Surveillance computed tomography after complete resection for non–small cell lung cancer: Results and costs

The significance of regular chest computed tomography in postoperative surveillance for surgically resected non-small cell lung cancer based on TNM 8th staging system

OBJECTIVES

Although several societies recommend regular chest computed tomography (CT) scans for the surveillance of surgically resected non-small cell lung cancer (NSCLC), there is paucity of evidence to support these statements. This study aimed to clarify whether regular CT scans improved the prognosis of patients with surgically resected NSCLC based on TNM 8th classification.

METHODS

Patients with pathologic Stage 0-III NSCLC who underwent complete surgical resection other than sublobar resection procedures were enrolled in the study. For these patients, clinicopathological data and postoperative surveillance data were collected by the retrospective review of medical records. Patients were categorized into the chest X-ray (CXR) group or the CT group according to whether they were followed-up with basic examinations including CXR or basic examinations plus regular chest CT. Postoperative overall survival was compared between the two groups.

RESULTS

Six hundred sixty five patients were categorized into the CXR (n = 245) and CT (n = 420) groups. The clinicopathological backgrounds did not differ to a statistically significant extent. Recurrence was seen in 68 (27.3%) patients in the CXR group and 117 (27.8%) patients in the CT group. The 5-year overall survival rates of the two groups did not differ to a statistically significant extent (CXR, 76.5%; CT, 78.3%, P = 0.22).

CONCLUSION

Regular chest CT scans may not improve the prognosis of surgically resected NSCLC. Further study is warranted to precisely evaluate the benefit of CT-based postoperative surveillance of NSCLC.

Clinical Value of Surveillance 18F-fluorodeoxyglucose PET/CT for Detecting Unsuspected Recurrence or Second Primary Cancer in Non-Small Cell Lung Cancer after Curative Therapy

Simple Summary

Non-small cell lung cancer (NSCLC) patients are at considerable risk of recurrence or second primary cancer (SPC) after curative therapy. The utility of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) surveillance to detect recurrent lesions in NSCLC patients without suspicion of recurrence has not been established. The aim of our retrospective study was to evaluate the diagnostic value of surveillance FDG PET/CT for detecting clinically unsuspected recurrence or SPC in patients with NSCLC after curative therapy. In a cohort of 2684 NSCLC patients after curative therapy, surveillance FDG PET/CT showed good diagnostic efficacy for detecting clinically unexpected recurrence or SPC. Furthermore, the diagnostic performance was improved in subgroups of patients with advanced stage prior to curative therapy, PET/CT scans performed within 3 years after curative-intent therapy, and curative surgery. Surveillance PET/CT can be more useful when performed soon after therapy in curative surgery recipients and those with an advanced disease stage considering its diagnostic efficacy and yield.

Abstract

We evaluated the diagnostic value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT surveillance for detecting clinically unsuspected recurrence or second primary cancer (SPC) in patients with non-small cell lung cancer (NSCLC) after curative therapy. A total of 4478 surveillance FDG PET/CT scans from 2864 NSCLC patients without suspicion of recurrence after curative therapy were reviewed retrospectively. In 274 of 2864 (9.6%) patients, recurrent NSCLC or SPC was found by surveillance PET/CT during clinical follow-up. Surveillance PET/CT scans showed sensitivity of 98.9% (274/277), specificity of 98.1% (4122/4201), accuracy of 98.2% (4396/4478), positive predictive value (PPV) of 77.6% (274/353), and negative predictive value of 99.9% (4122/4125). The specificity and accuracy in the curative surgery group were significantly higher than those in the curative radiotherapy group. PPV was significantly improved in subgroups of patients with advanced stage prior to curative therapy, PET/CT scans performed within 3 years after curative-intent therapy, and curative surgery. FDG PET/CT surveillance showed good diagnostic efficacy for detecting clinically unexpected recurrence or SPC in NSCLC patients after curative therapy. It can be more useful when performed soon after therapy in curative surgery recipients and those with an advanced disease stage considering its diagnostic efficacy and yield.

Katanin P80 correlates with larger tumor size, lymph node metastasis, and advanced TNM stage and predicts poor prognosis in non-small-cell lung cancer patients

Objective

The present study aimed to investigate the correlation of katanin P80 expression with clinicopathological features and survival profile in non–small‐cell lung cancer (NSCLC) patients.

Methods

Totally, 398 NSCLC patients treated by pulmonary resection were enrolled and their tumor specimens were collected to determine katanin P80 expression by immunohistochemistry (IHC) assay. Clinical data were collected at diagnosis, and survival data including disease‐free survival (DFS) and overall survival (OS) were assessed after treatment.

Results

There were 195 (49.0%) patients with katanin P80 high expression and 203 (51.0%) patients with katanin P80 low expression, respectively. Meanwhile, katanin P80 high expression was associated with larger tumor size (P = .001), lymph node (LYN) metastasis (P = .005), and advanced TNM stage (P = .001). As for survival data, katanin P80 high expression was correlated with reduced DFS (P < .001) and OS (P < .001). And forward stepwise multivariate Cox's regression revealed that katanin P80 high expression was an independent predictor for decreased DFS (P < .001) and OS (P < .001). Besides, further analysis indicated that DFS (P < .001) and OS (P < .001) were the shortest in patients with katanin P80 high+++ expression, followed by patients with katanin P80 high++ expression and then those with katanin P80 high + expression and katanin P80 low expression.

Conclusion

Katanin P80 correlates with larger tumor size, LYN metastasis, and advanced TNM stage, and serves as a potential biomarker for predicting poor survival in NSCLC patients.

Second malignancy versus recurrence after complete resection of thymoma

Background Patients undergoing complete resection of thymoma occasionally develop a recurrence of thymoma; they are also at risk of developing a second malignancy. The objective of our study was to compare the incidence and mortality of a second malignancy versus a recurrence of thymoma during the postoperative follow-up period after complete resection of thymoma. Methods A retrospective chart review was performed on our prospectively maintained database to identify patients undergoing complete resection of thymoma at our institution between 1991 and 2016. The incidence and related mortality of a second malignancy or recurrence of thymoma were recorded. Results One hundred and sixty-four patients were identified. Follow-up ranged from 1 to 239 months (median 54 months). During follow-up, 12 patients had a recurrence of thymoma and 14 developed a second malignancy. The mean risk ratio of recurrence to second malignancy was 0.58 (95% confidence interval: 0.48-0.69) at 5 years, 0.58 (95% confidence interval: 0.49-0.68) at 10 years, and 0.51 (95% confidence interval: 0.43-0.60) at 15 years. The mean risk ratio of recurrence versus second malignancy for related death was 0.59 (95% confidence interval: 0.50-0.70) at 5 years and 0.61 (95% confidence interval: 0.52-0.72) at 10 years. Conclusion It appears that patients undergoing complete resection of thymoma have a higher incidence of a second malignancy and a greater related mortality rate than a recurrence of thymoma. A multiinstitutional database is required to more rigorously evaluate both risks and to confirm our results.

Playing the odds: lung cancer surveillance after curative surgery

PURPOSE OF REVIEW

After 'curative' resection, many patients are still at risk for further lung cancer, either as a recurrence or a new metachronous primary. In theory, close follow-up should improve survival by catching relapse early - but in reality, many experts feel that surveillance for recurrence is of uncertain value. In this article, we explore the reasons behind the controversy, what the current guidelines recommend, and what future solutions are in development that may ultimately resolve this debate.

RECENT FINDINGS

Although postoperative surveillance for a new lung cancer may impart a survival advantage, this benefit does not appear to extend to the phenomenon of recurrence. Nevertheless, close radiographic follow-up after curative resection is still recommended by most professional societies, with more frequent scanning in the first 2 years, and then annual screening thereafter. Given the radiation risk, however, low-dose and minimal-dose computed tomography options are under investigation, as well as timing scans around expected peaks of recurrence rather than a set schedule.

SUMMARY

Applying the same surveillance algorithm to all lung cancer patients after curative resection may not be cost-effective or reasonable, especially if there is no demonstrable mortality benefit. Therefore, future research should focus on finding safer nonradiographic screening options, such as blood or breath biomarkers, or developing nomograms for predicting which patients will relapse and require closer follow-up. Ultimately, however, better tools for surveillance may be moot until we develop better treatment options for lung cancer recurrence.

Pattern of Imaging after Lung Cancer Resection. 1992-2005

RATIONALE

Imaging intensity after lung cancer resection performed with curative intent is unknown.

OBJECTIVES

To describe the pattern and trends in the use of computed tomography (CT) and positron emission tomography (PET) scans in patients after resection of early-stage lung cancer.

METHODS

Retrospective analysis of the linked Surveillance, Epidemiology and End Results (SEER)-Medicare database. Subjects included 8,621 Medicare beneficiaries (age, ≥66 yr) who underwent lung cancer resection with curative intent between 1992 and 2005. A surveillance CT or PET examination was defined as CT or PET imaging performed in an outpatient setting on patients who did not undergo chest radiography in the preceding 30 days.

MEASUREMENTS AND MAIN RESULTS

Overall, imaging use was higher within the first 2 years versus Years 3-5 after surgical resection. Use of surveillance CT scans increased sharply from 13.7 to 57.3% of those diagnosed in 1996-1997 and 2004-2005, respectively. PET scan use increased threefold, from 6.2% in 2000-2001 to 19.6% in 2004-2005. In multivariable analyses, we observed a 32% increase in the odds of undergoing surveillance CT or PET imaging for every year of diagnosis between 1998 and 2005. There was no substantial decline in the odds of having a surveillance CT or PET scan during each successive follow-up period, suggesting no change in the intensity of surveillance over the first 5 years after surgical resection. The proportion of surveillance CT imaging performed at freestanding imaging centers increased from 18.0% in 1998-1999 to 30.6% in 2004-2005.

CONCLUSIONS

The use of CT and PET imaging for surveillance after curative-intent surgical resection of early-stage lung cancer increased sharply in the United States between 1997-1998 and 2005. In the absence of evidence demonstrating favorable outcomes, this practice was likely driven by prevailing expert opinion embedded in clinical practice guidelines made available during that time. Research is clearly needed to determine the role and optimal approach to surveillance thoracic imaging after surgical resection of lung cancer.

Prediction of distant recurrence in resected stage I and II lung adenocarcinoma

OBJECTIVES

Optimal procedures for adjuvant treatment and post-surgical surveillance of resected non-small-cell lung cancer remain under discussion. Pathological features are the main determinant of follow-up therapy but have limited ability to identify patients at risk of recurrence. Increasingly, molecular markers are incorporated into clinical decision-making, including measures of tumor growth. The CCP score is a quantitative, molecular measure of proliferation derived from the RNA expression of 31 cell cycle genes and a component of the molecular prognostic score (mPS). The mPS score is a linear combination of CCP score and pathological stage. CCP score and mPS are independent predictors of survival in resected lung adenocarcinoma.

MATERIALS AND METHODS

CCP scores were determined by RT-qPCR for 318 patients diagnosed with stage I-II lung adenocarcinoma. Association of mPS and CCP score with distant recurrence and lung-cancer specific survival was assessed in Cox proportional hazards regression models adjusted for age, gender, tumor size, pathological stage and pleural invasion. Distant recurrence-free survival and lung-cancer specific survival by mPS risk group were calculated by Kaplan-Meier survival analysis.

RESULTS

CCP scores were obtained for 205 stage I and 84 stage II patients. CCP score and mPS were independent markers of distant recurrence (CCP: HR 1.62, 95%CI 1.15-2.29, p=0.0055; mPS: HR 2.22, 95%CI 1.11-4.44, p=0.023). Patients with low mPS tumors were at significantly reduced risk of distant recurrence (log-rank p=4.2×10^-5). Among stage I patients, stratification by mPS identified a patient group with increased risk of distant recurrence (36%, 95%CI 28-46%, log-rank p=0.0011) CONCLUSIONS: The molecular prognostic score stratifies early-stage, resected lung cancer patients for risk of distant recurrence and could be useful to inform treatment and surveillance decisions.

Survival Prediction Model Using Clinico-Pathologic Characteristics for Nonsmall Cell Lung Cancer Patients After Curative Resection

The current TNM staging system did not provide disease relapse information. The aim of study was try to establish a predictive survival model for disease and overall survival in nonsmall cell lung cancer patients who presented as resectable disease and to develop a reference for follow-up imaging tool selection.From January 2005 to December 2011, 442 patients who initially presented as resectable disease (stages I-IIIa) and received anatomic resection and mediastinal lymph node dissection were included in the study.Medical charts were thoroughly reviewed and clinico-pathologic factors were collected and analyzed.Visceral pleural invasion, tumor size >5 cm, and postoperative adjuvant therapy were identified as risk factors for poorer disease-free survival. The 5-year disease-free survival from score 0 to 3 was 68.7%, 46.6%, 31.9%, and 26.1%, respectively. The disease relapse percentage for scores 0 to 3 were 26.49%, 50.61%, 65.05%, and 73.81%, respectively. For analysis of overall survival, age >60 years, tumor size >3 cm, and total metastatic lymph node ratio >0.05 were correlated to worse overall survival. Because greater age may be correlated with poor general condition, we re-scored risk factors that correlated to disease severity that ranging from 0 to 2. The 5-year overall survival range from score 0 to 2 was 56.3%, 43.1%, and 13.1%, respectively.Poor prognostic factors correlated to disease-free survival were tumor size >5 cm, visceral pleural invasion, and patients needing to receive postoperative adjuvant therapy. Disease-free survival of resectable nonsmall cell lung cancer patients and disease relapse can be stratified by these 3 factors. Chest tomography may be recommended for patients with 1 or more poor disease-free survival risk factors.

Analytical and Clinical Validation of a Digital Sequencing Panel for Quantitative, Highly Accurate Evaluation of Cell-Free Circulating Tumor DNA

Next-generation sequencing of cell-free circulating solid tumor DNA addresses two challenges in contemporary cancer care. First this method of massively parallel and deep sequencing enables assessment of a comprehensive panel of genomic targets from a single sample, and second, it obviates the need for repeat invasive tissue biopsies. Digital Sequencing^TM is a novel method for high-quality sequencing of circulating tumor DNA simultaneously across a comprehensive panel of over 50 cancer-related genes with a simple blood test. Here we report the analytic and clinical validation of the gene panel. Analytic sensitivity down to 0.1% mutant allele fraction is demonstrated via serial dilution studies of known samples. Near-perfect analytic specificity (> 99.9999%) enables complete coverage of many genes without the false positives typically seen with traditional sequencing assays at mutant allele frequencies or fractions below 5%. We compared digital sequencing of plasma-derived cell-free DNA to tissue-based sequencing on 165 consecutive matched samples from five outside centers in patients with stage III-IV solid tumor cancers. Clinical sensitivity of plasma-derived NGS was 85.0%, comparable to 80.7% sensitivity for tissue. The assay success rate on 1,000 consecutive samples in clinical practice was 99.8%. Digital sequencing of plasma-derived DNA is indicated in advanced cancer patients to prevent repeated invasive biopsies when the initial biopsy is inadequate, unobtainable for genomic testing, or uninformative, or when the patient’s cancer has progressed despite treatment. Its clinical utility is derived from reduction in the costs, complications and delays associated with invasive tissue biopsies for genomic testing.

Stereotactic body radiation therapy for a new lung cancer arising after pneumonectomy: dosimetric evaluation and pulmonary toxicity

OBJECTIVE

To evaluate the tolerance of stereotactic body radiation therapy (SBRT) for the treatment of secondary lung tumours in patients who underwent previous pneumonectomy.

METHODS

12 patients were retrospectively analysed. The median maximum tumour diameter was 2.1 cm (1-4.5 cm). The median planning target volume was 20.7 cm(3) (2.4-101.2 cm(3)). Five patients were treated with a single fraction of 26 Gy and seven patients with fractionated schemes (3 × 10 Gy, 4 × 10 Gy, 4 × 12 Gy). Lung toxicity, correlated with volume (V) of lung receiving >5, >10 and >20 Gy, local control and survival rate were assessed. Median follow-up was 28 months.

RESULTS

None of the patients experienced pulmonary toxicity > grade 2 at the median dosimetric lung parameters of V5, V10 and V20 of 23.1% (range 10.7-56.7%), 7.3% (2.2-27.2%) and 2.7% (0.7-10.9%), respectively. No patients required oxygen or had deterioration of the performance status during follow-up if not as a result of clinical progression of disease. The local control probability at 2 years was 64.5%, and the overall survival at 2 years was 80%.

CONCLUSION

SBRT appears to be a safe and effective modality for treating patients with a second lung tumour after pneumonectomy.

ADVANCES IN KNOWLEDGE

Our results and similar literature results show that when keeping V5, V10 V20 <50%, <20% and <7%, respectively, the risk of significant lung toxicity is acceptable. Our experience also shows that biologically effective dose 10 >100 Gy, necessary for high local control rate, can be reached while complying with the dose constraints for most patients.

Imaging surveillance and survival for surgically resected non-small-cell lung cancer

INTRODUCTION

The importance of imaging surveillance after treatment for lung cancer is not well characterized. We examined the association between initial guideline recommended imaging surveillance and survival among early-stage resected non-small-cell lung cancer (NSCLC) patients.

METHODS

A retrospective study was conducted using Surveillance, Epidemiology, and End Results-Medicare data (1995-2010). Surgically resected patients, with stage I and II NSCLC, were categorized by imaging received during the initial surveillance period (4-8 mo) after surgery. Primary outcome was overall survival. Secondary treatment interventions were examined as intermediary outcomes.

RESULTS

Most (88%) patients had at least one outpatient clinic visit, and 24% received an initial computerized tomography (CT) during the first surveillance period. Five-year survival by initial surveillance imaging was 61% for CT, 58% for chest radiography, and 60% for no imaging. After adjustment, initial CT was not associated with improved overall survival (hazard ratio [HR], 1.04; 95% confidence interval [CI] 0.96-1.14). On subgroup analysis, restricted to patients with demonstrated initial postoperative follow-up, CT was associated with a lower overall risk of death for stage I patients (HR, 0.85; 95% CI, 0.74-0.98), but not for stage II (HR, 1.01; 95% CI, 0.71-1.42). There was no significant difference in rates of secondary interventions predicted by type of initial imaging surveillance.

CONCLUSIONS

Initial surveillance CT is not associated with improved overall or lung cancer-specific survival among early-stage NSCLC patients undergoing surgical resection. Stage I patients with early follow-up may represent a subpopulation that benefits from initial surveillance although this may be influenced by healthy patient selection bias.

Is computed tomography follow-up of patients after lobectomy for non-small cell lung cancer of benefit in terms of survival?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was whether following up patients after lobectomy for non-small cell lung cancer (NSCLC) with computed tomography (CT) scanning is of benefit in terms of survival. Altogether, 448 papers were found using the reported search, of which five represented the best evidence to answer the clinical question and three provided supporting evidence. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. There is no general consensus in the literature. From the limited number of papers that address the effect of CT follow-up on survival following surgery for NSCLC, three showed that CT scanning may improve the survival of patients by detecting local and distant recurrences at an earlier stage when the patient is asymptomatic. One paper showed that detection by the use of low-dose CT or simultaneous chest CT plus positron emission tomography-CT led to a longer duration of survival compared with detection by clinical suspicion (2.1 ± 0.3 vs 3.6 ± 0.2 years, p = 0.002). However, two papers broadly showed that follow-up with CT does not improve survival outcomes regardless of the site of recurrence. One such study showed that there was no clinically significant difference in survival whether patients were followed up using a strict CT protocol compared with a symptom-based follow-up (median survival after recurrence: strict 7.9 months, symptom-based 6.6 months, p = 0.219). The remaining papers supported the use of CT as a screening tool for recurrence but did not comment directly on survival. Owing to the limited and contradictory evidence, there is a need for an randomized controlled trial to assess the survival outcomes of patients followed up with a CT screening protocol vs a symptom-based follow-up.

Therapeutic implications of molecular imaging with PET in the combined modality treatment of lung cancer

Molecular imaging with PET, and certainly integrated PET-CT, combining functional and anatomical imaging, has many potential advantages over anatomical imaging alone in the combined modality treatment of lung cancer. The aim of the current article is to review the available evidence regarding PET with FDG and other tracers in the combined modality treatment of locally advanced lung cancer. The following topics are addressed: tumor volume definition, outcome prediction and the added value of PET after therapy, and finally its clinical implications and future perspectives. The additional value of FDG-PET in defining the primary tumor volume has been established, mainly in regions with atelectasis or post-treatment effects. Selective nodal irradiation (SNI) of FDG-PET positive nodal stations is the preferred treatment in NSCLC, being safe and leading to decreased normal tissue exposure, providing opportunities for dose escalation. First results in SCLC show similar results. FDG-uptake on the pre-treatment PET scan is of prognostic value. Data on the value of pre-treatment FDG-uptake to predict response to combined modality treatment are conflicting, but the limited data regarding early metabolic response during treatment do show predictive value. The FDG response after radical treatment is of prognostic significance. FDG-PET in the follow-up has potential benefit in NSCLC, while data in SCLC are lacking. Radiotherapy boosting of radioresistant areas identified with FDG-PET is subject of current research. Tracers other than (18)FDG are promising for treatment response assessment and the visualization of intra-tumor heterogeneity, but more research is needed before they can be clinically implemented.

Annual abdominal ultrasonographic examination after curative NSCLC resection

BACKGROUND

There is no established follow-up strategy in non-small cell lung cancer patients after complete resection. Follow-up regimens are different between nations, institutions, and surgeons. We tried to investigate the role of annual abdominal ultrasonographic examination in completely resected NSCLC patients.

METHODS

We reviewed 265 consecutive patients who had their NSCLC completely resected at our institution from July 1992 through December 2000 and were followed by a single surgeon. Annual abdominal ultrasonography was performed until 5 years after resection. Chest CT and abdominal CT are not included in our routine follow-up program. Instead, we used ultrasonography to survey the abdomen because abdominal ultrasonography is less costly than abdominal CT, is non-invasive, and does not require contrast media.

RESULTS

A total of 892 ultrasonographic examinations were performed. Fifty-nine (22.3%) patients developed recurrence. Annual ultrasonography detected lesions suspicious of recurrence in 15 patients. Further work-up diagnosed NSCLC recurrence in 2 (0.8%) patients (multiple liver metastases in one and right adrenal metastasis in one). The two patients soon developed disseminated disease and died in less than a year.

CONCLUSIONS

Annual abdominal ultrasonography in the follow-up protocol for completely resected NSCLC patients was not beneficial. Our experience in the present study may be used as valid evidence to exclude abdominal ultrasonography from future trials comparing follow-up regimens after complete resection of NSCLC. A better follow-up strategy needs to be established.

Does intensive follow-up alter outcome in patients with advanced lung cancer?

BACKGROUND

Despite aggressive multimodality treatment, 5-year survival of stage III non-small cell lung cancer (NSCLC) remains <30%. To detect relapse, progression, or development of a second primary cancer early, many clinicians perform follow-up scans. To assess the impact of routine scanning, we compared clinical trial patients who had study-mandated scans with those treated off-study who had less intensive radiologic follow-up.

METHODS

The hospital cancer registry and trials databases were searched for patients with locally advanced NSCLC who had undergone multimodality treatment with curative intent. Baseline demographics were collected as well as frequency and results of clinical and radiologic follow-up.

RESULTS

Forty trial patients and 35 nontrial control patients were identified. Trial patients underwent significantly more imaging, particularly in the first 2 years (2.9 versus 2.0 body scans per year, p = 0.0016; 1.1 versus 0.4 brain scans per year, p < 0.001) but did not have more frequent follow-up visits. Forty-five cancers were detected (41 relapses, four metachronous primary tumors) in 44 (59%) patients. Of these, 28 (64%) sought medical attention that led to detection before a scheduled appointment or procedure. There was no significant difference in time to relapse or second primary in trial and nontrial patients (p = 0.80). Twenty-three patients had localized relapse, but only 15 could be treated with curative intent. Despite the trial group demonstrating a higher number of asymptomatic cancers and being offered potentially curative therapy more frequently, there was no significant difference in survival between trial and nontrial patients.

CONCLUSION

In patients with locally advanced NSCLC, frequent cross-sectional imaging does not alter survival after combined modality therapy.

Accuracy of Surveillance Computed Tomography in Detecting Recurrent or New Primary Lung Cancer in Patients With Completely Resected Lung Cancer

BACKGROUND

To determine the eventual outcome of abnormalities detected on surveillance computed tomography (CT) in patients with previously resected nonsmall-cell lung cancer (NSCLC), and to assess the accuracy of CT when used by the thoracic surgeon, and to determine the characteristics of abnormalities on CT that correlate with the development of recurrent NSCLC.

METHODS

A cohort of patients who had abnormal postoperative CT scans of the chest and upper abdomen in 2002 were followed up into 2005. Abnormalities consisted of pulmonary nodules, pleural effusions, or adenopathy. Data collected included recurrence patterns, the availability of previous scans for comparison, the interval between initial resection and the abnormal CT, nodule size, growth, and multiplicity, as well as progression of pleural effusions or adenopathy.

RESULTS

In all, 105 scans in 92 patients were read as abnormal in 2002 by the radiologist. After further investigation or follow-up, or both, for a mean of 3.2 years, 78% of patients who had recurrent NSCLC had their site of first recurrence inside the chest. The negative predictive value of CT when used by the thoracic surgeon was 99%; however, the positive predictive value was only 53%. Abnormalities that correlated with the diagnosis of recurrent cancer included pulmonary nodules that either grew or were larger than 1 cm and pleural effusions that developed after the first postoperative year.

CONCLUSIONS

Intrathoracic recurrent NSCLC was rarely missed by the surgeon utilizing surveillance CT, but a significant number of negative investigations were generated by its use. Characteristics of abnormal surveillance CT findings exist that correlate with the presence of malignancy.

Cost Effectiveness of Chest Computed Tomography After Lung Cancer Resection: A Decision Analysis Model

BACKGROUND

Postoperative surveillance with chest computed tomography (CT) is often performed in patients who have undergone resection of non-small cell lung cancer (NSCLC), despite lack of supporting data. This study involves the creation of a decision analysis model to predict the cost effectiveness of postoperative surveillance CT.

METHODS

A decision analysis model was created in which a hypothetical cohort of patients underwent annual chest CT after resection of a stage IA NSCLC. The incidence of second primary lung cancer (SPLC), sensitivity and specificity of CT, as well as survival after resection of initial primary and SPLC were derived from published literature. The cost of CT and other procedures prompted by a positive finding on CT was calculated from Medicare reimbursement schedules. Cost effectiveness was defined as a cost of less than 60,000 dollars per quality-adjusted life-year gained in the cohort under surveillance compared with controls under no surveillance.

RESULTS

In the initial (base case) analysis, the cost of surveillance CT was 47,676 dollars per quality-adjusted life-year gained, implying cost effectiveness. However, factors that rendered surveillance CT cost ineffective were (1) age at entry into the surveillance program greater than 65 years, (2) cost of CT greater than 700 dollars, (3) incidence of SPLC of less than 1.6% per patient per year of follow-up, and (4) a false positive rate of surveillance CT greater than 14%.

CONCLUSIONS

Surveillance with postoperative CT may be a cost-effective intervention to detect SPLC in selected patients with previously resected stage IA NSCLC.