Sentinel lymph node after intramammary injection of superparamagnetic iron oxide

The purpose of this study was to evaluate enhancement (signal loss) of the axillary lymph nodes on MR lymphography after intramammary injection of superparamagnetic iron oxide (Ferumoxides) for detection of the sentinel lymph node. MR lymphography was performed in a total of 11 patients with breast cancer without palpable axillary lymph node swelling before operation. Coronal and axial images were obtained before and after intramammary injection of 1.5 ml Ferumoxides adjacent to the breast tumor. In all patients, decreased intensity was recognized in the axillary lymph nodes. MR lymphography could detect the sentinel lymph node with its decreased signal intensity 20 minutes after the intramammary injection of Ferumoxides.     

核素显像-染色法探测舌癌前哨淋巴结

目的探讨核素显像-染色法探测舌癌前哨淋巴结(SLN)和预测颈淋巴结转移的价值。方法N0期舌癌患者20例，术前ld于肿瘤周围组织注射^99Tc^m-硫胶体(SC)约18．5MBq，分别于5、10、30、60min及6h时进行显像，识别SLN并进行体表定位；术中于肿瘤周围注入亚甲蓝，据淋巴结蓝染和皮肤定位情况找出SLN，行冰冻病理检查，后常规切除原发灶，行选择性颈淋巴清扫并行病理检查，以观察其对舌癌颈淋巴结转移的预测价值。结果该组中未见假阳性和假阴性病例，SLN检出率为100％。结论核素显像．染色法在舌癌SLN探测与颈淋巴结转移预测中有重要的临床意义。     

Breast sentinel lymph node mapping at CT lymphography with iopamidol: preliminary experience

PURPOSE: To evaluate sentinel lymph node (SLN) mapping with interstitial computed tomographic (CT) lymphography with small volumes of iopamidol for direction of SLN biopsy in breast cancer. MATERIALS AND METHODS: Thin-section transverse and three-dimensional CT images that included the breast and axilla were acquired at multi-detector row helical CT in 17 patients with operable breast cancer before subcutaneous injection of 2 mL of undiluted iopamidol into peritumoral and periareolar areas and 1-5 minutes after massage of injection sites. Location and size of SLNs were assessed at CT lymphography and were compared with SLNs at standard axillary lymph node dissection with blue dye staining. RESULTS: CT lymphography allowed localization of SLNs in all patients by means of visualization of a direct connection between an SLN and its afferent lymphatic vessels draining from the injection sites. Afferent vessels were joined and drained into a single axillary SLN, except in four patients with two or three SLNs, including a parasternal one. SLNs did not enhance because of rerouting of lymph flow in four patients. At surgery, SLNs that were stained or not stained with blue dye were easily found with CT lymphographic guidance. Tumoral infiltration was not evident in any resected nodes, except for infiltration in one patient with micrometastasis in SLN alone and infiltration in four patients with massive metastasis in both SLN and distant nodes. CONCLUSION: Because preoperative CT lymphography-guided SLN mapping provides SLN position with detailed lymphatic anatomy, it may be useful for the direction of breast SLN biopsy.     

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

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

Lymph node imaging: basic principles

Lymph nodes are involved in a wide variety of diseases, particularly in cancer. In the latter, precise nodal staging is essential to guide therapeutic options and to determine prognosis. For long, imaging of the lymphatic system has been limited to lymph vessel,especially via the exclusive use of conventional lymphography, at the expense of invasive procedures and patient's discomfort. Three main technical advances, however, have recently completed the clinical armamentarium for lymph node imaging: first, the refinement of cross sectional imaging, i.e. CT and MRI, combined or not with dedicated contrast agents, has progressively replaced conventional lymphography in oncology situations; second, the development of intra-operative sentinel node mapping has profoundly modified the diagnostic and therapeutic procedures in several cancer situations, mostly melanoma and breast cancer; finally, the increased availability of functional imaging, especially through the use of FDG-PET, has greatly contributed to the accuracy improvement of nodal metastases identification. The aim of this review will thus be to briefly review the anatomy and physiology of the lymphatic systems and to overview the basic principles of up-to-date lymph node imaging.     

SPECT/CT在cN0期甲状腺乳头状癌前哨淋巴结定位中的应用价值

目的 评价SPECT/CT淋巴显像检测cN0期甲状腺乳头状癌（PTC）患者前哨淋巴结（SLN）的价值。 方法 选取2017年4月至11月在山西医科大学第一医院住院的16例淋巴结阴性（cN0）期PTC患者,其中男性2例、女性14例,年龄（47.0±8.4）岁,于手术前行99Tcm-硫体胶（99Tcm-SC）平面显像和SPECT/CT显像检测SLN。手术中使用γ探测仪探测放射性“热点”。将手术切除的SLN及颈部清扫标本进行病理学检查。 结果 16例患者术前 99Tcm-SC平面显像检出SLN 14例,检出率为87.50% （14/16）。术前99Tcm-SC平面显像、SPECT/CT显像分别检出31枚和35枚SLN。术中γ探测仪探测到SLN 13例,共计37枚,检出率为81.25% （13/16）。γ探测仪探测SLN数目与SPECT/CT淋巴显像数目有4例不一致,12例一致,两种方法的一致率为75% （12/16）。病理结果显示,15例患者有淋巴结转移,占93.75% （15/16）。SPECT/CT检测SLN的灵敏度为86.67% （13/15）、准确率为81.25% （13/16）、假阴性率为13.33% （2/15）。 结论 术前SPECT/CT淋巴显像能有效探测cN0期PTC患者的SLN,准确预测颈部淋巴结的转移情况。     

Sentinel Node Mapping of VX2 Carcinoma in Rabbit Thigh with CT Lymphography Using Ethiodized Oil

Objective

To assess the feasibility of computed tomography (CT) lymphography using ethiodized oil for sentinel node mapping in experimentally induced VX2 carcinoma in the rabbit thigh.

Materials and Methods

This experiment received approval from the institutional animal use and care administrative advisory committee. Twenty-three rabbits with VX2 carcinoma in the thigh underwent CT before and after (1 hour, 2 hour) peritumoral injection of 2 mL ethiodized oil. After the CT examination, sentinel nodes were identified by peritumoral injection of methylene blue and subsequently removed. The retrieved sentinel and non-sentinel lymph nodes were investigated with radiographic and pathologic examinations. Based on the comparison of CT findings with those of radiographic and pathologic examinations, the diagnostic performance of CT for sentinel node identification was assessed.

Results

All 23 rabbits showed 53 ethiodized oil retention nodes on post-injection CT and specimen radiography, and 52 methylene blue-stained nodes at the right femoroiliac area. Of the 52 blue-stained sentinel nodes, 50 nodes demonstrated ethiodized oil retention. Thus, the sentinel node detection rate of CT was 96% (50 of 52). On pathologic examination, 28 sentinel nodes in 17 rabbits (nodes/rabbit, mean ± standard deviation, 1.7 ± 0.6) harbored metastasis. Twenty seven of the 28 metastatic sentinel nodes were found to have ethiodized oil retention.

Conclusion

Computed tomography lymphography using ethiodized oil may be feasible for sentinel node mapping in experimentally induced VX2 carcinoma in the rabbit thigh.     

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.     

Lymphography and computed tomography in lymph node metastases from malignant melanoma

Contrast lymphography and regional computed tomography (CT) were performed prior to lymph node dissection in 49 patients with clinical suggestion of lymph node metastases from malignant melanoma. The overall specificity and sensitivity for lymphography was 62% and 70%, respectively, and for CT 83% and 70%, respectively. There was 67% concordance of the radiologic reports. The combined modality sensitivity and specificity were 79% and 84%, respectively. Clinical lymph node examination was poor in accurately diagnosing lymph node involvement with melanoma (42% true positive, 58% false positive). Lymphography produced too many false negative and false positive reports to be of value in detecting lymph node metastases on its own. CT was slightly superior to lymphography in correctly predicting the lymph node status of the upper extremity. The present clinical and radiologic techniques would seem to be inadequate for detecting lymph node metastases in malignant melanoma.     

Sentinel lymph node identification in breast cancer patients

PURPOSE: To evaluate the predictive value of sentinel lymph node biopsy versus axillary node dissection on lymph node status in patients with T1-T2 breast cancer. MATERIAL AND METHODS: Twenty-nine patients with T1 and 12 with T2 breast carcinoma and clinically N0 axillary lymph nodes, underwent lymphoscintigraphy following the administration of 99mTc-human albumin nanocolloids. The tracer was injected subdermally, over the tumor mass, in the 34 patients with palpable lesions and peritumorally (n=3) or intratumorally (n=4), under stereotactic or ultrasound guidance, in the 7 patients with non-palpable lesions. Anterior and lateral planar images were acquired 15 min after the injection of the tracer and repeated every 30 min up to 3 hr until identification of sentinel lymph node. At the end of the scintigraphic study, sentinel node skin projection was marked using a dermographic pen. Eighteen hours after lymphoscintigraphy, sentinel lymph node was identified and removed during surgery by hand-held gamma probe, then, the remaining axillary lymph nodes were dissected. All surgical specimens underwent histologic examination. Sentinel lymph nodes free of metastasis at histology, underwent additional examination with immunohistochemistry using monoclonal antibodies against cytokeratin and EMA to search for micrometastases. RESULTS: Sentinel lymph node was identified in the 34 patients injected subdermally and in the 3 patients injected peritumorally, while it remained undetected in the 4 patients injected intratumorally except for one case in which it was isolated by radioguided surgery but not scintigraphically. Sentinel nodes resulted free of metastases both at histology and immunohistochemistry in 32 cases and metastatic in 6. In the 32 patients with non-metastatic sentinel lymph nodes the other axillary nodes were also free of metastases. Among the 6 metastatic sentinel lymph nodes, in 3 cases they were the only metastatic nodes of the axilla while in the other 3 cases metastases were spread to other axillary nodes. CONCLUSIONS: In agreement with previous studies, our results showed that sentinel lymph node radioguided biopsy is a simple and reliable method for predicting axillary lymph nodes status and for avoiding axillary dissection in early breast cancer patients with sentinel node free of metastases.     

Lymphatic drainage from esophagogastric tract: feasibility of endoscopic CT lymphography for direct visualization of pathways

PURPOSE: To evaluate the feasibility of an endoscopic computed tomographic (CT) lymphography technique with submucosal injection of iopamidol for direct visualization of lymphatic drainage pathways in dogs and in patients with operable esophageal cancer. MATERIALS AND METHODS: With institutional animal committee approval, a total of 2 mL of undiluted iopamidol was injected into the esophageal (n = 6) or gastric (n = 3) submucosa in nine dogs by using a flexible endoscope. Multi-detector row CT images (section thickness, 1.25 mm) were obtained before contrast material injection and during the 10 minutes after injection. The animals were euthanized so that their lymphatic anatomy could be examined. With ethical committee approval and patient informed consent, nine patients with esophageal cancer also underwent CT lymphography with peritumoral injection of 2 mL of iopamidol, followed by esophagectomy and regional lymph node dissection with CT lymphographic guidance. The histopathologic features of dissected nodes, including sentinel lymph nodes (SLNs), were examined. RESULTS: CT lymphography depicted the direct connection of lymphatic drainage vessels with enhanced and/or unenhanced nodes (ie, SLNs) as early as within 5 minutes after contrast material injection in all subjects. All 13 SLNs in dogs (1.4 nodes per animal) and 18 SLNs in patients (two nodes per patient) were found and dissected at the correct location by using CT lymphographic guidance. In patients, histopathologic examination revealed the high predictive value of CT lymphographic-guided SLN biopsy: Only one of the preoperatively identified SLNs in three patients and both SLNs and adjacent nodes in two patients were positive for metastasis; all resected nodes in the remaining four patients were negative. CONCLUSION: Endoscopic CT lymphography is a feasible method for visualizing the direct connection between and the accurate anatomic location of SLNs and lymphatic drainage vessels.     

Sentinel node detection using contrast-enhanced power Doppler ultrasound lymphography

RATIONALE AND OBJECTIVES: To establish the feasibility of using contrast-enhanced interstitial ultrasound (US) lymphography as an alternative to current sentinel node detection methods. METHODS: Aqueous US contrast microbubble suspensions of varying diameter were evaluated in vitro to characterize response to insonation. Contrast media were then injected subcutaneously into the distal extremities of 11 normal dogs to target the cervical and popliteal lymph nodes (nodes, n = 40). First-order (sentinel) lymph nodes and second-order sublumbar nodes were imaged intermittently from 0 to at least 120 minutes following contrast injection using continuous power Doppler mode. Lymphoscintigraphy studies were performed on 4 dogs to verify lymphatic drainage patterns and sentinel lymph nodes. RESULTS: Contrast enhancement occurred in 34/40 (85%) sentinel nodes overall and in 30/32 (94%) nodes when submicron or near-micron diameter bubble formulations were used. In many instances, enhancement persisted throughout the imaging period. Contrast response was most pronounced using a high mechanical index and tissue artifact was reduced or eliminated when using a high pulse repetition frequency. CONCLUSIONS: Contrast-enhanced interstitial US lymphography could serve as an alternative to current sentinel node detection methods. Preliminary findings suggest that submicron or near-micron-diameter bubbles may be suitable for lymphatic imaging applications.     

间质磁共振淋巴管造影在检测乳腺癌患者前哨淋巴结转移情况中的应用价值

目的探讨间质磁共振(MR)淋巴管造影与弥散加权成像(DWI)序列相结合检测乳腺癌患者前哨淋巴结转移情况的应用价值。方法选取河南大学第一附属医院2018年6月至2019年6月30例前哨淋巴结阳性乳腺癌患者,并招募30名健康志愿者作为阴性组,给予MR间质淋巴造影检查,观察乳腺癌患者淋巴管及前哨淋巴结情况,对比分析2组淋巴管走行、管径情况和前哨淋巴结数目、大小、边缘、形态及弥散系数(ADC)值的指标。结果阳性组淋巴管走行、管径与阴性组对比差异有统计学意义(P<0.05);阳性组及阴性组前哨淋巴结平均数目差异无统计学意义(P>0.05);阳性组前哨淋巴结大小、边缘、形态及ADC值的指标均有明显差异(P<0.05)。结论 MR间质淋巴管造影与DWI序列相结合可以高分辨率的显示淋巴管和淋巴结的形态和功能,提高了乳腺癌患者前哨淋巴结转移的检出率。     

Intramammary sentinel lymph node preoperative identification with SPECT/CT in a patient with breast cancer. Clinical meaning and relevance

We present the case of a patient with breast cancer who underwent selective sentinel lymph node biopsy. An intramammary sentinel lymph node was identified with SPECT/CT in the preoperative lymphoscintigraphy. We describe our diagnostic and therapeutic procedure regarding this finding and the literature review to evaluate the clinical significance of their identification and metastases, especially in regards to more appropriate axillary management. Further studies with more statistical significance are necessary to elucidate the most suitable attitude when an intramammary sentinel lymph node is identified with the lymphoscintigraphy.     

MR间质淋巴造影显示乳腺癌前哨淋巴结初步研究

目的 探讨MR间质淋巴造影显示乳腺癌前哨淋巴结(SLN)的价值.方法 收集58例浸润性乳腺癌患者,用15 mL Gd-DTPA对比剂与2 mL 2%利多卡因配制对比剂混合液,按0.5 mL/人的剂量行乳晕外侧皮下注射,然后采用西门子3.0T Magnetom Trio MRI扫描仪体积插值屏气检查序列动态扫描,在最大密度投影(MIP)图像上追踪引流淋巴管并确定SLN,用胶囊标记的方法进行体表定位,将此标记的淋巴结定义为M-SLN.术中采用美兰示踪的方法,进行前哨淋巴结活检(SLNB)及切除,将美兰染色的淋巴结定义为D-SLN.对MR间质淋巴造影与美兰显示SLN的数目行配对样本比较的秩和检验,并采用Spearman等级相关分析两者的相关性.评估MR间质淋巴造影诊断M-SLN的敏感度,特异度,准确率.结果 MR间质淋巴造影共显示75枚M-SLN,平均(1.60±0.52)枚,在体表胶囊的标记下均在手术中成功获得.术中美兰为示踪剂显示91枚D-SLN,平均(1.94±0.63)枚,显著多于MR间质淋巴造影,但两者存在强相关性(Spearman等级相关系数0.69,P<0.001).MR间质淋巴造影诊断D-SLN转移的敏感度95.8%,特异度88.9%,准确率93.3%.结论 MR间质淋巴造影可以准确寻找诊断乳腺癌SLN并引导活检,具有较好的临床运用价值.     

前哨淋巴结检测术在宫颈癌诊疗中的研究进展

宫颈癌在女性生殖器官肿瘤中发病率最高,淋巴结转移是其最主要的转移方式,前哨淋巴结是在原发肿瘤淋巴引流区域内,淋巴结发生转移必经的首站淋巴结,前哨淋巴检测术具有操作简单、检出率高、阴性预测值高等特点,其方法、病理学检查、影像因素对指导早期宫颈癌的根治性切除术,减少手术创伤、淋巴结微转移和制定合理的放疗计划等的研究具有重要意义.     

Radioguided sentinel lymph node biopsy in breast cancer surgery.

The concept of sentinel lymph node biopsy in breast cancer surgery relates to the fact that the tumor drains in a logical way through the lymphatic system, from the first to upper levels. Therefore, the first lymph node met (the sentinel node) will most likely be the first to be affected by metastasis, and a negative sentinel node makes it highly unlikely that other nodes are affected. Because axillary node dissection does not improve prognosis of patients with breast cancer (being important only to stage the axilla), sentinel lymph node biopsy might replace complete axillary dissection to stage the axilla in clinically N0 patients. Sentinel lymph node biopsy would represent a significant advantage as a minimally invasive procedure, considering that, after surgery, about 70% of patients are found to be free from metastatic disease, yet axillary node dissection can lead to significant morbidity. Furthermore, histologic sampling errors can be reduced if a single (sentinel) node is assessed extensively rather than few histologic sections in a high number of lymph nodes per patient. Although the pattern of lymph drainage from breast cancer can be variable, the mammary gland and the overlying skin can be considered as a biologic unit in which lymphatics tend to follow the vasculature. Therefore, considering that tumor lymphatics are disorganized and relatively ineffective, subdermal and peritumoral injection of small aliquots of radiotracer is preferred to intratumoral administration. (99m)Tc-labeled colloids with most of the particles in the 100- to 200-nm size range would be ideal for radioguided sentinel node biopsy in breast cancer. Lymphoscintigraphy is an essential part of radioguided sentinel lymph node biopsy because images are used to direct the surgeon to the site of the node. The sentinel lymph node should have a significantly higher count than that of background (at least 10:1 intraoperatively). After removal of the sentinel node, the axilla must be reexamined to ensure that all radioactive sites are identified and removed for analysis. The sentinel lymph node should be processed for intraoperative frozen section examination in its entirety, based on conventional histopathology and, when needed, immune staining with anticytokeratin antibody. The success rate of radioguidance in localizing the sentinel lymph node in breast cancer surgery is about 94%--97% in institutions where a high number of procedures are performed and approaches 99% when combined with the vital blue dye technique. At present, there is no definite evidence that negative sentinel lymph node biopsy is invariably correlated with negative axillary status, except perhaps for T1a-b breast cancers, with a size of < or =1 cm. Randomized clinical trials should elucidate the impact of avoiding axillary node dissection on patients with a negative sentinel lymph node on the long-term clinical outcome of patients.     

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

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

甲状腺乳头状癌淋巴结转移的CT特征及临床意义

目的：探讨甲状腺乳头状癌淋巴结转移的CT特征性表现,提高甲状腺乳头状癌淋巴结转移的诊断正确率,为外科手术方案和手术范围选择提供可靠依据。方法回顾分析经手术病理证实的共334例甲状腺乳头状癌患者的CT影像资料,对其中141例发生颈部淋巴结转移的病例进行统计学分析。结果141例患者中包括仅有中央区（Ⅵ区）淋巴结转移79例,CT诊断符合为60例;中央区及侧颈区（Ⅱ～Ⅴ区）均转移者62例, CT诊断符合51例。结果采用χ2检验。102例淋巴结密度、强化程度与甲状腺癌相似,其中23例伴有囊变坏死,14例伴有颗粒状钙化灶,7例并发喉返神经侵犯或气管、血管侵犯。结论甲状腺癌转移淋巴结好发部位为中央区;但侧颈区亦同样常常有转移,应高度重视。转移淋巴结的CT扫描特征：淋巴结明显强化,强化程度与甲状腺乳头状癌保持一致,可发生囊性变或坏死,以及出现颗粒状钙化灶,CT检查对临床手术方案制定具有重要指导意义。     

Computed tomography lymphography with intrapulmonary injection of iopamidol for sentinel lymph node localization

PURPOSE: Experimental and clinical evaluation of the potential utility of indirect computed tomographic lymphography (CT-LG) with intrapulmonary injection of iopamidol for preoperative localization of sentinel lymph node station in non-small cell lung cancer. METHODS: CT-LG with intrapulmonary injection of 0.5 mL of undiluted iopamidol was performed in 10 dogs using a multidetector-row CT unit, followed by postmortem examination of enhanced lymph nodes in 5 of these dogs. The CT-LG with peritumoral injection of 1 mL of the contrast agent was also performed in 9 patients with non-small cell lung cancer without lymphadenopathy. At surgery, enhanced lymph nodes were resected under CT-LG guide, followed by standard lymph node dissection with macroscopic and histologic examination. A significant enhancement of lymph nodes was determined when CT attenuation value was increased with 30 Hounsfield units (HU) compared with precontrast images. RESULTS: CT-LG visualized a total of 15 enhanced lymph nodes (on average, 1.5 nodes per animal) within 2 minutes after contrast injection in the 10 dogs, with average size of 6.7+/- 1.9 mm and average maximum CT attenuation of 149 +/- 41 HU. All the 8 enhanced nodes in 5 dogs were found in the appropriate anatomic locations in postmortem examinations. Without noticeable complications, CT-LG visualized 30 ipsilateral intrathoracic lymph nodes including 19 hilar/pulmonary and 11 mediastinal nodes in the 9 patients (on average, 2.2 hilar/pulmonary and 1.1 mediastinal nodes per patient) within 2 minutes after contrast injection, with average size of 4.7+/- 0.4 mm and average maximum CT attenuation of 134 +/- 52 HU. At surgery, all these enhanced nodes could be accurately found and resected under CT-LG guidance. Metastasis was not evident in either of these enhanced lymph nodes or the remaining distant nodes in all patients. CONCLUSION: Quick and accurate localization of sentinel lymph node station on detailed underlying lung anatomy by using indirect CT-LG may be of value to guide selective lymph node dissection for minimally invasive surgery in non-small cell lung cancer.