Surgical management and outcome of osteosarcoma patients with unilateral pulmonary metastases

Minimally invasive and robotic-assisted approaches applied to pediatric surgical oncology

The management of pediatric tumors is complex, with surgery, chemotherapy, and radiotherapy being cornerstones in their treatment. Tumor removal is increasingly performed by a minimally invasive approach, which allows for quicker postoperative recovery and less postoperative pain. The goal of this report is to give an overview of minimally invasive surgical approaches for common pediatric tumors, with a focus on technical considerations and postoperative outcomes.

Primary Multi-Systemic Metastases in Osteosarcoma: Presentation, Treatment, and Survival of 83 Patients of the Cooperative Osteosarcoma Study Group

BACKGROUND

To evaluate patient and tumour characteristics, treatment, and their impact on survival in patients with multi-systemic metastases at initial diagnosis of high-grade osteosarcoma. Precedure: Eighty-three consecutive patients who presented with multi-systemic metastases at initial diagnosis of high-grade osteosarcoma were retrospectively reviewed. In cases of curative intent, the Cooperative Osteosarcoma Study Group recommended surgical removal of all detectable metastases in addition to complete resection of the primary tumour and chemotherapy.

RESULTS

Eighty-three eligible patients (1.8%) were identified among a total of 4605 individuals with high-grade osteosarcoma. Nine (10.8%) of these achieved complete surgical remission, of whom seven later had recurrences. The median follow-up time was 12 (range, 1-165) months for all patients. Actuarial event-free survival after 1, 2, and 5 years was 9.6 ± 3.2%, 1.4 ± 1.4%, and 1.4 ± 1.4%, and overall survival was 54.0 ± 5.6%, 23.2 ± 4.9%, and 8.7 ± 3.3%. In univariate analyses, elevated alkaline phosphatase before chemotherapy, pleural effusion, distant bones as metastatic sites, and more than one bone metastasis were negative prognostic factors. Among treatment-related factors, the microscopically complete resection of the primary tumour, a good response to first-line chemotherapy, the macroscopically complete resection of all affected tumour sites, and local treatment (surgery ± radiotherapy) of all bone metastases were associated with better outcomes. Tumour progression under first-line treatment significantly correlated with shorter survival times.

CONCLUSION

The outlook for patients with multi-systemic primary metastases from osteosarcoma remains very poor. The utmost importance of surgical resection of all tumour sites was confirmed. For unresectable bone metastases, radiotherapy might be considered. In the patient group studied, standard chemotherapy was often insufficiently effective. In the case of such advanced disease, alternative treatment options are urgently required.

Solitary pulmonary metastases at first recurrence of osteosarcoma: Presentation, treatment, and survival of 219 patients of the Cooperative Osteosarcoma Study Group

BACKGROUND

To evaluate patient and tumour characteristics, treatment and their impact on survival in patients with a solitary pulmonary metastasis at first relapse of high-grade osteosarcoma.

PROCEDURE

Two-hundred and nineteen consecutive patients who had achieved a complete surgical remission and then developed a solitary pulmonary metastasis at first recurrence of high-grade osteosarcoma were retrospectively reviewed.

RESULTS

Two hundred and three (94.9%) of 214 patients achieved a second complete remission. After a median time from initial diagnosis of osteosarcoma to first relapse of 2.3 years (range, 0.3-18.8 years), actuarial post-relapse overall survival after 2 and 5 years was 72.0% and 51.2%. Post-relapse event-free survival was 39.1% and 31.1%. Median follow-up time was 3.2 years (range, 0.1-29.4 years). A longer time until first relapse and diagnosis due to imaging were positive prognostic factors in uni- and multivariate analyses, as were a second complete surgical remission and, in regard to death, the absence of a subsequent relapse. The use of salvage chemotherapy and radiotherapy were not associated with patient outcomes, nor was the surgical approach (thoracoscopy vs. thoracotomy) nor the exploration (uni- vs. bilateral).

CONCLUSION

Approximately half of the patients who experience a solitary pulmonary relapse at first recurrence of osteosarcoma remain alive 5 years after this first relapse. Only one third will remain disease-free. A complete surgical resection of the lesion is essential for long-term survival while relapse chemotherapy does not seem to improve survival. Innovative therapies are required to improve outcomes.

Surgical Treatment for Pneumothorax and Tumor-bronchial Fistula Secondary to Pulmonary Metastasis of Osteosarcoma in Pediatric and Adolescent Patients

BACKGROUND

Pneumothorax and tumor-bronchial fistula are rare complications of pulmonary metastasis of osteosarcoma.

OBSERVATIONS

We herein report the cases of 3 pediatric and adolescent patients who developed pneumothorax or tumor-bronchial fistula during treatment of pulmonary metastasis of osteosarcoma with chemotherapeutics or antiangiogenic agents. Two patients developed pneumothorax, and the other patient developed tumor-bronchial fistula. All of the patients finally underwent the surgery to treat their complications.

CONCLUSIONS

Although it is not a curative surgery, surgery for pneumothorax and tumor-bronchial fistula is acceptable. The operative procedure should be considered on the basis of the predicted prognosis of the patient.

Effectiveness of Learning Systems from Common Image File Types to Detect Osteosarcoma Based on Convolutional Neural Networks (CNNs) Models

Osteosarcoma is a rare bone cancer which is more common in children than in adults and has a high chance of metastasizing to the patient’s lungs. Due to initiated cases, it is difficult to diagnose and hard to detect the nodule in a lung at the early state. Convolutional Neural Networks (CNNs) are effectively applied for early state detection by considering CT-scanned images. Transferring patients from small hospitals to the cancer specialized hospital, Lerdsin Hospital, poses difficulties in information sharing because of the privacy and safety regulations. CD-ROM media was allowed for transferring patients’ data to Lerdsin Hospital. Digital Imaging and Communications in Medicine (DICOM) files cannot be stored on a CD-ROM. DICOM must be converted into other common image formats, such as BMP, JPG and PNG formats. Quality of images can affect the accuracy of the CNN models. In this research, the effect of different image formats is studied and experimented. Three popular medical CNN models, VGG-16, ResNet-50 and MobileNet-V2, are considered and used for osteosarcoma detection. The positive and negative class images are corrected from Lerdsin Hospital, and 80% of all images are used as a training dataset, while the rest are used to validate the trained models. Limited training images are simulated by reducing images in the training dataset. Each model is trained and validated by three different image formats, resulting in 54 testing cases. F1-Score and accuracy are calculated and compared for the models’ performance. VGG-16 is the most robust of all the formats. PNG format is the most preferred image format, followed by BMP and JPG formats, respectively.

Indeterminate Pulmonary Nodules in Osteosarcoma Are Associated With Increased Risk of Pulmonary Metastasis

Osteosarcoma is the most common primary malignant bone tumor in children. In addition to pulmonary metastasis, computed tomography frequently detects indeterminate pulmonary nodules (IPN). We conducted this study to determine the clinical significance of IPN in terms of progression to pulmonary metastasis and its impact on survival. It was a retrospective cohort study of pediatric nonmetastatic osteosarcoma patients treated from January 2005 to December 2018. Baseline computed tomography scans were reviewed for the presence of IPN (defined as a single nodule of <10 mm or ≥3 nodules of <5 mm). Subsequent scans were reviewed for the development of pulmonary metastasis. Of 155 patients, 31.6% (n=49) had IPN at baseline. A total of 43% (n=21) of those with IPN subsequently progressed to pulmonary metastasis compared with only 26% (n=28) of those without IPN (P<0.001) with a relative risk of 1.6 (1.03 to 2.5) in the IPN group. Patients with ≥3 IPN at baseline were at significantly greater risk of pulmonary metastasis as compared with <3 IPN (P=0.013). Overall and event-free survival in patients with and without IPN was 58% and 35%, and 72% and 46%, respectively. Our results suggest that patients with IPN may be at greater risk for progressing to pulmonary metastasis.

Current surgical management of children with osteosarcoma and pulmonary metastatic disease: A survey of the American Pediatric Surgical Association

BACKGROUND

Rates of long-term survival for children with pulmonary metastatic osteosarcoma are low, and complete surgical resection of all visible pulmonary metastases is necessary for long term survival. Surgical approaches for metastasectomy include thoracotomy and thoracoscopy, with the approach chosen influenced by training and institutional bias. Thoracotomy with manual palpation of lung surfaces can identify nodules not seen on preoperative imaging, but no clear survival benefit has been demonstrated compared to complete thoracoscopic resection of all visible nodules.

METHODS

All member of the American Pediatric Surgical Association were surveyed, and 204 members responded.

RESULTS

Thoracoscopy was the preferred approach of 34% of surgeons for patients with 3 unilateral nodules but only 21% for those with 5 unilateral nodules. Hospital volume did not correlate with operative approach. Localization strategies are used by 37% of surgeons who prefer thoracotomy and 64% who prefer thoracoscopy. Importantly, the vast majority of responding surgeons (84%) expressed a willingness to participate in a randomized controlled trial of thoracotomy versus thoracoscopy.

CONCLUSION

Findings of this survey of North American pediatric surgeons confirm both the need for, and interest in, a prospective trial to define optimal surgical management of children with osteosarcoma with limited pulmonary metastasis.

LEVEL OF EVIDENCE

V.

Thoracoscopy vs thoracotomy for the management of metastatic osteosarcoma: A Pediatric Surgical Oncology Research Collaborative Study

Complete surgical resection of pulmonary metastatic disease in patients with osteosarcoma is crucial to long-term survival. Open thoracotomy allows palpation of nodules not identified on imaging but the impact on survival is unknown. The objective of this study was to compare overall survival (OS) and pulmonary disease-free survival (DFS) in children who underwent thoracotomy vs thoracoscopic surgery for pulmonary metastasectomy. A multi-institutional collaborative group retrospectively reviewed 202 pediatric patients with osteosarcoma who underwent pulmonary metastasectomy by thoracotomy (n = 154) or thoracoscopy (n = 48). Results were analyzed by Kaplan-Meier survival estimates and multivariate Cox proportional hazard regression models. With median follow-up of 45 months, 135 (67.5%) patients had a pulmonary relapse and 95 (47%) patients were deceased. Kaplan-Meier analysis showed no significant difference in 5-year pulmonary DFS (25% vs 38%; P = .18) or OS (49% vs 42%, P = .37) between the surgical approaches of thoracotomy and thoracoscopy. In Cox regression analysis controlling for other factors impacting outcome, there was a significantly increased risk of mortality (HR 2.11; P = .027; 95% CI 1.09-4.09) but not pulmonary recurrence (HR 0.96; P = .90; 95% CI 0.52-1.79) with a thoracoscopic approach. However, in the subset analysis limited to patients with oligometastatic disease, thoracoscopy had no increased risk of mortality (HR 1.16; P = .62; 0.64-2.11). In conclusion, patients with metastatic osteosarcoma and limited pulmonary disease burden demonstrate comparable outcomes after thoracotomy and thoracoscopy for metastasectomy. While significant selection bias in these surgical cohorts limits the generalizability of the conclusions, clinical equipoise for a randomized clinical trial in patients with oligometastatic disease is supported.

Effect of timing of pulmonary metastasis occurrence on the outcome of metastasectomy in osteosarcoma patients

BACKGROUND

Complete metastasectomy is the best predictor of survival in patients with osteosarcoma pulmonary metastases. There has been some controversy in the literature regarding the prognostic significance of the timing of occurrence of lung metastasis.

METHODS

We reviewed the clinical course of all osteosarcoma patients with pulmonary metastases treated by metastasectomy in our hospital from January 2008 through December 2016. Each patient who underwent metastasectomy was placed into one of three groups based on whether lung metastases were present at initial presentation (Group 1), developed during chemotherapy (Group 2), or appeared after completion of chemotherapy (Group 3). Data were obtained retrospectively and follow-up was obtained until the end of June 2017.

RESULTS

We identified 170 patients with pulmonary nodules of whom 99 (58.2%) underwent at least one metastasectomy (149 thoracotomies). Eleven patients had benign pulmonary nodules and were excluded. The other 88 patients were classified as Group 1 (37), Group 2 (18) or Group 3 (33). The median follow-up was 35 months (range 8 to 99). Postmetastasis 5-year overall survival (OS) was 38.1 ± 6.4%; event-free survival (EFS) was 25 ± 5.3%. By group, postmetastasis 5-year OS and EFS were 34.3 ± 13% and 18 ± 9.3% in Group 1, 8 ± 6.5% and 6.5 ± 5% in Group 2, and 52 ± 11.4% and 25 ± 9% in Group 3 (P < 0.001). In univariate analysis, the only significant factors associated with survival were timing of occurrence of lung metastasis and the number of lung nodules found.

CONCLUSION

The timing of occurrence of lung metastasis is an important prognostic factor among osteosarcoma patients eligible for metastasectomy. Patients whose metastases occurred during chemotherapy had the worst survival.

LEVEL OF EVIDENCE

Level II.

Pulmonary Metastasectomy in Pediatric Solid Tumors

Metastatic disease and the complications of treating metastatic disease are the primary causes of mortality in children with solid malignancies. Nearly 25% of children with solid tumors have metastatic disease at initial diagnosis and another 20% develop metastases during or after treatment. The most common location of these metastases is the lung. The role of surgery in metastatic disease depends greatly on the histology of the primary. In general, tumors that are refractory to adjuvant therapies are most appropriate for pulmonary metastasectomy. This article will summarize the indications for metastasectomy in pediatric solid tumors and discuss the ongoing debate over the technique of metastasectomy in osteosarcoma.

A 20-year retrospective analysis of CT-based pre-operative identification of pulmonary metastases in patients with osteosarcoma: A single-center review

PURPOSE

Cooperative studies support complete metastasectomy in osteosarcoma (OS). Pre-operative CT is used to identify and quantify metastases and can facilitate minimally invasive techniques. Here we assess the accuracy of pre-operative CT compared to findings at thoracotomy and its change over time.

METHODS

We reviewed OS thoracotomies performed at our institution from 1996 to 2015. The number of metastases identified on pre-operative chest CT was compared to the number of metastases seen on pathology (both metastases with viable cells and non-viable, osteoid-only metastases).

RESULTS

Eighty-eight patients underwent 161 thoracotomies with a median of 14days (range, 1-85) between CT and surgery, a median of 2 CT-identified lesions (range, 0-15), and a median of 4 resected lesions (range, 1-25). In 56 (34.8%) cases, more metastases were found surgically than were seen on CT, and among these, 34 (21.1%) had a greater number of viable metastases. There was poor overall correlation between CT and pathology findings (Kendall Tau-b=0.506), regardless of CT slice thickness, decade of thoracotomy, or total number of CT-identified lesions.

CONCLUSIONS

CT accuracy in pre-operatively quantifying OS pulmonary metastases has not improved in recent decades. Consequently, we recommend an open technique with direct lung palpation for complete identification and resection of OS pulmonary metastases.

LEVEL OF EVIDENCE

Level IV, retrospective study with no comparison group.

Surgical treatment of pulmonary metastases in pediatric solid tumors

Most children who succumb to solid malignancies do so because of the burden of metastatic disease or due to complications associated with the therapy administered to treat metastatic disease. Approximately one-quarter of children with solid tumors will present with metastatic disease, and an additional 20% ultimately develop metastatic disease, most commonly in the lung. The role of surgery in the treatment of metastatic solid tumors, given its disseminated nature, is not intuitive, yet there are circumstances in which surgical resection of metastatic disease can potentially be curative. However, the utility of surgery is very much dependent on histology, and generally is most appropriate for those malignancies with histologies that are refractory to other adjuvant therapies.

Metastasectomy of Pulmonary Metastases from Osteosarcoma: Prognostic Factors and Indication for Repeat Metastasectomy

Purpose. To identify prognostic factors for metastatic osteosarcoma patients and establish indication for repeat metastasectomy. Methods. Data from 37 patients with pulmonary metastasis from osteosarcoma who underwent metastasectomy in our institute from 1979 to 2013 were retrospectively reviewed. Results. Prognostic factors analyzed were age, sex, maximal diameter of the tumor at first pulmonary metastasectomy, total number of resected pulmonary metastases at first metastasectomy, number of surgeries, and disease free interval. In our analysis, characteristics associated with an increased overall survival were age > 15 years and fewer metastases (≤3). Of the 37 patients, 13 underwent repeat metastasectomy after the first metastasectomy. Of the 7 patients that underwent only two metastasectomies, three remained disease-free. In contrast, all six patients that underwent three or more metastasectomies died of relapse. Patients who had five or less lesions at second metastasectomy showed better survival compared to those who had six or more lesions. Conclusion. Age > 15 years and number of metastases at first metastasectomy were independent prognostic factors. Metastasectomy may provide curative treatment even in cases requiring repeat surgery. The number of metastases at second metastasectomy may be a potential predictor of the need for repeat surgery.

Variability in the reported management of pulmonary metastases in osteosarcoma

Nearly 20% of patients with newly diagnosed osteosarcoma have detectable metastases at diagnosis; the majority of which occur in the lungs. There are no established recommendations for the timing and modality of metastasectomy. Members of the Connective Tissue Oncology Society (CTOS) were emailed an anonymous 10-min survey assessing their management practices for pulmonary findings at the time of an osteosarcoma diagnosis. The questionnaire presented three scenarios and discussed the choice to perform surgery, the timing of resection, and the choice of surgical procedure. Analyses were stratified by medical profession. One hundred and eighty-three physicians responded to our questionnaire. Respondents were comprised of orthopedic surgeons (37%), medical oncologists (31%), pediatric oncologists (22%), and other medical subspecialties (10%). There was variability among the respondents in the management of the pulmonary nodules. The majority of physicians chose to resect the pulmonary nodules following neoadjuvant chemotherapy (46–63%). Thoracotomy was the preferred technique for surgical resection. When only unilateral findings were present, the majority of physicians did not explore the contralateral lung. The majority of respondents did not recommend resection if the pulmonary nodule disappeared following chemotherapy. The survey demonstrated heterogeneity in the management of pulmonary metastases in osteosarcoma. Prospective trials need to evaluate whether these differences in management have implications for outcomes for patients with metastatic osteosarcoma.

The Current and Future Therapies for Human Osteosarcoma

Osteosarcoma (OS) is the most common non-hematologic malignant tumor of bone in adults and children. As sarcomas are more common in adolescents and young adults than most other forms of cancer, there are a significant number of years of life lost secondary to these malignancies. OS is associated with a poor prognosis secondary to a high grade at presentation, resistance to chemotherapy and a propensity to metastasize to the lungs. Current OS management involves both chemotherapy and surgery. The incorporation of cytotoxic chemotherapy into therapeutic regimens escalated cure rates from <20% to current levels of 65-75%. Furthermore, limb-salvage surgery is now offered to the majority of OS patients. Despite advances in chemotherapy and surgical techniques over the past three decades, there has been stagnation in patient survival outcome improvement, especially in patients with metastatic OS. Thus, there is a critical need to identify novel and directed therapy for OS. Several Phase I trials for sarcoma therapies currently ongoing or recently completed have shown objective responses in OS. Novel drug delivery mechanisms are currently under phase II and III clinical trials. Furthermore, there is an abundance of preclinical research which holds great promise in the development of future OS-directed therapeutics. Our continuously improving knowledge of the molecular and cell-signaling pathways involved in OS will translate into more effective therapies for OS and ultimately improved patient survival. The present review will provide an overview of current therapies, ongoing clinical trials and therapeutic targets under investigation for OS.

Surgical treatment of lung metastases in patients with embryonal pediatric solid tumors: an update

Distant metastases regularly occur in children with solid tumors. The most affected organ is the lung. Nearly in all extracranial pediatric solid tumors, the presence of lung metastases is associated with an adverse prognosis for the children. Therefore, the correct treatment of lung metastases is essential and influences the outcome. Despite different national and international trials for pediatric tumor entities, specific surgical aspects or guidelines for lung metastases are usually not addressed thoroughly in these protocols. The aim of this article is to present the diagnostic challenges and principles of surgical treatment by focusing on the influence of surgery on the outcome of children. Special points of interest are discussed that emphasize sarcomas, nephroblastomas, hepatoblastomas, and other tumors. Surgery of lung metastases is safe, has a positive impact on the patients' prognosis, and should be aggressive depending on the tumor entity. An interdisciplinary approach, including pediatric oncology and radiology, is mandatory in any case.

Lung nodules in pediatric oncology patients: a prediction rule for when to biopsy

PURPOSE

The purpose of the study was to develop a prediction rule regarding the factors that most accurately predict the diagnosis of a malignancy in a lung nodule in the pediatric oncology patient.

METHODS

A retrospective review of pediatric oncology patients that underwent lung nodule resection between 1998 and 2007 was performed. Multivariable logistic regression was used to create a prediction rule.

RESULTS

Fifty pediatric oncology patients underwent 21 thoracotomies and 48 thoracoscopies to resect discrete lung nodules seen on computed tomographic scans during workup for metastasis or routine surveillance. The mean nodule size was 10.43 ± 7.08 mm. The most significant predictors of malignancy in a nodule were peripheral location (odds ratio [OR], 9.1); size between 5 and 10 mm (OR, 2.78); location within the right lower lobe (OR, 2.43); and patients with osteosarcoma (OR, 10.8), Ewing sarcoma (OR, 3.05), or hepatocellular carcinoma (OR, 2.38).

CONCLUSIONS

Lesions that are between 5 and 10 mm in size and peripherally located in patients with osteosarcoma, Ewing sarcoma, or hepatocellular carcinoma are most likely to be malignant. Use of a prediction rule can help guide clinical practice by determining which patients should undergo surgical resection of lung nodules and which patients may be closely observed with continued radiologic studies.

CT characteristics of lung nodules present at diagnosis of extrapulmonary malignancy in children

OBJECTIVE

The purpose of this study was to evaluate the CT characteristics of lung nodules present at diagnosis of extrapulmonary malignancies in children.

MATERIALS AND METHODS

We performed a retrospective analysis of CT images of children seen in our oncology service over a 6-year period. We included all children diagnosed with a non-CNS solid extrapulmonary malignancy or lymphoma who had also undergone chest CT at presentation. Images were reviewed for the presence of lung nodules; if present, the following nodular characteristics were recorded: sidedness, number, distribution, CT attenuation, shape, margins, calcification, and size. When available, pathology results were correlated with the nodules found on CT.

RESULTS

One hundred eleven infants and children (age range, 14 days-17 years 10 months; median age, 11 years 8 months) had lung nodules on CT. The nodules showed a variety of patterns, but the most common findings were bilateral lung nodules (71 of 111 patients), between two and 10 in number (60 patients), peripheral distribution (98 patients), < or = 5 mm (48 patients), oval shape (45 patients), solid attenuation (74 patients), smoothly marginated (91 patients), and noncalcified (107 patients). Twenty-seven patients underwent biopsy. Seventeen biopsies showed benign lesions and nine, malignant lesions; the results for the remaining biopsy were inconclusive. In the subgroup of lung nodules that underwent biopsy, none of the CT characteristics was able to differentiate benignity from malignancy.

CONCLUSION

Lung nodules in children with extrapulmonary malignancies showed a variety of patterns on CT. In the subgroup of lung nodules that underwent biopsy, none of the nodule features studied on CT reliably differentiated benignity from malignancy.

Should contralateral exploratory thoracotomy be advocated for children with osteosarcoma and early unilateral pulmonary metastases?

PURPOSE

Children presenting with osteosarcoma and pulmonary metastases have poor survival rates. The standard approach to treating unilateral metastases is ipsilateral thoracotomy with complete resection of the metastases whenever possible. We analyzed whether contralateral exploratory thoracotomy is beneficial in these patients.

METHODS

We reviewed the records of all osteosarcoma patients presenting with or developing early pulmonary metastases (within 24 months of diagnosis) at the St Jude Children's Research Hospital (Memphis, Tenn) between June 1980 and September 2005. Demographics, imaging results, treatment protocols, surgical procedures, and recurrence, survival, and timeline data were assessed.

RESULTS

Of the 109 patients, initial pulmonary involvement was radiographically identified as unilateral in 81 (74%) and bilateral in 28 (26%) patients. Of the patients presenting with unilateral pulmonary metastases, 2 years later, 13 (16%) had recurrence in the ipsilateral and 19 (23%) in the contralateral lung. In 2 (2.4%) patients, metastases recurred bilaterally. There was no evidence of statistically significant difference between the incidence of recurrence in the ipsilateral and contralateral lung (P = .18).

CONCLUSIONS

Children with osteosarcoma and unilateral pulmonary metastases had similar incidence of recurrence in the ipsilateral and contralateral lung. Their survival rates were also not significantly different. Therefore, contralateral exploratory thoracotomy in patients presenting with unilateral pulmonary metastases will probably not improve survival.

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.

Minimally invasive thoracoscopic ultrasound for localization of pulmonary nodules in children

PURPOSE

Children with cancer may develop lesions in the lung that may represent metastatic disease. Thoracotomy is considered the standard approach for resection of pulmonary nodules. Recently, thoracoscopic techniques have been applied in these situations. However, nodules that are deep in the lung parenchyma may not be visible. A technique has been developed whereby minimally invasive thoracoscopic ultrasound (MITUS) may be used to guide resection of deep pulmonary nodules.

METHODS

We conducted a retrospective review of children undergoing MITUS at our institution. Only patients with single isolated lesions were chosen to have this diagnostic procedure performed. Patients undergo single lung ventilation. Two 5-mm ports are inserted, one for the grasper and the other for the camera. One 12-mm port is inserted for the flexible 10-mm ultrasound probe and the endoscopic stapler. The patient has CO(2) insufflation to create a 5-mm Hg pneumothorax. Twenty mL/kg of normal saline is introduced into the chest cavity for acoustic coupling. The ultrasound probe is used to isolate the nodule(s), guide resection, and check margins. The specimen is removed and placed in a removable specimen bag to reduce the chance of port site recurrence. After the lung has been inspected, irrigation is removed, and a chest tube inserted.

RESULTS

Eight procedures were performed on 7 patients (5 males, 2 females) with a median age of 15.2 years (range, 4-18 years). Patients had primary diagnoses of osteosarcoma (n = 4), Wilms' (n = 2), and lymphoma (n = 1). The median size of the lesions that were being isolated was 0.6 cm (range, 0.3-2.9 cm). None of the nodules removed were visible on the surface of the lung. Of the 8 procedures, 7 led to the removal of a pulmonary nodule. Of the 7 nodules isolated, 5 were removed thoracoscopically, with two requiring minithoracotomy because of anatomical limitations. The histologic evaluation on these specimens included osteosarcoma (n = 4), abscesses (n = 2), fibrosis (n = 1), and lymph node (n = 1). The median hospitalization was 2.5 days (range, 2-39 days). One patient had a prolonged hospitalization because of air leak and sepsis.

CONCLUSION

Minimally invasive thoracoscopic ultrasound is a real time imaging tool that helps isolate small pulmonary lesions that may otherwise be difficult to see intraoperatively. We would advocate this technique for those patients having video-assisted thoracoscopy to assist clarifying whether focal lesions are malignant, thereby guiding therapy.

Pediatric pulmonary tumors: primary and metastatic

Pediatric pulmonary tumors are rare. There is often a significant delay in diagnosis of pulmonary tumors secondary to their rarity and nonspecific presenting physiologic and radiographic findings. A high index of suspicion in pediatric patients with recurrent or persistent pulmonary symptoms is of paramount importance in diagnosing pulmonary tumors at an early stage. Malignant pulmonary tumors are more frequently diagnosed than benign lesions, with metastatic cancers being the most common. Complete surgical resection remains the basis of therapy for primary lesions, and its role in secondary cancers is becoming more established. Adjuvant therapies are frequently employed depending on the precise tumor involved. Mortality rates vary greatly depending on tumor location, stage, and type.

Paediatric CT: the effects of increasing image noise on pulmonary nodule detection

BACKGROUND

A radiation dose of any magnitude can produce a detrimental effect manifesting as an increased risk of cancer. Cancer development may be delayed for many years following radiation exposure. Minimizing radiation dose in children is particularly important. However, reducing the dose can reduce image quality and may, therefore, hinder lesion detection.

OBJECTIVE

We investigated the effects of reducing the image signal-to-noise ratio (SNR) on CT lung nodule detection for a range of nodule sizes.

MATERIALS AND METHODS

A simulated nodule was placed at the periphery of the lung on an axial CT slice using image editing software. Multiple copies of the manipulated image were saved with various levels of superimposed noise. The image creation process was repeated for a range of nodule sizes. For a given nodule size, output images were read independently by four Fellows of The Royal College of Radiologists.

RESULTS

The overall sensitivities in detecting nodules for the SNR ranges 0.8-0.99, 1-1.49, and 1.5-2.35 were 40.5%, 77.3% and 90.3%, respectively, and the specificities were 47.9%, 73.3% and 75%, respectively. The sensitivity for detecting lung nodules increased with nodule size and increasing SNR. There was 100% sensitivity for the detection of nodules of 4-10 mm in diameter at SNRs greater than 1.5.

CONCLUSION

Reducing medical radiation doses in children is of paramount importance. For chest CT examinations this may be counterbalanced by reduced sensitivity and specificity combined with an increased uncertainty of pulmonary nodule detection. This study demonstrates that pulmonary nodules of 4 mm and greater in diameter can be detected with 100% sensitivity provided that the perceived image SNR is greater than 1.5.

Treatment algorithm for locally recurrent osteosarcoma based on local disease-free interval and the presence of lung metastasis

BACKGROUND

Local recurrence in osteosarcoma is clinically distinct from metastasis, although associated with a similar reduction in survival. The prognostic factors in locally recurrent osteosarcoma were investigated and these factors were translated into a management strategy.

METHODS

In all, 407 consecutive patients with skeletal osteosarcoma between 1977 and 2002 were analyzed. Twenty-three patients with resectable local recurrence were analyzed. Clinical and tumor-related factors were assessed for significance in relation to survival and a management strategy was formulated based on factors found to be independently significant for survival.

RESULTS

Seventeen of the 23 patients underwent primary resections and initial treatment, yielding an overall local recurrence rate of 4.2% for resectable cancer. Median time to local recurrence was 13 months (95% confidence interval, 9-16 months). The 5-year and 10-year survival rates in the recurrent cases were 29% and 10%, respectively. All patients received chemotherapy both for their primary and recurrent disease. Increased risk of local recurrence (P < .0001) was strongly correlated with positive margins of resection. The rate of local recurrence was not related to chemotherapy-associated necrosis in the primary tumor. Nevertheless, neoadjuvant therapy halved the risk of local recurrence (odds ratio, 1.92; P = .3, power 10%). The strongest correlate with poor survival was local recurrence within the first year after primary resection (P = .001), followed by metastasis at the time of first local recurrence (P = .04) and failure to achieve clinical remission after disease recurrence (P = .04). Chemotherapy-associated necrosis and margins of resection of the primary tumor were not significant prognostic variables for survival. Survival differed significantly among patients defined by local disease-free interval and lung metastasis (P = .0001). They required an individualized approach as captured in the management algorithm.

CONCLUSION

There is a residual risk of local recurrence in patients despite favorable chemotherapy-associated necrosis and negative margins of resection. A treatment strategy emphasizing clinical remission at all identifiable sites offers the highest likelihood of survival in this patient population.

Pulmonary metastasectomy in pediatric patients

This article describes the historical development of pediatric pulmonary metastasectomy but demonstrates that progress has been slow in understanding its proper applications. Because many pediatric metastatic tumors are rare, surgeons have grouped together patients of different histologies for the generation and analysis of case series. By examining tumor types individually, however, it is seen that certain histologies (adrenocortical carcinoma, alveolar soft part sarcoma, osteosarcoma) mandate surgical metastasectomy for patient survival. Other pediatric tumors (Wilms tumor, Ewing's sarcoma) are radiation sensitive, and the application of metastasectomy is controversial. In the case of still other types of tumor (neuroblastoma, differentiated thyroid cancer, rhabdomyosarcoma), metastasectomy is seldom performed except in highly unusual situations. Techniques for minimally invasive biopsy and for muscle-sparing thoracotomy are described for pediatric patients.

Distinguishing benign from malignant pulmonary nodules with helical chest CT in children with malignant solid tumors

PURPOSE

To retrospectively assess whether computed tomographic (CT) findings can indicate the benign or malignant nature of pulmonary nodules in pediatric patients with malignant solid primary tumors.

MATERIALS AND METHODS

With institutional review board approval, waived parental and patient consent, and HIPAA compliance, the authors determined the incidence of malignancy among 81 pulmonary nodules that were sampled at biopsy within 3 weeks after chest CT (January 1999 to September 2003) in 41 young patients with malignant solid tumors. Three radiologists independently and retrospectively reviewed these scans and the available previously obtained scans, classifying nodules as benign, malignant, or indeterminate on the basis of their number, unilateral versus bilateral distribution, size, margins (indistinct vs distinct), calcification, growth, and associated adenopathy. These classifications were compared with nodule histologic type, and interreviewer agreement was assessed.

RESULTS

The median patient age was 14.8 years (mean, 13.7 years; range, 5-21 years). Twenty-four of the 41 patients (58%) had at least one biopsy-proved malignant nodule. Four (10%) patients had both benign and malignant nodules; 17 (42%) had only benign nodules. Reviewer 1 classified 65% (39 of 60) of nodules correctly; reviewer 2, 57% (37 of 65); and reviewer 3, 67% (43 of 64). Interreviewer agreement was slight to moderate (kappa </= 0.43, P </= .03). In contrast to findings in adults, sharply defined nodules in younger individuals were more likely to be malignant (P = .03) and nodule size was not associated with malignancy (P >/= .32).

CONCLUSION

The frequency of benign nodules and the inconsistency of predictions based on CT features suggest the need for better predictors of pulmonary nodules being malignant or benign, so as to reduce unnecessary thoracotomy in pediatric patients with solid malignancy. .

Management of osteosarcoma pulmonary metastases

Although there has been considerable improvement in survival among children with osteosarcoma over the past 30 years, patients with metastatic disease fare very poorly. The best-case scenario for metastatic patients is a survival rate of 30% assuming complete resection of lung metastases without other disease. To achieve this optimal outcome, an aggressive surgical approach is recommended in which all metastatic disease is resected. This includes metastatic foci that are detected by imaging as well as those only identified by palpation at thoracotomy. Investigation into the biology of the metastatic process of osteosarcoma as well as in identification of molecular features that correlate with prognosis is very active and will likely yield important findings that will impact therapy in the future. An area of investigation that remains needed is the prospective evaluation of the surgical management of these patients with the goal of critically evaluating the impact of the various surgical strategies on patient outcome measures, such as disease-recurrence and survival.

Computed tomographic scan of the chest underestimates the number of metastatic lesions in osteosarcoma

PURPOSE

Survival in osteosarcoma correlates with complete resection of primary and metastatic disease. The feasibility of complete pulmonary metastasectomy using thoracoscopy has been raised. Because palpation is not possible, minimally invasive techniques require preoperative radiological enumeration and localization of metastases not presenting at the lung surface. We hypothesized that computed tomographic (CT) scanning underestimated the number of pulmonary metastases in these patients.

METHODS

Institutional review board approval was obtained. We determined the association between the number of lesions identified by CT scanning and the number of metastases found at thoracotomies for metastatic osteosarcoma from May 1996 to October 2004. Correlations between CT findings and pathology results were computed using the Kendall tau-b correlation coefficient. Depth, in millimeters, from the pleural surface was measured for those lesions seen on CT scan.

RESULTS

We analyzed 54 consecutive thoracotomies performed in 28 patients for whom complete imaging was available. Computed tomographic scanning was performed a median of 20 days before thoracotomy (range, 1-85 days). Correlation between the number of lesions identified by CT and the number of metastases resected at surgery was poor, with a Kendall tau-b correlation coefficient of 0.45 (P < .001). In 19 (35%) of 54 thoracotomies, CT scanning underestimated the number of pathologically proven, viable and nonviable metastases found by the surgeon. Accounting for viable metastases only, correlation between the number of lesions identified by CT and the number of metastases resected at surgery was 0.50 (P < .001), and CT scanning underestimated the number of viable metastases present in 14 (26%) of 54 thoracotomies. Many lesions (32%) were pleural-based, but nearly half (47%) were 5 mm or deeper from the pleural surface of the lung.

CONCLUSIONS

Even in the era of modern CT scanning, only a very rough correlation exists between CT findings and the number of lesions identified at thoracotomy. In more than one third of thoracotomies in our series, metastases would have been missed by any tactic besides manual palpation of the lung during open thoracotomy. Minimal access procedures should not be the approach of choice if the goal is resection of all pulmonary metastases in osteosarcoma.

Long-term survival after aggressive resection of pulmonary metastases among children and adolescents with osteosarcoma

PURPOSE

Although survival without resection of pulmonary metastases from osteosarcoma is unlikely, not all surgeons agree on an aggressive surgical approach. We have taken an approach to attempt surgical resection if at all feasible regardless of number of metastases and disease-free interval (DFI). This study presents information on long-term follow-up after this aggressive approach to resection.

METHODS

A single-institution retrospective cohort study of osteosarcoma patients younger than 21 years with pulmonary metastases, limited to the contemporary chemotherapeutic period (1980-2000), was conducted.

RESULTS

In 137 patients, synchronous (23.4%) or metachronous (76.6%) pulmonary nodules were identified. The median follow-up was 2.0 years (5 days to 20.1 years) for all patients. Overall survival among patients who had pulmonary nodules was 40.2% and 22.6% at 3 and 5 years, respectively. Ninety-nine patients underwent attempted pulmonary metastasectomy (mean survival, 33.6 months; 95% confidence interval, 25.1-42.1) and 38 patients did not (mean survival, 10.1 months; 95% confidence interval, 6.5-13.6; P < .001, t test). Characteristics that were associated with an increased likelihood of 5-year overall survival after pulmonary resection were primary tumor necrosis greater than 98% after neoadjuvant chemotherapy (P < .05) and DFI before developing lung metastases more than 1 year (P < .001). No statistically significant difference in overall survival or disease-free survival was found based on the number of pulmonary metastases resected. Characteristics including primary tumor size, site, or extension; chemotherapy; early vs late metastases; unilateral vs bilateral metastases; and resection margins did not significantly affect survival.

CONCLUSIONS

Most patient and tumor characteristics commonly used by surgeons to determine utility of resection of pulmonary metastases among patients with osteosarcoma are not associated with outcome. Biology of the particular tumor (response to preoperative chemotherapy, measured by tumor necrosis percentage, and DFI), as opposed to tumor burden, appears to influence survival more significantly. We would advocate considering repeat pulmonary resection for patients with recurrent metastases from osteosarcoma.

De novo osteogenic sarcoma in patients older than forty: benefit of multimodality therapy

The treatment of primary osteogenic sarcoma is well established in younger patients; however, controversy surrounds the treatment of this disease in the older population. To confirm multimodality therapy results in longer survival than surgery alone, 58 patients older than 40 years with primary osteogenic sarcoma were assessed retrospectively for the benefits of multimodality treatment versus surgery alone. We then asked whether specific patient and tumor characteristics and treatment modalities affected the rates of survival. Finally, we questioned whether pulmonary metastatectomy increased survival. The 5-year and 10-year overall survival for the group was 58% and 44%, respectively. Multimodality therapy increased survival compared with surgery alone in patients with high-grade disease. On multivariate analysis, considerable prognostic factors for improved overall survival for the entire group were age younger than 60 years, volume less than 100 cm, normal alkaline phosphatase, localized disease, negative surgical margins, and absence of recurrence. Pulmonary metastatectomy improved survival in selected patients.

LEVEL OF EVIDENCE

Therapeutic study, Level III-1 (retrospective cohort study). See the Guidelines for Authors for a complete description of levels of evidence.