ESTS guidelines for intraoperative lymph node staging in non-small cell lung cancer.

The European Society of Thoracic Surgeons (ESTS) organized a workshop dealing with lymph node staging in non-small cell lung cancer. The objective of this workshop was to develop guidelines for definitions and the surgical procedures of intraoperative lymph node staging, and the pathologic evaluation of resected lymph nodes in patients with non-small cell lung cancer (NSCLC). Relevant peer-reviewed publications on the subjects, the experience of the participants, and the opinion of the ESTS members contributing on line, were used to reach a consensus. Systematic nodal dissection is recommended in all cases to ensure complete resection. Lobe-specific systematic nodal dissection is acceptable for peripheral squamous T1 tumors, if hilar and interlobar nodes are negative on frozen section studies; it implies removal of, at least, three hilar and interlobar nodes and three mediastinal nodes from three stations in which the subcarinal is always included. Selected lymph node biopsies and sampling are justified to prove nodal involvement when resection is not possible. Pathologic evaluation includes all lymph nodes resected separately and those remaining in the lung specimen. Sections are done at the site of gross abnormalities. If macroscopic inspection does not detect any abnormal site, 2-mm slices of the nodes in the longitudinal plane are recommended. Routine search for micrometastases or isolated tumor cells in hematoxylin-eosin negative nodes would be desirable. Randomized controlled trials to evaluate adjuvant therapies for patients with these conditions are recommended. The adherence to these guidelines will standardize the intraoperative lymph node staging and pathologic evaluation, and improve pathologic staging, which will help decide on the best adjuvant therapy.     

The role of lymphadenectomy in lung cancer surgery

Adequate lymphadenectomy represents a fundamental procedure in lung cancer surgery for accurate staging and potential survival benefit. Various techniques are used in current surgical practice for the intraoperative lymph node removal associated with pulmonary resection, without definitive indications concerning the preferable option. Different studies in the last decades have compared complete mediastinal lymph node dissection with lymph node sampling regarding their effect on long-term survival, recurrence rate, accuracy of pathologic staging, and surgical morbidity. Literature data and technical aspects of lymph node dissection are reported and discussed in this article.     

Limited mediastinal lymph node dissection for non-small cell lung cancer according to intraoperative histologic examinations

BACKGROUND: Although radioisotopic procedures are commonly used to detect sentinel lymph nodes in breast cancer surgery, these procedures are often problematic and not necessarily suitable for lung cancer surgery. METHODS: Our previous study revealed that the mediastinal sentinel lymph node, defined as the regional mediastinal lymph node, consisted of nodes 2, 3, or 4 in right upper lobe cancers; 3, 7, or 8 in right lower lobe cancers; 4, 5, or 7 in left upper lobe cancers; and 4, 7, or 8 in left lower lobe cancers. On the basis of these findings, we pathologically investigated one representative lymph node at each of the 3 levels dissected during surgical intervention in 69 patients with non-small cell lung cancer from September 1993 through December 2002. Fifty-eight patients with lung cancer underwent lobectomies with limited mediastinal lymph node dissection according to this strategy. RESULTS: Mediastinal lymph node recurrence was observed in only one patient during 41 +/- 25 months (maximum, 98 months) of follow-up. The cancer-specific 5-year survivals were 96.6% in patients with pathologic stage IA disease (n = 31) and 67.4% in patients with stage IB disease (n = 16). CONCLUSION: These results suggested that limited mediastinal lymph node dissection is applicable to patients with non-small cell lung cancer whose regional mediastinal lymph nodes are not metastatic.     

Results of preoperative mediastinoscopy for small cell lung cancer

BACKGROUND: The significance of mediastinoscopy for small cell lung cancer is unclear owing to the small number of surgical cases. METHODS: To determine the N component of the TNM staging system, computed tomographic findings and the results of mediastinoscopy were compared with the pathologic examination of surgical specimens. RESULTS: Four cases among 37 patients (10.8%) were determined as inoperable by mediastinoscopy because of mediastinal lymph node metastasis. A thoracotomy was performed in 33 patients. Six patients (18.2%) who had been judged to have no metastasis by mediastinoscopy were found to have N2 disease after examination of the surgical specimens. In the identification of all mediastinal metastases, mediastinoscopy was 40.0% sensitive, 100% specific, and 83.8% accurate. When the superior mediastinal, paratracheal, pretracheal, tracheobronchial, and subcarinal lymph nodes were defined as approachable nodes, mediastinoscopy was 66.7% sensitive, 100% specific, and 94.6% accurate in the evaluation of these restricted nodes. Four cases among 8 patients with cN1 lesions resulted in a designation as pN2. CONCLUSIONS: Mediastinoscopy is useful for the diagnosis of an approachable mediastinal lymph node in small cell lung cancer cases. This exploration is necessary for patients with small cell lung cancer who are diagnosed as cN1 before thoracotomy.     

FDG/PET and spiral CT image fusion for medistinal lymph node assessment of non-small cell lung cancer patients

BACKGROUND: To assess the potential usefulness of 18F-FDG/PET and spiral-CT images concurrent assessment and coregistration in staging mediastinal lymph node involvement in patients with non small cell lung cancer. METHODS: 28 patients waiting to undergo surgical treatment underwent spiral-CT and PET examinations on the same day. The results of the two studies were interpreted separately, together (CT&PET) and following their fusion in a single image (CT+PET). Results of spiral-CT, PET, CT&PET and CT+PET were assessed with respect to the histological diagnosis. RESULTS: A correct assessment of mediastinal lymph nodes was achieved by spiral-CT in 21 of the 28 patients, in 22 of the 28 patients by PET, in 24 patients by CT&PET and in 25 patients by CT+PET. CONCLUSIONS: CT+PET is more accurate than spiral-CT and PET alone in staging mediastinal lymph node involvement in lung cancer patients, with possible implications for their prognosis and therapy.     

Limited resection for small peripheral lung cancer using intraoperative pathologic examination

From 1996 to 2002, we performed intentional limited resection for small peripheral lung cancer using intraoperative pathologic examination. Wedge resection was performed in patients who had small peripheral adenocarcinoma (< or = 20 mm), suspected of being Noguchi type A or B, and confirmed by intraoperative pathologic examination. Extended segmentectomy was performed in the rest of patients (tumor diameter < or = 20 mm), and not suspected of being Noguchi type A or B. Hilar and mediastinal lymph nodes sampling was performed in this group. If lymph node metastasis was detected by the intraoperative pathologic examination, the surgical procedures was converted into a lobectomy with lymph node dissection. Limited resection was performed in 27 patients, wedge resection in 8, and extended segmentectomy in 19. All patients received wedge resection are alive without sign of recurrence. In extended segmentectomy, 17 patients are alive with no evidence of disease, 1 patient died of non-pulmonary disease, and 1 patient is alive with recurrent disease. The overall survival rate at 5 years was 100% in wedge resection, 91% in extended segmentectomy, and 79% in standard lobectomy. We conclude that limited resection for small peripheral lung cancer using intraoperative pathologic examination may be safe and effective procedure.     

Predictors of lymph node and intrapulmonary metastasis in clinical stage IA non-small cell lung carcinoma

BACKGROUND: The feasibility of limited surgical resection for clinical stage IA non-small cell lung cancer still remains controversial. METHODS: From July 1987 through April 1998, 389 patients with clinical stage IA disease underwent major lung resection and complete mediastinal lymph node dissection. Univariate and multivariable analyses were performed to determine predictors of local or regional tumor spread: pathologic lymph node involvement, intrapulmonary metastases, and lymphatic invasion. RESULTS: Of the 389 patients, 88 (23%) had lymph node involvement or intrapulmonary metastases pathologically. According to multivariable analyses, grade of differentiation and pleural involvement were significant predictors of local or regional tumor spread (p < 0.01). Based on these results, more than 40% of clinical stage IA non-small cell lung cancer patients showed pathologic lymph node involvement or intrapulmonary metastases, or both, if the patients had both of the predictors of pathologic local or regional involvement: moderate or poor differentiation of the primary tumor and pleural involvement by tumor cells. CONCLUSIONS: Limited surgical resection is not feasible for clinical stage IA non-small cell lung cancer, especially when the tumor shows moderate or poor differentiation, or pleural involvement.     

Sentinel nodes in lung cancer: Review of our 10-year experience

Sentinel node (SN) identification in patients with lung cancer is useful not only to minimize lymph node dissection, but also to target the best lymph nodes for intraoperative frozen section during segmentectomy. Since 2000, we have identified the SN in lung cancer patients using radioisotope (RI). This review presents our data on SN identification, describing the following: the procedure, using a radioisotope tracer; the flow of Tc-99 tin colloid after the injection; the characteristics of patients whose SNs could not be identified; ex vivo SN identification; reliability of in vivo SN identification; the algorithm for reducing mediastinal lymph node dissection; the differences in SN identification between large and small radioisotope particles; SNs at segmental lymph nodes; SN navigation segmentectomy for clinical stage IA non-small cell lung cancer; and small metastasis in the SN.     

A clinical study for improving the survival rate of pN2 lung cancer through our case of 53 patients]

BACKGROUND: In management of non-small cell lung cancer, the evaluation and treatment of N2 disease has a lot of controversy. MATERIALS AND METHODS: Between 1983 and 1998, 53 patients of pN2 non-small cell lung cancer were operated by standard lymph node dissection method (R2) using CUSA system. We studied the sensitivity of the diagnosis of preoperative N factor, survival rate, and analysed the relationship between the postoperative mediastinal lymph node metastasis and the site of recurrence. RESULTS: Three-year and five-year survival rates for 53 cases were 46.8% and 33.4% respectivery. Preoperative sensitivity of CT scan for N factors were only 45% in squamous cell carcinoma and 24.2% in adenocarcinoma. Even with intraoperative findings, the sensitivity was not better. In a follow up survey, ipsilateral mediastinal lymph node recurrence was not detected, contralateral mediastinal lymph node recurrences were rare and the distant metastases were common cause of death. CONCLUSION: It is more important to accomplish the standard lymph node dissection completely in all cN cases than to evaluate the preoperative node stage aggressively using invasive methods.     

Analysis of lobectomy for small peripheral lung cancer supports extended segmentectomy

We reviewed the records of 53 patients who underwent lobectomy for peripheral non-small cell lung cancer under 2 cm in diameter and established a rationale for segmentectomy with intraoperative lymph nodes dissection (extended segmentectomy). Five patients (9.4%) had intrapulmonary metastases. Nodal status was NO in 34 patients (64.2%), N1 in 7 (13.2%), and N2 in 12 (22.6%). Based on examination of intraoperative frozen sections, 31 patients lacking lymph node metastases and visceral pleural involvement could have been candidates for extended segmentectomy. Twenty-seven had stage I disease on postoperative examination of paraffin-embedded sections. Of the remaining 4 patients, 1 had involvement of intrapulmonary lymph nodes in the segment where the primary lesion originated. Another patient had involvement only at the first mediastinal lymph node level, representing a “skipping metastasis”. The remaining 2 patients had no lymph node involvement, but had intrapulmonary metastases in the same segments as the primary lesion. We conclude that an extended segmentectomy may be as effective as lobectomy for treatment of peripheral non-small cell lung cancer under 2 cm in diameter without evident lymph node involvement.     

肺癌跳跃式纵隔淋巴结转移的临床病理探讨

目的　探索肺癌跳跃式纵隔淋巴结转移的病理特点 ,为合理施行淋巴结清除术提供可靠的理论依据。方法　 1992年 10月至 1998年 6月 ,为 398例肺癌病人施行了根治性肺切除、规范淋巴结清除术 ,对其中 4 7例 ( 2 9 4 % )跳跃式纵隔转移淋巴结病例进行病理学研究。结果　各型或各叶肺癌中 ,跳跃式转移淋巴结分布最密集的部位依次是第 7、4、3、5组淋巴结 ,分别占 2 9 8%、2 4 5 %、14 9%与10 6 % ;就鳞癌与腺癌而言 ,肿瘤长径在 1cm以内者均无跳跃式淋巴结转移 ,跳跃式淋巴结转移率随长径增加而增加 ;低分化腺癌淋巴结转移率明显高于高分化者 (P <0 0 1) ;发生跳跃式淋巴结转移的肿瘤平均长径鳞癌与腺癌分别为 15 3mm与 9 1mm。结论　对肺癌淋巴结的廓清 ,切勿仅凭手触摸或靠肉眼观察淋巴结大小而盲目判定其是否转移或清除。除T1 中肿瘤长径 <1cm的鳞癌外 ,淋巴结的规范清除应重视其跳跃性 ,原则上必须包括同侧胸腔的肺门及上、下纵隔各组淋巴结 ,尤其要重视跳跃式淋巴结转移分布较密集区域 ,即右侧的第 3、4、7组与左侧的第 4、5、7组淋巴结     

直径≤3cm的周围型非小细胞肺癌纵隔淋巴结转移规律的初步研究

目的探讨直径≤3cm的周围型非小细胞肺癌(non-small cell lung cancer,NSCLC)纵隔淋巴结转移的情况,分析早期周围型NSCLC纵隔淋巴结转移的规律。方法 2000年1月1日～2008年12月31日治疗直径≤3cm的周围型NSCLC161例,男89例,女72例,年龄(63.4±10.7)岁,行肺叶切除或肺局限性切除加系统性纵隔淋巴结清扫术,分析其临床特征、病理特点及纵隔淋巴结转移规律。结果全组手术顺利,无死亡及严重并发症发生。肺叶切除153例,肺楔形切除7例,肺段切除1例。全组共清扫淋巴结2456枚,平均每例4.5±1.6组、13.1±7.3枚。术后病理:腺癌99例,鳞癌30例,肺泡细胞癌19例,其他类型肺癌13例。术后TNM分期:ⅠA期50例,ⅠB期62例,ⅡA期6例,ⅡB期10例,ⅢA期33例。N1组淋巴结转移率为23.6%(38/161),N2组转移率为20.5%(33/161),其中隆突下淋巴结转移率为8.1%(13/161),跳跃式纵隔转移率为6.8%(11/161),全组未发现下纵隔淋巴结转移。肺泡细胞癌及直径≤2cm的鳞癌、直径≤1cm的腺癌均无pN2转移。上肺癌发生pN2转移时上纵隔100%(19/19)受累,其中21.1%(4/19)同时伴有隆突下淋巴结转移;下肺癌则除主要转移至隆突下外(64.3%,9/14),还常直接单独转移至上纵隔(35.7%,5/14)。转移的纵隔淋巴结左肺癌主要分布在第5、6、7组,右肺癌主要分布在第3、4、7组。结论对于直径≤3cm的周围型NSCLC,肿瘤直径越大,其纵隔淋巴结转移率越高,肺泡细胞癌、直径≤2cm的鳞癌和≤1cm的腺癌其纵隔淋巴结转移率相对较低;上肺癌主要转移在上纵隔,下肺癌则隆突下及上纵隔均可转移;第5、6、7组淋巴结是左肺癌主要转移的位置,第3、4、7组是右肺癌主要转移的位置,术中应重点清扫。     

支气管内超声引导针吸活检术在非小细胞肺癌术前分期中的临床应用

目的探讨支气管内超声引导针吸活检术(EBUS-TBNA)在非小细胞肺癌纵隔淋巴结分期中的应用价值。 方法2010年9月至2012年9月,北京大学人民医院利用EBUS-TBNA对术前确诊或CT扫描高度怀疑非小细胞肺癌且伴有纵隔淋巴结肿大(N₂站淋巴结短径≥1.0cm,或N₁站淋巴结短径≥1.0cm且N₂多站短径≥0.5cm者),有手术切除可能,术前无放、化疗史的126例患者进行纵隔淋巴结分期。最终入组82例非小细胞肺癌患者。 结果该组82例患者,经EBUS-TBNA检查证实纵隔淋巴结转移(阳性)者54例,未见纵隔淋巴结转移(阴性)者28例。EBUS-TBNA在该组肺癌术前纵隔淋巴结分期中的敏感度、特异度和准确性分别为94.7%(54/57)、100.0%(25/25)和96.3%(79/82),阳性预测值及阴性预测值分别为100.0%(54/54)和89.3%(25/28)。而CT对于本组患者纵隔淋巴结分期中的敏感度、特异度和准确性分别为98.2%(55/56)、38.5%(10/26)和79.3%(65/82),阳性预测值及阴性预测值分别为77.5%(55/71)和90.9%(10/11)。CT在术前纵隔淋巴结分期中的假阳性率为22.5%(16/71)。全组中,16例(19.5%)肺癌患者因EBUS-TBNA病理结果改变了治疗策略。 结论EBUS-TBNA用于非小细胞肺癌纵隔淋巴结分期的敏感性、特异性和准确性较高。EBUS-TBNA可以作为非小细胞肺癌术前分期、指导治疗策略的检查手段。     

Lymph node staging in non-small cell lung cancer: evaluation by [18F]FDG positron emission tomography (PET)

BACKGROUND: A study was undertaken to investigate the accuracy of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D- glucose (FDG) in the thoracic lymph node staging of non-small cell lung cancer (NSCLC). METHODS: Forty six patients with focal pulmonary tumours who underwent preoperative computed tomographic (CT) and FDG- PET scanning were evaluated retrospectively. Thirty two patients had NSCLC and 14 patients had a benign process. The final diagnosis was established by means of histopathological examination at thoracotomy, and the nodal classification in patients with lung cancer was performed by thorough dissection of the mediastinal nodes at surgery. RESULTS: FDG-PET was 80% sensitive, 100% specific, and 87.5% accurate in staging thoracic lymph nodes in patients with NSCLC, whereas CT scanning was 50% sensitive, 75% specific, and 59.4% accurate. The absence of lymph node tumour involvement was identified by FDG-PET in all 12 patients with NO disease compared with nine by CT scanning. Lymph node metastases were correctly detected by FDG-PET in three of five patients with N1 disease compared with two by CT scanning, in nine of 11 with N2 disease compared with six by CT scanning, an in all four with N3 nodes compared with two by CT scanning. CONCLUSIONS: FDG-PET provides a new and effective method for staging thoracic lymph nodes in patients with lung cancer and is superior to CT scanning in the assessment of hilar and mediastinal nodal metastases. With regard to resectability, FDG-PET could differentiate reliably between patients with N1/N2 disease and those with unresectable N3 disease.     

Is sampling really effective in staging non-small cell lung cancer? A prospective study

Is sampling really effective in staging non-small cell lung cancer? The aim of the study was to assess if systematic nodal dissection is necessary in order to stage non-small cell lung cancer correctly or whether mediastinal lymph node sampling can be used and whether in selected cases it could replace systematic nodal dissection for the treatment of lung cancer. A prospective study was conducted in 94 patients affected by clinically resectable non-small cell lung cancer (stages I-IIIB) who were surgically treated by the same team of surgeons. During surgery mediastinal lymph node sampling was done first and then another surgeon completed the systematic nodal dissection and performed the lung resection. One hundred and ninety-three mediastinal nodal stations were investigated using the American Thoracic Society lymph node map to identify them. On analysing the 193 mediastinal nodal stations investigated, it emerged that in 181 cases (94%) mediastinal lymph node sampling and systematic nodal dissection yielded the same histopathological findings, whereas in 12 cases (6%) there was no agreement between the two techniques. The negative predictive value of mediastinal lymph node sampling was 92.8% (103/111). The results of the study show no statistical difference between mediastinal lymph node sampling and systematic nodal dissection in staging non-small cell lung cancer. However, it is possible that in a limited percentage of cases a nodal station could be understaged and thus the surgical resection could prove incomplete if mediastinal lymph node sampling alone is performed. Moreover, in those cases where mediastinal lymph node sampling detects N2 disease and systematic nodal dissection has not been completed, the intervention cannot be considered radical.     

Thoracoscopic mediastinal lymph node dissection for lung cancer

Mediastinal lymph node staging is an important component of the assessment and management of patients with operable non-small cell lung cancer and is necessary to achieve complete resection. During minimally invasive surgery, performance of an equivalent oncologic resection, including adequate lymph node dissection similar in extent to open thoracotomy, is absolutely necessary. We describe our techniques for video-assisted thoracic surgery (VATS) and Robot-assisted VATS (R-VATS) mediastinal lymph node dissection when performing thoracoscopic lobectomy for lung cancer. Between 2008 and 2011, 200 consecutive patients who underwent VATS or R-VATS lobectomies for early stage lung cancer were analyzed. In our series, we removed about 25 lymph nodes per case in both complete VATS and R-VATS. A thorough lymph node dissection in lung cancer is possible with either VATS or R-VATS technique without oncological compromise.     

Lymph node dissection during surgery for lung cancer. Solely staging or therapy?

The accuracy of staging of lung cancer is reflected by the extent of mediastinal lymph node sampling. The more extensively a patient is tested, the more likely there will be the accurate N-stage diagnosed. Adequate lymph node dissection during surgery for lung cancer therefore requires complete dissection of all three ipsilateral mediastinal compartments including the infracarinal region. Additional contralateral mediastinal lymph node exploration may not be justified. A direct therapeutic effect of mediastinal lymph node removal may be attributed to the prevention of local tumor growth. However, its overall prognostic significance remains unclear because it must be assumed that proven tumor within the mediastinal lymph nodes reflects the state of tumor generalization that may not be cured by localized therapeutic means. New systemic interventions are clearly warranted to significantly improve prognosis in stage II and III lung cancer patients.     

Use of positron emission tomography in initial staging of nonsmall cell lung carcinoma: a regional teaching hospital experience

The ability to accurately diagnose mediastinal lymph node involvement is significantly important in patients with nonsmall cell lung cancer (NSCLC). Positron emission tomography (PET) imaging has become a standard technique to assess lymph node involvement in patients with NSCLC. The purpose of this study is to evaluate the accuracy of PET scan imaging as a mediastinal staging tool in patients with NSCLC at our regional teaching institution. We performed a single-institution, retrospective review of patients diagnosed with NSCLC from January 1, 2006, through December 31, 2007. We included only those patients who underwent computed tomography (CT), PET, and pathologic assessment of mediastinal lymph nodes. Using pathologic assessment as the criterion standard, the overall accuracy, sensitivity, specificity, and positive and negative predictive values of CT and PET were calculated. One hundred seventeen patients were identified for inclusion in the study. The overall accuracy was 81.2 per cent for CT and 91.5 per cent for PET. Sensitivity was 42.1 per cent for CT and 52.6 per cent for PET. Specificity was 88.8 per cent for CT and 99.0 per cent for PET. Positive predictive values were 42.1 per cent for CT and 90.9 per cent for PET; negative predictive values were 88.8 per cent for CT and 91.5 per cent for PET. False-negative result rates were 9.4 per cent for CT and 7.7 per cent for PET; false-positive result rates were 9.4 per cent for CT and 0.9 per cent for PET. Our analysis confirms the use of PET scan imaging in the staging of patients with NSCLC at a regional teaching institution.     

Lymphatic mapping and sentinel lymphadenectomy for primary and metastatic pulmonary malignant neoplasms

BACKGROUND: Mediastinal lymph node sampling understages a significant number of lung cancers, even when nodes are evaluated by immunohistochemical techniques. Intraoperative lymphatic mapping and sentinel lymphadenectomy allows focused pathologic evaluation of a few lymph nodes that accurately stage the entire basin. HYPOTHESIS: Lymphatic mapping and sentinel lymphadenectomy is a practical and accurate method of staging lymph nodes that drain primary and metastatic neoplasms of the lung. DESIGN AND SETTING: Retrospective review at a tertiary referral center. PATIENTS: Sixty-seven patients undergoing resection of lung tumors. MAIN OUTCOME MEASURES: Sentinel lymph node (SN) identification rate, number of SNs, nodal pathologic features, and survival. RESULTS: Twenty-eight patients had primary lung cancer and 39 had pulmonary metastases from melanoma (33 cases), squamous cell carcinoma (2 cases), colon cancer (2 cases), or other cancers (2 cases). Lymphatic mapping and sentinel lymphadenectomy was successful in all patients. The median number of lymph nodes identified by dye alone was 2 (range, 1-7); the median number identified by dye plus radiocolloid was 4 (range, 1-9). Most SNs (69%) were N1; 31% were N2. Lower lobe lesions drained to upper mediastinal nodes in 3 (13%) of 24 cases. Lymph node metastases were found in 11 patients with lung cancer (39%) and 8 patients with pulmonary metastases (21%). Ten (91%) of the 11 patients with lung cancer had SN involvement. In the 33 patients with metastatic melanoma, SN involvement significantly reduced the rate of 2-year survival (0% vs 48%). CONCLUSIONS: Lymphatic mapping and sentinel lymphadenectomy of intrapulmonary malignancies is technically challenging but feasible. Blue dye is most useful for in vivo identification of SNs; ex vivo radioactivity can confirm that excised nodes are SNs. Lymphatic mapping and sentinel lymphadenectomy can provide important prognostic information for patients with melanoma and lung metastases, and it may improve the staging of primary lung cancer.     

Intraoperative radioisotope sentinel lymph node mapping in non-small cell lung cancer

BACKGROUND: Lymph node metastases are the most significant prognostic factor in localized non-small cell lung cancer (NSCLC). Nodal micrometastases may not be detected. Identification of the first nodal drainage site (sentinel node) may improve detection of metastatic nodes. We performed intraoperative Technetium 99m sentinel lymph node (SN) mapping in patients with resectable NSCLC. METHODS: Fifty-two patients (31 men, 21 women) with resectable suspected NSCLC were enrolled. At thoracotomy, the primary tumor was injected with 2 mCi Tc-99. After dissection, scintographic readings of both the primary tumor and lymph nodes were obtained with a handheld gamma counter. Resection with mediastinal node dissection was performed and findings were correlated with histologic examination. RESULTS: Seven of the 52 patients did not have NSCLC (5 benign lesions, and 2 metastatic tumors) and were excluded. Forty-five patients had NSCLC completely resected. Mean time from injection of the radionucleide to identification of sentinel nodes was 63 minutes (range 23 to 170). Thirty-seven patients (82%) had a SN identified; 12 (32%) had metastatic disease. 35 of the 37 SNs (94%) were classified as true positive with no metastases found in other intrathoracic lymph nodes without concurrent SN involvement. Two inaccurately identified SNs were encountered (5%). SNs were mediastinal (N2) in 8 patients (22%). CONCLUSIONS: Intraoperative SN mapping with Tc-99 is an accurate way to identify the first site of potential nodal metastases of NSCLC. This method may improve the precision of pathologic staging and limit the need for mediastinal node dissection in selected patients.