The additional value of SPECT/CT in lymphatic mapping in breast cancer and melanoma.

The recently introduced SPECT/CT integrates the physiologic data of SPECT with the anatomic data of CT into a single image. The purpose of this pilot study was to explore the additional value of SPECT/CT in breast cancer patients and melanoma patients with inconclusive planar image findings. METHODS: Thirty-one patients had planar lymphoscintigrams showing unexpected lymphatic drainage, 6 had lymphoscintigrams that were difficult to interpret, and 3 showed no drainage on planar imaging. SPECT/CT was performed immediately after delayed planar imaging. RESULTS: In 4 patients, SPECT/CT showed 6 additional sentinel nodes, of which 2 were tumor-positive and led to upstaging and tailored management in 5% of patients. SPECT/CT depicted sentinel nodes in 3 patients whose delayed planar imaging had shown no drainage. CONCLUSION: SPECT/CT was of additional value in finding the exact anatomic location of sentinel nodes in patients with inconclusive planar image findings. SPECT/CT also detected sentinel nodes in addition to those found on planar images, and SPECT/CT detected sentinel nodes in patients whose planar images had shown none.     

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

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

The yield of SPECT/CT for anatomical lymphatic mapping in patients with breast cancer

Purpose  The recently introduced hybrid single-photon emission computed tomography camera with integrated CT (SPECT/CT) fuses tomographic lymphoscintigrams with anatomical data from CT. The purpose of this study was to explore this sophisticated technique in lymphatic mapping in breast cancer patients. Methods  We studied 134 patients who underwent SPECT/CT immediately after late planar imaging when these images showed an unusual drainage pattern (85 patients), a pattern that was difficult to interpret (27 patients), or nonvisualization (22 patients). Results  Planar imaging suggested 271 sentinel nodes in 112 of the 134 patients (84%). SPECT/CT showed 269 of these same nodes and indicated that two sites of radioactivity were caused by skin contamination. SPECT/CT visualized 19 additional sentinel nodes in 15 patients, of whom 11 had non-visualization on planar images. One or more tumour-positive sentinel nodes were seen in 27 patients, and in 4 of these patients (15%), these were visualized only by SPECT/CT. SPECT/CT had no additional value for the surgical approach in 11 patients with persisting nonvisualization (8%), and was of questionable value in 67 other patients (50%). Based on the SPECT/CT images, a more precise incision was made in 48 patients (36%), an extra incision was made in 6 (4%), and an incision was omitted in 2 (1.5%). Conclusion  SPECT/CT detected additional sentinel nodes and showed the exact anatomical location of sentinel nodes in breast cancer patients with inconclusive planar images. SPECT/CT was able to visualize drainage in patients whose planar images did not reveal a sentinel node. Therefore, SPECT/CT facilitates surgical exploration in difficult cases and may improve staging.     

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.     

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.     

Lymphoscintigraphy and SPECT/CT in multicentric and multifocal breast cancer: does each tumour have a separate drainage pattern?

Purpose

To investigate whether lymphoscintigraphy and SPECT/CT after intralesional injection of radiopharmaceutical into each tumour separately in patients with multiple malignancies in one breast yields additional sentinel nodes compared to intralesional injection of the largest tumour only.

Methods

Patients were included prospectively at four centres in The Netherlands. Lymphatic flow was studied using planar lymphoscintigraphy and SPECT/CT until 4?h after administration of ^99mTc-nanocolloid in the largest tumour. Subsequently, the smaller tumour(s) was injected intratumorally followed by the same imaging sequence. Sentinel nodes were intraoperatively localized using a gamma ray detection probe and vital blue dye.

Results

Included in the study were 50 patients. Additional lymphatic drainage was depicted after the second and/or third injection in 32 patients (64?%). Comparison of planar images and SPECT/CT images after consecutive injections enabled visualization of the number and location of additional sentinel nodes (32 axillary, 11 internal mammary chain, 2 intramammary, and 1 interpectoral. A sentinel node contained metastases in 17 patients (34?%). In five patients with a tumour-positive node in the axilla that was visualized after the first injection, an additional involved axillary node was found after the second injection. In two patients, isolated tumour cells were found in sentinel nodes that were only visualized after the second injection, whilst the sentinel nodes identified after the first injection were tumour-negative.

Conclusion

Lymphoscintigraphy and SPECT/CT after consecutive intratumoral injections of tracer enable lymphatic mapping of each tumour separately in patients with multiple malignancies within one breast. The high incidence of additional sentinel nodes draining from tumours other than the largest one suggests that separate tumour-related tracer injections may be a more accurate approach to mapping and sampling of sentinel nodes in patients with multicentric or multifocal breast cancer.     

SPECT/CT.

In view of the commercial success of integrated PET/CT scanners, there is an increasing interest in comparable SPECT/CT systems. SPECT in combination with CT enables a direct correlation of anatomic information and functional information, resulting in better localization and definition of scintigraphic findings. Besides anatomic referencing, the added value of CT coregistration is based on the attenuation correction capabilities of CT. The number of clinical studies is limited, but pilot studies have indicated a higher specificity and a significant reduction in indeterminate findings. The superiority of SPECT/CT over planar imaging or SPECT has been demonstrated in bone scintigraphy, somatostatin receptor scintigraphy, parathyroid scintigraphy, and adrenal gland scintigraphy. Also, rates of detection of sentinel nodes by biopsy can be increased with SPECT/CT. This review highlights recent technical developments in integrated SPECT/CT systems and summarizes the current literature on potential clinical uses and future directions for SPECT/CT in cardiac, neurologic, and oncologic applications.     

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

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

Improved sentinel node identification by SPECT/CT in overweight patients with breast cancer.

Overweight has been reported as a cause for the nonvisualization of sentinel nodes (SNs) on preoperative planar lymphoscintigraphy in patients with breast cancer. The purpose of this study was to assess whether SPECT/CT may improve SN identification in overweight patients. METHODS: Lymphoscintigraphy was performed in 220 consecutive patients with breast cancer. Body mass index (BMI) was calculated for each. A total of 122 patients were overweight or obese (BMI, > or = 25). Planar images and SPECT/CT images were interpreted separately, and SN identification on each of the modalities was related to BMI and to findings at surgery. RESULTS: Planar imaging identified SNs in 171 patients (78%) with a BMI (mean +/- SD) of 25.2 +/- 4 kg/m2 and failed to do so in 49 patients (22%) with a BMI of 28 +/- 8 kg/m2. In 29 of the latter patients (59%), SNs were identified on SPECT/CT. SPECT/CT detected "hot" nodes in 200 patients (91%) and failed to do so in 20 patients with a BMI of 29.2 +/- 6.6 kg/m2. For the 122 overweight or obese patients, planar assessment failed to identify SNs in 34 patients (28%) and SPECT/CT failed to do so in 13 patients (11%) (P < 0.001). For 116 patients, surgery took place in our hospital (Tel-Aviv Sourasky Medical Center). An intraoperative blue dye technique failed to detect SNs in 48 patients (41%) with a BMI of 28.2 +/- 7 kg/m2. SPECT/CT localized hot nodes in 36 (75%) of the latter patients, and planar imaging did so in 22 (46%) of those patients. Of 19 patients for whom scintigraphy failed, 6 (32%) had nodal metastatic involvement. CONCLUSION: The addition of SPECT/CT to lymphoscintigraphy improved SN identification in overweight patients with breast cancer. Moreover, SPECT/CT accurately identified SNs in 75% of patients for whom the identification of SNs by the intraoperative blue dye technique failed.     

Comparison of SPECT/CT, SPECT, and planar imaging with single- and dual-phase (99m)Tc-sestamibi parathyroid scintigraphy.

Various methodologies for (99m)Tc-sestamibi parathyroid scintigraphy are in clinical use. There are few direct comparisons between the different methods and even less evidence supporting the superiority of one over another. Some reports suggest that SPECT is superior to planar imaging. The addition of CT to SPECT may further improve parathyroid adenoma localization. The purpose of our investigation was to compare hybrid SPECT/CT, SPECT, and planar imaging and to determine whether dual-phase imaging is advantageous for the 3 methodologies. METHODS: Scintigraphy was performed on 110 patients with primary hyperparathyroidism and no prior neck surgery. Of these, 98 had single adenomas and are the subject of this review. Planar imaging and SPECT/CT were performed at 15 min and 2 h after injection. Six image sets (early and delayed planar imaging, SPECT, and SPECT/CT) and combinations of the 2 image sets were reviewed for adenoma localization at 13 possible sites. Each review was scored for location and certainty of focus by 2 reviewer groups. Surgical location served as the standard. Sensitivity, specificity, area under the curve, positive predictive value, negative predictive value, and kappa-values were determined for each method. RESULTS: The overall kappa-coefficient (certainty of adenoma focus) between reading groups was 0.68 (95% confidence interval, 0.66-0.70). The highest values were for dual-phase studies that included SPECT/CT. Dual-phase planar imaging, SPECT, and SPECT/CT were statistically significantly superior to single-phase early or delayed imaging in sensitivity, area under the curve, and positive predictive value. Neither single-phase nor dual-phase SPECT was statistically superior to dual-phase planar imaging. Early-phase SPECT/CT in combination with any delayed imaging method was superior to dual-phase planar imaging or SPECT for sensitivity, area under the curve, and positive predictive value. CONCLUSION: Early SPECT/CT in combination with any delayed imaging method was statistically significantly superior to any single- or dual-phase planar or SPECT study for parathyroid adenoma localization. Localization with dual-phase acquisition was more accurate than with single-phase (99m)Tc-sestamibi scintigraphy for planar imaging, SPECT, and SPECT/CT.     

Lymphoscintigraphy for sentinel node mapping using a hybrid SPECT/CT system.

Lymphoscintigraphy is performed before sentinel node (SN) biopsy for SN mapping. It is of clinical importance mainly if the tumor is located in body parts with ambiguous lymph node drainage. The purpose of this study was to assess the clinical benefit of fused SPECT/CT images to planar images for SN mapping. METHODS: Thirty-four consecutive patients with cutaneous malignant melanoma (n = 28) and squamous cell carcinoma (n = 6) and scheduled for SN biopsy were enrolled. Primary tumors were located in the trunk (n = 12), in the extremities (n = 12), in the head and neck (n = 9), and in the penis (n = 1). Scintigraphy was performed using a hybrid gamma-camera/low-dose CT system. Planar images and fused SPECT/CT images were interpreted separately. RESULTS: SPECT/CT identified multiple draining basins in 6 of 12 patients (50%) with trunk melanoma and in 3 of 9 patients (33%) with head and neck melanoma or mucosal tumor. In 9 of 21 patients (43%) with a primary tumor located in the head and neck or trunk region, SPECT/CT-fused images identified SNs that were missed on planar images, 2 of which were involved with tumor. Three of the 9 nodes were located close to the injection site and were hidden by its scattered radiation, and 2 were in-transit nodes. Another 4 nodes, identified on fused images only, were located in an additional basin to those identified on planar images. Fused images were of no added value either in patients with limb melanoma or in a patient with a penile melanoma. CONCLUSION: SPECT/CT SN mapping provides additional data that are of clinical relevance to SN biopsy in patients with trunk or head and neck melanoma and in patients with mucosal head and neck tumor.     

Evaluation of diagnostic abilities of Ga-SPECT for head and neck lesions

OBJECTIVE: Single-photon emission computed tomography (SPECT) using gallium (Ga) has been frequently used for diagnosing head and neck tumors in patients. Although the usefulness of Ga-SPECT is well known, the degree of the increase in diagnostic ability with Ga-SPECT for head and neck tumors has not been reported. We compared the ability of the planar images of Ga scintigraphy, SPECT images of Ga scintigraphy, and CT images to diagnose head and neck primary tumors and neck metastases. METHODS: The subjects of this study were 167 patients with malignant head/neck lesions. For Ga scintigraphy, Ga-67-citrate (74 MBq) was injected via a cubital vein. Planar and SPECT images were taken 72 h after the Ga-67-citrate injection. The rate of detection of the primary lesions was compared first between SPECT and planar images then between SPECT and CT images. The rate of detection for each stage of disease according to the TNM classification was also analyzed. RESULTS: The rate of detection of primary lesions was 50% with planar imaging and 69% with SPECT. And similarly, regarding the rate of detection of lymph node metastases, there was a significant difference between planar imaging and SPECT. The rate of detection of primary lesions was 70% for both CT and SPECT. At T stage, the rates of detection of primary lesions with each imaging technique were 11% with planar imaging and 39% with SPECT, and 22% with CT for stage T1. CONCLUSIONS: This study revealed the marked superiority of SPECT images over planar images in terms of the ability to detect primary tumors and tumor metastasis to cervical lymph nodes. Furthermore, the primary T1 tumor detection rate of SPECT images was higher than that of CT images. On the basis of these results, the concomitant use of SPECT is highly recommended when Ga scintigraphy is performed to check for malignant head/neck tumors.     

Use of tomographic nuclear medicine procedures, SPECT and pinhole SPECT, with cationic lipophilic radiotracers for the evaluation of axillary lymph node status in breast cancer patients

Scintimammography with the cationic lipophilic (99m)Tc-tetrofosmin and (99m)Tc-methoxyisobutylisonitrile (MIBI) is one of the most widely available non-invasive imaging methods employed in the preoperative evaluation of breast cancer axillary lymph node status, for which, at present, axillary lymph node dissection (ALND) is still considered the method of choice. Comparative studies have demonstrated that single-photon emission computed tomography (SPECT) acquisition significantly improves the sensitivity and accuracy achieved with planar scintimammography, particularly when lymph nodes are non-palpable, small in size and limited in number. Thus, SPECT should be preferred to planar imaging, particularly in those patients without clinical suspicion of axillary metastatic involvement, given its high negative predictive value; however, false negative results have been reported due to the small size of lymph nodes and/or to partial or micrometastatic involvement. SPECT could also find clinical application in combination with radioguided sentinel lymph node (SLN) biopsy, providing additional useful information in selected cases. The performance of SPECT can be improved by using a pinhole collimator (pinhole SPECT), as recently demonstrated in comparative studies, and this method also determines the number of lymph nodes, thus delivering important prognostic information. Moreover, pinhole SPECT, the principal limitation of which (as with imaging methods) lies in its inability to detect micrometastases, has also proved capable of increasing the accuracy of radioguided SLN biopsy. However, only limited data relating to pinhole SPECT are available as yet, and clinical trials are necessary to validate its potential value.     

The diagnostic value of adding dynamic scintigraphy to standard delayed planar imaging for sentinel node identification in melanoma patients

Purpose  

The aim of this study was to compare early dynamic imaging combined with delayed static imaging and single photon emission computed tomography (SPECT)/CT with delayed, planar, static imaging alone for sentinel node (SN) identification in melanoma patients.     

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.     

SPECT和CT融合骨显像在小儿神经母细胞瘤中的应用

目的探讨SPECT和CT融合骨显像在探测小儿神经母细胞瘤（NB）转移性骨肿瘤中的临床价值。方法回顾性分析24例NB患儿,均行全身平面骨显像及局部SPECT和CT融合骨显像。将骨病灶显示的清晰度分为5级（不可见、模糊、可见、清晰、非常清晰）,良恶性诊断的确定性分为3级（不确定、可以确定、十分确定）,诊断效能指标包括灵敏度、特异性及准确性。对显像图像在骨病灶的清晰度显示、良恶性确定性诊断及探测恶性骨病灶的诊断效能方面进行分析,采用秩和检验及χ^2检验进行比较。结果24例NB患儿,全身平面骨显像发现骨病灶72个,有5个骨病灶未能显示,SPECT和CT融合显像和单独SPECT显像均分别发现骨病灶77个。对骨病灶的清晰度显示SPECT和CT融合显像,单独SPECT显像均优于平面显像（日值均为69．000,P均〈0．05）。平面显像和SPECT显像诊断恶性骨病灶的准确性分别为45．45％（35／77）和62．34％（48／77;χ^2=4．416,P〈0．05）,SPECT和CT融合诊断恶性骨病灶的灵敏度、特异性和准确性均较平面显像有提高,分别为82．35％（42／51）和53．19％（25／47）、88．46％（23／26）和40．00％（10／25）、84．42％（65／77）和45．45％（35／77）,χ^2=12．571,14．016和25．667,P均〈0．01。与SPECT显像的特异性（14／26,53．85％）和准确性（48／77,62．34％）相比,SPECT和cT融合诊断恶性骨病灶的特异性和准确性提高（χ^2=7．589,9．606,P均〈0．01）,两者间灵敏度差异无统计学意义（χ^2=2．942,P〉0．05）。SPECT和CT融合显像骨病灶良恶性的确定性诊断优于SPECT（H=28．000,P〈0．05）和平面显像（H=21．000,P〈0．05）。结论SPECT和CT融合骨显像能探测到NB患儿更多的骨病灶,是一种较好的探测NB患儿转移性骨肿瘤的显像方法。     

^99mTc—平阳霉素显像在肺癌分期中的临床应用研究

肺癌的分期对其获得适当的治疗尤为重要。对３０例原发性肺癌行９９ｍＴｃ－平阳霉素（ＰＹＭ）显像分期研究，单光子发射计算机断层（ＳＰＥＣＴ）对纵隔及肺门淋巴结浸润的发现能力与Ｘ－ＣＴ一致（肺门９／９，纵隔１３／１３），肝转移显示３／４。对恶性胸水除可显示积液外，尚可较好地显示原发病灶（平面６／７，ＳＰＥＣＴ７／７），提示该显像可用于肺癌分期检查     

The Clinical Value of Hybrid Sentinel Lymphoscintigraphy to Predict Metastatic Sentinel Lymph Nodes in Breast Cancer

Purpose

Hybrid imaging techniques can provide functional and anatomical information about sentinel lymph nodes in breast cancer. Our aim in this study was to evaluate which imaging parameters on hybrid sentinel lymphoscintigraphy predicted metastatic involvement of sentinel lymph nodes (SLNs) in patients with breast cancer.

Methods

Among 56 patients who underwent conventional sentinel lymphoscintigraphy, 45 patients (age, 53.1 ± 9.5 years) underwent hybrid sentinel lymphoscintigraphy using a single-photon emission computed tomography (SPECT)/computed tomography (CT) gamma camera. On hybrid SPECT/CT images, we compared the shape and size (long-to-short axis [L/S] ratio) of the SLN, and SLN/periareolar injection site (S/P) count ratio between metastatic and non-metastatic SLNs. Metastatic involvement of sentinel lymph nodes was confirmed by pathological biopsy.

Results

Pathological biopsy revealed that 21 patients (46.7 %) had metastatic SLNs, while 24 (53.3 %) had non-metastatic SLNs. In the 21 patients with metastatic SLNs, the SLN was mostly round (57.1 %) or had an eccentric cortical rim (38.1 %). Of 24 patients with non-metastatic SLNs, 13 patients (54.1 %) had an SLN with a C-shape rim or eccentric cortex. L/S ratio was 2.04 for metastatic SLNs and 2.38 for non-metastatic SLNs. Seven (33 %) patients had T1 primary tumors and 14 (66 %) had T2 primary tumors in the metastatic SLN group. In contrast, 18 (75 %) patients had T1 primary tumors and six (25 %) had T2 tumors in the non-metastatic SLN group. S/P count ratio was significantly lower in the metastatic SLN group than the non-metastatic SLN group for those patients with a T1 primary tumor (p = 0.007).

Conclusions

Hybrid SPECT/CT offers the physiologic data of SPECT together with the anatomic data of CT in a single image. This hybrid imaging improved the anatomic localization of SLNs in breast cancer patients and predicted the metastatic involvement of SLNs in the subgroup of breast cancer patients with T1 primary tumors.     

~(131)I SPECT/CT断层融合显像在分化型甲状腺癌中的临床价值

目的：探讨131^I SPECT/CT断层融合显像在分化型甲状腺癌诊治检测中的临床价值。材料和方法：选择术后病理证实并接受131^I治疗的分化型甲状腺癌（DTC）患者97例,行131^I全身扫描（131^I-WBS）和病灶部位的SPECT断层加同机CT融合显像。将131^I-WBS与断层融合图像进行对比分析,探讨断层融合显像的特点与临床价值。结果：97例分化型甲癌患者共进行131^I-WBS251次,断层融合显像102次,每例患者至少行一次断层融合显像。与131^I-WBS比较,断层融合显像有如下特点：能够获得直观的断层融合显像和三维立体图像;②发现更多的病灶;③更准确地判断病变部位;④定位CT可以发现无摄碘功能的病灶;⑤鉴别病灶和生理显影或污染。结论：131^I SPECT/CT断层融合显像可以直观病变立体形态、大小、摄取程度和毗邻关系,在鉴别病灶与生理显像或污染、确定病灶是否有摄碘功能方面有重要价值,是131^I-WBS的重要补充。     

The Current Status of SPECT or SPECT/CT in South Korea

The first step to nuclear medicine in Korea started with introduction of the gamma camera in 1969. Although planar images with the gamma camera give important functional information, they have the limitations that result from 2-dimensional images. Single-photon emission computed tomography (SPECT) due to its 3-dimensional image acquisition is superior to earlier planar gamma imaging in image resolution and diagnostic accuracy. As demand for a hybrid functional and anatomical imaging device has increased, integrated SPECT/CT systems have been used. In Korea, SPECT/CT was for the first time installed in 2003. SPECT/CT can eliminate many possible pitfalls on SPECT-alone images, making better attenuation correction and thereby improving image quality. Therefore, SPECT/CT is clinically preferred in many hospitals in various aspects. More recently, additional SPECT/CT images taken from the region with equivocal uptake on planar images have been helpful in making precise interpretation as part of their clinical workup in postoperative thyroid cancer patients. SPECT and SPECT/CT have various advantages, but its clinical application has gradually decreased in recent few years. While some researchers investigated the myocardial blood flow with cardiac PET using F-18 FDG or N-13 ammonia, myocardial perfusion SPECT is, at present, the radionuclide imaging study of choice for the risk stratification and guiding therapy in the coronary artery disease patients in Korea. New diagnostic radiopharmaceuticals for AD have received increasing attention; nevertheless, brain SPECT will remain the most reliable modality evaluating cerebral perfusion.