Bronchogenic carcinoma: analysis of staging in the mediastinum with CT by correlative lymph node mapping and sampling.

One hundred forty-three patients with bronchogenic carcinoma were studied prospectively with computed tomography (CT) to determine the accuracy of CT in the evaluation of mediastinal nodal metastases. Mediastinal lymph nodes were localized according to the lymph node mapping scheme of the American Thoracic Society and were considered abnormal if they exceeded 1 cm in short-axis diameter. All patients underwent surgical staging, which consisted of either mediastinoscopy alone or mediastinoscopy and thoracotomy. At the time of surgical staging, all accessible nodes were either removed or sampled. The sensitivity of CT for mediastinal nodes on a per-patient basis was 64%, with a specificity of 62%. The sensitivity of CT for individual nodal stations involved with tumor was only 44%. The presence of obstructive pneumonitis did not appreciably alter the sensitivity of CT, but the specificity was lower (43%). The likelihood of metastases increased with lymph node size; however, seven of 19 (37%) lymph nodes that measured 2-4 cm in short-axis diameter were hyperplastic and did not contain metastases. The relative insensitivity of CT makes formal nodal sampling at the time of mediastinoscopy or thoracotomy essential to detect lymph node metastases.     

The additional value of FDG PET imaging for distinguishing N0 or N1 from N2 stage in preoperative staging of non-small cell lung cancer in region where the prevalence of inflammatory lung disease is high

PURPOSE: The aim of this study was to evaluate the efficacy of PET imaging and compare it with the performance of CT in mediastinal and hilar lymph node staging in potentially operable non-small cell lung cancer (NSCLC). METHODS: Fifty-nine patients with potentially resectable NSCLC who underwent preoperative PET and CT imaging were enrolled into this prospective study. All patients underwent surgical evaluation by means of mediastinoscopy with mediastinal lymph node sampling (14 patients) or thoracotomy (45 patients). RESULTS: The prevalence of lymph node metastases was 53%. Overall, the sensitivity, specificity, accuracy, PPV, and NPV of PET were 79%, 76%, 78%, 86%, and 76% for N0 and N1 lymph nodes and 76%, 79%, 80%, 67%, and 83% for N2 lymph nodes, while those values for CT were 66%, 43%, 58%, 68%, and 43% for N0 and N1 stations and 43%, 66%, 54%, 41%, and 66% for N2 lymph nodes, respectively. PET correctly differentiated cases with mediastinal lymph node involvement (N2) from those without such involvement (N0 or N1) in 76% of cases. Statistical analysis of the diagnostic accuracy of nodal involvement showed that PET improves diagnostic accuracy significantly in the detection of both N0 or N1 and N2 status in the individual patient based on analysis, compared with CT (P < 0.01 and P < 0.01, respectively). When preoperative nodal staging was compared with postoperative histopathological staging, 38 (65%) patients were correctly staged, 9 (15%) were overstaged, and 12 (20%) were understaged by PET, while 29 patients (49%) were correctly staged, 13 (22%) were overstaged, and 17 (29%) were understaged by CT. CONCLUSION: It has been clearly shown that PET is more accurate than CT for the differentiation of N0 or N1 from N2 disease in patients with NSCLC. However, PET imaging alone does not appear to be sufficient to replace mediastinoscopy for mediastinal staging in patients with lung cancer, especially in geographic regions with high granulomatous or inflammatory mediastinal disease prevalence.     

Role of computed tomography and mediastinoscopy in preoperative staging of lung carcinoma

One hundred fifty-three patients with bronchogenic carcinoma were evaluated prospectively by CT and mediastinoscopy. Nodes larger than 5 mm were considered potentially metastatic. All results were correlated with surgical findings. Computed tomography is more sensitive (89%) in the detection of mediastinal metastases than mediastinoscopy (67%). Computed tomography has a poor predictive value (47%); however, a negative examination is highly accurate (89%). Within a group of 100 node sites, 72% of the nodes involved by tumor were larger than 1 cm in diameter. Squamous cell carcinoma and adenocarcinoma have the highest percentages of sensitivity by CT. The very low incidence of metastatic involvement in nodes under 5 mm allows one to forego mediastinoscopy in the presence of a negative CT.     

淋巴结反应性增生的CT诊断

目的分析淋巴结反应性增生的CT表现及CT的诊断价值。方法回顾性分析13例经手术及病理证实的淋巴结反应性增生的CT表现。结果13例淋巴结反应性增生中,单独侵犯颈外侧淋巴结7例,同时侵犯颈外侧区及面淋巴结、颏下淋巴结各2例,1例侵犯腋窝及腹股沟淋巴结,1例为颈、腋、纵隔、腹膜后区和腹股沟淋巴结同时肿大。肿大淋巴结短径最小0.6 cm,最大2.6 cm,平均1.6 cm。肿大淋巴结孤立存在12例,仅1例有融合。1例因相互融合而密度不均,12例密度均匀并有明显强化,增强后CT值增加19.1~113.2 HU,平均59.1 HU。结论淋巴结反应性增生的CT表现有一定的特征性,CT检查对该病的定性诊断与鉴别诊断具有重要价值。     

Reliability of computerized tomography in the definition of the "N" parameter in the preoperative evaluation of primary bronchopulmonary tumors

In order to evaluate the reliability of thoraco-mediastinal CT in the preoperative evaluation of primary lung cancer, regarding "N" (lymph nodes) parameter, we compared CT data with those obtained at histopathology of mediastinal lymph nodes. We re-examined 130 patients who had undergone lobectomy or pneumonectomy combined with mediastinal node dissection. CT criterion of neoplastic nodal involvement is morphological, based on size of the node as related to its location. CT is very sensitive in evaluating both normal and pathological nodes but not likewise specific; in fact, it does not allow differential diagnosis between neoplastic and phlogistic causes. This limitation must be kept in mind in the preoperative evaluation of the "N" parameter. Moreover, CT findings of mediastinal involvement on the opposite side (N3) must be confirmed with mediastinoscopy or CT-guided biopsy before ruling radical surgery out.     

直肠周围间隙淋巴结转移的术前MSCT评估

目的:分析直肠周围间隙淋巴结转移的多层CT(MSCT)表现,探讨CT诊断直肠癌淋巴结转移(N分期)的价值.方法:术前行盆腔MSCT检查的154例直肠癌病例,均行全直肠系膜切除术,对直肠周围间隙淋巴结进行病理检查,采用双盲法,记录每枚淋巴结的CT表现,包括淋巴结短轴直径、边缘、密度、分布方式.结果:以手术病理为标准.直肠周围间隙淋巴结CT检出率为86.3%(471/546),病理共检出直肠周围间隙淋巴结546枚,CT检出481枚,其中471枚(阳性172枚,阴性299枚)淋巴结与病理相匹配.CT诊断直肠周围间隙淋巴结转移的各种判断标准(淋巴结大小、边缘、密度、分布方式)的敏感性分别为83.1%、72.2%、70.1%、73.5%,特异性分别为80.5%、85.1%、82.4%、75.1%.CT显示的淋巴结大小、边缘、密度、分布方式的差异与阳性率有显著相关性,P<0.005.结论:直肠周围间隙淋巴结有良性和恶性淋巴结,综合分析淋巴结大小、形态、密度及分布对诊断直肠周围间隙淋巴结转移有很大帮助.     

The mediastinum in non-small cell lung cancer: CT-surgical correlation

Computed tomography was used to evaluate the mediastinum preoperatively in 60 patients with non-small cell lung cancer; 49 of these patients had thorough surgical-pathologic determination of mediastinal node status. Mediastinal lymph nodes were located by CT using the node-mapping scheme suggested by the American Thoracic Society and were considered abnormal when larger than 100 mm2 in cross-sectional area. The sensitivity of CT was 95% in detecting malignant mediastinal adenopathy; however, specificity was only 64%. Receiver operating characteristic (ROC) curve analysis showed that the optimal size criterion for diagnosing malignant mediastinal adenopathy is 1.0-1.5 cm when the short axis of a node is measured. CT staging of the mediastinum in patients with non-small cell lung cancer is clinically useful; negative mediastinal CT makes mediastinoscopy unnecessary, whereas positive CT should lead to biopsy of the enlarged node.     

Location,size, and distribution of mediastinal lymph node enlargement in chronic congestive heart failure

PURPOSE: The purpose of this study is to identify the prevalence, location, and size of enlarged mediastinal lymph nodes in patients with chronic congestive heart failure and to correlate the presence of lymph node enlargement with cardiac ejection fraction. METHODS: Sixty-six consecutive, retrospectively identified patients underwent computer tomography (CT) imaging of the thorax as part of a routine work-up prior to cardiac transplantation from 1993 to 1996. CT images of 44 of these patients were independently examined by 3 radiologists for evidence of pulmonary edema, pleural effusions, and the presence, size, and location of lymph nodes >1 cm in short axis. Multigated acquisition (MUGA) scans were available for cardiac ejection fraction assessment in 38 of the 44 patients. RESULTS: Twenty-nine (66%) patients had at least 1 mediastinal lymph node >1 cm. The mean ejection fraction was significantly less for patients with lymph node enlargement when compared with patients without lymph node enlargement (20% versus 35%; P < 0.01). Adenopathy was observed in 81% of patients with a calculated ejection fraction of <35%. No patient with an ejection fraction of >35% had lymph node enlargement. There was no correlation between pulmonary edema and the frequency of lymph node appearance. Sixty-three percent of the enlarged nodes were pretracheal, with a mean short axis diameter for all the enlarged nodes of 1.3 cm. CONCLUSIONS: Enlarged mediastinal lymph nodes were observed in 81% of patients with a calculated ejection fraction of <35%, most commonly in the pretracheal group. The presence of the lymph nodes did not correlate with CT evidence of pulmonary edema.     

8例组织细胞坏死性淋巴结炎18F-FDG PET/CT表现及临床分析

目的 分析组织细胞坏死性淋巴结炎（HNL）病人的 ¹⁸F-脱氧葡萄糖（FDG）PET/CT表现及临床资料,提高对该病认识水平。 方法 回顾性分析8例经病理证实的HNL病人的 ¹⁸F-FDG PET/CT资料,其中男4例、女4例,中位年龄26.5岁。分析HNL在 ¹⁸F-FDG PET/CT成像上所示的受累淋巴结分布、形态、密度及摄取,并采用Pearson相关分析来确定淋巴结的 ¹⁸F-FDG最大标准化摄取值（SUV_max）与其长径、短径之间的相关性。 结果 8例HNL病人 ¹⁸F-FDG PET/CT成像均有多部位淋巴结受累,位于颈部8例（6例双侧、2例单侧）,腋窝7例（5例双侧、2例单侧）,肺门及纵隔4例,腹部4例,盆腔3例及腹股沟区2例（均为双侧）。受累淋巴结大都呈椭圆形,无融合,密度较均匀,无钙化及液化坏死。受累淋巴结SUV_max为12.86±5.70,长径为（1.41±0.42） cm,短径为（0.84±0.26） cm,CT值为（44.77±9.59） HU。其中短径<1 cm的淋巴结约占63.4%,SUV_max为11.21±5.80。受累淋巴结SUV_max与长径呈低度正相关（r=0.349,P=0.025）,与短径呈中度正相关（r=0.504,P=0.001）。 结论 ¹⁸F-FDG PET/CT成像在HNL诊断、鉴别诊断及淋巴结活检定位中发挥重要作用。     

Accuracy of the plain radiograph in the detection of aortopulmonary lymphadenopathy

Detection of aortopulmonary window lymph node enlargement by chest radiography was assessed in 67 patients with bronchogenic carcinoma. All patients underwent computed tomography (CT). Surgical confirmation of the radiographic and CT findings was available in all patients with lymph node size smaller than 2.5 cm in diameter on CT (47 patients) and in 6 of 20 patients with nodes greater than 2.5 cm in diameter. Forty-one had normal-sized and 26 had enlarged (greater than 1.5 cm diameter) aortopulmonary nodes. Lymphadenopathy was detected on the chest radiograph in 21 of the 26 patients with enlarged nodes. It was wrongly suspected in one of the 41 patients with normal-sized aortopulmonary nodes on CT. Three patients with lymphadenopathy had a normal aortopulmonary window on the chest radiograph. In these patients, the nodes measured 1.6-2.6 cm in diameter. In two patients with enlarged nodes and in two with normal-sized nodes, the aortopulmonary window could not be assessed on the radiograph because it was obscured by concomitant atelectasis and obstructive pneumonitis of the left upper lobe. We conclude that in the absence of left upper lobe atelectasis, chest radiography has a high sensitivity (87%) and specificity (97%) in detecting aortopulmonary lymph nodes larger than 1.5 cm in diameter. In only one patient was metastatic disease detected at surgery in a node smaller than 1.5 cm diameter.     

周围型小细胞肺癌的CT征象分析

目的 探讨周围型小细胞肺癌(SCLC)的CT征象.方法 回顾分析78例经病理证实的周围型SCLC的CT影像特点.根据有无纵隔淋巴结转移及其大小,将78例周围型SCLC分为2型:Ⅰ型孤立病灶型、Ⅱ型肺内病灶+淋巴结型;又将Ⅱ型分为2个亚型:Ⅱa型,肺门、纵隔淋巴结短径<10 mm;Ⅱb型,肺门、纵隔淋巴结短径≥10 mm.结果 Ⅰ型7例,Ⅱ型71例,其中Ⅱa型8例,Ⅱb型63例.78例SCLC均为实性病变;圆形、类圆形52例,纺锤形、蠕虫状9例,其他形状17例.71例行CT增强扫描,9例呈均匀强化,58例呈不均匀强化,4例病灶内见大面积不强化坏死区.边缘光整65例,毛糙12例,模糊1例.支气管充气征3例,空泡征4例,钙化4例.分叶征46例,毛刺征5例;支气管血管束增粗、结节41例,胸膜凹陷6例,边缘磨玻璃影5例,血管集束征1例;肺气肿42例,阻塞性肺炎4例;支气管与结节边缘截断18例.纵隔淋巴结转移63例,纵隔淋巴结大于肺原发灶42例.少量胸腔积液9例.     

Accuracy of CT in the demonstration of lymph node metastasis in pulmonary carcinoma

The CT, surgical and histological findings were examined of 350 lymph nodes in a perspective study of 50 patients affected with lung cancer. CT accuracy could thus be evaluated in assessing the size of hilar and mediastinal lymph nodes; the incidence of histologically-proven metastases in nodes more/less than 10 cm in diameter could also be determined, together with CT diagnostic accuracy for nodal metastases. Finally, CT capabilities were also evaluated in distinguishing N0 from N1-N2 patients. CT proved to have high negative predictive value and low positive predictive value, which caused the authors to raise the normal threshold value of CT evaluation of the greatest diameter for hilo-mediastinal nodes from 10 to 20 mm.     

Mediastinal lymph node involvement in non-small cell lung cancer: evaluation with 99mTc-tetrofosmin SPECT and comparison with CT.

In patients with non-small cell lung cancer (NSCLC), surgical resection offers the best chance of cure. The preoperative assessment of mediastinal lymph node involvement is crucial to selecting those patients for whom surgery is indicated. METHODS: To evaluate the possible clinical role of (99m)Tc-tetrofosmin scintigraphy in the presurgical detection of mediastinal node metastases from NSCLC, we performed a prospective comparative study with CT on 83 patients (48 men, 35 women; age range, 38-81 y) with primary NSCLC (36 adenocarcinomas, 39 epidermoid squamous cell carcinomas, and 8 large cell anaplastic carcinomas). They underwent chest SPECT 20 min after (99m)Tc-tetrofosmin injection (740 MBq intravenously). The metastatic involvement of mediastinal nodes was assessed by histologic examination after mediastinoscopy or thoracotomy. Both chest CT and (99m)Tc-tetrofosmin scintigraphy were performed within 2 wk before the surgical staging. RESULTS: Metastatic mediastinal lymph nodes were found in 35 patients. (99m)Tc-Tetrofosmin imaging in assessing the mediastinal involvement yielded a sensitivity of 85.7%, a specificity of 89.6%, and an accuracy of 88.0%; CT results were 68.6%, 75.0%, and 72.3%, respectively. SPECT accuracy was significantly higher than CT accuracy (P < 0.05). However, precise anatomic localization of (99m)Tc-tetrofosmin uptake in the mediastinum was not always present on SPECT images. (99m)Tc-Tetrofosmin SPECT precisely detected the presence or absence of lymph node metastases in 33 of the 36 patients with positive CT findings (enlarged mediastinal nodes with a short axis > or =1 cm), with an accuracy (91.7%) significantly higher (P < 0.05) than that of CT (66.7%). CONCLUSION: (99m)Tc-Tetrofosmin SPECT is a useful presurgical noninvasive method to assess mediastinal lymph node involvement in NSCLC. In particular, it could play a clinical role in reducing the number of invasive staging surgical procedures in selected patients, especially in those with enlarged lymph nodes at CT. Fusing SPECT with CT images could further improve the interpretation of the scintigraphic data.     

Staging of lymph nodes with FDG dual-headed PET in patients with non-small-cell lung cancer

Accurate assessment of mediastinal lymph node involvement in patients with non-small-cell lung cancer (NSCLC) is necessary to select patients for direct surgical treatment. The aims of the present study were to assess the feasibility of staging NSCLC with FDG using a dual-headed positron emission tomographic (PET) camera and to compare this non-invasive technique with computed tomography (CT) and lymph node sampling, since both modalities are currently used for staging NSCLC. Thirty-three patients (29 men and 4 women, mean age 60 years) with newly diagnosed NSCLC were studied. In all patients, CT, FDG dual-headed PET and mediastinoscopy were performed within 4 weeks. The results of mediastinoscopy were used to select patients for thoracotomy. For both the assessment of individual lymph node involvement and the patient-based classification, the results of FDG dual-headed PET and CT were compared using the McNemar test. Thirty-one of 187 lymph nodes studied contained tumour metastases. FDG dual-headed PET showed a significantly higher sensitivity (P < 0.001) and specificity (P < 0.001) than CT. FDG dual-headed PET and CT correctly staged 27 and 20 patients, respectively. Due to the significantly higher negative predictive value of FDG dual-headed PET versus CT (P = 0.012), it was a better non-invasive diagnostic tool for selecting patients for surgery. In seven of eight patients, additional intrapulmonary sites of increased uptake were found, which revealed malignancy on histological examination. CT was false-negative in three of these patients. In one patients, increased FDG uptake was caused by an infection. In conclusion, it is possible to stage mediastinal lymph nodes in patients with NSCLC using a dual-headed PET camera. The high negative predictive value of FDG dual-headed PET suggests that mediastinoscopy may be omitted in patients with NSCLC.     

Comparison of dynamic helical CT and dynamic MR imaging in the evaluation of pelvic lymph nodes in cervical carcinoma

OBJECTIVE: This study compares dynamic helical CT with dynamic MR imaging in the evaluation of pelvic lymph nodes in cervical carcinoma. SUBJECTS AND METHODS: Women with biopsy-proven cervical carcinoma prospectively underwent dynamic helical CT and MR imaging before surgery. A metastatic node on CT and MR imaging was defined as a rounded soft-tissue structure greater than 10 mm in maximal axial diameter or a node with central necrosis. Imaging results were compared with pathology, and receiver operating characteristic curves for size and shape were plotted on a hemipelvis basis. Nodal density and signal intensity on CT and MR images, respectively, were reviewed for differences between benign and malignant disease. RESULTS: A total of 949 lymph nodes were found at pathology in 76 hemipelves in 43 women, of which 69 lymph nodes (7%) in 17 hemipelves (22%) were metastatic. Sensitivity, specificity, positive and negative predictive values, and accuracy of helical CT and MR imaging in the diagnosis of lymph node metastasis on a hemipelvis basis was 64.7%, 96.6%, 84.6%, 90.5%, and 89.5% and 70.6%, 89.8%, 66. 7%, 91.4%, and 85.5%, respectively. Receiver operating characteristic curves for helical CT and MR imaging gave cutoff values of 9 and 12 mm in maximal axial diameter, respectively, in the prediction of metastasis. Central necrosis had a positive predictive value of 100% in the diagnosis of metastasis. Signal intensity on MR imaging and density-enhancement pattern on CT in patients with metastatic nodes did not differ from those in patients with negative nodes. CONCLUSION: Helical CT and MR imaging show similar accuracy in the evaluation of pelvic lymph nodes in patients with cervical carcinoma. Central necrosis is useful in the diagnosis of metastasis in pelvic lymph nodes in cervical cancer.     

甲状腺癌颈淋巴结转移的螺旋CT表现

目的探讨甲状腺癌颈淋巴结转移的螺旋CT表现.方法1998-11～1999-12资料齐全44例甲状腺癌术前螺旋CT扫描图像进行回顾性分析,并与术后病理对照.观察淋巴结密度、分区和钙化,评价甲状腺癌颈淋巴结转移螺旋CT表现特点.结果据颈淋巴结转移一般特征中心坏死和环状强化.还具有(1)甲状腺癌颈转移淋巴结内细沙样钙化或斑块样钙化,(2)增强有明显强化22例(53.66%).平扫CT值28.00～50.54HU,增强后CT值62.85～145.78HU,并大多接近100HU或大于100HU.结论甲状腺癌颈淋巴结转移除中心低密度囊变、坏死和环状强化,淋巴结内见细沙样和斑块样钙化提示甲状腺内占位为恶性,淋巴结增强多较明显,CT值多接近或大于100HU.     

A problem in diagnosing N3 disease using FDG-PET in patients with lung cancer —High false positive rate with visual assessment—

OBJECTIVE: To evaluate the accuracy of diagnosing N3 disease using positron emission tomography (PET) with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) in patients with pulmonary disease. SUBJECTS AND METHODS: Twenty patients diagnosed as FDG-PET N3 were enrolled. On FDG-PET, lymph nodes were considered to be positive when increased uptake as compared with that of the surrounding mediastinum was visually observed, or the mean standardized uptake ratio (SUR) was more than 2, 2.5, or 3. On CT, lymph nodes exceeding 1 cm in the shortest diameter were regarded as positive. RESULTS: The PET result was true positive (TP) in 2 patients and false positive (FP) in 18 with an overall accuracy (OA) of 10% using visual criteria. Using an SUR of more than 2.5, the result was TP in 2, FP in 3, and true negative (TN) in 15, the false negative (FN) in 0, with an OA of 85%. CT diagnosis was TP in 2, FP in 9, and TN in 9 with an OA of 55%. The accuracy using the SUR criteria of more than 2.5 was superior to that of CT. CONCLUSION: Of 20 patients with the diagnosis of PET N3, we found frequent over-diagnosis in nodal staging using the visual criteria.     

Lymph node staging of gastric cancer using (18)F-FDG PET: a comparison study with CT.

This study was performed to compare (18)F-FDG PET with CT for the evaluation of primary tumors and lymph node metastases in gastric cancer. METHODS: Eighty-one patients (28 women and 53 men; mean age, 56.6 y; age range; 32-82 y) who had undergone radical (n = 74) or palliative (n = 7) gastrectomy and lymph node dissection for the management of gastric cancer were included. Preoperative (18)F-FDG PET and CT were reviewed retrospectively for primary tumors of the stomach and lymph node metastases. Any increased (18)F-FDG uptake exceeding that of the adjacent normal gastric wall was considered positive for the primary tumor. Lymph nodes were classified into 3 groups based on their anatomic sites. Because perigastric lymph nodes (N1) were often not clearly differentiated from primary tumors, N1 lymph node metastases were determined when possible. Lymph nodes were considered positive or negative on the basis of the group as a whole. Final conclusions for primary tumors and lymph node metastases were based on histopathologic specimens in all patients. RESULTS: There were 17 patients with early gastric cancer (EGC) and 64 patients with advanced gastric cancer (AGC). For primary tumors, both PET and CT showed a sensitivity of 47% (8/17) for EGC and 98% (63/64) for AGC. The sensitivity of CT for N1 disease was significantly higher than that of PET. (18)F-FDG PET had a sensitivity, specificity, and accuracy of 34% (11/32), 96% (47/49), and 72% (58/81), respectively, for N2 metastases, whereas the corresponding CT values were 44% (14/32), 86% (42/49), and 69% (56/81). For N3 metastases, PET and CT had the same sensitivity, specificity, and accuracy: 50% (3/6), 99% (74/75), and 95% (77/81), respectively. Overall, the sensitivity, specificity, and accuracy of (18)F-FDG PET were not significantly different from those of CT for primary tumors or for N2 and N3 metastases. CONCLUSION: (18)F-FDG PET is as accurate as CT for the detection of primary tumors of either EGC or AGC. The low sensitivities of PET and CT were insufficient to allow decision making on the extent of lymphadenectomy. In contrast, the high specificity of PET for N disease appeared valuable, and the presence of N disease on PET may have a clinically significant impact on the choice of initial therapy.     

The usefulness of Tc-99m-tetrofosmin SPECT/CT in the detection of residual tumors and axillary lymph node metastases in breast cancer patients following neoadjuvant therapy

Single photon emission computed tomography (SPECT)/CT is emerging as a useful diagnostic tool in several oncological fields. In this prospective study, we assessed the usefulness of Tc-99m-tetrofosmin SPECT/CT in the detection of both residual breast tumors and axillary lymph node metastases following neoadjuvant therapy. Thirty-seven consecutive breast cancer patients scheduled to surgery following neoadjuvant therapy preoperatively underwent a Tc-99m-tetrofosmin SPECT/CT study, using a dual head gamma camera integrated with a x-ray tube for low-dose CT, including both breasts and axillary regions in the field of view. Within 1 week of SPECT/CT, all 37 patients had breast surgery with associated axillary lymph node dissection in 33/37 cases. At surgery, 31/37 patients had breast residues (microscopic in 4/31 cases and macroscopic in 27/31 cases). Axillary lymph node metastases were ascertained in 19/33 cases (N1mi: 2 cases, N1a: 8 cases, N2a: 6 cases, N2b: 3 cases). SPECT/CT sensitivity, specificity, and accuracy in detecting residual tumors were 87%, 100%, and 89.2%, respectively; the corresponding values in detecting axillary lymph node metastases were 36.8%, 92.8%, and 60.6%. SPECT/CT missed breast cancer residues in 4/31 patients, including 2 cases with microscopic residual disease. Moreover, lymph node metastases were missed in 12/19 patients (10/12 with pN1mi or pN1a metastases), all with lymph nodes with post-therapy fibrotic changes and small deposits of metastases. Tc-99m-tetrofosmin SPECT/CT proved a useful diagnostic tool in the detection and in the localization of residual breast tumors following neoadjuvant therapy. The procedure lacked in sensitivity in identifying axillary lymph node metastases, especially in patients with a limited lymph node involvement. According to our data, SPECT/CT may guide the surgeon to the most appropriate breast surgical treatment and to eventually select the most suitable axillary lymph node sampling (axillary lymph node dissection or sentinel node biopsy).     

Computed tomography of corpus luteal cysts

OBJECTIVE: To describe the computed tomography (CT) features of corpus luteal cysts. METHODS: We retrospectively identified 10 patients with a diagnosis of corpus luteal cysts established by ultrasound who had also undergone contemporaneous CT. A single attending radiologist, without knowledge of other clinical or radiologic findings, recorded the morphologic features of the cysts based on the CT images. RESULTS: The corpus luteal cyst seen at sonography was visible at CT in all 10 patients. All cysts were unilocular, with a mean density of 25 HU (range, 12 to 45). The mean maximum axial cyst diameter was 2.2 cm (range, 1.4 to 2.9). The mean cyst wall thickness was 3 mm (range, 2 to 4). All cyst walls were crenulated. Cyst wall enhancement was hyperdense in 6 cases, isodense in 3 cases, and hypodense in 1 case. Free fluid was seen in 9 of 10 patients. CONCLUSIONS: At CT, corpus luteal cysts are typically less than 3 cm in diameter and are characterized by a thick, crenulated, or hyperdense wall. Recognition of these CT findings should prevent misinterpretation or inappropriate management.