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

Predictors of pulmonary metastases on chest computed tomography in children and adolescents with osteosarcoma-tips for qualifying patients for thoracotomy

BACKGROUND

Osteosarcoma is the most common primary malignant bone tumour in children and adolescents. Lungs are the most frequent and often the only site of metastatic disease. The presence of pulmonary metastases is a significant unfavourable prognostic factor. Thoracotomy is strongly recommended in these patients, while computed tomography (CT) remains the gold imaging standard. The purpose of our study was to create tools for the CT-based qualification for thoracotomy in osteosarcoma patients in order to reduce the rate of useless thoracotomies.

METHODS

Sixty-four osteosarcoma paediatric patients suspected of lung metastases on CT and their first-time thoracotomies (n = 100) were included in this retrospective analysis. All CT scans were analysed using a compartmental evaluation method based on the number and size of nodules. Calcification and location of lung lesions were also analysed. Inter-observer reliability between two experienced radiologists was assessed. The CT findings were then correlated with the histopathological results of thoracotomies. Various multivariate predictive models (logistic regression, classification tree and random forest) were built and predictors of lung metastases were identified.

RESULTS

All applied models proved that calcified nodules on the preoperative CT scan best predict the presence of pulmonary metastases. The rating of the operated lung on the preoperative CT scan, dependent on the number and size of nodules, and the total number of nodules on this scan were also found to be important predictors. All three models achieved a relatively high sensitivity (72-92%), positive predictive value (81-90%) and accuracy (74-79%). The positive predictive value of each model was higher than of the qualification for thoracotomy performed at the time of treatment. Inter-observer reliability was at least substantial for qualitative variables and excellent for quantitative variables.

CONCLUSIONS

The multivariate models built and tested in our study may be useful in the qualification of osteosarcoma patients for metastasectomy through thoracotomy and may contribute to reducing the rate of unnecessary invasive procedures in the future.

CT-guided hook-wire localization of pulmonary nodules in children prior to atypical resection by thoracoscopy: Practical aspects

In the multidisciplinary treatment of pediatric oncologic patients, multiple imaging tests, biopsies, and resections are required for diagnosis, initial staging, and posterior restaging. In these patients, pulmonary nodules are not always metastases, so the correct diagnosis of these lesions affects their treatment and the patient's survival. Percutaneous localization of pulmonary nodules is key for two reasons: it enables the surgeon to resect the smallest amount of lung tissue possible and it guarantees that the nodule will be included in the resected specimen. Without percutaneous localization, it can be impossible to accomplish these two objectives in patients with very small nodules that are separated from the pleural surface and therefore impossible to see by thoracoscopy. This article reviews the technique for hook-wire localization of pulmonary nodules and the keys to ensuring the best results.

CT classification of acute myeloid leukemia with pulmonary infiltration

PURPOSE

To characterize and categorize the CT findings of pulmonary leukemic infiltration (PLI) in patients with acute myeloid leukemia (AML).

MATERIALS AND METHODS

Among 435 patients with AML, 20 patients with PLI were retrospectively selected, and clinical characteristics and CT findings were analyzed. PLI was categorized into four patterns according to CT findings: type A, multiple nodules and/or masses; type B, bilateral perihilar airspace opacities (GGA or consolidation) without any nodules or masses; type C, mixture of type A and B; and type D, PLI without visible abnormal lung opacity. The difference in overall survival among four CT patterns was also examined.

RESULTS

The frequency of complex karyotypes was higher in AML patients with PLI than in whole AML patients. Percentages of patients with CT findings of type A, B, C, and D were 35%, 20%, 35%, and 10%, respectively. There was a clear difference in the localization of opacities according to the type of infiltrates, i.e., nodules/masses were mainly detected in the lower/peripheral portion. Conversely, GGA was mainly located in the upper/central portion. The median overall survival from diagnosis of PLI was 262 days (range 12-1148). The CT pattern was not significantly associated with survival (p = 0.3), with the exception of patients with type C tending to have significantly better outcomes compared to patients with type B (p = 0.05).

CONCLUSION

This classification can contribute in accurate non-invasive diagnosis and possibly in the estimation of prognosis.

CT Features of Benign Intrapulmonary Lymph Nodes in Pediatric Patients With Known Extrapulmonary Solid Malignancy

OBJECTIVE. The purpose of our study was to determine the CT features of benign intrapulmonary lymph nodes in pediatric patients with known extrapulmonary solid malignancy. MATERIALS AND METHODS. A retrospective review of surgical pathology archives was performed to identify consecutive chest CT studies of pediatric patients (≤ 18 years) with extrapulmonary solid malignancy and histologically confirmed benign intrapulmonary lymph nodes between January 1, 2004, and March 15, 2020. CT features of intrapulmonary lymph nodes-including size, shape, margin, type, associated calcification or fat, and location-were independently evaluated by two pediatric radiologist reviewers. The CT features of benign intrapulmonary lymph nodes in pediatric patients were analyzed using summary statistics. Interobserver agreement was measured with the kappa coefficient. RESULTS. There were 36 pathology-confirmed benign intrapulmonary lymph nodes in 27 pediatric patients (18 boys and nine girls; mean age, 12 years; age range, 1-18.2 years). Twenty-three (63.9%) of the benign intrapulmonary lymph nodes were biopsied from the right lung and 13 (36.1%) from the left lung (p = .03). The mean size, determined from CT studies, of benign intrapulmonary lymph nodes was 3.6 mm (SD, 1.4 mm; range, 1.3-7.8 mm). Triangular shape (25/36, 69.4%) was the most common shape of the benign intrapulmonary lymph nodes. Less commonly seen shapes of benign intrapulmonary lymph nodes were oval (6/36, 16.7%), round (3/36, 8.3%), and trapezoidal (2/36, 5.6%). All benign intrapulmonary lymph nodes were smoothly marginated and solid without associated calcification or fat. Of the 36 benign intrapulmonary lymph nodes, 15 (41.7%) were pleura-based; 11 (30.6%), perifissural; and 10 (27.8%), parenchymal. The kappa value for interobserver agreement between the two reviewers was 0.917 (95% CI, 0.825-1.000; standard error, 0.047), which corresponds to near-perfect agreement. CONCLUSION. In pediatric patients with known extrapulmonary solid malignancy, benign intrapulmonary lymph nodes are subcentimeter (mean size, 3.6 mm), smoothly marginated, and solid without containing calcification or fat on CT. In particular, triangular shape was the most commonly encountered shape of a benign intrapulmonary lymph node.

How Are Indeterminate Pulmonary Nodules at Diagnosis Associated with Survival in Patients with High-Grade Osteosarcoma?

BACKGROUND

Pulmonary metastases are a poor prognostic factor in patients with osteosarcoma; however, the clinical significance of subcentimeter lung nodules and whether they represent a tumor is not fully known. Because the clinician is faced with decisions regarding biopsy, resection, or observation of lung nodules and the potential impact they have on decisions about resection of the primary tumor, this remains an area of uncertainty in patient treatment. Surgical management of the primary tumor is tailored to prognosis, and it is unclear how aggressively patients with indeterminate pulmonary nodules (IPNs), defined as nodules smaller than 1 cm at presentation, should be treated. There is a clear need to better understand the clinical importance of these nodules.

QUESTIONS/PURPOSES

(1) What percentage of patients with high-grade osteosarcoma and spindle cell sarcoma of bone have IPNs at diagnosis? (2) Are IPNs at diagnosis associated with worse metastasis-free and overall survival? (3) Are there any clinical or radiologic factors associated with worse overall survival in patients with IPN?

METHODS

Between 2008 and 2016, 484 patients with a first presentation of osteosarcoma or spindle cell sarcoma of bone were retrospectively identified from an institutional database. Patients with the following were excluded: treatment at another institution (6%, 27 of 484), death related to complications of neoadjuvant chemotherapy (1%, 3 of 484), Grade 1 or 2 on final pathology (4%, 21 of 484) and lack of staging chest CT available for review (0.4%, 2 of 484). All patients with abnormalities on their staging chest CT underwent imaging re-review by a senior radiology consultant and were divided into three groups for comparison: no metastases (70%, 302 of 431), IPN (16%, 68 of 431), and metastases (14%, 61 of 431) at the time of diagnosis. A random subset of CT scans was reviewed by a senior radiology registrar and there was very good agreement between the two reviewers (κ = 0.88). Demographic and oncologic variables as well as treatment details and clinical course were gleaned from a longitudinally maintained institutional database. The three groups did not differ with regard to age, gender, subtype, presence of pathological fracture, tumor site, or chemotherapy-induced necrosis. They differed according to local control strategy and tumor size, with a larger proportion of patients in the metastases group presenting with larger tumor size and undergoing nonoperative treatment. There was no differential loss to follow-up among the three groups. Two percent (6 of 302) of patients with no metastases, no patients with IPN, and 2% (1 of 61) of patients with metastases were lost to follow-up at 1 year postdiagnosis but were not known to have died. Individual treatment decisions were determined as part of a multidisciplinary conference, but in general, patients without obvious metastases received (neo)adjuvant chemotherapy and surgical resection for local control. Patients in the no metastases and IPN groups did not differ in local control strategy. For patients in the IPN group, staging CT images were inspected for IPN characteristics including number, distribution, size, location, presence of mineralization, and shape. Subsequent chest CT images were examined by the same radiologist to reevaluate known nodules for interval change in size and to identify the presence of new nodules. A random subset of chest CT scans were re-reviewed by a senior radiology resident (κ = 0.62). The association of demographic and oncologic variables with metastasis-free and overall survival was first explored using the Kaplan-Meier method (log-rank test) in univariable analyses. All variables that were statistically significant (p < 0.05) in univariable analyses were entered into Cox regression multivariable analyses.

RESULTS

Following re-review of staging chest CTs, IPNs were found in 16% (68 of 431) of patients, while an additional 14% (61 of 431) of patients had lung metastases (parenchymal nodules 10 mm or larger). After controlling for potential confounding variables like local control strategy, tumor size, and chemotherapy-induced necrosis, we found that the presence of an IPN was associated with worse overall survival and a higher incidence of metastases (hazard ratio 1.9 [95% CI 1.3 to 2.8]; p = 0.001 and HR 3.6 [95% CI 2.5 to 5.2]; p < 0.001, respectively). Two-year overall survival for patients with no metastases, IPN, or metastases was 83% [95% CI 78 to 87], 65% [95% CI 52 to 75] and 45% [95% CI 32 to 57], respectively (p = 0.001). In 74% (50 of 68) of patients with IPNs, it became apparent that they were true metastatic lesions at a median of 5.3 months. Eighty-six percent (43 of 50) of these patients had disease progression by 2 years after diagnosis. In multivariable analysis, local control strategy and tumor subtype correlated with overall survival for patients with IPNs. Patients who were treated nonoperatively and who had a secondary sarcoma had worse outcomes (HR 3.6 [95% CI 1.5 to 8.3]; p = 0.003 and HR 3.4 [95% CI 1.1 to 10.0]; p = 0.03). The presence of nodule mineralization was associated with improved overall survival in the univariable analysis (87% [95% CI 39 to 98] versus 57% [95% CI 43 to 69]; p = 0.008), however, because we could not control for other factors in a multivariable analysis, the relationship between mineralization and survival could not be determined. We were unable to detect an association between any other nodule radiologic features and survival.

CONCLUSION

The findings show that the presence of IPNs at diagnosis is associated with poorer survival of affected patients compared with those with normal staging chest CTs. IPNs noted at presentation in patients with high-grade osteosarcoma and spindle cell sarcoma of bone should be discussed with the patient and be considered when making treatment decisions. Further work is required to elucidate how the nodules should be managed.

LEVEL OF EVIDENCE

Level III, prognostic study.

Primary lung adenocarcinoma in three adolescent patients affected by bone sarcomas

Pediatric primary lung carcinomas are extremely rare. Apart from known associations with congenital adenomatoid malformations, cases of primary lung adenocarcinomas after prolonged treatments of pediatric malignancy have been reported. We describe the morphological and molecular features of three cases of lung adenocarcinoma developed in adolescents aged 8 to 17 years during progression of their bone osteosarcoma or Ewing sarcomas. The morphological features overlapped those of adult lung adenocarcinoma including in situ, minimally invasive, and invasive forms. EGFR gene mutations were found in all three cases by targeted next-generation sequencing. The two patients with Ewing sarcoma had no progression of their lung cancer and no further progression of the metastatic bone tumor after additional chemo- and radio-therapy. Conversely, the osteosarcoma patient refused further treatments after thoracic surgery for metastatic osteosarcoma and locally advanced adenocarcinoma and died 2 years later of widespread distant metastases. Our results indicate that primary lung cancer might originate in pediatric patients during prolonged adjuvant therapies for primary bone neoplasm, and this possibility should be considered in the presence of suspected lung disease progression to correctly monitor the primary tumor evolution and define the appropriate therapeutic strategy at each time point. If appropriately treated, second primary lung cancer may not affect the patients' prognosis. The pathogenetic mechanisms of these rare lung adenocarcinomas are not clear, but the presence of EGFR mutations in all three cases indicates an oncogene addiction of the lung tumor, rather than a direct cancerogenic effect of the sarcoma-related treatment.

Feasibility of fast non local means filter in pediatric chest x-ray for increasing of pulmonary nodule detectability with 3D printed lung nodule phantom

General x-ray images have a lower probability of nodule detection than other modalities. Especially in children, the probability of nodule detection can likely drop due to poor image quality from using low radiation dose. To demonstrate the effectiveness of fast non-local means (FNLM) filter to increase the probability of nodule detection in pediatric chest x-ray images and reduce radiation dose while maintaining image quality. Quantitative assessment of normalised noise power spectrum (NNPS), coefficient of variation (COV) and contrast to noise ratio (CNR) were performed after applying four filters (median, Wiener, total variation and FNLM) on a 1-year-old child phantom. A 3D-printed patient nodule phantom was inserted into the phantom. Assessment was performed on AP and LAT view images acquired with the tube voltage reduced to 38 and 27%, and tube current reduced to 84 and 61%, respectively. The results showed the lowest NNPS and COV values and the highest CNR value when the FNLM filter applied. Moreover, the AP view results showed 37% decrease in COV and 30% increase in CNR in images with the FNLM filter applied (images exposed with the tube voltage and current reduced to 29% and 50%, respectively). The LAT view results showed 5% decrease in COV and 36% increase in CNR in images with the FNLM filter applied (images exposed with the tube current reduced by 27%). By applying the FNLM filter, the probability of nodule detection could be increased by denoising and contrast enhancement. Moreover, using the FNLM filter could reduce cancer risk in pediatric patients by reducing radiation dose about 30% to 44%.

Computed Tomography-Guided Wire-Marking for Thoracoscopic Resection of Small Lung Nodules in Children

Introduction: In pediatric patients, thoracoscopic wedge-resection of pulmonary nodules is an established therapy. However, intraoperative localization of small lesions is still challenging. Purpose of this study was to evaluate the efficacy of preoperative computed tomography (CT)-guided wire-marking of small lung nodules. Materials and Methods: Between 2012 and 2017 a total of six cases receiving thoracoscopic resection of CT-marked lung nodules were analyzed. The nodules were preoperatively tagged by a wire, which was attached to the thoracic wall by sterile dressing. Characteristics of interest were stability of wire, complete resection, and prevention of open thoracotomy. Results: Six procedures were performed on five patients, including four men and one woman. Median age at intervention was 16 years (range 11-19 years). All patients had a history of primary malignancies, including osteosarcoma (n = 4) and synovial sarcoma (n = 1). A total of 10 nodules were visualized in CT of which 9 were marked by wire. The median expected size of nodules was 6 mm (range 2-23 mm). Two patients had bilateral, two left-sided and two right-sided lung lesions. There was no wire slippage. In five procedures wedge resection was possible; one case needed a near total lobe resection. In one case a mini-thoracotomy at port insertion site was performed to extract the specimen. There was no conversion to thoracotomy. Histopathology showed R0 resection in all patients. Malignancy was found in all specimens. In one patient postoperative hemorrhagic anemia necessitated transfusion. Conclusions: Preoperative wire-localization of small lung nodules is a safe and effective tool to enable thoracoscopic resection in children and to avoid thoracotomic interventions.

Use of radiotracer labeling of pulmonary nodules to facilitate excisional biopsy and metastasectomy in children with solid tumors

PURPOSE

Excision of suspected pulmonary metastases in children is challenging in the setting of multiple nodules or nodules that are small, deep, or soft. This study describes preoperative technetium macro-aggregated albumin (Tc 99m MAA) localization of pulmonary lesions to aid in intraoperative identification and resection.

METHODS

Patients with past or present pediatric solid tumors who underwent resection of pulmonary nodules following CT-guided Tc 99m MAA labeling were identified. The primary outcomes were successful preoperative localization and subsequent resection.

RESULTS

Metastasectomy following Tc 99m MAA localization was performed 15 times in 11 patients from 2014 to 2016. Mean age was 13years; the most common diagnosis was osteosarcoma (33%). Tc 99m MAA labeling was attempted in 24 nodules with mean nodule diameter 6±5mm and mean depth from the pleural surface of 12±17mm; localization was successful in 23 nodules (96%). Subsequent resection was performed by thoracotomy in 12 cases and thoracoscopy in 3. All labeled nodules were identified intraoperatively; two were not resected and 17 of the 21 nodules resected demonstrated metastatic disease on pathology.

CONCLUSION

Tc 99m MAA labeling of pulmonary nodules in children is effective in facilitating resection of sub-centimeter intraparenchymal metastases identified on preoperative imaging. Furthermore, this technique allows for thoracoscopic metastasectomy in select patients.

TYPE OF STUDY/LEVEL OF EVIDENCE

Case Series/Level IV.

The impact of reconstruction techniques on observer performance for the detection and characterization of small pulmonary nodules in chest CT of children under 13 years

OBJECTIVE

To compare three different reconstruction techniques of CT data for the detection of pulmonary nodules in children under 13 years. Secondly to assess the prevalence of perifissural nodular opacities.

MATERIALS AND METHODS

The study consisted of chest CTs of 31 children (median age 6.9 years, range 2.1-12.7), of whom 17 had known extra-thoracic malignancies. Four observers assessed three techniques for the presence of nodules: axial 5 mm maximum intensity projections (MIPs) used in conjunction with 1 mm slices (mode A), 1 mm slices alone (mode B) and 3 mm slices (mode C). All modes were available in 3D. Per mode sensitivities were determined above a certain threshold of reader agreement. Confidence level and reader agreement for identification of an opacity as nodule served as surrogate for quality of nodule characterization.

RESULTS

103 nodules (median size 2.0 mm) were detected. Mode A yielded the highest interreader agreement (κ 0.336) and a superior sensitivity (71%, p = 0.003) compared to mode B and C (κ 0.218, sensitivity 57% and κ 0.247, sensitivity 56%, respectively). Mode B provided the highest confidence level and interreader agreement with respect to nodule identification (mean 4.3/5, κw 0.508). Double reading improved and evened interreader agreement for all modes (κ 0.450), mode A maintained the highest sensitivity (89.1%, p = 0.05-0.08). A median of 1 intrapulmonary lymph node/patient was seen in children with and without malignancy.

CONCLUSION

MIP improves the detection of pulmonary nodules in chest CTs of children, but overall interreader agreement is only fair. Double reading represents a powerful tool to increase diagnostic reliability in chest CTs of children with a malignancy. Nodule characterization is best with 1 mm slices. Intrapulmonary lymph nodes occur in children with and without malignancy.

Pulmonary Nodule Size <5 mm Still Warrants Investigation in Patients With Osteosarcoma and Ewing Sarcoma

BACKGROUND

Osteosarcoma (OS) and Ewing sarcoma (ES) have a high propensity to develop pulmonary metastases. Lung lesions with calcification, peripheral location, and size >5 mm are more likely to represent malignant metastases. We evaluated the incidence of malignancy in nodules 5 mm or less to potentially guide decisions between biopsy and observation.

MATERIALS AND METHODS

A retrospective review of patients <25 years of age with metastatic OS and ES treated at our institution between 2001 and 2014 who had undergone pulmonary nodule biopsy was performed. Computed tomographic scans were reviewed to evaluate nodule size and change over time.

RESULTS

Thirty-five patients (27 OS, 8 ES) met inclusion criteria. One hundred sixteen nodules were biopsied (97 OS, 19 ES). Nodule size at biopsy was not significantly different between the malignant (median, 6 mm, range, 1 to 79 mm) and benign (median, 3 mm, range, 1 to 21 mm) lesions (P=0.063). Size of pulmonary nodules <5 mm was not entirely predictive of benign status, with sensitivity estimate of 0.709 (95% confidence interval, 0.465-0.872; P=0.091) and specificity estimate of 0.776 (95% confidence interval, 0.324-0.962; P=0.219) for all nodules biopsied.

CONCLUSIONS

Pulmonary nodules in patients with OS and ES <5 mm cannot be excluded from biopsy considerations.

Predictive factors for malignancy in incidental pulmonary nodules detected in breast cancer patients at baseline CT

OBJECTIVES

Pulmonary nodules are commonly encountered at staging CTs in patients with extrathoracic malignancies, but their significance on a per-patient basis remains uncertain.

METHODS

We undertook a retrospective analysis of pulmonary nodules identified in patients with a diagnosis of breast cancer from 2010 - 2015, evaluating nodules present at a baseline CT (i.e. prevalent nodules). We reviewed 211 patients with 248 individual nodules.

RESULTS

The rate of malignancy in prevalent nodules is low, approximately 13 %. Variables associated with metastasis include pleural studding, hilar lymphadenopathy and the presence of extrapulmonary metastasis, as well as number of nodules, nodule size and nodule shape. Using a combination of these factors, we have developed an evidence-based multivariate decision tree to predict which nodules are malignant in these patients, which is 91 % accurate and 100 % sensitive for metastasis.

CONCLUSIONS

We propose a simplified clinical prediction algorithm to guide radiologists and oncologists in managing patients with breast cancer and incidental pulmonary nodules.

KEY POINTS

• Incidental pulmonary nodules are common on computed tomography in breast cancer patients. • Nodules present at baseline have a lower malignancy risk than incident nodules. • We present an evidence-based decision algorithm predicting which nodules are likely malignant. • This algorithm can help direct patient management.

Spontaneous Regression of Pulmonary Nodules Presenting as Epstein-Barr Virus-related Atypical Infectious Mononucleosis

BACKGROUND

Pulmonary nodules associated with Epstein-Barr virus (EBV)-related atypical infectious mononucleosis have rarely been described.

OBSERVATIONS

A 12-year-old Japanese boy, upon admission, revealed multiple small round nodules (a total of 7 nodules in 4 to 8 mm size) in the lungs on computed tomography. The hemorrhagic pharyngeal tonsils with hot signals on 18F-fluorodeoxyglucose-positron emission tomography-computed tomography were biopsied revealing the presence of EBV-encoded small nuclear RNA (EBER)-positive cells; however, no lymphoma was noted. The patient was diagnosed as having atypical EBV-infectious mononucleosis associated with primary EBV infection. Pulmonary nodules markedly reduced in numbers and sizes spontaneously over a 2-year period.

CONCLUSIONS

Differential diagnosis of pulmonary nodules in childhood should include atypical EBV infection.

Pulmonary coccidiomycosis masquerading as refractory metastatic Ewing sarcoma

We report the case of a patient who presented with a large pelvic mass, which was biopsy-proven to be Ewing sarcoma. The patient was also found to have 18 pulmonary lesions on a staging CT that were presumed to represent metastatic disease. After induction chemotherapy, a PET/CT scan revealed a marked reduction in his pelvic mass along with improvement in nearly all his pulmonary lesions except 2, which increased in size. The mixed response to chemotherapy was unusual and the decision was made to resect one of the growing lesions. Fungal culture from the excised lesion grew Coccidioides immitis.

Surgery for metastatic disease

PURPOSE OF REVIEW

Outcomes for children with cancer have steadily improved and the long-term survival for most early-stage childhood malignancies is now greater than 90%. On the contrary, the prognosis for children with metastatic cancer, though significantly improved from a generation ago, is generally still very disappointing. Surgery continues to play a role in the increasingly aggressive treatment of children with metastatic disease with the ultimate goal of prolonging survival and improving quality of life.

RECENT FINDINGS

Most childhood tumors are relatively rare and are therefore studied using a multi-institutional cooperative group model that standardizes protocols and pools resources and data, accounting for the remarkable progress that has been made in the care of children with cancer. In some cases, this has also allowed us to recognize the utility of certain surgical therapies and the need to further study others.

SUMMARY

Modern surgery and critical care allow us to consider offering children with metastatic disease more aggressive surgical options in circumstances where the data suggest the potential for long-term survival. In situations where data are lacking, children might be offered a surgical option as part of an ongoing trial.