to 40 minutes after the initiation of lymphoscintigraphy. Sentinel lymphadenectomy can be performed as near to 40 minutes after the initiation of lymphoscintigraphy as is logistically reasonable. However, there may be substantial latitude in delayed performance of sentinel lymphadenectomy.     

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.     

The use of periareolar intradermal Tc-99m tin colloid and peritumoral intraparenchymal isosulfan blue dye injections for determination of the sentinel lymph node

PURPOSE: The purpose of the present study was to evaluate the use of lymphoscintigraphy, blue dye, and gamma probe detection methods for determination of the sentinel lymph node (SLN) using both periareolar intradermal injection of Tc-99m tin colloid and peritumoral intraparenchymal injection of isosulfan blue dye. METHODS: One hundred patients with T1-2 breast cancer and clinically negative nodes were enrolled in the present study. The study was composed of 2 groups. Backup axillary lymph node dissection (ALND) was mandatory in group 1 (20 patients) regardless of their lymph node status. In group 2 (80 patients), complete ALND was performed when intraoperative frozen section analysis of SLN revealed metastases. Otherwise, only SLN biopsy was performed without ALND. One day before surgery, Tc-99m tin colloid was injected at 4 periareolar sites intradermally. Lymphoscintigraphy was performed 1 to 2 hours after injection of the radiocolloid. Twenty minutes before surgery, isosulfan blue dye was injected into parenchyma surrounding the tumor or the biopsy cavity. RESULTS: The detection rates of SLN and false-negative rate of lymphoscintigraphy, blue dye, and gamma probe detection were 85%, 95% 100%, and 0% in group 1, 91%, 87%, and 95% in group 2, respectively. Detection rate by the combination of blue dye and radio tracer was 98%. CONCLUSIONS: According to the results of our study, we conclude that perioareolar intradermal injection of Tc-99m tin colloid combined with peritumoral intraparenchymal injection of blue dye is an accurate and easy method of locating the sentinel node with very high detection rates. It is recommended that the combination of all methods such as lymphoscintigraphy, blue dye, and gamma probe application will increase the success rate of SLN detection in patients with breast cancer.     

Comparison of subareolar injection lymphoscintigraphy with the 1-day and the 2-day protocols for the detection of sentinel lymph nodes in patients with breast cancer

Objective  Lymphoscintigraphy and sentinel node biopsy are used for the detection of axillary lymph node metastasis in breast cancer patients. However, currently there is no standardized technique. For the detection of axillary lymph node metastasis by lymphoscintigraphy and sentinel node biopsy, in patients with breast cancer, we compared the results of subareolar injections administered on the day of surgery (1-day protocol) with injections administered on the day before surgery (2-day protocol). Materials and methods  This study included 412 breast cancer patients who underwent surgery between 2001 and 2004. For the 1-day protocol (1 h before surgery) 0.8 ml of Tc-99m Tin-Colloid (37 MBq) was injected in 203 in the subareolar region on the morning of the surgery. For the 2-day protocol (16 h before surgery) 0.8 ml of Tc-99m Tin-Colloid (185 MBq) was injected in 209 patients on the afternoon before surgery. Lymphoscintigraphy was performed in the supine position and sentinel node identification was performed by hand-held gamma probe during surgery. Results  Among 203 patients with the 1-day protocol, 185 cases (91.1%) were identified by sentinel node lymphoscintigraphy, and 182 cases (89.7%) were identified by gamma probe. Among the 209 patients, in the 2-day protocol, 189 cases (90.4%) had the sentinel node identified by lymphoscintigraphy, and 182 cases (87.1%) by the gamma probe. There was no significant difference in the identification rate of the sentinel node between the 1-day and 2-day protocols by lymphoscintigraphy and the gamma probe (p > 0.05, p > 0.05). Conclusions  The results of the identification of the sentinel node by subareolar injection according to 1-day or 2-day protocol, in breast cancer patients, showed no significant differences. Because the 2-day protocol allows for an adequate amount of time to perform the lymphoscintigraphy, it is a more useful protocol for the identification of sentinel nodes in patients with breast cancer.     

Preoperative evaluation of sentinel lymph node status in melanoma by means of (99m)Tc-MIBI and lymphoscintigraphy: a case report

Previous reports have shown that (99m)Tc-sestamibi (MIBI) could detect clinically occult metastatic melanoma lesions. This article reports on a patient with invasive melanoma of the right heel in whom the sentinel node status was preoperatively evaluated with this tracer. Although regional lymph nodes were clinically negative, (99m)Tc-MIBI scintigraphy showed focal increased tracer uptake in the right groin that corresponded to the location of 2 sentinel nodes visualized by lymphoscintigraphy with (99m)Tc-colloidal rhenium sulfide performed the same day. A gamma-probe was used intraoperatively to guide the excision of the sentinel nodes that were further classified as metastatic by histopathology. This double-technique approach is technically feasible and has the potential of selecting a group of patients who might benefit from a selective complete lymphadenectomy.     

Effect of high specific-activity sulfur colloid preparations on sentinel node count rates.

PURPOSE: Preliminary results by other investigators suggest that increasing the specific activity of Tc-99m nanocolloid preparations increases the measured counts in sentinel nodes compared with lower specific-activity (SA) preparations using the same initial injected dose. The authors set out to determine whether a similar result could be perceived with Tc-99m sulfur colloid (SC) preparations. METHODS: Twenty-three consecutive patients (low SA group) with successful visualization of sentinel nodes by lymphoscintigraphy before our standard protocol was changed to a higher SA preparation were compared with 28 patients (high SA group) just after the switch. Injection techniques were similar in both groups: peritumoral injections at two to four points of a mixture of half-filtered (0.22 microm filter) and unfiltered Tc-99m sulfur colloid in 6 ml followed immediately by intradermal injections of filtered sulfur colloid above the tumor. Activity levels for both types of injections ranged from 3.7 to 11.1 mBq (100 to 300 microCi). Preparation of the higher SA mixture of sulfur colloid was achieved by using only one eighth of the sulfur colloid vial contents when the same activity (125 mCi) of Tc-99 was added. Regions of interest were drawn around the images of sentinel nodes and the initial injection site in the anterior and lateral projections. Ratios of sentinel node to initial injection site count were calculated for both groups. RESULTS: The mean ratio of sentinel node to injection site count in the high SA group was 2.9 times greater than that in the low SA group. The median ratio value was 2.7 times greater in the high SA group. CONCLUSION: These preliminary results suggest higher counts in the sentinel node are possible with a higher SA preparation.     

Fusion lymphoscintigraphy with a 24-hour Tc-99m MDP bone scan for sentinel lymph node detection and imaging

A 62-year-old woman with right breast carcinoma who had a breast biopsy 3 weeks earlier was referred for a whole-body Tc-99m MDP bone scan to identify possible osseous metastases. Twenty-four hours later, she underwent lymphoscintigraphy using four peritumoral injections of 250 microCi filtered Tc-99m sulfur colloid of 0.22 microm each. The lymphoscintigraphic images showed good delineation of three right axillary lymph nodes in relation to the rib cage. Performing a bone scan just before lymphoscintigraphy for sentinel node detection may help the surgeon to identify sentinel lymph nodes. This is more anatomically precise than using a flood source to delineate body contour. A Tc-99m MDP bone scan followed by lymphoscintigraphy should be considered in patients with breast carcinoma who will have both bone imaging and lymphoscintigraphy.     

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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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%.     

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.     

Identification of sentinel lymph node in breast cancer by lymphoscintigraphy and surgical gamma probe with peritumoral injection of scintimammographic agent "99mTc MIbI"

The purpose of this study was to evaluate the efficacy of lymphoscintigraphy and the surgical gamma probe (SGP) with peritumoral injection of 99mTc MIBI in sentinel lymph node (SLN) detection in breast cancer regardless of whether metastatic or not. METHOD: Thirty patients with T1/ T2 breast cancer had peritumoral injections of 99mTc MIBI (74 MBq/0.2 ml at 4 different locations) at 2, 6 and 24 hours before surgery. Anterior, anterolateral, and lateral spot images were taken at 10, 30, 45, 60 and 120 minutes. Counts were collected from the injection site, affected breast tissue, internal mammaries, axillary and supraclavicular regions, and the contralateral side. Peritumoral blue dye was also injected at surgery. The first lymph nodes with counts twice the background tissue and/or with blue dye uptake were surgically isolated, and histopathological evaluations were made. Modified radical mastectomy was performed on all patients. RESULTS: 23/30 patients had lymph nodes in scintigrams and the sentinel lymph nodes were identified with SGP in 25/30 patients. CONCLUSION: Lymphoscintigraphy and subsequent SGP detection with peritumoral injection of 99mTc MIBI can be used for identifying SLN in breast cancer.     

Tc-99m Diphosphonate as a Potential Radiotracer to Detect Sentinel Lymph Nodes in Patients with Breast Cancer

Purpose

To evaluate the potential of Tc-99m diphosphonate as a tracer for sentinel lymph node biopsy in breast cancer.

Methods

Lymphoscintigraphs of 35 patients (50.9 ± 10.2 years) with breast cancer were acquired after administering a subareolar intradermal injection of Tc-99m diphosphonate 18 h before surgery. Static images were taken within 15 min (early phase) and 15 h after injection (delayed phase). The lymphoscintigraphic identification rate was defined as the percentage of subjects studied with visible foci at axillae. Sentinel lymph node biopsies were performed using a gamma probe and by blue dye injection. Any node that was radioactive or stained with blue dye was labeled as a sentinel lymph node. Lymph nodes without radioactivity or blue dye staining were defined as non-sentinel lymph nodes. The intraoperative identification rate was defined as the percentage of patients with a radioactive sentinel lymph node. Percentages of lymphoid cells expressing S-100, CD83, and CD1a were compared.

Results

The lymphoscintigraphic identification rate was 94.3% (33/35) during the early phase and 96.9% (31/32) during the delayed phase, whereas the intraoperative identification rate was 94.3% (33/35). The mean percentages of lymphoid cells that stained positively for S-100 or CD83 were lower in sentinel lymph nodes than in non-sentinel lymph nodes (1.5% vs. 9.0% for S-100, and 4.5% vs. 9.3% for CD83, respectively, p = 0.0286). The mean percentages of lymphoid cells in sentinel lymph nodes and non- sentinel lymph nodes expressing CD1a were 3.3% and 7.0%, respectively (p = ns).

Conclusions

Tc-99m diphosphonate can reliably detect regional lymph nodes in 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.     

Sentinel node biopsy in male breast cancer

OBJECTIVE: Male breast cancer is a rare disease and axillary status is the most important prognostic indicator. Lymphoscintigraphy associated with gamma-probe guided surgery has been proved to reliably detect sentinel nodes in female patients with breast cancer. This study evaluates the feasibility of the surgical identification of sentinel node by using lymphoscintigraphy and a gamma-detecting probe in male patients, in order to select subjects who would be suitable for complete axillary lymphadenectomy. METHODS: Colloid human albumin labelled with 99Tc was administered to 18 male patients with breast cancer and clinically negative axillary lymph nodes. Lymphoscintigraphy was performed the day before surgery. An intraoperative gamma-detecting probe was used to identify sentinel nodes during surgery. RESULTS: Lymphoscintigraphy and biopsy of the sentinel node were successful in all cases. A total of 20 sentinel nodes were removed. Pathological examinations showed 11 infiltrating ductal carcinomas, two intraductal carcinomas and five intracystic papillary carcinomas. Six patients (33%) had positive sentinel node (micrometastases were found in three patients). These patients underwent axillary dissection; in five of them (83%) the sentinel node was the only positive node. Twelve patients (67%) showed negative sentinel nodes; in all of them no further surgical treatments were planned. CONCLUSIONS: As in women, lymphoscintigraphy and sentinel node biopsy under the guidance of a gamma-detecting probe proved to be an easy method for the detection of sentinel nodes in male breast carcinoma. In male patients with early stage cancer, sentinel node biopsy might represent the standard surgical procedure in order to avoid unnecessary morbidity after surgery, preserving accurate staging of the disease in the axilla.     

Comparison of subdermal and peritumoral injection techniques of lymphoscintigraphy to determine the sentinel lymph node in breast cancer

PURPOSE: The purpose of this study was to evaluate 2 different injection techniques for lymphoscintigraphy to determine the axillary sentinel lymph node (SLN) in patients with breast cancer. METHODS: Thirty-six patients with early breast cancer were studied prospectively. Both peritumoral (PT) and subdermal (SD) injections were performed on each patient with Tc-99m rhenium sulfide colloid. PT injections were done 1 to 8 days before surgery and SD injections were done on the day of operation. An intraoperative gamma probe was used to explore the axillary SLNs prior to tumor excision and axillary dissection. All surgical specimens were evaluated histopathologically. RESULTS: In 19 of 36 patients, the same lymphatic drainage sites were observed with both techniques. Of these, 17 patients showed only axillary, 1 showed axillary and internal mammary (IM), and 1 showed axillary and subclavicular drainage sites. With PT injections 26 of 36 patients (72%), and with SD injections 33 of 36 patients (92%), showed axillary drainage and axillary SLNs. With PT injections 9 patients, and with SD injections only 2 patients, did not show any drainage site. During the operation with a gamma probe, axillary SLNs were excised in 35 patients (success rate, 97%). IM drainage was seen in 8 of 36 patients who underwent PT injections and in 3 of 36 with SD injections. CONCLUSION: The success rate was found to be higher with the SD injection technique than with PT injections to visualize the axillary SLN. To increase the visualization of both axillary and IM SLNs, it may be useful to perform lymphoscintigraphy with SD and PT injections together.     

Radioguided sentinel lymph node biopsy in malignant cutaneous melanoma.

The procedure of sentinel lymph node biopsy in patients with malignant cutaneous melanoma has evolved from the notion that the tumor drains in a logical way through the lymphatic system, from the first to subsequent levels. As a consequence, the first lymph node encountered (the sentinel node) will most likely be the first affected by metastasis; therefore, a negative sentinel node makes it highly unlikely that other nodes in the same lymphatic basin are affected. Although the long-term therapeutic benefit of the sentinel lymph node biopsy per se has not yet been ascertained, this procedure distinguishes patients without nodal metastases, who can avoid nodal basin dissection with its associated risk of lymphedema, from those with metastatic involvement, who may benefit from additional therapy. Sentinel lymph node biopsy would represent a significant advantage as a minimally invasive procedure, considering that an average of only 20% of melanoma patients with a Breslow thickness between 1.5 and 4 mm harbor metastasis in their sentinel node and are therefore candidates for elective lymph node dissection. Furthermore, histologic sampling errors (amounting to approximately 12% of lymph nodes in the conventional routine) can be reduced if one assesses a single (sentinel) node extensively rather than assessing the standard few histologic sections in a high number of lymph nodes per patient. The cells from which cutaneous melanomas originate are located between the dermis and the epidermis, a zone that drains to the inner lymphatic network in the reticular dermis and, in turn, to larger collecting lymphatics in the subcutis. Therefore, the optimal route for interstitial administration of radiocolloids for lymphoscintigraphy and subsequent radioguided sentinel lymph node biopsy is intradermal or subdermal injection. (99m)Tc-Labeled colloids in various size ranges are equally adequate for radioguided sentinel lymph node biopsy in patients with cutaneous melanoma, depending on local experience and availability. For melanomas along the midline of the head, neck, and trunk, particular consideration should be given to ambiguous lymphatic drainage, which frequently requires interstitial administration virtually all around the tumor or surgical scar from prior excision of the melanoma. Lymphoscintigraphy is an essential part of radioguided sentinel lymph node biopsy because images are used to direct the surgeon to the sites of the nodes. The sentinel lymph node should have a significantly higher count than that of the background (at least 10:1 intraoperatively). After removal of the sentinel node, the surgical bed must be reexamined to ensure that all radioactive sites are identified and removed for analysis. Virtually the entire sentinel lymph node should be processed for histopathology, including both conventional hematoxylin-eosin staining and immune staining with antibodies to the S-100 and HMB-45 antigens. The success rate of radioguidance in localizing the sentinel lymph node in melanoma patients is approximately 98% in institutions that perform a high number of procedures and approaches 99% when combined with the vital blue-dye technique. Growing evidence of the high correlation between a sentinel lymph node biopsy negative for cancer and a negative status for the lymphatic basin-evidence, therefore, of the high prognostic value of sentinel node biopsy-has led to the procedure's being included in the most recent version of the TNM staging system and starting to become the standard of care for patients with cutaneous melanoma.     

Three-dimensional localization of sentinel lymph nodes using combined emission and transmission SPECT data

PURPOSE: With conventional planar imaging, preoperative anatomic localization of a sentinel lymph node is possible in only two dimensions. To improve spatial localization of sentinel lymph nodes, a dual-head camera equipped with a transmission source was used to create combined transmission-emission SPECT images in a patient with a malignant melanoma of the left forearm. METHODS: Lymph node scintigraphy was performed after injection of Tc-99m-labeled nanocolloid around the tumor site 1 day before operation. SPECT was performed using a gamma camera equipped with a transmission collimator system originally designed to correct attenuation. Transmission and emission images were created simultaneously, matched, and displayed in three dimensions. RESULTS: In the combined emission-transmission images, the sentinel lymph node was clearly located in the left axilla. The lymph nodes could be identified during operation at the same location as that detected by SPECT. Based on preoperative information, the sentinel lymph node was identified rapidly and the extent and duration of the operation were minimized. CONCLUSIONS: This method provides better anatomic information, especially in deep structures such as the axilla or pelvis. With accurate three-dimensional preoperative information, intraoperative access is quicker and less invasive for the patient.     

Radioguided sentinel node detection in breast cancer patients: comparison of 99mTc phytate and 99mTc rhenium colloid efficacy

BACKGROUND: Radioguided sentinel node biopsy (SNB) of breast cancer patients has become a standard method for detecting early stage breast cancer. However, no standard radiopharmaceutical exists. METHODS: 99mTc rhenium colloid or 99mTc phytate SNB was used to aid detection in breast cancer patients. For each radiopharmaceutical, 100 patients were examined. The following points were compared: (1) scintigraphic detection rate of axillary sentinel nodes (detectability and number when detectable) and internal mammary sentinel nodes; (2) the number of nodes detected scintigraphically and the number detected during surgery; (3) sensitivity, specificity, accuracy, negative predictive value, and positive predictive value for axillary sentinel nodes. RESULTS: Axillary sentinel nodes of patients were biopsied using either 99mTc rhenium or 99mTc phytate. The number of axillary nodes surgically removed from patients given 99mTc rhenium was 2.28+/-1.08 (mean+/-SD), and the number of axillary nodes surgically removed from patients given 99mTc phytate was 1.68+/-0.82. Some patients given 99mTc rhenium showed a spill-over of radioactivity from sentinel nodes. Concordance of scintigraphically detected nodes and surgical removed nodes was superior for 99mTc phytate compared to that with 99mTc rhenium, with a statistically significant difference. The sensitivity and negative predictive value was superior with 99mTc phytate compared to that with 99mTc rhenium, even though no statistical difference was detectable. However, visualization of internal mammary nodes was superior with 99mTc rhenium. CONCLUSION: In breast cancer patients, 99mTc phytate is a better choice for the detection of axillary SNB than 99mTc rhenium colloid. However, 99mTc rhenium colloid is a better choice for the detection of internal mammary nodes.     

Can preoperative lymphoscintigraphy be used as a guide in treatment planning of breast cancer?

PURPOSE: The purpose of this study was to map the lymphatic drainage patterns of breast cancer with lymphoscintigraphy to evaluate the variability of drainage and to determine whether lymphatic mapping can help to increase the certainty of breast cancer staging. MATERIALS AND METHODS: Fifty women with breast cancer (mean age, 49 years) were included in the study. Lymphoscintigraphy was performed with 1 mCi Tc-99m rhenium sulfide colloid in a 2-ml volume injected into the four quadrants of the peritumoral area using a 25-gauge needle. Ten-minute dynamic images and 2-hour delayed static images were obtained in the anterior and lateral positions using a gamma camera with a high-resolution collimator. All patients had a modified radical mastectomy and axillary dissection. The results were evaluated with histopathologic findings of the axilla. RESULTS: Six patients had excision biopsies before surgery. Of 13 patients with centrally located tumors, 84% had axillary lymphatic drainage, whereas 53% drained to internal mammary lymphatics. Of 23 patients with outer quadrant tumors, 4 showed no lymphatic drainage and all of them had metastatic tumor in the axillary lymph nodes. Axillary drainage was seen in 82% of patients and internal mammary lymphatic drainage in 23%. Of eight patients with inner quadrant tumors, one patient with no lymphatic drainage was found to have metastases in the axilla. In this group, 62% had axillary and 50% had internal mammary lymphatic drainage, and one patient had supraclavicular drainage. CONCLUSIONS: Lymphoscintigraphy indicates that drainage routes may vary, and thus it may play a guiding role in patients with breast cancer who need radiotherapy. In patients with internal mammary lymphatic drainage, the accuracy of radiotherapy planning may increase if internal mammary lymphoscintigraphy is added to the protocol. In patients with internal mammary drainage, obtaining an internal mammary lymphatic biopsy during surgery will also increase the accuracy of staging.