Helical Computed Tomography Inaccuracy in the Detection of Pulmonary Metastases: Can It Be Improved?

Osteosarcoma immune prognostic index can indicate the nature of indeterminate pulmonary nodules and predict the metachronous metastasis in osteosarcoma patients

Purpose

The relationship between indeterminate pulmonary nodules (IPNs) and metastasis is difficult to determine. We expect to explore a predictive model that can assist in indicating the nature of IPNs, as well as predicting the probability of metachronous metastasis in osteosarcoma patients.

Patients and methods

We conducted a retrospective study including 184 osteosarcoma patients at West China Hospital from January 2016 to January 2021. Hematological markers and clinical features of osteosarcoma patients were collected and analyzed.

Results

In this study, we constructed an osteosarcoma immune prognostic index (OIPI) based on the lung immune prognostic index (LIPI). Compared to other hematological markers and clinical features, OIPI had a better ability to predict metastasis. OIPI divided 184 patients into four groups, with the no-OIPI group (34 patients), the light-OIPI group (35 patients), the moderate-OIPI group (75 patients), and the severe-OIPI group (40 patients) (P < 0.0001). Subgroup analysis showed that the OIPI could have a stable predictive effect in both the no-nodule group and the IPN group. Spearman’s rank correlation test and Kruskal–Wallis test demonstrated that the OIPI was related to metastatic site and metastatic time, respectively. In addition, patients with IPNs in high-OIPI (moderate and severe) groups were more likely to develop metastasis than those in low-OIPI (none and light) groups. Furthermore, the combination of OIPI with IPNs can more accurately identify patients with metastasis, in which the high-OIPI group had a higher metastasis rate, and the severe-OIPI group tended to develop metastasis earlier than the no-OIPI group. Finally, we constructed an OIPI-based nomogram to predict 3- and 5-year metastasis rates. This nomogram could bring net benefits for more patients according to the decision curve analysis and clinical impact curve.

Conclusion

This study is the first to assist chest CT in diagnosing the nature of IPNs in osteosarcoma based on hematological markers. Our findings suggested that the OIPI was superior to other hematological markers and that OIPI can act as an auxiliary tool to determine the malignant transformation tendency of IPNs. The combination of OIPI with IPNs can further improve the metastatic predictive ability in osteosarcoma patients.

Necessity of Thin Section CT in the Detection of Pulmonary Metastases: Comparison between 5 mm and 1 mm Sections of CT

Background: The aim of this study was to evaluate the difference in the ability of 1-mm and 5-mm section Computed Tomography(CT) to detect pulmonary metastases in patients with pulmonary metastases.

Methods: We retrospectively analyzed the CT findings of 106 patients with pulmonary metastases due to malignancies treated at Toho University Omori Medical Center between 2013 and 2020.

Results: Cases with only one nodule evaluated by 5-mm section CT had significantly lower discordance with 1-mm section CT than cases with two or more nodules detected by a 5 mm section (p = 0.0161). After reference to a 1 mm section, cases with only one nodule reevaluated by 5-mm section CT had significantly lower discordance than cases with two or more nodules reevaluated using 5-mm section CT. In cases with only one nodule, reevaluation using a 5 mm section was consistent with evaluation using a 1 mm section. However, this was not observed in cases with two or more nodules, with a significant difference between one nodule and two or more nodules.

Conclusions: If there are two or more nodules observed in 5-mm section CT it may be necessary to reevaluate using 1-mm section CT to determine the exact number of pulmonary metastases.

Utility of fast non-local means (FNLM) filter for detection of pulmonary nodules in chest CT for pediatric patient

PURPOSE

This study was aimed to evaluate the utility based on imaging quality of the fast non-local means (FNLM) filter in diagnosing lung nodules in pediatric chest computed tomography (CT).

METHODS

We retrospectively reviewed the chest CT reconstructed with both filtered back projection (FBP) and iterative reconstruction (IR) in pediatric patients with metastatic lung nodules. After applying FNLM filter with six h values (0.0001, 0.001, 0.01, 0.1, 1, and 10) to the FBP images, eight sets of images including FBP, IR, and FNLM were analyzed. The image quality of the lung nodules was evaluated objectively for coefficient of variation (COV), contrast to noise ratio (CNR), and point spread function (PSF), and subjectively for noise, sharpness, artifacts, and diagnostic acceptability.

RESULTS

The COV was lowest in IR images and decreased according to increasing h values and highest with FBP images (P < 0.001). The CNR was highest with IR images, increased according to increasing h values and lowest with FBP images (P < 0.001). The PSF was lower only in FNLM filter with h value of 0.0001 or 0.001 than in IR images (P < 0.001). In subjective analysis, only images of FNLM filter with h value of 0.0001 or 0.001 rarely showed unacceptable quality and had comparable results with IR images. There were less artifacts in FNLM images with h value of 0.0001 compared with IR images (p < 0.001).

CONCLUSION

FNLM filter with h values of 0.0001 allows comparable image quality with less artifacts compared with IR in diagnosing metastatic lung nodules in pediatric chest CT.

Clinical significance of indeterminate pulmonary nodules on the survival of 364 patients with nonmetastatic, high-grade, localized osteosarcoma: A 12-year retrospective cohort study

BACKGROUND AND OBJECTIVES

We investigated the clinical significance of indeterminate pulmonary nodules (IPNs) in patients diagnosed with nonmetastatic, high-grade localized osteosarcoma.

METHODS

We retrospectively analyzed the clinical data of 364 patients with nonmetastatic, high-grade localized osteosarcoma. Based on pulmonary computed tomography findings at presentation, the patients were categorized into the no-nodules and the IPNs group and were further categorized into subgroups based on age (<18 and ≥18 years). We performed an intergroup comparison of event-free survival (EFS) and overall survival (OS).

RESULTS

At presentation, 276 (75.8%) patients showed no nodules, and 88 (24.2%) patients showed IPNs. The EFS and OS were similar between adults with IPNs (n = 54 [30.5%]) and without nodules (n = 123 [69.5%]) (p = .200 and p = .609, respectively). No significant intergroup difference in OS was observed in pediatric patients (p = .093). However, pediatric patients with IPNs (n = 34 [18.2%]) had poorer EFS than those without nodules (n = 153 [81.8%]) (p = .016). Multivariate analyses confirmed that IPNs were independently associated with poorer EFS in pediatric patients (hazard ratio 1.788, 95% confidence interval 1.092-2.926, p = .021).

CONCLUSIONS

This study showed that IPNs at presentation did not affect the survival of adults with nonmetastatic, high-grade localized osteosarcoma but were associated with poorer EFS in pediatric patients.

Past, present, and future perspectives of pulmonary metastasectomy for patients with advanced colorectal cancer

Over a half-century has passed since Thomford et al. proposed the selection criteria for pulmonary metastasectomy, and several prognostic factors have been identified. Although screening modalities and operations have changed dramatically, the important concepts of the selection criteria remain unchanged. Recent improvements in the survival outcomes of colorectal cancer patients undergoing pulmonary metastasectomy may be the result of strict adherence to the selection criteria for oligometastatic lung tumors, which can mimic local disease. Pulmonary metastasectomy has become an important option for selected patients with oligometastasis, based mainly on a large amount of retrospective data, but its effect on survival remains unclear. Curable pulmonary metastasis might be regarded as a "semi-local disease" under the spontaneous control of an acquired alteration in host immune status. The current practice of pulmonary metastasectomy for colorectal cancer focuses on selecting the most appropriate operation for selected patients. However, in the rapidly evolving era of immunotherapy, treatment-naïve patients for whom surgery is not suitable might be pre-conditioned by immunotherapy so that they may be considered for salvage surgery.

Improving Quality of Chest Computed Tomography for Evaluation of Pediatric Malignancies

Introduction

Atelectasis is a problem in sedated pediatric patients undergoing cross-sectional imaging, impairing the ability to accurately interpret chest computed tomography (CT) imaging for the presence of malignancy, often leading to additional maneuvers and/or repeat imaging with additional radiation exposure.

Methods

A quality improvement team established a best-practice protocol to improve the quality of thoracic CT imaging in young patients with suspected primary or metastatic pulmonary malignancy. The specific aim was to increase the percentage of chest CT scans obtained for the evaluation of pulmonary nodules with acceptable atelectasis scores (0-1) in patients aged 0-5 years with malignancy, from a baseline of 45% to a goal of 75%.

Results

A retrospective cohort consisted of 94 patients undergoing chest CT between February 2014 and January 2015 before protocol implementation. The prospective cohort included 195 patients imaged between February 2015 and April 2018. The baseline percentage of CT scans that were scored 0 or 1 on the atelectasis scale was 44.7%, which improved to 75% with protocol implementation. The mean atelectasis score improved from 1.79 (±0.14) to 0.7 (±0.09). Sedation incidence decreased substantially from 73.2% to 26.5% during the study period.

Conclusions

Using quality improvement methodology including standardization of care, the percentage of children with atelectasis scores of 0-1 undergoing cross-sectional thoracic imaging improved from 45% to 75%. Also, eliminating the need for sedation in these patients has further improved image quality, potentially allowing for optimal detection of smaller nodules, and minimizing morbidity.

Computer-assisted detection of metastatic lung tumors on computed tomography

BACKGROUND

This retrospective study examined the performance of computer-assisted detection in the identification of pulmonary metastases.

METHODS

Fifty-five patients (41.8% male) who underwent surgery for metastatic lung tumors in our hospital from 2005 to 2012 were included. Computer-assisted detection software configured to display the top five nodule candidates according to likelihood was applied as the first reader for the preoperative computed tomography images. Results from the software were classified as "metastatic nodule", "benign nodule", or "false-positive finding" by two observers.

RESULTS

Computer-assisted detection identified 85.3% (64/75) of pulmonary metastases that radiologists had detected, and 3 more (4%, 3/75) that radiologists had overlooked. Nodule candidates identified by computer-assisted detection included 86 benign nodules (median size 3.1 mm, range 1.2-18.7 mm) and 121 false-positive findings.

CONCLUSIONS

Computer-assisted detection identified pulmonary metastases overlooked by radiologists. However, this was at the cost of identifying a substantial number of benign nodules and false-positive findings.

Thoracoscopic surgery versus open surgery for lung metastases of colorectal cancer: a multi-institutional retrospective analysis using propensity score adjustment†

OBJECTIVES

Thoracoscopic surgery for lung metastasectomy remains controversial. The study aimed at determining the efficacy of thoracoscopic surgery for lung metastasectomy.

METHODS

This was a multi-institutional, retrospective study that included 1047 patients who underwent lung metastasectomy for colorectal cancer between 1999 and 2014. Prognostic factors of overall survival were compared between the thoracoscopic and open thoracotomy groups using the multivariate Cox proportional hazard model. The propensity score, calculated using the preoperative covariates, included the era of lung surgery as a covariate. A stepwise backward elimination method, with a probability level of 0.15, was used to select the most powerful sets of outcome predictors. The difference between the radiological tumour number and the resected tumour number (delta_num) was also evaluated.

RESULTS

The c -statistics and the P -value of the Hosmer-Lemeshow Chi-square of the propensity score model were 0.7149 and 0.1579, respectively. After adjusting for the propensity score, the thoracoscopy group had a better survival rate than the open group (stratified log-rank test: P  = 0.0353). After adjusting for the propensity score, the most powerful predictive model for overall survival was that which combined thoracoscopy [hazard ratio (HR): 0.468, 95% CI: 0.262-0.838, P  = 0.011] and anatomical resection (HR: 1.49, 95% CI: 1.134-1.953, P  = 0.004). Before adjusting for the propensity score, the delta_num was significantly greater in the open group than in the thoracoscopy group (thoracoscopy: 0.06, open: 0.33, P  = 0.001); however, after adjustment, there was no difference in the delta_num (thoracoscopy: 0.04, open: 0.19, P  = 0.114).

CONCLUSIONS

Thoracoscopic metastasectomy showed better overall survival than the open approach in this analysis. The thoracoscopic approach may be an acceptable option for resection of pulmonary metastases in terms of tumour identification and survival outcome in the current era.

The Role of Minimally Invasive Surgery in the Treatment of Lung Metastases

INTRODUCTION

The ideal surgical approach for pulmonary metastasectomy remains controversial. Thoracoscopic surgery may offer advantages in quality of life outcomes, with equivalent oncologic long-term results. This study aimed to demonstrate the validity of video-assisted thoracoscopic surgery (VATS) in the treatment of lung metastases.

METHODS

In all 224 patients who underwent 300 VATS metastasectomies from January 2000 to December 2013 were retrospectively reviewed. Sixty-nine patients underwent major resection (68 thoracoscopic lobectomies and one pneumonectomy) and 155 patients underwent a wedge resection/segmentectomy. Complete curative pulmonary resections were performed in 219 (97%) cases. The Kaplan-Meier method was used to estimate survival curves. Univariate and subsequent multivariate Cox model regression were performed to identify independent factors of overall survival.

RESULTS

One hundred eighty-six patients developed lung metastases from epithelial tumors, 28 from sarcomas, seven from melanomas, and three from germ cell tumors. The final pathological examination revealed no cases of R1 disease. After a mean follow-up of 40 months, 118 patients (53%) had died. According to a multivariate analysis, a better prognosis was not observed for patients with a particular histological type; in addition, disease-free interval time, age, number of metastases, and type of surgery did not have any statistical influence on long-term survival.

CONCLUSIONS

Thoracoscopic surgery is a safe and efficacious procedure, with a five-year overall survival that is equivalent to open surgery.

Is manual palpation of the lung necessary in patients undergoing pulmonary metastasectomy?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether manual palpation of the lung is necessary in patients undergoing pulmonary metastasectomy. In total, 56 articles were found using the described search strategy. After screening these articles and their references, 18 publications represented the best evidence to answer the clinical question. No randomized controlled trial addressing the three-part question was available. The authors, journal, date and country of publication, patient group, study type, relevant outcomes and results of these papers were tabulated. The studies reported on 1472 patients with different primary cancers. The patients underwent more than 1630 pulmonary metastasectomies between 1990 and 2014 after the treatment of primary cancer. Almost three quarters of patients underwent open procedures like thoracotomy or sternotomy. Most frequently, helical CT with a slice thickness ranging between 1 and 10 mm was used for preoperative imaging. The sensitivity in detecting pulmonary nodules ranged from 34 to 97%. The corresponding sensitivity rates for PET-CT were 66-67.5 and 75% for high-resolution CT. The positive predictive value for lesions detected by helical CT varied from 47 to 96%. Helical CT reached a specificity between 54 and 93% in detecting pulmonary nodules. The surgeons identified more nodules by meticulous palpation than helical CT. It is noteworthy that up to 48.5% of these palpated nodules were benign lesions (false-positive). Patients with smaller imaged nodules, multiple imaged nodules or primary mesenchymal tumour are more likely to have occult pulmonary nodules. We conclude that not all palpable pulmonary nodules can be imaged preoperatively. Thoracotomy allows the manual palpation of the ipsilateral hemithorax and might be superior to video-assisted thoracic surgery regarding radical resection. However, not all palpable nodules are malignant, and the impact of non-resected pulmonary metastases on patient survival is not clearly evaluated.

Agreement Between Computed Tomography and Pathologic Nodule Counts in Colorectal Lung Metastases

BACKGROUND

Computed tomography is the most common technique used to estimate the number of pulmonary metastases and their resectability. A lack of agreement between radiologic and surgical pathologic findings could potentially lead to incomplete resection or to rejection of patients for potentially curative treatments. The objective of this study was to estimate the disagreement between the number of radiologic lesions and the number of histologically confirmed malignant lesions excised from patients with pulmonary metastases from colorectal cancer.

METHODS

This was a multicenter longitudinal study using a national registry. All patients underwent open surgery for pulmonary metastasectomy.

RESULTS

Radiologic unilateral involvement was documented in 345 of 404 patients (85%); 253 (73%) presented with single nodules. The radiologic and malignant pathologic findings were concordant in 316 (78%) patients. The two independent predictors of discordance between computed tomography and the number of pathologic metastases were the bilateral involvement and the number of radiologic nodules. This model explained 28% of the variability in the disagreement frequency and discriminated between agreement and disagreement in 85% of the patients. Discrepancies increased with the nodule count with an odds ratio of 6.17 (95% confidence interval, 4.08 to 9.33) per additional nodule. For similar nodule counts, a lower disagreement frequency was observed among bilateral cases (odds ratio, 0.2; 95% confidence interval, 0.07 to 0.55).

CONCLUSIONS

Differences between the radiologic and pathologic findings were documented in 1 of every 5 patients. The correlation was very accurate in patients with single radiologic nodules. However, half of the patients with more nodules showed discrepancies.

Pulmonary metastasectomy: role of pulmonary metastasectomy and type of surgery

OPINION STATEMENT

Patients with untreated metastatic disease have a less than 5 % to 10 % 5-year survival, and for the patient who has metastatic disease isolated to the lungs, pulmonary metastasectomy remains the best hope for cure. Pulmonary metastasectomy has been performed for decades. However, despite hundreds of studies spanning several decades, randomized control data in support of pulmonary metastasectomy is still lacking, and the evidence upon which we base this commonly accepted surgical practice is for the most part weak. While well-accepted surgical selection criteria exist, controversies related to pulmonary metastasectomy abound. Unanswered and clearly debatable are questions related to: optimal preoperative imaging, if mediastinal staging should be performed and if so when, is video-assisted thoracic surgery (VATS) equivalent to open thoracotomy, is finger palpation of the lung mandatory, is repeat pulmonary metastasectomy justified, and what is the interrelationship of pulmonary metastasectomy to other treatments. Current practice to the surgical approach to pulmonary metastasectomy remains quite variable.

Video-assisted thoracoscopic surgery versus open thoracotomy for pulmonary metastasectomy: a systematic review

BACKGROUND

Pulmonary metastasectomy has become a popular procedure for patients with pulmonary metastases. It can be achieved via the traditional open thoracotomy or the more recently developed video-assisted thoracoscopic surgery (VATS). However, there has been much debate as to which approach is better in terms of detection of pulmonary metastases and, in turn, survival and recurrence outcomes. We aim to compare the two different approaches in terms of survival and recurrence outcomes.

METHODS

Medline and EMBASE databases were searched for relevant publications dated prior to May 2013. The bibliographies of the included articles were examined for additional relevant articles that were not included in the search. All publications reporting on overall survival and recurrence-free survival were included. The articles were carefully examined and data were extracted. STATA 12L and RevMan5.2 software were used to combine the data using the random effects model.

RESULTS

A total of 1960 studies were identified through the search. Thirty-two articles had extractable data regarding overall survival and recurrence-free survival. However, only eight articles were included in the end as the other 24 articles had incomplete data. From the included articles, we found that the VATS group had slightly higher odds of 1-, 3- and 5-year overall survival with odds ratios of 1.53, 1.69 and 1.41, respectively, and also higher odds of 1-, 3- and 5-year recurrence-free survival with odds ratios of 1.29, 1.54 and 1.54, respectively.

CONCLUSION

VATS offers a suitable alternative to open thoracotomy for the treatment of pulmonary metastases.

Role of segmentectomy for pulmonary metastases

Pulmonary metastasectomy has not been proven by randomized trials to be more effective than non-operative management, but currently has a well-accepted role for certain primary cancers, in particular colorectal cancer and sarcoma. One of the principal tenets for pulmonary metastasectomy is that all lesions are resected. A major technical difference compared to surgical management of primary lung cancer is that management of metastatic disease frequently requires the resection of multiple and possibly bilateral lesions. In addition, surgeons and patients must often consider repeat surgery for management of metachronous lesions that develop some time after a previous resection, given the nature of metastatic cancer. Therefore, surgeons must ensure complete resection of lesions with negative margins but also must be cognizant of minimizing resection of functional lung tissue as much as possible, in order to ensure that both current and future lesions can be resected while leaving patients with adequate pulmonary function. Segmentectomy is generally infrequently utilized for pulmonary metastasectomy, but has a role for lesions for which a wedge resection is technically not possible but a lobectomy is not required. Segmentectomy can be an important tool in achieving the dual goals of complete resection and impacting pulmonary function as little as possible. Using minimally invasive techniques with thoracoscopy to perform segmentectomy is associated with less short-term morbidity than thoracotomy. Although the use of minimally invasive techniques limits manual palpation and therefore potential resection of small lesions not identified by pre-resection imaging, the current literature does not suggest that these procedures should be done via thoracotomy.

Hand-assisted thoracoscopic surgery for pulmonary metastasectomy through sternocostal triangle access: superiority in detection of non-imaged pulmonary nodules

Hand-Assisted Thoracoscopic Surgery for pulmonary metastasectomy through sternocostal triangle access allows manual palpation of both lungs, thus permitting effective treatment of lung metastases. In our research, 62 patients from November 2001 to January 2012 underwent our Hand-Assisted Thoracoscopic Surgery procedures for pulmonary metastasectomy. Clinical data, including the number of pulmonary metastases determined by Computed Tomography/Positron Emission Tomography-Computed Tomography, surgical findings and survival data of these patients were collected. We found that the median follow-up time was 23.7 months (range 2.4 to 85.6 months). 30 cases of them had post-operative recurrences and the median disease-free survival period was 27.4 months. For Computed Tomography scan, the overall sensitivity for proved metastases was 63% (115/182). 67 non-imaged malignant nodules were palpated and removed in 14 cases. For Positron Emission Tomography-Computed Tomography scan, the overall sensitivity was 66% (79/120). 41 non-imaged malignant nodules were palpated and removed in 12 cases. This study show that the Hand-Assisted Thoracoscopic Surgery provides an easier way for routine bilateral pleural exploration, and thus is critical and effective in detection of non-imaged malignant pulmonary metastases, which might contribute to long-term disease-free survival.

Determination of a low risk group for having metastatic nodules not detected by computed tomography scan in lung metastases surgery

INTRODUCTION

In recent years, there has been debate regarding the diagnostic accuracy of computed tomography (CT) in the identification of lung metastases and the need for lung palpation to determine the number of metastatic nodules. The aim of this study was to determine in which patients the CT scan was more effective in detecting all metastases.

METHODS

We studied all patients who underwent curative thoracotomy for pulmonary metastasis between 1998 and 2012. All cases were reviewed by two expert pulmonary radiologists before surgery. Statistical analyses were performed using Systat version 13.

RESULTS

The study included 183 patients (63.6% male) with a mean age of 61.7 years who underwent 217 interventions. The CT scan was correct in 185 cases (85.3%). Discrepancies observed: 26 patients (11.9%) with more metastases resected than observed and 6 cases (2.8%) with fewer metastases. In patients with one or two metastases of colorectal origin or a single metastasis of any other origin, the probability of finding extra nodules was 9.5%. In the remaining patients, the probability was 27.8%, with statistically significant differences (P=.001). The mean age of the patients in whom no unobserved nodules were detected was 62.9 years compared to 56.5 years on average in patients who were free from any metastases (P=.001).

CONCLUSIONS

Patients older than 60 years, with one or two metastases of colorectal origin or a single metastasis from any other origin were considered to be the group with low probability of having more metastases resected than observed.

Thoracoscopic resection of solitary lung metastases evaluated by using thin-section chest computed tomography: is thoracoscopic surgery still a valid option?

OBJECTIVE

This study evaluated long-term outcomes of pulmonary metastasectomy for solitary lung metastases to clarify the role of video-assisted thoracoscopic surgery in the selected population.

METHODS

We retrospectively investigated oncologic results after the resection of solitary lung metastases guided by thin-section chest computed tomography scans in 105 patients. Pulmonary metastasectomy for solitary lung metastases was approached by thoracotomy (n = 43) and by thoracoscopy (n = 62).

RESULTS

Compared to the thoracotomy group, the thoracoscopy group had a shorter hospital stay (p < 0.001) postoperatively. Intrathoracic recurrence developed in 11 (25.6 %) patients in the thoracotomy group and 15 (24.2 %) in the thoracoscopy group. 19 patients (18.1 %) underwent re-metastasectomy during the median 36-month (5-113) follow-up (p = 0.693). Re-metastasectomy was performed in 8 patients (18.6 %) in the thoracotomy group and in 11 patients (17.7 %) in the thoracoscopy group (p = 0.910). Overall survival was not significantly different between the two groups (p = 0.210). Intrathoracic recurrence was the only significant risk factor for overall survival (p = 0.036) in multivariate analysis.

CONCLUSIONS

In a highly selected group with solitary lung metastases, pulmonary metastasectomy by thoracotomy or thoracoscopy did not affect survival. There were comparable oncologic results from both surgeries when applied in solitary lung metastases from an extra-thoracic malignancy. Thoracoscopic metastasectomy is a promising option in small, solitary pulmonary metastases.

Thoracoscopic lung metastasectomies: a 10-year, single-center experience

Introduction

The ideal surgical treatment for pulmonary metastasectomy remains controversial. Minimally invasive surgery may offer advantages for quality of life outcomes, with equivalent oncologic long-term results. The purpose of our study was to confirm the validity of the thoracoscopic approach for pulmonary metastasectomy.

Methods

We retrospectively reviewed 164 patients who underwent 212 lung metastasectomies from January 2000 to December 2010. Complete curative pulmonary resections were performed in 159 (96.95 %) cases; 126 patients developed lung metastases from epithelial tumors: 28 from sarcoma, 7 from melanoma, and 3 from germ cell tumors. The mean disease-free interval (DFI) was 38.75 months. Fifty-four patients underwent a major VATS resection (53 thoracoscopic lobectomies and 1 pneumonectomy), and 110 patients underwent a wedge resection/segmentectomy. Lymph node sampling was performed in 117 cases.

Results

After a mean follow-up of 38 months, 87 patients (53 %) had died. All resection margins were tumor-free at final pathological examination. Multivariate analysis not confirmed in our series a better prognosis for patients with a particular histologic type and also DFI, age, number of metastases, and type of surgery did not statistically influence long-term survival.

Conclusions

Thoracoscopic surgery is an acceptable procedure, safe and efficacious, with a 5-year overall survival that is equivalent to open surgery.

Do characteristics of pulmonary nodules on computed tomography in children with known osteosarcoma help distinguish whether the nodules are malignant or benign?

PURPOSE

To determine if selected computed tomography (CT) characteristics of pulmonary nodules in pediatric patients with osteosarcoma can help distinguish the nodules as benign or malignant.

METHODS

The institutional review board approved this HIPAA (Health Insurance Portability and Accountability Act-compliant, retrospective study of 30 pediatric osteosarcoma patients (median age 14 years, range 8-22) who underwent chest CT with resection of 117 pulmonary nodules from January 2001 to December 2006. Two pediatric radiologists and one chest radiologist independently and retrospectively reviewed the CT scans and classified nodules as benign, malignant, or indeterminate on the basis of nodule size, laterality, number, location, growth, density, margin appearance, and calcification. Generalized estimating equations were used to examine which characteristics were independent predictors of nodule malignancy.

RESULTS

Of the 117 nodules, 80 (68%) were malignant and 37 (32%) were benign by pathologic review. The readers correctly classified 93% to 94% of the malignant nodules. For benign lesions, the results were not as accurate, with the readers correctly classifying only 11% to 30% of lesions. Most of the benign lesions were classified as indeterminate by the readers (54%-65%). Nodule size (≥5 mm) and the presence of calcifications were associated with an increased probability of malignancy (P b .05).

CONCLUSION

On chest CT, nodule size 5 mm or greater and the presence of calcifications are associated with an increased probability of malignant nodule histology in pediatric patients with osteosarcoma. However, nodule characteristics, apart from size and calcification, at chest CT cannot reliably distinguish benign from malignant pulmonary nodules in these patients.

Imaging requirements in the practice of pulmonary metastasectomy

The primary imaging modality for the detection of pulmonary metastases is computed tomography (CT). Ideally, a helical CT scan with 3- to 5-mm reconstruction thickness or a volumetric thin section scanning should be performed within 4 weeks of pulmonary metastasectomy. A period of observation to see whether further metastases develop does not seem to allow better patient selection. If positron emission tomography is available, it may identify the extrathoracic metastatic sites in 10 to 15% of patients. Despite helical CT scan, palpation identifies the metastases not detected by imaging in 20 to 25% of patients and remains the standard. No data define the optimal interval for follow-up surveillance imaging.

Indications and approach to surgical resection of lung metastases

Pulmonary metastasectomy is a curative option for selected patients with cancer spread to the lungs. Complete surgical removal of pulmonary metastases can improve survival and is recommended under certain criteria. Specific issues that require consideration in a multidisciplinary setting when planning pulmonary metastasectomy include: adherence to established indications for resection, the surgical strategy including the use of minimally invasive techniques, pulmonary parenchyma preservation, and the role of lymphadenectomy.

Surgical management of pulmonary metastases

Metastasectomy is the only curative option for some patients with secondary pulmonary malignancy. Many studies suggest a survival benefit in selected patients if complete resection of pulmonary metastases is accomplished. There are several operative approaches that may be used, with the goal of complete resection and with minimal parenchymal loss. Evaluation for resection must include ascertainment of control of the primary tumor and assessment of the ability to achieve complete resection. Minimally invasive approaches may offer advantages in quality of life outcomes, with equivalent oncologic outcomes.

Current status of pulmonary metastasectomy from primary epithelial tumors

The resection of pulmonary metastases can prolong the survival of selected patients and its therapeutic value is now accepted. The criteria for eligibility have also evolved. We reviewed the recent literature on pulmonary metastasectomy for various epithelial primary tumors and tried to establish better prognostic indicators for its surgical application. In addition to the welldefined requisites for pulmonary metastasectomy, other requirements include the absence of mediastinal lymph node involvement, a limited number of pulmonary metastatic lesions, a long disease-free interval, small metastasis, and no elevation of tumor markers, although the clinical importance of each factor varies among the primary tumors. On the other hand, with the development of video-assisted thoracoscopic surgery (VATS) and advances in thoracic imaging technology, VATS metastasectomy might become an accepted treatment for metastatic nodules located in the periphery of the lung, which can be easily removed by a wedge resection. Repeat surgery is also possible during follow-up after VATS.

Osteosarcoma lung metastases detection and principles of multimodal therapy

The management of pulmonary metastases poses a challenge to the multidisciplinary team involved in the treatment of osteosarcoma. A postal survey on the management of pulmonary metastases in osteosarcoma involving 17 representatives from international study groups and selected institutions was performed in which a response rate of 94% was achieved. The results showed uniform approaches in areas like the imaging methods used for initial staging and the use of manual exploration with thoracotomy. However, it demonstrated diverse practices regarding exploration of the unaffected site in unilateral pulmonary disease, and the approach to lesions disappearing under chemotherapy. Furthermore, agreement on the size of a lesion considered to distinguish between benign and of metastatic origin, varied. Based on the survey and a review of the current literature, detection methods and principles of multimodal therapy will be discussed. Prognostic factors in synchronous and metachronous pulmonary metastases and their implications for a multimodal therapy is also presented.