T1N0M0 lung cancer: evaluation with CT

Lymph node metastasis in Chinese patients with clinical T1 non-small cell lung cancer: A multicenter real-world observational study

Background

Approximately 8.3–15.9% of patients with clinical stage I non‐small cell lung cancer are subsequently shown to have lymph node metastasis. However, the clinical characteristics of patients with lymph node metastasis in China are not fully understood.

Methods

This is a multicenter retrospective analysis of pathological T1 non‐small cell lung cancer patients who underwent surgical resection from 2 January 2014 to 27 December 2017. Clinical and pathological information was collected with the assistance of the Large‐scale Data Analysis Center of Cancer Precision Medicine‐LinkDoc database. The clinical and pathological factors associated with lymph node metastasis were analyzed by univariate and multivariate logistic regression.

Results

A total of 10 885 participants (51.6% women; 15.3% squamous cell carcinoma) were included in the analysis. The median age was 60.0 years (range 12.9–86.6 years). A total of 1159 patients (10.6%) had metastases in mediastinal nodes (N2), and 640 patients (5.9%) had metastasis in pulmonary lymph nodes (N1). Most patients had T1b lung cancer (4766, 43.8%). Of the patients, 3260 (29.9%) were current or former smokers. The univariate and multivariate analyses showed that younger age, squamous cell carcinoma, poor differentiation, larger tumor size, carcinoembryonic antigen level ≥5 ng/mL, and vascular invasion (+) were significantly associated with higher percentages of lymph node metastases (P < 0.001 for all).

Conclusion

This real‐world study showed the significant association of lymph node metastasis with age, tumor size, histology and differentiation, carcinoembryonic antigen levels, and status of vascular invasion. Female patients with T1a adenocarcinoma in the right upper lobe barely had lymph node metastasis.

Computed Tomography-Guided Interstitial High-Dose-Rate Brachytherapy in Combination With Regional Positive Lymph Node Intensity-Modulated Radiation Therapy in Locally Advanced Peripheral Non-Small Cell Lung Cancer: A Phase 1 Clinical Trial

PURPOSE

To assess the technical safety, adverse events, and efficacy of computed tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy in combination with regional positive lymph node intensity modulated radiation therapy in patients with locally advanced peripheral non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

Twenty-six patients with histologically confirmed NSCLC were enrolled in a prospective, officially approved phase 1 trial. Primary tumors were treated with HDR brachytherapy. A single 30-Gy dose was delivered to the 90% isodose line of the gross lung tumor volume. A total dose of at least 70 Gy was administered to the 95% isodose line of the planning target volume of malignant lymph nodes using 6-MV X-rays. The patients received concurrent or sequential chemotherapy. We assessed treatment efficacy, adverse events, and radiation toxicity.

RESULTS

The median follow-up time was 28 months (range, 7-44 months). There were 3 cases of mild pneumothorax but no cases of hemothorax, dyspnea, or pyothorax after the procedure. Grade 3 or 4 acute hematologic toxicity was observed in 5 patients. During follow-up, mild fibrosis around the puncture point was observed on the CT scans of 2 patients, but both patients were asymptomatic. The overall response rates (complete and partial) for the primary mass and positive lymph nodes were 100% and 92.3%, respectively. The 1-year and 2-year overall survival (OS) rates were 90.9% and 67%, respectively, with a median OS of 22.5 months.

CONCLUSION

Our findings suggest that HDR brachytherapy is safe and feasible for peripheral locally advanced NSCLC, justifying a phase 2 clinical trial.

T1 non-small cell lung cancer: imaging and histopathologic findings and their prognostic implications

About 5% of T1 non-small cell lung cancers (ie, lung cancers less than 3 cm in diameter), mostly focal nodular bronchioloalveolar carcinomas and carcinoid tumors, demonstrate no uptake at fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and appear to be indolent in growth; consequently, they are associated with long-term patient survival. About 21% of T1 lung cancers show mediastinal nodal metastasis at the time of diagnosis and about 24% show extrathoracic metastasis, mostly brain metastasis, either at the time of diagnosis or at 1-year follow-up. T1 lung cancers with a large ground-glass attenuation component (50% of tumor volume) at thin-section computed tomography (CT) have a good prognosis with less likelihood of mediastinal nodal or extrathoracic metastasis. On the other hand, solid cancer lesions, especially those with a spiculated margin or with bronchovascular bundle thickening in the surrounding lung, more frequently demonstrate local vessel invasion, lymph node metastasis, and extrathoracic metastasis. In these tumors, work-up for extrathoracic metastases (including whole-body FDG PET or brain magnetic resonance imaging and mediastinoscopy for mediastinal nodes) may be needed, even when CT demonstrates no enlarged nodes in the mediastinum.

In vivo identification of sentinel lymph nodes for clinical stage I non-small cell lung cancer for abbreviation of mediastinal lymph node dissection

BACKGROUND

We previously reported that an identification of sentinel lymph node (SN) with a techenetium-99m (99mTc) tin colloid by ex vivo counting, i.e. the radio-activity of dissected lymph nodes, was a reliable method of establishing the first site of nodal metastasis in non-small cell lung cancer [J. Thorac. Cardiovasc. Surg. 124(2002)486]. However, for SN navigation surgery, SN should be identified before lymph node dissection (in vivo) but not after that (ex vivo). In order to reduce mediastinal lymph node dissection for clinical stage I non-small cell lung cancer (NSCLC) by SN navigation surgery, the SN identifications for hilar lymph nodes by ex vivo counting, and for mediastinal lymph nodes by in vivo, were evaluated.

METHODS

Intra-operative SN identification using 99mTc tin colloid was conducted on 104 patients with clinical stage I NSCLC who had had major lung resections with mediastinal lymph node dissections. The hilar SNs were identified by ex vivo counting (after lung resection) and the mediastinal SNs were identified by in vivo counting (before lymph node dissection). To evaluate the accuracy of mediastinal SN identification by in vivo counting, it was compared with the data by ex vivo counting.

RESULTS

SNs were identified in 84 patients (81%). SNs were identified at the hilum by ex vivo counting in 78 patients (93%) and at the mediastinum by in vivo counting in 40 patients (48%). While 15 patients had lymph node metastases, i.e. N1 in six and N2 in nine, the SNs could be found to have metastases during operation in 13 of the 15 patients (87%). The in vivo counting of the mediastinum missed out the mediastinal SNs identified by ex vivo counting in four of the 84 patients (5%).

CONCLUSION

If the hilar SNs identified by ex vivo counting and the mediastinal SNs identified by in vivo counting had no metastases, then mediastinal lymph node dissection could be abbreviated for patients with clinical stage I NSCLC.

Radiation therapy alone in early stage non-small cell lung cancer

Among the patients with early stage (I/II) non-small cell lung cancer (NSCLC), there are those who, due to medical comorbidities, advanced age, or refusal, never undergo surgery. For them, exclusive radiation therapy (RT) has been the treatment of choice, achieving median survival times of 30 months and 5-year survival of up to 42%. Doses of > or =65 Gy with standard fractionation (or its radiobiological equivalent when altered fractionation is used) are necessary for long-lasting local control of the disease, with smaller tumors having a more favorable prognosis. The issue of elective nodal irradiation (ENI) remains controversial, since failure patterns identified local failure as the predominant pattern. None of the potential pretreatment patient- and tumor-related prognostic factors has been shown to clearly influence survival. Toxicity is generally mild to moderate, although high doses (e.g., 80 Gy) may carry a risk for an excessive rate of side effects. Conformal treatment and consideration of comorbidities such as altered lung function may be essential, since simultaneous supportive treatment of acute sequelae (mainly acute esophagitis) is necessary. RT is an effective treatment modality in technically operable, but medically inoperable patients with early stage NSCLC and offers a long-lasting cure.

Staging of non-small cell lung cancer: imaging of intrathoracic disease

This article reviews the contribution of diagnostic imaging to the intrathoracic staging of non-small cell lung cancer. The principle features of the current staging system are discussed along with the relative roles of the various imaging modalities in the evaluation of the primary tumour and metastatic disease. The emerging role of positron emission tomography with fluorodeoxyglucose (FDG-PET) as a clinically useful, potentially cost effective, complementary imaging technique is also reviewed.

Radiotherapy alone in technically operable, medically inoperable, early-stage (I/II) non-small-cell lung cancer

PURPOSE

To investigate the effectiveness of high-dose, curative radiotherapy (RT) given alone in technically operable, but medically inoperable, patients with early-stage (I-II) non-small-cell lung cancer (NSCLC).

METHODS AND MATERIALS

Computerized and manual searches were done to identify published reports dealing with curative RT for NSCLC. Relevant studies were identified and the information provided therein was extracted regarding patient and treatment characteristics, treatment outcome, and various pretreatment and treatment-related factors influencing outcome, as well as toxicity and quality-of-life issues.

RESULTS

Although a large variation of pretreatment and treatment characteristics was noted in the available studies, a median survival time of >30 months and a 5-year survival rate of up to 30% had been achieved. Accumulated experience seems to suggest that doses of at least 65 Gy with standard fractionation, or its equivalent when altered fractionation is used, are necessary for control of NSCLC. Smaller tumors seem to have a favorable prognosis, and the issue of elective nodal RT continues to be controversial. Analyses of patterns of failure have clearly identified local failure as the predominant pattern. Although a number of potential pretreatment patient- and tumor-related prognostic factors have been examined, none has been shown to clearly influence survival. Toxicity was usually low, but very high doses (e.g., 80 Gy) given with a conventional approach may carry a risk of an excessive rate of side effects.

CONCLUSION

High-dose, curative RT is an effective treatment modality in technically operable, but medically inoperable, patients with early-stage NSCLC.

T1 lung cancer on CT: frequency of extrathoracic metastases

PURPOSE

To determine the frequency of extrathoracic metastases in T1 non-small-cell lung cancer.

METHOD

Ninety patients with T1 lung cancer identified on CT were included. Extrathoracic metastases were evaluated at the time of initial diagnosis and during a 1-year follow-up study. The frequency of metastases was compared in terms of cell type (squamous or nonsquamous), size (<2 cm or >2 cm), and the initial CT findings of the tumor.

RESULTS

Extrathoracic metastases were identified in 12 (13%) of 90 patients at the time of diagnosis and in 10 patients at the 1-year follow-up study (total, 22 of 90 [24%] patients). Tumors with ground-glass opacity on CT were associated with a significantly lower prevalence of metastases (p = 0.042). The area of ground-glass opacity was seen in 1 of 13 (85%) patients with bronchioloalveolar carcinoma and in 12 of 53 (23%) patients with adenocarcinoma other than bronchioloalveolar carcinoma (p < 0.001). There was no significant difference in the prevalence of metastases between squamous and nonsquamous cell carcinoma, between tumors smaller than 2 cm (n = 17) and larger than 2 cm in diameter (n = 73) and between tumors with or without mediastinal nodal metastases (p>0.05).

CONCLUSION

Extrathoracic metastases were apparent at the initial examination in 13% of patients and at the 1-year follow-up examination in 11% of patients. The prevalence is significantly lower in tumors with ground-glass opacity.

Non-small cell lung cancer: FDG PET for nodal staging in patients with stage I disease

PURPOSE

To determine the accuracy of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the evaluation of regional lymph nodes in patients with stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Imaging and clinical findings obtained during 5 years in 84 patients (mean age, 66 years) were reviewed. Patients had thoracic computed tomographic findings of stage I NSCLC, an FDG PET study, and histopathologic proof of lung cancer. At the time of diagnosis, disease stage was assigned on the basis of FDG PET results and was compared with the histopathologic stage to determine the accuracy of PET.

RESULTS

When PET stage was compared with histopathologic stage, the disease in 72 (86%) patients was accurately staged with PET, understaged in two (2%), and overstaged in 10 (12%). The overall sensitivity, specificity, and positive and negative predictive values for PET of regional lymph nodal metastases were 82%, 86%, 47%, and 97%, respectively.

CONCLUSION

FDG PET enables accurate staging of regional lymph node disease in patients with stage I NSCLC. A negative PET scan in these patients suggests that mediastinoscopy is unnecessary and that these patients can proceed directly to thoracotomy.

Bronchogenic carcinoma: a survey of CT protocols for staging disease

RATIONALE AND OBJECTIVES

To determine whether a standard computed tomographic (CT) protocol is used in the staging of lung cancer.

MATERIALS AND METHODS

A questionnaire was designed to determine what type of CT scanner is used, whether intravenous contrast material is used, how often the abdomen is scanned and at what level, and the section thicknesses used in scanning the chest and abdomen in patients with lung cancer. A total of 1,118 survey forms were mailed to members of the Society of Thoracic Radiology and to all community hospitals in the United States with at least 300 beds.

RESULTS

The authors received 520 responses (47%) to the 1,118 questionnaires mailed. Of these 520 responses, 140 were from society members, 256 were from hospitals with 300-500 beds, and 124 were from hospitals with more than 500 beds. One-half of hospital respondents used helical CT scanners. Significantly more society members used helical CT scanners (P < .001). Intravenous contrast material was used to opacify mediastinal blood vessels at 449 (86%) of 520 hospitals. Intravenous contrast material was used for liver scanning at 363 (82%) of 444 hospitals, but it was used less often at hospitals in the northeast region and by society members than at hospitals in other regions (P < .001). A mixture of section thicknesses was commonly used (252 [48%] of 520 responses) for scanning the chest; a thickness of 8-10 mm was used in scanning the abdomen at most hospitals (348 [78%] of 445 responses).

CONCLUSION

No CT protocol is consistently used for the examination of patients with lung cancer. Use of intravenous contrast material during chest or liver CT also is not uniform.

Lung cancer staging: the role of computed tomography and magnetic resonance imaging

Because complete resection remains the only reliable method of cure of lung cancer, one important aim of preoperative staging is to select patients with localised disease who may benefit from surgery, while avoiding unnecessary thoracotomies in patients with unresectable neoplasm. Computed tomography (CT) of the chest is a valuable method for staging local and regional spread of lung neoplasms, although limitations in its accuracy are well-known. While gross invasion of the mediastinum and major structures as well as the presence of metastatic disease can be easily demonstrated with CT, differentiation between tumour contiguity and subtle invasion of mediastinum or chest wall often remains a problem. Although magnetic resonance imaging (MRI) may have the same limitations as CT, in specific situations it may be superior in diagnosing minimal chest wall or mediastinal invasion. Moreover, MRI is useful in the assessment of patients with superior sulcus tumours as well as in patients with contraindication to intravenous administration of ionic contrast material. Since nodal size is the only useful criterion for evaluating lymph node metastases, CT and MRI show similar, poor accuracies in lymph node staging resulting from both low sensitivity (normal-sized nodes may contain microscopic metastases) and low specificity (enlarged lymph nodes may be reactive). For this reason, if enlarged lymph nodes are detected, further evaluation is recommended before excluding the patient from a potentially curative resection. Advantages and limitations of CT and MRI in the preoperative staging of non-small-cell carcinoma are reviewed in this article. The imaging of small-cell carcinoma is not included because most patients with this cell type do not benefit from surgical resection. Similarly we do not discuss imaging of distant metastases.

Distribution of distant metastases from newly diagnosed non-small cell lung cancer

BACKGROUND

The purpose of our study was to determine the incidence and locations of M1 disease at presentation in patients with non-small cell lung cancer to help design appropriate preoperative imaging algorithms.

METHODS

All patients with non-small cell lung cancer seen between 1991 and 1993 were identified, and records were reviewed. For patients with M1 disease, the sites of distant metastases and the methods of diagnosis were recorded.

RESULTS

Of 348 patients identified, 276 (79%) had M0 disease and 72 (21%) had M1 disease. In 40 of 72 patients (56%), M1 disease was detected via chest or abdominal computed tomography (CT). Brain, bone, liver, and adrenal glands were the most common sites of metastatic disease, in decreasing order. Brain metastases often occurred as an isolated finding, although isolated liver metastases were uncommon.

CONCLUSIONS

M1 disease was common at presentation, and was often detectable via chest CT. The incremental yield of abdominal CT over chest CT was very small, and therefore abdominal CT is not an effective method of screening for metastases if chest CT has been performed.

Thoracic nodal staging with PET imaging with 18FDG in patients with bronchogenic carcinoma

PURPOSE

To assess the role of positron emission tomographic (PET) imaging with 18-fluoro-2-deoxyglucose (18FDG) in detecting thoracic lymph node metastases in patients with bronchogenic carcinoma.

MATERIALS AND METHODS

Over a 2-year period, any patient presenting to our institution with newly diagnosed bronchogenic carcinoma who was to have thoracic nodes sampled was considered eligible. All PET studies were performed prior to nodal sampling and areas of increased uptake were mapped according to the American Thoracic Society classification. Studies were correlated with CT and pathology. Sensitivity and specificity for predicting nodal metastases was calculated.

RESULTS

Forty-two patients had 62 nodal stations (40 hilar/lobar, 22 mediastinal) sampled. The sensitivity and specificity for hilar/lobar lymph node station metastases using PET imaging was 73% and 76%, respectively. With CT, the sensitivity and specificity were 27% and 86%. The sensitivity and specificity using PET imaging for mediastinal node station metastases was 92% and 100%, respectively, while with CT the figures were 58% and 80%. The sensitivity and specificity for combined thoracic nodal station metastases using PET imaging was 83% and 82%, respectively, while with CT it was 43% and 85%. There was a strong statistical relationship between positive PET imaging and lymph node abnormalities.

CONCLUSIONS

18FDG-PET imaging is accurate in detecting thoracic lymph node metastases in patients with bronchogenic carcinoma. Normal results of PET studies virtually preclude the need for mediastinal nodal sampling prior to surgery, whereas abnormal results of studies most likely represent mediastinal metastases. Treatment can be based on the extent of disease suggested by PET imaging.

Computed tomography of the chest in T1NoMo non-small cell bronchial carcinoma

There has been controversy within the recent literature as to the value of computed tomography (CT) of the chest in patients with T1NoMo non-small cell bronchial carcinoma, as staged by plain radiography and bronchoscopy. This paper reports on 63 such patients, nine (14.2%) of whom were shown correctly by CT of the chest to have metastatic spread which rendered them inoperable. Of these nine, four had stage N3 mediastinal disease; the other five had metastatic disease, either pulmonary or bony. Patients with lesions less than 2 cm in diameter were also looked at separately: 4/20 had inoperable disease on CT of the chest. In both groups the detection rate of inoperability by CT of the chest justifies its use pre-operatively in all T1NoMo non-small cell bronchial carcinomas, in terms of clinical morbidity, mortality and cost.

Imaging techniques in the evaluation of pulmonary parenchymal neoplasms

Conventional PA and lateral chest radiographs continue to be the initial examination of choice to evaluate patients who are suspected of having a pulmonary parenchymal neoplasm. A lung lesion can be characterized as probably benign or malignant based on its radiographic appearance (size, shape, margins, presence of calcification, cavitation or air bronchograms, growth rate). A spiculated or lobulated lesion greater than 3 cm in size that is noncalcified is highly suspicious for malignancy. A lung lesion less than 3 cm in size with smooth borders that appears noncalcified on conventional radiographs should be examined by CT, including densitometry to detect calcification or fat, which indicates benignity. In patients with known lung cancer, CT can help to stage the tumor by indicating hilar or mediastinal involvement, or distant metastases. Currently, MR imaging has a limited role, but can be used as a "problem solving" modality for selected cases in evaluating pulmonary parenchymal neoplasms.

Survival after conservative resection for T1 N0 M0 non-small cell lung cancer

Two hundred forty-four veterans, with a mean age of 62.4 years, mainly asymptomatic (pulmonary), were admitted generally for other disease or pension evaluation and underwent lobectomy (131), segmentectomy (107), or wedge resection (6) for T1 N0 M0 lung cancer between 1966 and 1988. Conservative resection was preferred during the past decade. The average lesion diameter was 2 cm. Thirty-day mortality was 2.9%, similar for the three procedures. Absolute 5-year survival, 51%, was 78% if only deaths from the initial lesion are considered; 19% died of comorbidity, and 8% died of second lung cancers. Routine preoperative computed tomographic staging and intraoperative sampling of even normal-sized hilar and mediastinal nodes, conducted after 1982, improved survival (p less than 0.006). Patients with lesions less than 2 cm in diameter (146) did better (p less than 0.04), and those with squamous tumors improved similarly (p less than 0.02). Lesions that communicated with a bronchus (88) were more malignant than those (156) that did not (p less than 0.02), because from that locus undifferentiated nonsquamous tumors metastasized widely. These results suggest that the T1 N0 M0 category is not uniform. Histology, size, and location in the lung are significant variables. Results of conservative resection were similar or better than those of lobectomy. The latter was used more in deep-seated lesions, however, when major intersegmental planes were transgressed, and before modern preoperative and intraoperative staging. The T1 N0 M0 category should include lesions 2 cm or less in diameter as a discrete entity.

Computed tomography in bronchogenic carcinoma

As was indicated at the beginning of this review, a concensus does not exist regarding many aspects of the use of CT in evaluating bronchogenic carcinoma. When and how CT is used, therefore, becomes a function of the beliefs of the physician caring for the patient. The radiologist must be familiar with this philosophy to be able to advise when CT will be of value. Despite all of the variables considered on the preceding pages, there are some facts. (1) Normal mediastinal lymph nodes may be larger than 1 cm in maximal transverse diameter; the majority are not. (2) An enlarged node (independent of definition) need not harbor metastases. Histologic proof is necessary, especially if this information will preclude surgery. (3) CT less frequently offers usable information in small peripheral cancers. The use of CT in peripheral cancers is very much dependent on the surgeon's philosophy. (4) Important information for patient care is more frequently obtained in patients with central lesions or peripheral lesions associated with abnormal hili or mediastinums. This is also closely related to surgical philosophy. (5) Prediction of either chest wall or mediastinal invasion is treacherous and should only be diagnosed when the findings are certain.