Laparoscopic sentinel lymph node dissection--a novel technique for the staging of prostate cancer

OBJECTIVES: Pelvic lymph node metastases indicate a poor prognosis for prostate cancer patients. The aim of this study was to evaluate the suitability of laparoscopic radioisotope guided sentinel lymph node (SLN) dissection in staging of prostate carcinoma. METHODS: 28 patients with prostate cancer and intermediate or high risk for lymph node metastases considered for external beam radiotherapy underwent laparoscopic pelvic lymphadenectomy at our institution. For visualization of individual SLN distribution, an image fusion system consisting of a gamma-camera with integrated X-ray tube was used. During laparoscopic lymphadenectomy, SLN were identified using a laparoscopic gamma probe. RESULTS: Preoperative imaging and laparoscopic gamma probe allowed an excellent delineation of SLN. 57% (preoperative imaging) as well as 48% (intraoperative measurements) of SLN were found outside the obturator fossa. All SLN were removed successfully without intra- or postoperative complications. Despite extended lymphadenectomy, no significant lymphocele appeared. 10 lymph node metastases were found in 7 out of the 31 patients (23%) with 3 of the 10 metastases lying outside the obturator fossa representing the standard lymphadenectomy area. CONCLUSIONS: The present data demonstrate that laparoscopic SLN dissection is an excellent minimally invasive and technically feasible tool for staging of intermediate and high risk prostate cancer.     

Detection of early lymph node metastases in prostate cancer by laparoscopic radioisotope guided sentinel lymph node dissection

PURPOSE: Radioisotope guided sentinel lymph node (SLN) dissection (SLND) for prostate cancer has been shown to increase the sensitivity of detecting early metastases in open pelvic lymph node dissection. We developed a technique that allows SLND to be performed by laparoscopy in conjunction with laparoscopic radical prostatectomy. MATERIALS AND METHODS: In 71 consecutive patients SLND was performed by 1 surgeon preceding laparoscopic radical prostatectomy. Mean preoperative prostate specific antigen was 8.88 ng/ml (range 2.1 to 25.4). At 24 hours prior to surgery 3 ml (200 MBq) Tc labeled human albumin colloid were injected into the prostate gland under transrectal ultrasound guidance. An especially designed laparoscopic gamma probe was used to measure radioactivity during surgery. SLNs were identified and removed. If frozen section analysis showed metastases, extended pelvic lymph node dissection was performed. RESULTS: Radioactivity was detected on 2, 1 and no sides in 50 (70.4%), 19 (26.7%) and 2 patients (2.8%), respectively. In 81 of the 142 pelvic side walls (54.7%) SLNs were exclusively outside of the obturator fossa. Histopathological examination showed metastases to SLNs in 9 patients (12.9%). Eight of the 11 detected metastases (72.7%) were outside of the obturator fossa. Lymph node metastases were exclusively found in Tc marked lymph nodes. Mean tumor size was 1.7 mm (range 0.2 to 3.9). CONCLUSIONS: SLND is feasible by laparoscopy. It detects micrometastases outside of the obturator fossa in a significant number of patients. We noted that the transperitoneal approach allowing wide exposure and a gamma probe with a 90-degree lateral energy window is the most important factor to enable successful laparoscopic SLND.     

Modified concept for radioisotope-guided sentinel lymph node dissection in prostate cancer

Purpose

To present a modified concept for sentinel lymph node (SLN)-guided pelvic lymph node dissection in prostate cancer.

Methods

A total of 463 patients with histologically proven prostate cancer underwent SLN-guided lymph node dissection. The day before surgery patients received intraprostatic injection of Tc-99 m-labeled nanocolloid (Tc-NC) under transrectal ultrasound guidance. At the time of surgery, the lymph nodes of the obturator fossa were dissected routinely in all patients. After meticulous testing with a handheld gamma probe, all lymphatic tissues in predefined anatomic regions (external iliac, internal iliac, common iliacal and presacral) with Tc-NC uptake were additionally resected.

Results

In 146 (12.8%) patients, SLN were located exclusively in the obturator fossa, but 317 patients (87.2%) underwent resection of additional sentinel regions. In 28 (6.1%) patients, 62 lymph node metastases were detected, and 32 (51.6%) of these were located outside the obturator fossa. Eight (28.6%) patients displayed lymph node metastases exclusively outside the obturator fossa and had been resected only because of positive SLN probing.

Conclusions

The obturator fossa comprises the major landing site of lymph node metastases, but more than half of the metastases are located outside this anatomic region. Routine resection of the obturator fossa with additional resection of positive sentinel regions improves staging accuracy compared to resection of the obturator fossa only.     

Technology insight: radioguided sentinel lymph node dissection in the staging of prostate cancer

Pelvic lymph node dissection is the only reliable method of staging for clinically localized prostate cancer. Despite the obvious prognostic advantages conferred by accurate staging, pelvic lymph node dissection is associated with significant morbidity and prolonged operative time. A substantial decrease in the sensitivity to lymph node metastasis occurs by simple reduction of the dissection area to the obturator fossa. Radioguided sentinel lymph node dissection provides accurate staging despite use of a minimal-area dissection template. Results from studies in prostate cancer indicate that this method has a high sensitivity for very early detection of lymphatic spread. A substantial number of the detected metastases are of a small size, solitary and widely distributed throughout the pelvic lymph nodes. These features make metastases undetectable by preoperative imaging modalities, and by the current, standard method of lymph node dissection limited to the obturator fossa.     

Detection of pelvic lymph node metastases in patients with clinically localized prostate cancer: comparison of [18F]fluorocholine positron emission tomography-computerized tomography and laparoscopic radioisotope guided sentinel lymph node dissection

PURPOSE: Accurate detection of lymph node metastases in prostate cancer has important implications for prognosis and approach to treatment. We investigated whether preoperative [18F]fluorocholine combined in-line positron emission tomography-computerized tomography and intraoperative laparoscopic radioisotope guided sentinel pelvic lymph node dissection can detect pelvic lymph node metastases in patients with clinically localized prostate cancer as reliably as extended pelvic lymph node dissection. MATERIALS AND METHODS: A total of 20 patients (mean age 63.9 +/- 6.7 years, range 52 to 75) with clinically localized prostate cancer, prostate specific antigen greater than 10 ng/ml, and/or a Gleason score sum of 7 or greater and negative bone scan were enrolled in the study. [18F]fluorocholine combined in-line positron emission tomography-computerized tomography was performed before surgery. Sentinel pelvic lymph node dissection preceded extended pelvic lymph node dissection including the area of the obturator fossa, external iliac artery/vein and internal iliac artery/vein up to the bifurcation of the common iliac artery. Laparoscopic radical prostatectomy was performed afterward. RESULTS: In 10 of the 20 patients (50%) lymph node metastases were detected, and were exclusively found outside the obturator fossa in 62%. These metastases would not have been identified with standard lymph node dissection of the obturator fossa only. [18F]fluorocholine combined in-line positron emission tomography-computerized tomography was true positive in 1, false-positive in 2, false-negative in 9 and true negative in 8 patients. The largest lymph node metastasis not seen with [18F]fluorocholine combined in-line positron emission tomography-computerized tomography was 8 mm. Laparoscopic sentinel guided lymph node dissection revealed lymph node metastases in 8 of 10 patients. In the other 2 patients sentinel lymph node dissection was not conclusive. In 1 patient normal nodal tissue was completely replaced by cancer and, therefore, there was no tracer uptake in the involved pelvic sidewall/node, and the other patient had no tracer activity at all in the involved pelvic sidewall. Extended pelvic lymph node dissection missed 1 lymph node metastasis (2 mm diameter near pudendal artery) which was detected by sentinel pelvic lymph node dissection only. CONCLUSIONS: Extended pelvic lymph node dissection reveals a higher number of lymph node metastases as described for obturator fossa dissection only. [18F]fluorocholine combined in-line positron emission tomography-computerized tomography is not useful in searching for occult lymph node metastases in clinically localized prostate cancer. Sentinel guided pelvic lymph node dissection allows the detection of even small lymph node metastases. The accuracy of sentinel pelvic lymph node dissection is comparable to that of extended pelvic lymph node dissection when the limitations of the method are taken into consideration.     

Sentinel lymph node dissection combined with meticulous histology increases the detection rate of nodal metastases in prostate cancer

Purpose

To evaluate benefits of sentinel lymph node (SLN) biopsy for staging accuracy in prostate cancer. Extended pelvic lymph node dissection (ePLND) is a preferred staging tool; however, it may underestimate the incidence of nodal involvement.

Methods

Eighty patients with estimated risk of lymphadenopathy above 5 % based on Briganti nomogram had Tc-99m-labeled nanocolloid injected into the prostate. Planar lymphoscintigraphy and single-photon emission computed tomography/CT were performed to localize SLNs. Radioguided SLN dissection was followed by backup ePLND comprising external iliac, obturator and internal iliac regions. All SLNs were serially sectioned every 150 μm and examined using hematoxylin and eosin; immunohistochemical staining was applied every 300 μm.

Results

A total of 335 SLNs were detected, and 17 % were located outside ePLND template. Nodal metastases were diagnosed in 32 patients (40 %). Without radioguided SLN localization, solitary metastases posteriorly to the branches of the internal ilaic vessels, in pararectal and common iliac regions would not have been removed in five of 32 patients (16 %). Using standard histology protocol, we would have diagnosed metastases in 23 patients with median size of 2.8 mm. Serial sectioning of SLN and immunohistochemistry led to the detection of metastases in additional nine patients (28 %) with median size of 0.2 mm.

Conclusion

ePLND comprised 83 % of SLNs, at least one SLN laid outside its template in 28 % of patients. ePLND and SLN dissection combined with nodal serial sectioning and immunohistochemistry increased the detection rate of nodal metastases by 68 % in comparison with ePLND alone and standard histology protocol.     

Laparoscopic extended pelvic lymph node dissection for prostate cancer: description of the surgical technique and initial results

OBJECTIVE: In patients with prostate cancer, extended pelvic lymph node dissection (ePLND) yields a higher number of lymph node metastases (LNM) than standard pelvic lymph node dissection (PLND) of the obturator fossa only. We describe our laparoscopic technique of extended lymph node dissection and provide the number and locations of positive lymph nodes from our experience. METHODS: In a total of 35 selected patients with clinically localized prostate cancer, laparoscopic ePLND was performed prior to laparoscopic radical prostatectomy. The template included the genitofemoral nerve up to the bifurcation of the common iliac artery and down to the epigastric artery. In the "split and roll" technique the internal and external iliac arteries including the bifurcation and the external iliac vein were completely mobilized. After freeing the obturator nerve, the entire lymph node package was released from the pelvic side wall. RESULTS: Mean operative time was 90min/patient. The complications were two temporary and reversible neurapraxias (ischiatic nerve and obturator nerve), one deep vein thrombosis, and two lymphoceles. One lymphocele healed conservatively; the second was marsupialized laparoscopically. Eleven (31.4%) patients had lymph node metastases; their mean prostate-specific antigen (PSA) level was 20.3+/-7.0 ng/ml (range: 5.2-39.7 ng/ml) and their median Gleason sum in biopsy was 7 (range: 6-8). Mean size of the LNM was 3.1+/-1.0 mm (range: 0.2-8). In 5 of the 11 patients with LNM these were detected exclusively outside the obturator fossa. LNM were in the obturator fossa only in two (one bilateral), around the external iliac artery only in two, around the internal iliac artery only in two, and around the external iliac artery and internal iliac only in one patient. CONCLUSIONS: Laparoscopic ePLND can be combined with laparoscopic radical prostatectomy. Standardization of the technique facilitates surgery to a great extent. e-PLND detects LNM in a significant number of patients. The majority of LNM are outside the obturator fossa. The transperitoneal approach allows a wide exposure and is the most important factor to enable successful ePLND.     

A preclinical study of prostate sentinel lymph node mapping with [99mTC]diethylenetetramine pentaacetic acid-mannosyl-dextran

PURPOSE: SLN identification could improve the pathological staging of prostate cancer. Prior SLN studies have been compromised by delayed radiotracer uptake rates and significant diffusion rates out of the sentinel nodes. Lymphoseek is a new radiopharmaceutical specifically designed for SLN mapping. It shows rapid and sustained SLN uptake. MATERIALS AND METHODS: We investigated the use of Lymphoseek for prostate SLN mapping by measuring SLN uptake in 12 anesthetized pigs. The prostate was injected with 0.05 ml of a 1:1 volume per volume mixture of Lymphazurin and 1.0 mCi Lymphoseek (1 nmole). Within 5 to 19 minutes the pelvic lymph nodes were dissected and assayed with a gamma probe. A lymph node was considered a sentinel node if it had count rates that exceeded 10 times the background count. We calculated the percent of injected dose of each lymph node excised and the prostate gland. RESULTS: A total of 35 SLNs were identified in the 12 studies. Of the SLNs 81% were located outside of the obturator fossa in this pig model. The SLN percent of injected dose was 0.05% to 7.75% (mean +/- 1 SD 1.74% +/- 1.92%). The mean percent of injected dose in the prostate was 27% +/- 12%. There was no correlation between the side of SLN and the lobe injected. CONCLUSIONS: After prostate administration of Lymphoseek pelvic SLNs attain high signal-to-background ratios within 10 minutes. This property should permit intraoperative injection and SLN mapping without significantly adding to the duration of prostatectomy. A phase I clinical trial has been initiated, which will later incorporate minimally invasive techniques.     

Limitations of radioguided surgery in high-risk prostate cancer

OBJECTIVES: To determine how many men with high-risk prostate cancer (prostate-specific antigen [PSA]>20 ng/ml or biopsy Gleason score 8-10) have positive lymph nodes (sentinel lymph nodes [SLNs] and nonsentinel lymph nodes [NSLNs]) and whether these positive nodes are localised in the region of SLN dissection or in other regions, too. METHODS: In 228 men with high-risk prostate cancer radical retropubic prostatectomy combined with radioguided pelvic lymph node dissection and extended lymphadenectomy were performed. Serial sections of the SLNs were analysed immunohistochemically. RESULTS: A median of 7 SLNs (mean, 7) and 11 NSLNs (mean, 11) were dissected per patient. Ninety-six of 228 men (42.1%) had lymph node metastases. Most men had positive lymph nodes along the internal iliac artery alone or in combination with other regions. Twenty-two men had only micrometastatic disease. In 94 of 96 men the SLNs were positive. Twenty-six of 96 men had also positive NSLNs. When SLNs and NSLNs were positive, in more than half the patients the NSLNs were localised outside the region of sentinel lymphadenectomy. CONCLUSIONS: The dissection of SLNs in prostate cancer has a high sensitivity in detecting positive nodes. When SLNs are negative, the other pelvic lymph nodes are also negative in a high percentage of men (sensitivity 97.1%). When the SLNs are positive, patients with high-risk disease also have a high incidence of positive NSLNs. Therefore, when it is aspired to remove all pelvic lymph node metastases sentinel and extended lymphadenectomy should be performed.     

Sentinel lymph node dissection for localized prostate cancer

Proper assessment of lymph node status is of crucial importance in the management of newly diagnosed prostate cancer. Early stage metastatic disease takes the form of microscopic tumor-cell deposits rather than grossly enlarged nodes. So far there is no imaging technique, however, which allows detecting small metastases in the range of a few millimetres. Therefore pelvic lymph node dissection (PLND) is the only reliable method of staging for clinically localized prostate cancer. The cornerstone of radioguided prostate surgery is a radiopharmaceutical--a carrier molecule labeled by radionuclide. After injection to at the prostate, the radiopharmaceutical crosses the lymphatic pores and migrates into the lymph vessels and from there to the first echelon of lymph nodes. We were the first to show that sentinel PLND can be performed by means of laparoscopy preceding laparoscopic radical prostatectomy. Our most recent publication presents data of 140 patients with clinically localized prostate cancer in which laparoscopic sentinel PLND was performed preceding radical prostatectomy from November 2001 to January 2005. On the preoperative scintigraphy SLNs were detected bilaterally,unilaterally, not on the pelvic-walls in 113 (80.7%), 20 (14.2%) and 6 (4.2%) patients and intraoperatively in 96 (68.6%), 36 (25.7%), 8 (5.7%) patients respectively. In 99 out of 140 patients (70.7%) intraoperatively SLN was detected in the same position as on preoperative scan. At least one SLN was detected in 133 patients (95.3%). Whenever PLND is indicated it should not be limited to lymph node sampling as provided by standard limited PLND but has to be performed in the template of extended PLND. There is only limited experience with sentinel PLND, but all the data collected so far indicate that this method has the potential to become an alternative to extended PLND since it allows for reduction of the extent of PLND without compromising diagnostic accuracy.     

The influence of serial sections,immunohistochemistry, and extension of pelvic lymph node dissection on the lymph node status in clinically localized prostate cancer

OBJECTIVES: Pelvic lymph node metastases indicate a poor prognosis for patients with clinically localized prostate cancer. The aim of the study was to investigate the value of extended histopathological techniques considering the extent of pelvic lymphadenectomy and preoperative risk factors. METHODS: Total of 194 patients with prostate cancer were examined. At first all patients had a sampling of the sentinel lymph nodes (SLN) followed in most cases by a modified or extended pelvic lymphadenectomy. Step sections, serial sections and immunohistochemistry (IHC, pancytokeratin antibody) were analyzed in all SLN and so-called non-SLN of the first 100 patients. Later serial sections and IHC of non-SLN were left out. RESULTS: In 26.8% lymphatic metastases were found. The detection rate of lymph node-positive patients depend significantly on the chosen extension of pelvic lymphadenectomy. Limiting the histopathological investigation to the lymph node specimen of the obturator fossa only 44.2% of lymph node-positive cases would have been identified. An additional inclusion of all lymph nodes surrounding the external iliac vessels improves the sensitivity to 65.4% (46.7% and 73.3% for the first 100 patients). Compared to the extension of pelvic lymphadenectomy the diagnostic gain of serial section and IHC (13.8% versus 53.3%) was comparably low. CONCLUSIONS: The extension of pelvic lymph node dissection is of outstanding value for the identification of node-positive patients. Limiting the number of lymph nodes to the ones with the highest probability of bearing lymphatic spread (SLN) makes the use of extensive histopathological techniques more feasible.     

Sentinel-Lymphadenektomie beim Prostatakarzinom – Aktueller Stand

Sentinel lymph node (SLN) dissection is an excellent staging procedure with high sensitivity (>95%) for detecting positive nodes. When the sentinel node is negative, there is high certainty that other lymph nodes are also negative. Limitations of this technique include the use of hormone therapy over several months and a preceding transurethral resection or suprapubic adenomectomy. When sentinel node dissection is performed in patients with intermediate and high-risk prostate cancer, it should be kept in mind that when the SLN is positive, other lymph nodes can be positive, too. The positive non-SLN can be located outside the SLN region. Therefore, both sentinel and extended lymph node dissection should be used in men with a higher risk of lymph node metastases.     

Characteristics of the sentinel lymph node in breast cancer predict further involvement of higher-echelon nodes in the axilla: a study to evaluate the need for complete axillary lymph node dissection

BACKGROUND: Sentinel lymph node (SLN) biopsy techniques provide accurate nodal staging for breast cancer. In the past, complete lymph node dissection (CLND) (levels 1 and 2) was performed for breast cancer staging, although the therapeutic benefit of this more extensive procedure has remained controversial. HYPOTHESIS: It has been demonstrated that if the axillary SLN has no evidence of micrometastases, the nonsentinel lymph nodes (NSLNs) are unlikely to have metastases. OBJECTIVE: To determine which variables predict the probability of NSLN involvement in patients with primary breast carcinoma and SLN metastases. METHODS: An analysis of 101 women with SLN metastases and subsequent CLND was performed. Variables included size of the primary tumor, tumor volume in the SLN, staining techniques used to initially identify the micrometastases (cytokeratin immunohistochemical vs hematoxylin-eosin), number of SLNs harvested, and number of NSLNs involved with the metastases. Tumor size was determined by the invasive component of the primary tumor. Patients with ductal carcinoma in situ who were upstaged with cytokeratin staining were considered to have stage T1a tumors. RESULTS: Sentinel lymph node micrometastases (<2 mm) detected initially by cytokeratin staining were associated with a 7.6% (2/26) incidence of positive CLND compared with a 25% (5/20) incidence when micrometastases were detected initially by routine hematoxylin-eosin staining. Sentinel lymph node micrometastases, regardless of identification technique, inferred a risk of 15.2% (7/46) for NSLN involvement. As the volume of tumor in the SLN increased (ie, <2 mm, >2 mm, grossly visible tumor), so did the risk of NSLN metastases (P<.001). CONCLUSIONS: Our study demonstrated that patients with micrometastases detected initially by cytokeratin staining had low-volume disease in the SLN with a small chance of having metastases in higher-echelon nodes in the regional basin other than the SLN. Characteristics of the SLN can provide information to determine the need for a complete axillary CLND. Complete lymph node dissection may not be necessary in patients with micrometastases detected initially by cytokeratin staining since the disease is confined to the SLN 92.4% of the time. However, the therapeutic value of CLND in breast cancer remains to be determined by further investigation.     

Is a limited lymph node dissection an adequate staging procedure for prostate cancer?

PURPOSE: Generally lymph node dissection is only considered a staging procedure for prostate cancer. Therefore, the need for meticulous lymph node dissection is often questioned and only sampling is suggested. We performed a prospective study to identify the pattern of lymph node metastasis in prostate cancer and determine how extensive lymph node dissection must be not to under stage cases. MATERIALS AND METHODS: All patients with clinically organ confined prostate cancer, no prior hormonal treatment, negative preoperative staging computerized tomography and bone scan, who underwent radical prostatectomy between 1989 and 1999, were evaluated prospectively as to the number and location of lymph node metastasis. A meticulous lymph node dissection was performed along the external iliac vein, obturator nerve and internal iliac (hypogastric) vessels. Nodes from each location and side were submitted separately for histological evaluation. RESULTS: In 365 patients with a median serum prostate specific antigen of 11.9 ng./ml. (range 0.4 to 172) the median number of nodes removed was 21 (range 6 to 50). Lymph nodes were positive in 88 (24%) patients and the median number of positive nodes was 2 (range 1 to 19). Internal iliac lymph nodes were positive in 51 (58%) of the 88 patients, including 34 with additional positive lymph nodes along the external iliac vein and/or obturator nerve. Internal iliac lymph nodes alone were positive in 17 (19%) of 88 patients. CONCLUSIONS: There were significant numbers of lymph node metastases at all 3 different areas of lymphadenectomy. Positive lymph nodes were found along the internal iliac artery in more than half (58%) of the patients and exclusively in 19%. Therefore, we consider lymph node dissection along the internal iliac (hypogastric) vessels essential for representative staging. Without this dissection a fifth of node positive cases would have been under staged and diseased nodes would have remained in more than half of the cases.     

Identification and evaluation of axillary sentinel lymph nodes in patients with breast carcinoma treated with neoadjuvant chemotherapy

Sentinel lymph node (SLN) biopsy has been shown to predict axillary metastases accurately in early stage breast cancer. Some patients with locally advanced breast cancer receive preoperative (neoadjuvant) chemotherapy, which may alter lymphatic drainage and lymph node structure. In this study, we examined the feasibility and accuracy of SLN mapping in these patients and whether serial sectioning and keratin immunohistochemical (IHC) staining would improve the identification of metastases in lymph nodes with chemotherapy-induced changes. Thirty-eight patients with stage II or III breast cancer treated with neoadjuvant chemotherapy were included. In all patients, SLN biopsy was attempted, and immediately afterward, axillary lymph node dissection was performed. If the result of the SLN biopsy was negative on initial hematoxylin and eosin-stained sections, all axillary nodes were examined with three additional hematoxylin and eosin sections and one keratin IHC stain. SLNs were identified in 31 (82%) of 38 patients. The SLN accurately predicted axillary status in 28 (90%) of 31 patients (three false negatives). On examination of the original hematoxylin and eosin-stained sections, 20 patients were found to have tumor-free SLNs. With the additional sections, 4 (20%) of these 20 patients were found to have occult lymph node metastases. These metastatic foci were seen on the hematoxylin and eosin staining and keratin IHC staining. Our findings indicate that lymph node mapping in patients with breast cancer treated with neoadjuvant chemotherapy can identify the SLN, and SLN biopsy in this group accurately predicts axillary nodal status in most patients. Furthermore, serial sectioning and IHC staining aid in the identification of occult micrometastases in lymph nodes with chemotherapy-induced changes.     

Sentinel Lymph Node Detection in Breast Cancer Patients by Real‐Time Virtual Sonography Constructed With Three‐Dimensional Computed Tomography‐Lymphography

Abstract: Ultrasonography (US) is one tool for preoperative diagnosis of lymph node metastases in breast cancer. However, US cannot detect true sentinel lymph nodes (SLNs). We identified SLNs in 60 clinically node‐negative breast cancer patients using a real‐time virtual sonography (RVS) system to display in real time a virtual multi‐planar reconstruction obtained from computed tomography (CT) volume data corresponding to the same cross‐sectional image from US. CT volume data were obtained from our original three‐dimensional CT lymphography (3DCT‐LG), which accurately detects SLNs in breast cancer. SLN metastases were assessed by shape and visibility of the hilum. All patients underwent SLN biopsy and SLN metastases were examined pathologically. In all 60 patients, we were able to detect the same SLNs visualized by 3DCT‐LG. Suspicious SLN metastases were identified in seven of the 60 patients, and four of seven patients were pathologically positive. Positive predictive value was 57%. The remaining 53 patients displayed non‐suspect SLNs in which absence of metastasis from the SLN was confirmed histologically. Overall accuracy was 95%. This is a first attempt at preoperatively identifying SLNs using US guided by the RVS system in breast cancer patients. Although evaluation of SLN metastases was unsatisfactory, this method may be useful for preoperative fine‐needle aspiration cytology for diagnosis of SLN metastases.     

Clinicopathologic analysis of sentinel lymph node mapping in early breast cancer

Axillary nodal status is the most significant prognosticator for predicting survival and guiding adjuvant therapy in breast cancer patients. Sentinel lymph node biopsy (SLNB) represents a minimally invasive procedure with low morbidity for staging axillary nodal status. In this article we review and report our experiences in patients with early breast cancer who underwent SLNB at the Revlon/UCLA Breast Center. Between September 1998 and May 2000, a total 83 SLNBs were performed in 81 patients with proven breast cancer and negative axillary examination who elected to have SLNB as the first step of nodal staging. Two patients had bilateral breast cancer. SLNB was localized by using both 99Tc sulfur colloid (83 cases) and isosulfan blue dye (75 cases). Data of these patients were prospectively collected and analyzed. The clinical and pathologic characteristics of women with positive and negative sentinel lymph nodes (SLNs) were compared to identify features predictive of SLN metastasis. Of the 83 cases, the SLN was successfully localized in 82 (98.8%). Sixty-three percent of patients had SLNs found in level I only, 18.3% in both level I and II, and 4.9% in level II alone. The vast majority (84.3%) of these cases had T1 breast cancer with an average size of 1.55 cm for the entire series. Twenty-three patients (28%) had positive SLNs, with an average of 1.5 positive SLNs per patient. Fifteen had metastases detected by hematoxylin and eosin staining and 8 had micrometastases detected by immunohistochemistry (IHC) using anticytokeratin antibodies. Ten of the former group agreed to and 2 of the latter group opted for full axillary lymph node dissection (ALND). An average of 17.5 lymph nodes were removed from each ALND procedure. Additional metastases or micrometastases were found in seven patients (in a total of 28 lymph nodes). Three patients with completely negative SLNs experienced additional axillary lymph node removal due to their election of free flap reconstruction. None had metastases detected in these lymph nodes. The absence of estrogen and progesterone receptors (ER/PR) by IHC (p = 0.036) and the presence of lymphatic/vascular invasion (LVI) (p = 0.002) predicted positive SLNs in patients with early breast cancer in a univariate analysis; in a multivariate analysis only LVI was predictive (p = 0.0125). Histologic type, nuclear grade, tumor differentiation, HER-2/neu and p53 status, S-phase fraction, and DNA ploidy did not predict SLN status. Immediate postoperative complications were uncommon and delayed complications completely absent. Because of the high detection rate, accurate staging, and minimal morbidity, SLNB should be offered as a choice to women with small breast cancers and clinically negative nodes. Because positive LVI and negative ER/PR status are highly predictive of pathologically positive SLNs in small breast cancers, women whose cancers meet these criteria should be advised preoperatively about their risk of having a positive SLN and may benefit from intraoperative assessment (frozen section and/or touch preparation) of their SLNs.     

Sentinel lymph node biopsy in rectal cancer--not yet ready for routine clinical use

BACKGROUND: The value of sentinel node biopsy in visceral cancers is uncertain. We evaluated the feasibility and utility of radiocolloid lymphatic mapping and selective lymph node sampling in patients with rectal cancer. METHODS: Forty-eight patients with rectal cancer were investigated. Thirty-seven patients had already undergone preoperative radiochemotherapy for locally advanced tumors. Eleven patients underwent primary surgery. An endoscopic injection of 1 mL technetium 99m-sulfur-colloid into the peritumoral submucosa was performed 15 to 17 hours before surgery. Ex vivo identification of the nuclide-enriched "sentinel lymph nodes" (SLNs) was performed using a hand-held gamma-probe. The selected SLNs were then carefully and systematically examined using serial sections and immunohistochemistry. RESULTS: One or more SLNs were found in 46 of the 48 patients. The SLN detection rate was 96%. Sixteen of the 48 patients had lymph node metastases (35%). In 7 of the 16 patients, the SLNs correctly represented the nodal status. In 9 of the 16 patients, the SLN was tumor-free whereas non-SLN harbored metastases. This result represents a sensitivity of only 44%, and a false-negative rate of 56%. Further analysis showed that the method correctly predicted the nodal status only in the small subgroup of 5 patients with early cancer without preoperative radiation. In 4 patients, juxtaregional lymph nodes were excised on the basis of intraoperative radiocolloid detection, leading to upward staging in 1 patient. CONCLUSIONS: Sentinel lymph node biopsy using the radiocolloid technique with ex vivo lymph node identification shows a relatively high detection rate; however, the sensitivity in patients with locally advanced/irradiated rectal cancer is low. Nevertheless, the detection of juxtaregional metastases can improve staging in some patients. Further studies should focus on patients with early rectal cancers where the data were more promising.     

前哨淋巴结绘图在子宫内膜癌手术中的应用

目的探讨亚甲蓝示踪前哨淋巴结(SLN)绘图在子宫内膜癌手术中的应用价值。 方法67例子宫内膜癌患者行(广泛)全子宫 ＋ 双附件切除 ＋ 盆腔 ± 腹主动脉旁淋巴结清扫术,术前2 h于宫颈3、6、9、12点钟位置注射亚甲蓝,术中识别并记录蓝染SLN的部位、数量。术后所有淋巴结经苏木精-伊红染色及免疫组化病理学检查。 结果67例患者中腹腔镜手术53例,机器人手术14例。总体及双侧盆腔SLN检出率分别为82.0% (55/67)及71.6% (48/67),灵敏度87.5% (7/8),假阴性率12.5% (1/8)。切除SLN、盆腔淋巴结、腹主动脉旁淋巴结的中位数分别为2、7、0枚。SLN集中分布于闭孔窝及髂外血管周围。 结论亚甲蓝示踪SLN绘图具有灵敏度高、操作简便的优点,可作为子宫内膜癌手术中预测盆腔淋巴结转移情况的常规方法。     

Technical Details of Sentinel Lymph Node Mapping in Colorectal Cancer and Its Impact on Staging

Background: Sentinel lymph node (SLN) mapping for melanoma and breast cancer has greatly enhanced the identification of micrometastases in many patients, thereby upstaging a subset of these patients. The purpose of this study was to see if SLN mapping technique could be used to identify SLNs in colorectal cancer and to assess its impact on pathological staging and treatment.Methods: At the time of surgery, 1 ml of Lymphazurin 1% was injected subserosally around the tumor without injecting into the lumen. The first to fourth blue nodes identified were considered the SLNs, which have the highest probability to contain metastases. A standard oncological resection of the bowel was then performed. Multilevel microsections of the SLNs, including a detailed pathological examination of the entire specimen, was performed.Results: SLN was successfully identified in 85 (98.8%) of 86 patients. In 85 patients, there were 1367 (16 per patient) lymph nodes examined, of which 140 (1.6 per patient) were identified as SLNs. In 53 (95%) of 56, of whom the SLNs were without metastases (negative), all other non-SLNs also were negative. In 29 (34% of 85) patients, SLNs were positive for metastases; in 14 of the 29 patients, other non-SLNs also were positive in addition to the SLNs. In the other 15 of the 29 patients (18% of 85 patients), SLNs were the only site of metastases, and all other non-SLNs were negative. In 7 patients (8.2% of 85 patients), micrometastases were identified only in 1 or 2 of the 10 sections of a single SLN. In five of seven patients, such micrometastases were detected by hematoxylin and eosin staining and immunohistochemistry; in the other two patients, it was detected only by immunohistochemistry. In patients with negative SLNs, the rate of occurrence of micrometastases in non-SLNs was 5 (0.4%) of 1184 lymph nodes.Conclusions: SLN mapping can be performed easily in colorectal cancer patients, with an accuracy of more than 95%. The identification of submicroscopic lymph node metastases by this technique may have upstaged these patients (18%) from stage I/II to stage III disease, who may then benefit from further adjuvant chemotherapy.