<Superscript>99m</Superscript>Tc-rituximab as a tracer for sentinel lymph node biopsy in breast cancer patients: a single-center analysis

Purpose

This study aimed to determine the long-term prognosis of breast cancer patients with ^99mTc-rituximab for sentinel lymph node biopsy (SLNB).

Methods

A total of 2947 patients with negative sentinel lymph nodes (SLNs) omitting axillary lymph node dissection (ALND), treated between June 2005 and December 2013, were retrospectively analyzed. SLNB was performed prior to adjuvant therapy.

Results

After a median follow-up of 62 months, 22 cases of axillary recurrence (AR) were observed. The 5-year AR rate (ARR) was 0.7% [95% confidence interval (CI) 0.3–1.1%] and the 5-year relapse-free survival (RFS) was 95.2% (95% CI 94.4–96.0%). Multivariate analysis showed that abnormal axillary ultrasound with negative fine-needle aspiration (FNA) [hazard ratio (HR) 3.79, 95% CI 1.55–9.28; P = 0.004], not receiving radiotherapy (HR 4.38, 95% CI 1.47–13.05; P = 0.008), and age ≤ 40 years (HR 2.93, 95% CI 1.19–7.20; P = 0.020) were independent risk factors for AR.

Conclusions

ARR of SLNB-negative patients with ^99mTc-rituximab is low. Abnormal axillary ultrasound with negative FNA, not receiving radiotherapy, and age ≤ 40 years were prognostic factors for higher ARRs.

     

Post-lumpectomy intracavitary retention and lymph node targeting of <Superscript>99m</Superscript>Tc-encapsulated liposomes in nude rats with breast cancer xenograft

Liposomes are recognized drug delivery systems with tumor-targeting capability. In addition, therapeutic or diagnostic radionuclides can be efficiently loaded into liposomes. This study investigated the feasibility of utilizing radiotherapeutic liposomes as a new post-lumpectomy radiotherapy for early-stage breast cancer by determining the locoregional retention and systemic distribution of liposomes radiolabeled with technetium-99m (^99mTc) in an orthotopic MDA-MB-231 breast cancer xenograft nude rat model. To test this new brachytherapy approach, a positive surgical margin lumpectomy model was set up by surgically removing the xenograft and deliberately leaving a small tumor remnant in the surgical cavity. Neutral, anionic, and cationic surface-charged fluorescent liposomes of 100 and 400 nm diameter were manufactured and labeled with ^99mTc-BMEDA. Locoregional retention and systemic distribution of ^99mTc-liposomes injected into the post-lumpectomy cavity were determined using non-invasive nuclear imaging, ex vivo tissue gamma counting and fluorescent stereomicroscopic imaging. The results indicated that ^99mTc-liposomes were effectively retained in the surgical cavity (average retention was 55.7 ± 24.2% of injected dose for all rats at 44 h post-injection) and also accumulated in the tumor remnant (66.9 ± 100.4%/g for all rats). The majority of cleared ^99mTc was metabolized quickly and excreted into feces and urine, exerting low radiation burden on vital organs. In certain animals ^99mTc-liposomes significantly accumulated in the peripheral lymph nodes, especially 100 nm liposomes with anionic surface charge. The results suggest that post-lumpectomy intracavitary administration of therapeutic radionuclides delivered by 100-nm anionic liposome carrier is a potential therapy for the simultaneous treatment of the surgical cavity and the draining lymph nodes of early-stage breast cancer.     

Sentinel lymph node identification in breast cancer: feasibility study

The aim of the study was to evaluate in our institute the technique of sentinel node (SN) identification and biopsy in the surgical treatment of early breast cancer. Between June 1998 and November 1999 54 patients (age range, 31-75 years) where studied. Inclusion criteria were age less than 75 years, indication for conservative surgery, absence of palpable axillary nodes, Karnofksy index >70. Lymphoscintigraphy was performed 16-18 hours prior to surgery, following injection of 0.1-0.2 mL of 99mTc-Nanocoll: the administered activity was 3-4 MBq in group A (44 pts) and 7-8 MBq in group B (10 pts). The colloids were administered by transdermal supralesional injection in 49 patients with palpable nodules and by intraparenchymal ultrasound-guided injection in five patients with non-palpable nodules. Planar projections were performed starting from the 5th until the 80th min (or 180th in the event of late migration). In 10 patients further projections were acquired 14-18 h following tracer administration. All nodes identified by gamma probe (MR 100 Pol.Hi.Tech) were histologically evaluated by immunohistochemistry and standard histology. Scintigraphic visualization of the SN was obtained in 49 patients: in 38 of these patients there was only one SN while in 11 patients there were two or three SNs. The delayed scan made in 10 patients did not show any further nodes. In all patients given US-guided perilesional injections migration was late (after at least 60 min). Our study confirms the validity of the scintigraphic procedure, its safety for patients and health care workers, and the feasibility of interdisciplinary collaboration.     

乳腺癌前哨淋巴结活检30例分析

目反同位素为示踪剂探测乳腺癌前哨淋巴结（ｓｅｎｔｉｎｅｌ ｌｙｍｐｈ ｎｏｄｅ,ＳＬＮ）,并根据前哨淋巴结活检和腋淋巴结清扫的病理结果,评价前哨淋巴结预测腋窝淋巴结转移的准确性。方法：研究对象为自２０００年５月份起我院乳腺科收治的３０例Ｔ１－２Ｎ０的乳腺癌患者,使用＾９９ｍＴｃ－硫胶体（＾９９ｍＴｃ－ｓｕｌｐｈｕｒ ｃｏｌｌｏｉｄ）为示踪剂,用Ｇａｍｍａ探测仪进行前哨淋巴结探测活检,之后行腋窝清扫。结果：２７例患者中成功地发现了ＳＬＮ,发现率为９０％（２７／３０）,前哨淋巴结的数量为１－３个,平均每例１．５个,非前哨淋巴结（ｎｏｎｓｅｎｔｉｎｅｌ ｎｏｄｅ）５－２０个,平均数１３．３个,２７例ＳＮＢ成功的患者中１４（５２％）例有腋窝淋巴结转移,前哨淋巴结未发现转移而非前哨淋巴结有转移的有２例,假阴性率７．４％（     

Sentinel lymph node biopsy in patients with multifocal breast cancer.

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

染料法乳腺癌前哨淋巴结活检的临床应用

为了探讨影响染料法乳腺癌前哨淋巴结活检（SLNB）成功率的因素及其可能机制,使用亚甲蓝染色法对89例乳腺癌进行SLNB,分析其可能的影响因素和机制.结果：78例成功检出前哨淋巴结（SLN）,检出率为87.6%.术前未触及肿大淋巴结者,SLN检出率明显高于可触及肿大淋巴结者（P＜0.05）,而假阴性率显著低于后者,P＜0.05;实验后期64例SLNB检出率高于实验早期25例的检出率,P＜0.05.初步研究结果提示,腋窝淋巴结肿大影响SLNB的检出率;SLNB技术学习曲线也可影响SLN的检出率.SLNB可用于指导乳腺癌的外科治疗.     

Comparative study of<Superscript>99m</Superscript>TcN (NOEt)<Subscript>2</Subscript> and<Superscript>99m</Superscript>Tc-MIBI imaging in mice bearing Ehrlich ascites tumor

Objective To evaluate and compare the ability to detect tumor by bis (N-ethoxy-N-ethyl dithiocarbamato) nitrido^99mTc(V) [^99mTcN(NOEt)₂] and^99mTc hexakis-2- methoxyisobutyl isonitrile [^99mTc-MIBI]. Methods ^99mTcN(NOEt)₂ was prepared and quality control was performed using ascending thin-layer chromatography. Four mice bearing Ehrich ascites tumor cells underwent whole body planar imaging at 30 min, 2 h and 4 h after injection of^99mTc-MIBI or^99mTcN(NOEt)₂. ROIs were drawn around the tumor, head, chest, and contralateral limbs in whole body planar images, and ratios of radioactivity in tumor in head (T/H), chest (T/C), and contralateral limbs (T/L) were calculated. The mice of^99mTcN (NOEt)₂ group were killed, then blood was collected, and the tumor and organs were excised, weighed and the radioactivity was measured. Results ^99mTcN(NOEt)₂ was stable after 4h at the room temperature.^99mTcN(NOEt)₂ was delivered to the tumor selectively and efficiently.^99mTcN(NOEt)₂ was found to provide excellent tumor-to-nontumor contrast for all the tissue except the abdomen. The T/L ratios increased to their maximums (4.87) at 2 h after injection. There was significant difference between the^99mTcN(NOEt)₂ imaging group and^99mTc-MIBI imaging group. In vitro the radioactivity ratios per unit weight of tumor to blood, muscle, skeleton, lung, heart, and spleen were much higher than those of tumor to liver, instestine. Conclusion In mice bearing Ehrich ascites tumor,^99mTcN(NOEt)₂ exhibits a set of features essential for a good tracer for tumor imaging, including a rapid washout from blood, high uptake rate in tumor tissue, prolonged retention and high tumor-to-nontumor uptake ratio. The imaging quality of^99mTcN(NOEt)₂ was superior to that of^99mTc-MIBI. These features indicate that^99mTcN(NOEt)₂ may be a better tracer to detect tumor than^99mTc-MIBI.     

Sentinel lymph node biopsy in male patients with early breast cancer

Mastectomy with axillary dissection is still the most commonly recommended procedure for male breast cancer. The aim of this study was to retrospectively evaluate our experience in 32 male patients with early breast cancer who underwent sentinel lymph node biopsy (SLNB) and axillary dissection only in cases of metastases in the sentinel lymph node (SLN). The median age was 58 years (range, 33-80). Lymphoscintigraphy was successful in all patients, with a mean number of visualized SLNs per patient of 1.3 (range, 1-2). At surgery, the identification rate of the SLN was 100%, with a mean number of removed SLNs per patient of 1.5 (range, 1-3). Twenty-six patients had negative SLNs, six patients had positive SLNs. Two patients with metastatic SLNs had additional positive nodes. After a median follow-up of 30 months (range, 1-63) no axillary reappearance of the disease occurred. As with women, we recommend SLNB in male patients with breast cancer and clinically negative axilla.     

Use of <Superscript>99m</Superscript>Tc-MIBI scintigraphy in the evaluation of the response to chemotherapy for osteosarcoma: comparison with <Superscript>201</Superscript>Tl scintigraphy and angiography

Background  

In the treatment of osteosarcoma, the chemotherapeutic effect influences decisions regarding the surgical margin, continuation of chemotherapy, and choice of anticancer drugs for further chemotherapy. Therefore, it is necessary to evaluate the response to chemotherapy in the middle of the chemotherapy course. In this study, we investigated the use of ^99mTc-hexakis-2-methoxyisobutyl-isonitrile (^99mTc-MIBI) scintigraphy in evaluating the response to chemotherapy of patients with osteosarcoma in comparison with ²⁰¹Tl scintigraphy and angiography.     

单光子发射计算机断层显像/CT在乳腺癌前哨淋巴结探测中的应用

目的探讨用放射性硫胶体(SC)单光子发射计算机断层显像(SPECT)/CT探测乳腺癌前哨淋巴结(SLN)的应用价值。 方法按照入组和排除标准,收集2015年4～8月在青岛大学附属医院确诊的118例女性乳腺癌患者临床资料进行回顾性分析。患者术前行⁹⁹Tc^m-SC SPECT/CT联合术中蓝染法定位SLN,以联合法(SPECT/CT＋蓝染法)检出结果为标准,比较单纯平面显像、蓝染法、SPECT/CT 3种方法对SLN的检出率,并对所有检出的SLN送病理检查。组间SLN检出率(以病例数分析)的比较采用Fisher精确概率法,SLN检出率(以淋巴结数分析)的比较及SLN病理阳性率的比较采用配对χ²检验。 结果以联合法(SPECT/CT＋蓝染法)检出结果为标准,从病例数角度分析,平面显像、SPECT/CT及蓝染法的SLN检出率分别为91.53%(108/118)、97.46%(115/118)和97.46%(115/118),差异有统计学意义(P＝0.020),SPECT/CT及蓝染法的SLN检出率高于平面显像(χ²＝5.143、5.143,P＝0.023、0.023)。从淋巴结数的角度分析,平面显像、SPECT/CT及蓝染法的SLN检出率分别为61.72%(158/256)、96.88%(248/256)和95.70%(245/256),差异有统计学意义(χ²＝158.072,P<0.001),SPECT/CT与蓝染法的SLN检出率也高于平面显像(χ²＝90.000、87.000,P<0.001)。对于腋窝区SLN,平面显像、SPECT/CT及蓝染法的检出率分别为64.44%(154/239)、96.65%(231/239)和100.00%(239/239),差异有统计学意义(χ²＝163.312,P<0.001),SPECT/CT与蓝染法均高于平面显像(χ²＝77.000、85.000,P均<0.001),蓝染法高于SPECT/CT(χ²＝6.125,P＝0.013)。对于非腋窝区SLN,平面显像、SPECT/CT及蓝染法的检出率分别为4/17、17/17和6/17,差异有统计学意义(χ²＝23.139,P<0.001),SPECT/CT高于平面显像及蓝染法(χ²＝11.077、9.091,P＝0.001、0.003)。SPECT/CT与蓝染法检出的SLN病理阳性率分别为24.22%(62/256)和21.09%(54/256),差异无统计学意义(χ²＝3.500,P＝0.061)。对于腋窝区淋巴结,蓝染法比SPECT/CT多发现8枚,其中3枚SPECT/CT阴性的淋巴结经病理证实为淋巴结宏转移,另5枚均为非转移淋巴结。对于非腋窝区淋巴结,SPECT/CT比蓝染法多发现11枚(3枚内乳淋巴结,5枚胸肌间淋巴结,3枚乳腺内淋巴结),病理证实9枚微转移淋巴结,2枚宏转移淋巴结。 结论SPECT/CT的应用能够更精确地指导SLN活组织检查定位,而且在提高病理阳性SLN的检出率,尤其是探测非腋窝SLN方面,SPECT/CT较蓝染法有较大优势。     

Sentinel lymph node mapping in breast cancer

Sentinel lymph node (SLN) biopsy is a rapidly emerging treatment option for patients with early-stage invasive breast cancer and a clinically negative axilla. In the era of mammographic detection, SLN biopsy has the potential to eliminate axillary dissection for the enlarging cohort of breast cancer patients who are node-negative. Using radioisotope, blue dye, or both methods, experienced surgeons can successfully localize SLNs in more than 90% of cases. The effects of isotope and blue dye may be additive. Sentinel lymph node biopsy reliably predicts axillary node status in 98% of all patients and 95% of those who are node-positive. The operation is best learned under a formalized protocol in which a backup axillary dissection is performed to validate the technique during the surgeon's early experience. Enhanced pathologic analysis, including serial sections and immunohistochemical (IHC) staining, is an essential element of the procedure. In experienced hands, SLN biopsy has less morbidity and greater accuracy than conventional axillary dissection.     

Sentinel lymph node biopsy in breast cancer patients with previous breast augmentation surgery

The number of breast augmentation surgeries (BAS) has increased. Therefore, the number of breast cancer patients with history of BAS has also increased. In this paper, we present two cases of sentinel lymph node biopsy (SLNB) in patients with previous BAS who were diagnosed with breast cancer. The patients were augmented using different approach; the first case was augmented through transaxillary incision, whereas the second case was augmented through periareolar incision. Lymphoscintigraphy (LPG) was performed on the patients 1 day prior to operation, enabling confirmation of lymphatic flow and SLN in both patients. SLNB was successfully performed in both cases. In one patient, SLNB was performed using indocyanine green (ICG) fluorescence and the Photodynamic Eye (PDE) system. Regardless of history of BAS, ICG and PDE system showed lymphatic flow and SLN in real time. LPG and ICG fluorescence were useful methods for SLN detection in patients with previous BAS, being able to confirm lymph flow before operation. Biopsy methods using LPG and PDE system were considered useful for difficult confirmation of lymph flow after breast augmentation. This is the first report of SLNB using ICG and PDE system for patients with previous BAS.     

Sentinel lymph node biopsy in male breast cancer patients.

The concept of sentinel node biopsy has been validated for female breast cancer patients whereas, ALND remains the standard of care for male breast cancer patients with similar tumours. We evaluated the results of SLN biopsy in male breast cancer patients with clinically negative axillae. This study included all male breast cancer patients who underwent SLN biopsy between February 1998 and October 2003. All patients had negative axillae on clinical examination. All patients underwent pre-operative lymphoscintigraphy. SLN biopsy was performed using a combination of Patent blue V and 99mTc-radiolabelled colloidal albumin injected peritumourally. Nine patients, 26-79 years of age, were included in the study. Pre-operative lymphoscinitgraphy identified SLNs in all patients. Intraoperatively, SLNs were successfully localised in all patients. The mean number of SLNs encountered was 2.4. Five patients had a positive SLN, four a negative SLN. Five patients (one with a negative SLN, four with a positive SLN) had been elected pre-operatively to undergo ALND regardless of findings on SLN biopsy. ALND confirmed the SLN to be negative in one patient (false-negative rate: 0%) and three of the four patients with positive SLN(s) had additional positive nodes in the axilla. SLN biopsy accurately predicted axillary lymph node status in these five patients. These findings compare favourably with findings reported in the literature regarding SLN biopsy in female breast cancer patients. SLN biopsy accurately staged the axilla in male breast cancer patients and should be considered for axillary staging in male breast cancer patients with clinically negative axillae.     

Sentinel lymph node biopsy compared with axillary lymph node dissection in early breast cancer: a meta-analysis

Sentinel lymph node biopsy (SLNB) has been recommended as the standard performance for negative sentinel lymph node (SLN) patients without axillary lymph node dissection (ALND) in the surgical management of early breast cancer; however, the efficiency of SLNB for patients with positive SLNs is still unclear. We performed this meta-analysis to compare the effectiveness and safety of SLNB with ALND. Randomized controlled trials (RCTs) comparing SLNB with ALND in early breast cancer were identified in Pubmed, Embase, and The Cochrane Library. Overall survival (OS), disease-free survival (DFS), regional lymph node recurrence, postoperative morbidity, and quality of life (QOL) between the two groups were assessed by using the methods provided by the Cochrane Handbook for Systematic Reviews of Interventions. Eight well-designed RCTs (total 8,560 patients; 4,301 for SLNB and 4,259 for ALND) were included. Meta-analysis showed that there was no statistical difference in OS (HR = 1.07, 95% CI: 0.90–1.27), DFS (HR = 1.00, 95% CI: 0.88–1.14), and regional lymph node recurrence (OR = 1.65, 95% CI: 0.77–3.56) between SLNB and ALND group, whether for SLN (+) subgroup or for SLN (−) subgroup. However, SLNB results in a significant reduction of postoperative morbidity and improved QOL. In conclusion, SLNB can be recommended as preferred care for SLN-negative patients and selected patients with SLN-micrometastasis. Despite this, ALND remains the standard management in breast cancer patients with SLN-macrometastasis.     

Sentinel lymph node biopsy in breast cancer patients treated with neoadjuvant chemotherapy

BACKGROUND:

Sentinel lymph node biopsy (SLNB) is a widely used staging method for patients with early breast cancer. Neoadjuvant chemotherapy modifies the anatomical conditions in the breast and axilla, and thus SLNB remains controversial in patients treated preoperatively. The aim of this study was to demonstrate the reliability and accuracy of this procedure in this particular group of patients.

METHODS:

The retrospective study analyzed medical records of patients diagnosed with primary breast cancer between the years 2005 and 2009. Of the patients treated by neoadjuvant therapy, 343 underwent lymphatic mapping to identify sentinel lymph nodes, and these were included in the analysis.

RESULTS:

The overall detection rate of sentinel lymph nodes was 80.8%. It was strongly influenced by clinical lymph node status (significantly higher success rate in lymph node‐negative patients); higher detection rates were also associated with age <50 years, estrogen receptor positivity, lower proliferation index, and absent lymphovascular space invasion. The false‐negative rate was 19.5% and was only marginally significantly dependent on lymphovascular space invasion. The overall accuracy of the method was 91.5%.

CONCLUSIONS:

By using the present technique, sentinel lymph node biopsy cannot be recommended as a reliable predictor of axillary lymph node status when performed at the authors' institution after neoadjuvant chemotherapy. Infrequent use of blue dye for lymphatic mapping, low number of resected sentinel lymph nodes, and absence of any selection among patients included in the study could be the main factors responsible for the low detection rate and high false‐negative rate. Cancer 2011;. © 2011 American Cancer Society.     

前哨淋巴结识别应用于早期宫颈癌诊治的研究进展

淋巴结转移是影响早期宫颈癌患者预后的重要因素,常规术前检查往往不能发现淋巴结转移.应用前哨淋巴结活检技术,可对淋巴结转移情况做出较好预测.目前文献报道的前哨淋巴结识别方法较多,主要包括:染料示踪法、核素示踪法及联合示踪法.     

Sentinel lymph node biopsy in breast cancer.

The concept of sentinel lymph node (SLN) biopsy in breast cancer patients is simple, attractive and rapidly emerging as a new standard of care. Several aspects of the technique of lymphatic mapping, case selection, pathologic analysis and the finding of micrometastases, and the accuracy of the technique are important subjects of study and debate in the literature and will be discussed in this review. High identification rates can be attained by the use of both radioguided and blue dye lymphatic mapping. Intradermal injection of tracers has reported to be successful, suggesting that dermal and parenchymal lymphatics drain to the same SLN. Extra axillary drainage is only seen after peri- or intratumoural injection. SLN biopsy is most widely used for both palpable and non-palpable T1 and T2 tumours, and limited experience exists for other indications. Accuracy is high only in experienced hands. The impact of failure of the procedure on regional disease control and survival will be assessed in a trial of the NSABP (National Adjuvant Breast and Bowel Project). The influence of a positive SLN biopsy with and without axillary dissection on survival and local control will be studied in trials of the BASO (British Association of Surgical Oncology), ACOSOG (American College of Surgeons Oncology Group) and EORTC (European Organisation for Research and Treatment of Cancer). These phase III trials and related studies on the importance of micrometastases in the SLN will give new insights in the safety of the SLN procedure and in the importance of treatment of regional lymph nodes in relation to local disease control and survival.     

宫颈癌前哨淋巴结检测的初步探讨

背景与目的：近几年已开展宫颈癌前哨淋巴结(sentinel lymph node,SLN)的研究,目前影响宫颈癌SLN的检出还存在很多未知因素。本研究使用亚甲蓝作为示踪剂检测宫颈癌SLN,分析影响SLN检出的因素。方法：41例宫颈癌Ⅰbt～Ⅲb)期患者,术前90～400min在宫颈瘤周分4～6点注射亚甲蓝2～4ml,蓝染淋巴结即定为SLN,术后将SLN行多层切片HE染色和细胞角蛋白(cytokeratin,CK)免疫组化,其余淋巴结作常规病理检查,根据SLN检出率、假阴性率来探讨使用亚甲蓝检测宫颈癌SLN的影响因素。结果：41例中,31例成功定位出SLN共85枚,总检出率为75．6％,最常见部位为闭孔窝淋巴结。其中未行术前放化疗者检出率为87．0％(20／23);已行术前放化疗者检出率为61．1％(11／18)。27例注射亚甲蓝量为2～3ml的患者检出率仅为63．0％(17／27),显著低于注射量为3．4～4ml的患者(100％,14／14)。病理结果示：一共8例患者有盆腔淋巴结转移。结论：使用亚甲蓝检测宫颈癌SNL的注射剂量以3～4ml为宜。宫颈癌SLN定位个体差异较大,以闭孔窝最多见。