Preoperative assessment for lung cancer surgery

Head-to-Head Prospective Comparison of Quantitative Lung Scintigraphy and Segment Counting in Predicting Pulmonary Function in Lung Cancer Patients Undergoing Video-Assisted Thoracoscopic Lobectomy

Prediction of postoperative pulmonary function in lung cancer patients before tumor resection is essential for patient selection for surgery and is conventionally done with a nonimaging segment counting method (SC) or 2-dimensional planar lung perfusion scintigraphy (PS). The purpose of this study was to compare quantitative analysis of PS to SPECT/CT and to estimate the accuracy of SC, PS, and SPECT/CT in predicting postoperative pulmonary function in patients undergoing lobectomy. Methods: Seventy-five non-small cell lung cancer patients planned for lobectomy were prospectively enrolled (68% male; average age, 68.1 ± 8 y). All patients completed tests of preoperative forced expiratory volume capacity in 1 s (FEV1) and diffusing capacity of the lungs for carbon monoxide (DLCO), as well as ^99mTc-macroaggregated albumin PS and SPECT/CT quantification. A subgroup of 60 patients underwent video-assisted thoracoscopic lobectomy and measurement of postoperative FEV1 and DLCO. Relative uptake of the lung lobes estimated by PS and SPECT/CT was compared. Predicted postoperative FEV1 and DLCO were derived from SC, PS, and SPECT/CT. Prediction results were compared between the different methods and the true postoperative measurements in patients who underwent lobectomy. Results: Relative uptake measurements differed significantly between PS and SPECT/CT in right lung lobes, with a mean difference of -8.2 ± 3.8, 18.0 ± 5.0, and -11.5 ± 6.1 for right upper, middle, and lower lobes, respectively (P < 0.001). The differences between the methods in the left lung lobes were minor, with a mean difference of -0.4 ± 4.4 (P > 0.05) and -2.0 ± 4.0 (P < 0.001) for left upper and lower lobes, respectively. No significant difference and a strong correlation (R = 0.6-0.76, P < 0.001) were found between predicted postoperative lung function values according to SC, PS, SPECT/CT, and the actual postoperative FEV1 and DLCO. Conclusion: Although lobar quantification parameters differed significantly between PS and SPECT/CT, no significant differences were found between the predicted postoperative lung function results derived from these methods and the actual postoperative results. The additional time and effort of SPECT/CT quantification may not have an added value in patient selection for surgery. SPECT/CT may be advantageous in patients planned for right lobectomy, but further research is warranted.

Simple Anatomical Calculations Possibly As Accurate As Three-Dimensional Lobar Quantification with SPECT-CT in Predicting Lung Function after Pulmonary Resection

The estimation of predicted postoperative (PPO) lung function is important in lung resection candidates. We utilized simple anatomical calculations and single-photon emission computed tomography combined with computed tomography (SPECT-CT) to calculate PPO in 24 consecutive patients with impaired pulmonary function who underwent lung resection. PPO values calculated by anatomical calculations and three-dimensional lobar SPECT-CT quantification both correlated well with the postoperative forced expiratory volume in 1 s, with r = 0.825, p < 0.001 and r = 0.796, p < 0.001, respectively. Both techniques fared well at predicting postoperative lung function, but our observations unexpectedly suggested that simple anatomical calculations might be equivalent to three-dimensional SPECT-CT lobar quantification.

A comparison of the functional parameters of operability in patients with post-inflammatory lung disease and those with lung cancer requiring lung resection

Background

It is a common, yet unproven, belief that patients with post-inflammatory lung disease have a better functional reserve than patients with lung cancer when compared with their respective functional parameters of operability – forced expiratory volume in one second (FEV₁), maximum oxygen uptake in litres per minute (VO₂ max) and the diffusion capacity for carbon monoxide (DLCO).

Objectives

The aim of this study was to compare a group of patients with lung cancer with a group with post-inflammatory lung disease according to their respective functional parameters of operability. We also aimed to investigate any associations of FEV₁ and/or DLCO with VO₂ max within the two groups.

Methods

We retrospectively included 100 adult patients considered for lung resection. All patients were worked up using a validated algorithm and were then sub-analysed according to their parameters of functional operability.

Results

Two-thirds of patients had post-inflammatory lung diseases whilst the rest had lung cancer. The majority of the patients in the lung cancer group had coexistent chronic obstructive pulmonary disease (COPD) (n=18). Most (n=47) of the patients in the post-inflammatory group were diagnosed with a form of pulmonary TB (active or previous). Among the two groups, the lung cancer group had a higher median %FEV₁ value (62.0%; interquartile range (IQR) 51.0 - 76.0) compared with the post-inflammatory group (52%; IQR 42.0 - 63.0; p=0.01). There was no difference for the %DLCO and %VO₂ max values. The lung cancer group also had higher predicted postoperative (ppo) values for %FEV₁ (41.0%; IQR 31.0 - 58.0 v. 34.0%; IQR 23.0 - 46.0; p=0.03, respectively) and %VO₂ max (58.0%; IQR 44.0 - 68.0 v. 46.0%; IQR 35.0 - 60.0; p=0.02). There was no difference in the %DLCO ppo values between the groups.

Conclusion

Patients with lung cancer had higher percentage values for FEV₁ and ppo parameters for %FEV₁ and %VO₂ max compared with those who had post-inflammatory lung disease. Our findings suggest that lung cancer patients have a better functional reserve.

Functional evaluation before lung resection

Lung cancer is the leading cause of cancer-related death worldwide, and lung resection remains the only curative approach. In the Western world, lung cancer is one of the main indications for lung resection, despite only 15% to 25% of all lung cancers being operable at the time of presentation. In most cases of operable lung cancer, a substantial part of functional lung tissue has to be resected, leading to a permanent loss of pulmonary function. Resection in patients with insufficient pulmonary reserves can result in permanent respiratory disability. This article reviews the current standards of preoperative assessment.

Evaluation and treatment of high-risk patients with early-stage lung cancer

Standard therapy for early-stage non-small cell lung cancer is lobectomy for patients who are able to tolerate such surgery. However, the risk of postoperative morbidity is not trivial, with a 30% to 40% incidence of postoperative complications and a 1% to 5% incidence of operative mortality. Some patients, though technically resectable, refuse surgery or are considered medically inoperable because of insufficient respiratory reserve, cardiovascular disease, or general frailty. This group is considered either "high risk" or "medically inoperable."

Radiologic features, staging, and operability of primary lung cancer in the Western cape, South Africa: a 1-year retrospective study

INTRODUCTION

This retrospective study was performed to evaluate the radiologic features, staging, and resectability of lung cancer at the time of presentation in patients from the Western Cape of South Africa.

METHOD

We included all patients with primary lung cancer reviewed during a 12-month period (January 2009 to December 2009) who had a definite tissue diagnosis and whose staging computed tomography scans were available. Fifteen radiologic parameters were assessed.

RESULTS

Data were complete in 204 patients. The proportion and median size of the various histologic subtypes were as follows: adenocarcinoma 53.9%, 53.4 mm; squamous cell 25.9%, 80.2 mm; small cell 14.2%, 80.8 mm; large cell 2.4%, 74.2 mm; bronchioloalveolar carcinoma 1.5%, 50.0 mm; and others 2%, 57.6 mm, respectively. The overall median size of tumor was 61.5 mm. Tumors were located centrally in 43.6%, peripherally in 46.6%, indeterminate in 9.8%, mediastinal in 11.3%, right lung in 53.4%, and in the left lung in 35.3%. Tuberculosis-related lung fibrosis was present in 16%, but only 5.4% patients had coexisting tumor and fibrosis at the same site. We observed no difference in the proportion of coexisting fibrosis between adenocarcinoma and squamous carcinoma. Only 16.2% of the patients were potential candidates for radical treatment, with an actual resection rate of 4.4%.

CONCLUSIONS

In the Western Cape, adenocarcinoma is the commonest histologic subtype of bronchogenic carcinoma. Most patients present with late-stage primary tumors, and the percentage of patients with potentially resectable cancer is much lower than in Europe.

Correlation of computed tomography densitometry and pathological grading of emphysema with the variation of respiratory function after lobectomy for lung cancer

The presence of emphysema may lead to an underestimation of postoperative respiratory function after lobectomy when evaluated by standard functional assessment. The aim of the study was to assess the correlation between computed tomography (CT) densitometry, pathological grading of emphysema and variation of pulmonary function after lobectomy for lung cancer. Forty-one patients entered the study. Respiratory function was assessed preoperatively and after a mean period of 4.04 months following surgery. Postoperative function remained unchanged or increased after surgery in nine patients (Group A). In the remaining 32 patients (Group B) postoperative function was reduced after surgery. Preoperative forced expiratory volume in 1 s (FEV(1))% was 68.5+/-13.1% in Group A and 91.7+/-21.0% in Group B. CT densitometry of the lobe to be resected was -877.8+/-57.6 HU in Group A and -827.5+/-64.4 HU in Group B. Pathological grading of emphysema of the resected lobe (range 0-10) was 4.1+/-2.2 in Group A and 3.1+/-1.2 in Group B. A significant correlation was observed (Spearman rank correlation) between the variation of FEV(1) and preoperative FEV(1) (P=0.003; r=-0.455), CT quantitative assessment (P=0.036; r=-0.430) and pathological grading (P=0.008; r=0.673). Patients with a higher degree of emphysema had a lower reduction of respiratory function after lobectomy and CT densitometry and pathological grading of emphysema correlated with the variation in respiratory function.

Diffusion lung capacity for carbon monoxide (DLCO) is an independent prognostic factor for long-term survival after curative lung resection for cancer

INTRODUCTION

We examined the early and late prognostic significance of DLCO and forced expiratory volume in 1 sec (FEV1) in patients who underwent surgical resection of lung cancer.

METHODS

From 1997 to 2004, 462 patients underwent successful complete resection of their lung cancer and had full pulmonary function testing including DLCO performed. Mean follow-up was over 5 years (64.8 months--range: 0-158 months).

RESULTS

Postoperative 90-day mortality was 2.6% (12/462). At last follow-up, of the remaining 450 patients, 182 patients were alive, 130 had died of cancer, and 138 have died of other causes and did not have recurrent cancer. Mean DLCO values were 69.4%, 66.8%, and 53.9%, respectively. Mean FEV1 values were 81.3%, 78.1%, and 71.5%, respectively. Mean DLCOs and FEV1s between patients who died of cancer versus other causes were significantly different (P < 0.0001 and P = 0.0157). When cause-specific survival was analyzed for both DLCO and FEV1 simultaneously, DLCO had a very significant effect on survival from other causes (HR 0.966, P < 0.0001) when adjusted for FEV1. However, when adjusted by DLCO, FEV1 had no significant effect. A DLCO <40% best predicted decreased survival from causes other than cancer within stage I lung cancers (stage IA HR 0.953, P < 0.0001; stage IB HR 0.968, P < 0.0001).

CONCLUSIONS

DLCO was found to be a significant prognostic factor for long-term survival after lung cancer surgery. This may serve as a surrogate for competing morbidities with declining values predicting a higher risk of late non-cancer-related death.

Preoperative evaluation for thoracic surgery

The goal of the preoperative evaluation for thoracic surgery is to assess and implement measures to decrease perioperative complications and prepare high-risk patients for surgery. Major respiratory complications, such as atelectasis, pneumonia, and respiratory failure, occur in 15% to 20% of patients and account for most of the 3% to 4% mortality rate. Development of pulmonary complications has been associated with higher postoperative mortality rates. Strategies aimed at preventing postoperative difficulties have the potential to reduce morbidity and mortality, decrease hospital stay, and improve resource use. One lung ventilation leads to a significant derangement of gas exchange, and hypoxemia can develop due to increased intrapulmonary shunting. Recent advances in anesthetic management, monitoring devices, improved lung isolation techniques, and improved critical care management have increased the number of patients who were previously considered inoperable. In addition, there is a growing tendency to offer surgery to patients with significant lung function impairment; hence a higher incidence of intraoperative gas-exchange abnormalities can be expected. The anesthesiologist must also consider the risks of denying or postponing a potentially curative operation in patients with lung cancer. Detailed consideration of the information provided by preoperative testing is essential to successful outcomes following thoracic surgery.

Stair climbing in the functional assessment of lung resection candidates

BACKGROUND

Algorithms for the pre-operative evaluation of lung resection candidates with impaired lung function invariably include maximum oxygen uptake (VO(2)MAX) as a critical parameter of functional reserves, with a VO(2)MAX >or=20 ml/kg/min generally considered sufficient for pneumonectomy. Stair climbing is a low-cost alternative to assess exercise capacity.

OBJECTIVES

As stair climbing is not standardised, we aimed to compare the altitude reached and the speed of ascent with VO(2)MAX measured by cycle ergometry.

METHODS

We prospectively enrolled 44 pulmonary resection candidates (mean age: 47.6 +/- 12.5 years) with an FEV(1) <80%. Patients were asked to climb as high and as fast as they could, to a maximum elevation of 20 m. The altitude reached and the average speed of ascent were compared to VO(2)MAX.

RESULTS

Forty-three patients reached a 20-metre elevation. Thirteen of them, as well as the patient who did not reach this height, had a VO(2)MAX <20 ml/kg/min. There was a linear correlation between speed of ascent and VO(2)MAX/kg (R(2) = 0.67), but not between altitude and VO(2)MAX/kg. All 24 patients with a speed >or=15 m/min had a VO(2)MAX >or=20 ml/kg/min. Thirty-nine of 40 patients with a speed >or=12 m/min had a VO(2)MAX >or=15 ml/kg/min.

CONCLUSIONS

The average speed of ascent during stair climbing was an accurate semiquantitative predictor of VO(2)MAX/kg, whereas altitude was not. We were able to identify potential cut-off values for lobectomy or pneumonectomy. Pending validation with clinical endpoints, stair climbing may replace formal exercise testing at much lower costs in a large proportion of lung resection candidates.

Physiologic evaluation of the patient with lung cancer being considered for resectional surgery: ACCP evidenced-based clinical practice guidelines (2nd edition)

BACKGROUND

This section of the guidelines is intended to provide an evidence-based approach to the preoperative physiologic assessment of a patient being considered for surgical resection of lung cancer.

METHODS

Current guidelines and medical literature applicable to this issue were identified by computerized search and evaluated using standardized methods. Recommendations were framed using the approach described by the Health and Science Policy Committee.

RESULTS

The preoperative physiologic assessment should begin with a cardiovascular evaluation and spirometry to measure the FEV(1). If diffuse parenchymal lung disease is evident on radiographic studies or if there is dyspnea on exertion that is clinically out of proportion to the FEV(1), the diffusing capacity of the lung for carbon monoxide (Dlco) should also be measured. In patients with either an FEV(1) or Dlco < 80% predicted, the likely postoperative pulmonary reserve should be estimated by either the perfusion scan method for pneumonectomy or the anatomic method, based on counting the number of segments to be removed, for lobectomy. An estimated postoperative FEV(1) or Dlco < 40% predicted indicates an increased risk for perioperative complications, including death, from a standard lung cancer resection (lobectomy or greater removal of lung tissue). Cardiopulmonary exercise testing (CPET) to measure maximal oxygen consumption (Vo(2)max) should be performed to further define the perioperative risk of surgery; a Vo(2)max of < 15 mL/kg/min indicates an increased risk of perioperative complications. Alternative types of exercise testing, such as stair climbing, the shuttle walk, and the 6-min walk, should be considered if CPET is not available. Although often not performed in a standardized manner, patients who cannot climb one flight of stairs are expected to have a Vo(2)max of < 10 mL/kg/min. Data on the shuttle walk and 6-min walk are limited, but patients who cannot complete 25 shuttles on two occasions will likely have a Vo(2)max of < 10 mL/kg/min. Desaturation during an exercise test has not clearly been associated with an increased risk for perioperative complications. Lung volume reduction surgery (LVRS) improves survival in selected patients with severe emphysema. Accumulating experience suggests that patients with extremely poor lung function who are deemed inoperable by conventional criteria might tolerate combined LVRS and curative-intent resection of lung cancer with an acceptable mortality rate and good postoperative outcomes. Combining LVRS and lung cancer resection should be considered in patients with a cancer in an area of upper lobe emphysema, an FEV(1) of > 20% predicted, and a Dlco of > 20% predicted.

CONCLUSIONS

A careful preoperative physiologic assessment will be useful to identify those patients who are at increased risk with standard lung cancer resection and to enable an informed decision by the patient about the appropriate therapeutic approach to treating their lung cancer. This preoperative risk assessment must be placed in the context that surgery for early-stage lung cancer is the most effective currently available treatment for this disease.

Usefulness of lung perfusion scintigraphy before lung cancer resection in patients with ventilatory obstruction

BACKGROUND

The study was conducted to evaluate the efficacy of preoperative lung perfusion scintigraphy performed by planar acquisition and single-photon emission computed tomography (SPECT) in predicting postoperative pulmonary function of patients with resectable lung cancer and obstructive ventilatory defect.

METHODS

The study enrolled 39 patients (mean age, 67 +/- 2.1 years). All patients underwent preoperative and postoperative pulmonary function tests. Cut-off values for postoperative forced expiratory volume in 1 second (FEV1) were 65% of the predicted value for pneumonectomy and 45% for lobectomy. A semiquantitative analysis of planar and SPECT lung perfusion scintigraphy images was performed preoperatively to estimate postoperative predicted FEV1 (FEV1ppo). Relationships between FEV1ppo and measured postoperative FEV1 were tested by the Pearson correlation and Bland Altman agreement tests.

RESULTS

Twenty-eight lobectomies and 11 pneumonectomies were performed. The FEV1ppo estimated by mean planar lung scintigraphy was 1.85 +/- 0.38 L, with a Pearson correlation coefficient to the measured FEV1 of 0.8632 (p < 0.001). The mean FEV1ppo estimated by SPECT was 1.78 +/- 0.31 L, with a Pearson coefficient to the measured FEV1 of 0.8527 (p < 0.001). Both values showed a more significant correlation with postoperative measured FEV1 after lobectomy (p < 0.001) than after pneumonectomy (p = 0.045). The Bland Altman test confirmed satisfactory agreement of FEV1ppo estimated by both planar lung scintigraphy and SPECT with FEV1 measured by spirometry.

CONCLUSIONS

Both planar lung scintigraphy and SPECT can accurately predict postoperative FEV1 and can therefore be considered reliable tools in establishing operability of patients with lung cancer and ventilatory obstruction.

Pulmonary dysfunction as a major cause of inoperability among patients with non-small-cell lung cancer

PURPOSE

We wanted to assess the prevalence of pulmonary dysfunction as the underlying reason for inoperability among patients with non-small-cell lung cancer (NSCLC) who were considered for surgical treatment at the time of diagnosis.

PATIENTS AND METHODS

This is a retrospective analysis of all patients with NSCLC referred to our pulmonary function laboratory for preoperative evaluation between January 2001 and November 2001. Pulmonary function testing consisted of measurement of spirometric indices (forced expiratory volume in 1 second [FEV1]), lung volumes and diffusing capacity for carbon monoxide, Xenon-133 quantitative ventilation and perfusion studies, and exercise testing when indicated. Patient demographics and clinical characteristics at the time of the evaluation were reviewed.

RESULTS

The group comprised 206 consecutive potential surgical candidates (mean age, 64.7 years +/- 10.1 years) with NSCLC. Nearly half (45.6%) of the patients had early-stage (I/II) disease, and the remainder had late-stage disease at the time of pulmonary evaluation. The average predicted FEV1 among all patients was 70.3% +/- 19.6% (range, 25%-123%). One hundred eight patients (52.4%) were deemed surgically inoperable after the preoperative assessment. Severe pulmonary function impairment was identified as the reason for surgical inoperability in more than one third of these patients (40 of 108).

CONCLUSION

A substantial number of patients with anatomically resectable NSCLC are deemed surgically ineligible based on poor lung function. Recognition of the magnitude of this problem is fundamental to the development of effective treatment options, which might include preoperative management strategies that could better prepare patients for surgery or, alternatively, aggressive nonsurgical approaches.