Frequency and significance of pulmonary nodules on thin-section CT in patients with extrapulmonary malignant neoplasms

New insights into imaging of pulmonary metastases from extra-thoracic neoplasms

The lung is one of the most common sites of metastases from extra-thoracic neoplasms. Lung metastases can show heterogeneous imaging appearance, thus mimicking a wide range of lung diseases, from benign lesions to primary lung cancer. The proper interpretation of pulmonary findings is crucial for prognostic assessment and treatment planning, even to avoid unnecessary procedures and patient anxiety. For this purpose, computed tomography (CT) is one of the most used imaging modalities. In the last decades, cancer patients' population has steadily increased and, due to the widespread application of CT for staging and surveillance, the detection of pulmonary nodules has raised, making their characterization and management an urgent and mostly unsolved problem for both radiologists and clinicians. This review will highlight the pathways of dissemination of extra-thoracic tumours to the lungs and the heterogeneous CT imaging appearance of pulmonary metastases, providing useful clues to properly address the diagnosis. Furthermore, we will deal with the promising applications of radiomics in this field. Finally, a focus on the hot-topic of pulmonary nodule management in patients with extra-thoracic neoplasms (ETNs) will be discussed.

Soft tissue tumor imaging in adults: whole-body staging in sarcoma, non-malignant entities requiring special algorithms, pitfalls and special imaging aspects. Guidelines 2024 from the European Society of Musculoskeletal Radiology (ESSR)

OBJECTIVES

The revised European Society of Musculoskeletal Radiology (ESSR) consensus guidelines on soft tissue tumor imaging represent an update of 2015 after technical advancements, further insights into specific entities, and revised World Health Organization (2020) and AJCC (2017) classifications. This second of three papers covers algorithms once histology is confirmed: (1) standardized whole-body staging, (2) special algorithms for non-malignant entities, and (3) multiplicity, genetic tumor syndromes, and pitfalls.

MATERIALS AND METHODS

A validated Delphi method based on peer-reviewed literature was used to derive consensus among a panel of 46 specialized musculoskeletal radiologists from 12 European countries. Statements that had undergone interdisciplinary revision were scored online by the level of agreement (0 to 10) during two iterative rounds, that could result in 'group consensus', 'group agreement', or 'lack of agreement'.

RESULTS

The three sections contain 24 statements with comments. Group consensus was reached in 95.8% and group agreement in 4.2%. For whole-body staging, pulmonary MDCT should be performed in all high-grade sarcomas. Whole-body MRI is preferred for staging bone metastasis, with [18F]FDG-PET/CT as an alternative modality in PET-avid tumors. Patients with alveolar soft part sarcoma, clear cell sarcoma, and angiosarcoma should be screened for brain metastases. Special algorithms are recommended for entities such as rhabdomyosarcoma, extraskeletal Ewing sarcoma, myxoid liposarcoma, and neurofibromatosis type 1 associated malignant peripheral nerve sheath tumors. Satisfaction of search should be avoided in potential multiplicity.

CONCLUSION

Standardized whole-body staging includes pulmonary MDCT in all high-grade sarcomas; entity-dependent modifications and specific algorithms are recommended for sarcomas and non-malignant soft tissue tumors.

CLINICAL RELEVANCE STATEMENT

These updated ESSR soft tissue tumor imaging guidelines aim to provide support in decision-making, helping to avoid common pitfalls, by providing general and entity-specific algorithms, techniques, and reporting recommendations for whole-body staging in sarcoma and non-malignant soft tissue tumors.

KEY POINTS

An early, accurate, diagnosis is crucial for the prognosis of patients with soft tissue tumors. These updated guidelines provide best practice expert consensus for standardized imaging algorithms, techniques, and reporting. Standardization can improve the comparability examinations and provide databases for large data analysis.

Pulmonary lesion after surgery for renal cancer: progression or new primary?

PURPOSE

To investigate clinical and radiological differences between kidney metastases to the lung (RCCM +) and metachronous lung cancer (LC) detected during follow-up in patients surgically treated for Renal Cell Carcinoma (RCC).

METHODS

cM0 surgically-treated RCC who harbored a pulmonary mass during follow-up were retrospectively scrutinized. Univariate logistic regression assessed predictive features for differentiating between LC and RCCM + . Multivariable analyses (MVA) were fitted to predict factors that could influence time between detection and histological diagnosis of the pulmonary mass, and how this interval could impact on survivals.

RESULTS

87% had RCCM + and 13% had LC. LC were more likely to have smoking history (75% vs. 29%, p < 0.001) and less aggressive RCC features (cT1-2: 94% vs. 65%, p = 0.01; pT1-2: 88% vs. 41%, p = 0.02; G1-2: 88% vs. 37%, p < 0.001). The median interval between RCC surgery and lung mass detection was longer between LC (55 months [32.8-107.2] vs. 20 months [9.0-45.0], p = 0.01). RCCM + had a higher likelihood of multiple (3[1-4] vs. 1[1-1], p < 0.001) and bilateral (51% vs. 6%, p = 0.002) pulmonary nodules, whereas LC usually presented with a solitary pulmonary nodule, less than 20 mm. Univariate analyses revealed that smoking history (OR:0.79; 95% CI 0.70-0.89; p < 0.001) and interval between RCC surgery and lung mass detection (OR:0.99; 95% CI 0.97-1.00; p = 0.002) predicted a higher risk of LC. Conversely, size (OR:1.02; 95% CI 1.01-1.04; p = 0.003), clinical stage (OR:1.14; 95% CI 1.06-1.23; p < 0.001), pathological stage (OR:1.14; 95% CI 1.07-1.22; p < 0.001), grade (OR:1.15; 95% CI 1.07-1.23; p < 0.001), presence of necrosis (OR:1.17; 95% CI 1.04-1.32; p = 0.01), and lymphovascular invasion (OR:1.18; 95% CI 1.01-1.37; p = 0.03) of primary RCC predicted a higher risk of RCCM + . Furthermore, number (OR:1.08; 95% CI 1.04-1.12; p < 0.001) and bilaterality (OR:1.23; 95% CI 1.09-1.38; p < 0.001) of pulmonary lesions predicted a higher risk of RCCM + . Survival analysis showed a median second PFS of 10.9 years (95% CI 3.3-not reached) for LC and a 3.8 years (95% CI 3.2-8.4) for RCCM + . The median OS time was 6.5 years (95% CI 4.4-not reached) for LC and 6 years (95% CI 4.3-11.6) for RCCM + .

CONCLUSIONS

Smoking history, primary grade and stage of RCC, interval between RCC surgery and lung mass detection, and number of pulmonary lesions appear to be the most valuable predictors for differentiating new primary lung cancer from RCC progression.

Prediction of pulmonary metastasis in esophageal carcinoma patients with indeterminate pulmonary nodules

BACKGROUND

Indeterminate pulmonary nodules (IPNs) are common after surgery for esophageal cancer. The paucity of data on postoperative IPNs for esophageal cancer causes a clinical dilemma.

OBJECTIVE

The aim of this study was to identify the characteristics and clinical significance of IPNs after radical esophagectomy for metastatic esophageal cancer, determine the risk factors for pulmonary metastasis, and construct a risk score model to standardize the appropriate time to either follow up or treat the patient.

METHODS

All consecutive patients with esophageal squamous cell carcinoma (ESCC) who underwent radical surgery between 2013 and 2016 were included in this retrospective study. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors and develop risk score models.

RESULTS

A total of 816 patients were enrolled in the study. During a median follow-up period of 45 months, IPNs were detected in 221 (27.1%) patients, of whom 66 (29.9%) were diagnosed with pulmonary metastases. The following five variables maintained prognostic significance after multivariate analyses: the pathologic N category, number of IPNs, shape of IPNs, time of detection of IPNs, and size of IPNs. The Pulmonary Metastasis Prediction Model (PMPM) scale ranges from 0 to 15 points, and patients with higher scores have a higher probability of pulmonary metastases. The Hosmer-Lemeshow test showed a good calibration performance of the clinical prediction model (χ2 = 8.573, P = 0.380). After validation, the PMPM scale showed good discrimination with an AUC of 0.939.

CONCLUSION

A PMPM scale for IPNs in patients who underwent esophagectomy for ESCC may be clinically useful for diagnostic and therapeutic decision-making.

Unusual Presentation of Multiple Lung Nodules in a Patient With Supraglottic Squamous Cancer: A Rare Infectious Cause Revealed

Pulmonary nodules are commonly encountered in medical practice, necessitating thorough evaluation due to their diverse etiologies. Identifying the underlying cause is of utmost importance, particularly in patients with a history of extrapulmonary cancer, to differentiate between metastasis and other etiologies. We present a rare case of a 24-year-old male with supraglottic squamous cancer who developed multiple pulmonary nodules, which surprisingly were caused by a rare infectious agent. The patient presented with bilateral infiltrates on imaging, raising strong suspicion of metastatic disease from primary cancer. However, bronchoscopy and biopsy revealed no malignancy but confirmed the presence of Corynebacterium amycolatum, leading to a change in the treatment approach from palliative to curative. This case highlights the importance of considering other etiologies, especially infections, in patients with cancer and pulmonary nodules. Accurate diagnosis is crucial to guide appropriate management decisions and optimize patient outcomes.

What Is the Significance of Indeterminate Pulmonary Nodules in High-Grade Soft Tissue Sarcomas? A Retrospective Cohort Study

BACKGROUND

Sarcomas are rare, aggressive cancers which frequently metastasise to the lungs. Following diagnosis, patients typically undergo staging by means of a CT scan of their chest. This often identifies indeterminate pulmonary nodules (IPNs), but the significance of these in high-grade soft tissue sarcoma (STS) is unclear. Identifying whether these are benign or malignant is important for clinical decision making. This study analyses the clinical relevance of IPNs in high-grade STS.

METHODS

All patients treated at our centre for high-grade soft tissue sarcoma between 2010 and 2020 were identified from a prospective database. CT scans and their reports were reviewed, and survival data were collected from patient records.

RESULTS

389 suitable patients were identified; 34.4% had IPNs on their CT staging scan and 20.1% progressed into lung metastases. Progression was more likely with IPNs ≥ 5 mm in diameter (p = 0.006), multiple IPNs (p = 0.013) or bilateral IPNs (p = 0.022), as well as in patients with primaries ≥ 5 cm (p = 0.014), grade 3 primaries (p = 0.009) or primaries arising deep to the fascia (p = 0.041). The median time to progression was 143 days. IPNs at diagnosis were associated with an increased risk of developing lung metastases and decreased OS in patients with grade 3 STS (p = 0.0019 and p = 0.0016, respectively); this was not observed in grade 2 patients.

CONCLUSIONS

IPNs at diagnosis are associated with significantly worse OS in patients with grade 3 STS. It is crucial to consider the primary tumour as well as the IPNs when considering the risk of progression. Surveillance CT scans should be carried out within 6 months.

Small nodules (≤ 6 mm in diameter) of multiple primary lung cancers: prevalence and management

Background

Synchronous multiple primary lung cancers associated with small non-dominant nodules are commonly encountered. However, the incidence, follow-up, and treatment of small non-dominant tumors have been but little studied. We explored the prevalence and management of small non-dominant tumors and factors associated with interval growth.

Methods

This observational, consecutive, retrospective single-center study enrolled patients diagnosed with synchronous multiple primary lung cancers and small non-dominant tumors (≤ 6 mm in diameter) who underwent resection of the dominant tumor. The incidence, follow-up, and management of small non-dominant tumors and predictors of nodule growth were analyzed.

Results

There were 88 patients (12% of all lung cancer patients) with pathological diagnoses of synchronous multiple primary lung cancers. A total of 131 (18%) patients were clinically diagnosed with at least one small (≤ 6 mm in diameter) multiple primary lung cancer non-dominant tumor. 94 patients with 125 small-nodule non-dominant tumors clinically diagnosed as multiple primary lung cancers were followed-up for at least 6 months. A total of 29 (29/125, 23.2%) evidenced small pulmonary nodules (≤ 6 mm in diameter) that exhibited interval growth on follow-up computed tomography (CT). On multivariate analysis, a part-solid nodule (compared to a pGGN) (OR 1.23; 95% CI 1.08–1.40) or a solid nodule (compared to a pGGN) (OR 3.50; 95% CI 1.94–6.30) predicted small nodule interval growth.

Conclusion

We found a relatively high incidence of multiple primary lung cancers with small non-dominant tumors exhibiting interval growth on follow-up CT, suggesting that resection of non-dominant tumors at the time of dominant tumor resection, especially when the nodules are part-solid or solid, is the optimal treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-02022-2.

Detection of pulmonary nodules with scoutless fixed-dose ultra-low-dose CT: a prospective study

OBJECTIVES

To determine the accuracy of scoutless, fixed-dose ultra-low-dose (ULD) CT compared to standard-dose (SD) CT for pulmonary nodule detection and semi-automated nodule measurement, across different patient sizes.

METHODS

Sixty-three patients underwent ULD and SD CT. Two readers examined all studies visually and with computer-aided detection (CAD). Nodules detected on SD CT were included in the reference standard by consensus and stratified into 4 categories (nodule category, NODCAT) from the Dutch-Belgian Lung Cancer Screening trial (NELSON). Effects of NODCAT and patient size on nodule detection were determined. For each nodule, volume and diameter were compared between both scans.

RESULTS

The reference standard comprised 173 nodules. For both readers, detection rates on ULD versus SD CT were not significantly different for NODCAT 3 and 4 nodules > 50 mm³ (reader 1: 93% versus 89% (p = 0.257); reader 2: 96% versus 98% (p = 0.317)). For NODCAT 1 and 2 nodules < 50 mm³, detection rates on ULD versus SD CT dropped significantly (reader 1: 66% versus 80% (p = 0.023); reader 2: 77% versus 87% (p = 0.039)). Body mass index and chest circumference did not influence nodule detectability (p = 0.229 and p = 0.362, respectively). Calculated volumes and diameters were smaller on ULD CT (p < 0.0001), without altering NODCAT (84% agreement).

CONCLUSIONS

Scoutless ULD CT reliably detects solid lung nodules with a clinically relevant volume (> 50 mm³) in lung cancer screening, irrespective of patient size. Since detection rates were lower compared to SD CT for nodules < 50 mm³, its use for lung metastasis detection should be considered on a case-by-case basis.

KEY POINTS

• Detection rates of pulmonary nodules > 50 mm³are not significantly different between scoutless ULD and SD CT (i.e. volumes clinically relevant in lung cancer screening based on the NELSON trial), but were different for the detection of nodules < 50 mm³(i.e. volumes still potentially relevant in lung metastasis screening). • Calculated nodule volumes were on average 0.03 mL or 9% smaller on ULD CT, which is below the 20-25% interscan variability previously reported with software-based volumetry. • Even though a scoutless, fixed-dose ULD CT protocol was used (CTDI_vol0.15 mGy), pulmonary nodule detection was not influenced by patient size.

Contribution of positron emission tomography/magnetic resonance imaging in musculoskeletal malignancies

Positron emission tomography/computed tomography (PET/CT) is a promising hybrid imaging technique for evaluating musculoskeletal malignancies. Both technologies, independently are useful for evaluating this type of tumors. PET/MR has great potential combining metabolic and functional imaging PET with soft tissue contrast and multiparametric sequences of MR. In this paper we review the existing literature and discuss the different protocols, new available radiotracers to conclude with the scarce evidence available the most useful/probable indications of the PET MR for the for musculoskeletal malignancies.

Evaluating the Patient With a Pulmonary Nodule: A Review

IMPORTANCE

Pulmonary nodules are identified in approximately 1.6 million patients per year in the US and are detected on approximately 30% of computed tomographic (CT) images of the chest. Optimal treatment of an individual with a pulmonary nodule can lead to early detection of cancer while minimizing testing for a benign nodule.

OBSERVATIONS

At least 95% of all pulmonary nodules identified are benign, most often granulomas or intrapulmonary lymph nodes. Smaller nodules are more likely to be benign. Pulmonary nodules are categorized as small solid (<8 mm), larger solid (≥8 mm), and subsolid. Subsolid nodules are divided into ground-glass nodules (no solid component) and part-solid (both ground-glass and solid components). The probability of malignancy is less than 1% for all nodules smaller than 6 mm and 1% to 2% for nodules 6 mm to 8 mm. Nodules that are 6 mm to 8 mm can be followed with a repeat chest CT in 6 to 12 months, depending on the presence of patient risk factors and imaging characteristics associated with lung malignancy, clinical judgment about the probability of malignancy, and patient preferences. The treatment of an individual with a solid pulmonary nodule 8 mm or larger is based on the estimated probability of malignancy; the presence of patient comorbidities, such as chronic obstructive pulmonary disease and coronary artery disease; and patient preferences. Management options include surveillance imaging, defined as monitoring for nodule growth with chest CT imaging, positron emission tomography-CT imaging, nonsurgical biopsy with bronchoscopy or transthoracic needle biopsy, and surgical resection. Part-solid pulmonary nodules are managed according to the size of the solid component. Larger solid components are associated with a higher risk of malignancy. Ground-glass pulmonary nodules have a probability of malignancy of 10% to 50% when they persist beyond 3 months and are larger than 10 mm in diameter. A malignant nodule that is entirely ground glass in appearance is typically slow growing. Current bronchoscopy and transthoracic needle biopsy methods yield a sensitivity of 70% to 90% for a diagnosis of lung cancer.

CONCLUSIONS AND RELEVANCE

Pulmonary nodules are identified in approximately 1.6 million people per year in the US and approximately 30% of chest CT images. The treatment of an individual with a pulmonary nodule should be guided by the probability that the nodule is malignant, safety of testing, the likelihood that additional testing will be informative, and patient preferences.

Chest PET/MRI in Solid Cancers: Comparing the Diagnostic Performance of a Free-Breathing 3D-T1-GRE Stack-of-Stars Volume Interpolated Breath-Hold Examination (StarVIBE) Acquisition With That of a 3D-T1-GRE Volume Interpolated Breath-Hold Examination (VIBE) for Chest Staging During Whole-Body PET/MRI

BACKGROUND

Whole-body positron emission tomography/magnetic resonance imaging (WB-PET/MRI) is increasingly used in oncology. However, chest staging remains challenging.

PURPOSE

To compare the diagnostic performance of a free-breathing 3D-T1-GRE stack-of-stars volume interpolated breath-hold examination (StarVIBE) with that of a 3D-T1-GRE volume interpolated breath-hold examination (VIBE) during WB-PET/MRI for chest staging.

STUDY TYPE

Retrospective, cohort study.

POPULATION

One hundred and twenty-three patients were referred for initial staging of solid cancer, 46 of whom had pulmonary nodules and 14 had pulmonary metastasis.

FIELD STRENGTH/SEQUENCE

Free-breathing 3D-T1-GRE stack-of-stars (StarVIBE) and Cartesian 3D-T1-GRE VIBE at 3.0 T.

ASSESSMENT

Image quality was assessed using a 4-point scale and using the signal-to-noise ratio (SNR) of lung parenchyma and contrast-to-noise ratio (CNR) of pulmonary nodules. Diagnostic performances of both sequences were determined by three independent radiologists for detection of pulmonary nodules, lymph node involvement, and bone metastases using chest CT, pathology, and follow-up as reference standards.

STATISTICAL TESTS

Paired Student's t-test; chi-squared; Fisher's exact test. A P value <0.05 was considered statistically significant.

RESULTS

StarVIBE quality was judged as better in 34% of cases and at least equivalent to VIBE in 89% of cases, with significantly higher quality scores (4 [4-4] vs. 3 [3-4], respectively). SNR and CNR values were significantly higher with StarVIBE (8 ± 1.3 and 9.7 ± 4.6, respectively) than with VIBE (1.8 ± 0.2 and 5.5 ± 3.3, respectively). Compared to VIBE, StarVIBE showed significantly higher sensitivity (73% [95% CI 62-82] vs. 44% [95% CI 33-55], respectively) and specificity (95% [95% CI 88-99] vs. 67% [95% CI 56-77]) for pulmonary nodules detection and significantly higher sensitivity (100% [95% CI 89-100] vs. 67% [95% CI 48-82], respectively) for detection of lymph node involvement. Sensitivities for bone metastases detection were not significantly different (100% [95% CI 88-100] vs. 82% [95% CI 63-94], P = 0.054).

DATA CONCLUSION

Owing to improved SNR and CNR and spatial resolution, a free-breathing 3D stack-of-stars T1-GRE sequence improves chest staging in comparison with standard 3D-T1-GRE VIBE and may be integrated in WB-PET/MRI acquisitions for initial staging of solid cancer.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Electromagnetic navigation bronchoscopy localization of lung nodules for thoracoscopic resection

Background

Thoracoscopic localization of small peripheral pulmonary nodules is a concern. Failure can lead to larger parenchymal resection or conversion to thoracotomy. This study evaluates our experience in preoperative electromagnetic navigation bronchoscopy-guided localization of small peripheral lung lesions.

Methods

From January 2017 to March 2020 clinical, radiographic, surgical, and pathological data of patients who underwent electromagnetic navigation bronchoscopy (ENB)-guided methylene blue pleural marking of highly suspected pulmonary lesions before a full thoracoscopic resection were evaluated. Localization was performed for solid or mixed subpleural nodules measuring <10 mm, solid nodules measuring <20 mm located at more than 1 cm from the pleura and any pure ground glass opacity. Successful localization was defined as successful identification and thoracoscopic resection of target lesions.

Results

Forty-eight patients were included: 30 solid nodules (63%), 12 pure GGO (25%) and 6 mixed (13%). The median largest diameter at CT-scan was 11 mm (IQR, 9-14 mm) while the median distance from the pleural surface was 12 mm (IQR, 6-16 mm). The median ENB length was 25 min (19-33 min). Localization procedure was successful in 45 cases (94%). No procedural-related complications were reported.

Conclusions

ENB is a safe and accurate preoperative procedure to localize small lung peripheral lesions. The high successful rate, the absence of related complications, the possibility of performing the procedure in the same operating room with a single general anesthesia, make ENB-guided dye marking an advantageous tool for thoracoscopic pulmonary resection.

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.

The diagnosis of pulmonary metastases on chest computed tomography in primary bone sarcoma and musculoskeletal soft tissue sarcoma

The lungs are the commonest site of metastasis for primary high-grade bone and soft tissue sarcoma, but current guidelines on the management of pulmonary nodules do not specifically cater for this group of patients. The current article reviews the literature from the past 20 years that has reported the CT features of pulmonary metastases in the setting of known primary bone and soft tissue sarcoma, with emphasis on osteosarcoma, chondrosarcoma, and trunk and extremity soft tissue sarcoma, the aim being to aid radiologists who report chest CT of musculoskeletal sarcoma patients in deciding which lesions should be considered metastatic, which lesions are indeterminate and require follow-up, and which lesions are of no concern.

Lung Nodules in Melanoma Patients: Morphologic Criteria to Differentiate Non-Metastatic and Metastatic Lesions

Lung nodules are frequent findings in chest computed tomography (CT) in patients with metastatic melanoma. In this study, we assessed the frequency and compared morphologic differences of metastases and benign nodules. We retrospectively evaluated 85 patients with melanoma (AJCC stage III or IV). Inclusion criteria were ≤20 lung nodules and follow-up using CT ≥183 days after baseline. Lung nodules were evaluated for size and morphology. Nodules with significant growth, nodule regression in line with RECIST assessment or histologic confirmation were judged to be metastases. A total of 438 lung nodules were evaluated, of which 68% were metastases. At least one metastasis was found in 78% of patients. A 10 mm diameter cut-off (used for RECIST) showed a specificity of 95% and a sensitivity of 20% for diagnosing metastases. Central location (n = 122) was more common in metastatic nodules (p = 0.009). Subsolid morphology (n = 53) was more frequent (p < 0.001), and calcifications (n = 13) were solely found in non-metastatic lung nodules (p < 0.001). Our data show that lung nodules are prevalent in about two-thirds of melanoma patients (AJCC stage III/IV) and the majority are metastases. Even though we found a few morphologic indicators for metastatic or non-metastatic lung nodules, morphology has limited value to predict the presence of lung metastases.

Preoperative evaluation and indications for pulmonary metastasectomy

Pulmonary metastasectomy (PM) is an established treatment that can provide improved long-term survival for patients with metastatic tumor(s) in the lung. In the current era, where treatment options other than PM such as stereotactic body radiation therapy (SBRT), immunotherapy, and molecular-targeted therapy are available, thoracic surgeons should review the approach to the preoperative evaluation and the indications. Preoperative evaluation consists of history and physical examinations, physiological tests, and radiological examinations. Radiological examinations serve to identify the differential diagnosis of the pulmonary nodules, evaluate their precise number, location, and features, and search for extra thoracic metastases. The indication of PM should be considered from both physiological and oncological points of view. The general criteria for PM are as follows; (I) the patient has a good general condition, (II) the primary malignancy is controlled, (III) there is no other extrapulmonary metastases, and (IV) the pulmonary lesion(s) are thought to be completely resectable. In addition to the general eligibility criteria of PM, prognostic factors of each tumor type should be considered when deciding the indication for PM. When patients have multiple poor prognostic factors and/or a short disease-free interval (DFI), thoracic surgeons should not hesitate to observe the patient for a certain period before deciding on the indication for PM. A multidisciplinary discussion is needed in order to decide the indication for PM.

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.

Indeterminate pulmonary nodules are not associated with worse overall survival in Ewing Sarcoma

AIM

Lung metastases are a negative prognostic factor in Ewing sarcoma, however, the incidence and significance of sub-centimetre pulmonary nodules at diagnosis is unclear. The aims of this study were to (1): determine the incidence of indeterminate pulmonary nodules (IPNs) in patients diagnosed with Ewing sarcoma (2); establish the impact of IPNs on overall and metastasis-free survival and (3) identify patient, oncological and radiological factors that correlate with poorer prognosis in patients that present with IPNs on their staging chest CT.

MATERIALS & METHODS

Between 2008 and 2016, 173 patients with a first presentation of Ewing sarcoma of bone were retrospectively identified from an institutional database. Staging and follow-up chest CTs for all patients with IPN were reviewed by a senior radiologist. Clinical and radiologic course were examined to determine overall- and metastasis-free survival for IPN patients and to identify demographic, oncological or nodule-specific features that predict which IPN represent true lung metastases.

RESULTS

Following radiologic re-review, IPN were found in 8.7% of patients. Overall survival for IPN patients was comparable to those with a normal staging chest CT (2-year overall survival of 73.3% [95% CI 43.6-89] and 89.4% [95% CI 81.6-94], respectively; p = 0.34) and was significantly better than for patients with clear metastases (46.0% [95% CI 31.9-59]; p < 0.0001). Similarly, there was no difference in metastasis-free survival between 'No Metastases' and 'IPN' patients (p = 0.16). Lung metastases developed in 40% of IPN patients at a median 9.6 months. Reduction of nodule size on neoadjuvant chemotherapy was associated with worse overall survival in IPN patients (p = 0.0084).

CONCLUSION

IPN are not uncommon in patients diagnosed with Ewing sarcoma. In this study, we were unable to detect a difference in overall- or metastasis-free survival between patients with IPN at diagnosis and patients with normal staging chest CTs.

The value of chest and skeletal staging studies in conventional chondrosarcoma

OBJECTIVE

To determine the value of chest and skeletal staging in patients presenting with conventional chondrosarcoma (CS).

MATERIALS AND METHODS

Retrospective review of patients with CS diagnosed between January 2007 and December 2019. Data collected included age, sex, skeletal location and results of chest CT and whole-body bone scintigraphy (WB-BSc) obtained at initial diagnosis. The histological tumour grade based on surgical resection or needle biopsy was classified as low-grade (LGCT), high-grade (HGCT) and dedifferentiated (DD-CS). Findings of chest CT and WB-BSc were correlated with tumour grade.

RESULTS

Four hundred twenty patients were included (234 males and 186 females with mean age 54.5 years, range 9-91 years). The major long bones were involved in 205 cases, the flat bones in 166 cases, the mobile spine in 14 cases and the small bones of the hands and feet in 35 cases. Three hundred fifty tumours were central in location, 39 peripheral and 31 on the surface of the bone. There were 151 LGCTs, 196 HGCTs and 73 DD-CSs. Of patients with LGCT, 41.7% underwent chest CT and 25.2% WB-BSc. Of patients with HGCT, 95.4% underwent chest CT and 76.5% WB-BSc. Of patients with DD-CS, 98.6% underwent chest CT and 86.3% WB-BSc. Metastases were diagnosed in 2 (3.3%) chest CT studies and 0 WB-BSc in LGCT, in 8 (4.3%) chest CT studies and 0 WB-BSc in HGCT and in 21 (30%) chest CT studies and 6 (21%) WB-BSc in DD-CS.

DISCUSSION

Staging chest CT and WB-BSc is of little or no value except in DD-CS.

Management of Pulmonary Nodules in Oncologic Patients: AJR Expert Panel Narrative Review

Cancer survivors are at higher risk than the general population for development of a new primary malignancy, most commonly lung cancer. Current lung cancer screening guidelines recommend low-dose chest CT for high-risk individuals, including patients with a history of cancer and a qualifying smoking history. However, major lung cancer screening trials have inconsistently included cancer survivors, and few studies have assessed management of lung nodules in this population. This narrative review highlights relevant literature and provides expert opinion for management of pulmonary nodules detected incidentally or by screening in oncologic patients. In patients with previously treated lung cancer, a new nodule most likely represents distant metastasis from the initial lung cancer or a second primary lung cancer; CT features such as nodule size and composition should guide decisions regarding biopsy, PET/CT, and CT surveillance. In patients with extrapulmonary cancers, nodule management requires individualized risk assessment; smoking is associated with increased odds of primary lung cancer, whereas specific primary cancer types are associated with increased odds of pulmonary metastasis. Nonneoplastic causes, such as infection, medication toxicity, and postradiation or postsurgical change, should also be considered. Future prospective studies are warranted to provide evidence-based data to assist clinical decision-making in this context.

A review of staging chest CT in trunk and extremity soft tissue sarcoma

OBJECTIVES

To determine the incidence of pulmonary metastases on chest CT in trunk and extremity soft tissue sarcoma based on two size criteria, and to identify factors associated with metastases.

METHODS

Retrospective review of chest CT studies in patients with trunk and extremity soft tissue sarcoma over an 18-month period. Data collected included patient age/sex, tumour location, size and relationship to fascia. All chest CTs were reviewed for the presence of metastases which were diagnosed according to two size criteria: multiple nodules > 5 mm in size or multiple nodules > 10 mm in size. Follow-up CT studies were reviewed in cases initially considered indeterminate.

RESULTS

127 males and 73 females were included (mean age 57.1 years; range 10-90 years). 147 (73.5%) tumours were deep to the fascia and 53 (26.5%) superficial. Tumour size classified according to the 12 AJCC 2019 criteria was: T1 = 52, T2 = 76, T3 = 39, T4 = 33. Based on nodule size >5 mm, 73 (36.5%) patients had no metastases, 42 (21%) had metastases, while 85 (42.5%) studies were indeterminate. Based on nodule size >10 mm, 73 (36.5%) patients had no metastases, 28 (14%) had metastases, while 99 (49.5%) studies were indeterminate. Larger maximum dimension of the primary tumour was a risk factor for pulmonary metastases using both size criteria.

CONCLUSION

The incidence of pulmonary metastases at presentation in trunk and extremity soft tissue sarcoma is 14-21%. 42.5-49.5% of chest CTs were indeterminate.

ADVANCES IN KNOWLEDGE

The incidence of pulmonary metastases at presentation in trunk and extremity soft tissue sarcoma is 14-21%. Indeterminate pulmonary nodules are also very common.

The value of re-staging chest CT at first local recurrence of extremity and trunk soft tissue sarcoma

OBJECTIVE

To determine the prevalence of pulmonary metastases on re-staging chest CT at the time of first local recurrence (LR) of trunk or extremity soft tissue sarcoma (STS).

MATERIALS AND METHODS

Retrospective review of all patients diagnosed with recurrent STS between May 2007 and April 2018. Data collected included patient age and sex, site of primary STS, time to LR, recurrence site, initial tumour grade, recurrent tumour grade, findings of initial staging chest CT, and prevalence of pulmonary metastases on re-staging chest CT.

RESULTS

The study included 109 patients (males = 68, females = 41; mean age 56 years, range 9-92 years). The commonest tumour sub-types were myxofibrosarcoma (27.5%), undifferentiated pleomorphic/spindle cell sarcoma (20.2%), synovial sarcoma (10.1%), and malignant peripheral nerve sheath tumour (10.1%). Initial staging chest CT demonstrated pulmonary metastases in 1 of 77 (1.3%) patients for whom CT was available for review. The mean time to LR was 30.8 months (range 3-224 months). Pulmonary metastases were diagnosed on re-staging chest CT in 26 of 109 cases (23.9%), being commonest with grade 3 STS (36.1%). Pleomorphic sarcoma (85.7%) and undifferentiated spindle cell sarcoma (33.3%) were the 2 commonest tumour sub-types associated with pulmonary metastases at first LR.

CONCLUSION

Re-staging chest CT at the time of first LR of STS identified a prevalence of 23.9% pulmonary metastases, which supports the need for chest CT at the time of LR in line with the UK guidelines for the management of bone and soft tissue sarcoma.

KEY POINTS

• Pulmonary metastases were diagnosed in 1.3% of soft tissue sarcomas at presentation. • Pulmonary metastases were identified in ~ 24% of patients at first local recurrence of soft tissue sarcoma, most commonly with pleomorphic sarcoma and Trojani grade tumours. • No patient with a low-grade recurrence had pulmonary metastases.

Factors associated with subcentimeter pulmonary nodule outcomes followed with computed tomography imaging in oncology patients

•

PNs with irregular, lobuled or spiculated margins exhibited faster growth than PNs with regular, smooth margins.

•

Malignancy was significantly associated with male gender, a colorectal cancer diagnosis and advanced stage disease.

•

Oncologic patients should have an individualized CT follow-up strategy, as the rate of malignant pulmonary nodules is higher than in the general population.

Introduction

Technological advancements in computed tomography (CT) have enabled the frequent detection of small pulmonary nodules (PNs), especially in patients with an oncologic history. It is important the malignant versus benign etiology of PNs be determined. The aim of the present study was to evaluate the behavior and clinical/radiological characteristics of subcentimeter PNs detected by CT in oncologic patients.

Methods

An observational, longitudinal, retrospective and single-center study was conducted with a sample of 100 patients with a diagnosis of a primary malignant solid tumor outside of the lungs who developed indeterminate subcentimeter PNs (n = 251) detected on consecutive thoracic CT scans from 2015 to 2017. Follow-up CTs for each patients were examined in each of three periods (0–3 months, 3–6 months, and 6 months to 1 year).

Results

In our study sample, 28 patients (28 %) showed one or more signs suspicious of pulmonary metastasis, including ≥50 % PN growth, nodule growth followed by size reduction in patients undergoing chemotherapy, and the appearance of multiple nodules. The majority (56 %) of the PNs were detected during the 3–6-month follow-up CT scan. PNs with irregular, lobuled, or spiculated margins exhibited faster growth than PNs with regular, smooth margins. Malignancy of PNs was found to be significantly associated with being male, a primary colorectal cancer diagnosis, and advanced stage disease.

Conclusion

Our findings reinforce the necessity of an individualized CT follow-up strategy for patients with an oncologic history, as well as the importance of early nodule screening, with the inter-scan interval being dependent on the primary neoplasm.

Management of pulmonary nodules

Pulmonary nodules are frequently detected during clinical practice and require a structured approach in their management in order to identify early lung cancers and avoid harm from over investigation. The article reviews the 2015 British Thoracic Society guidelines for the management of pulmonary nodules and the evidence behind them.

The management of hydatidiform mole with lung nodule: a retrospective analysis in 53 patients

Objective

To investigate the significance of lung nodule in hydatidiform mole, we retrospectively compared the clinical outcomes of those patients treated with different strategies.

Methods

The patients were divided into three groups: chemotherapy immediately once lung nodule was detected (group 1, n=17), delayed chemotherapy until human chorionic gonadotrophin (hCG) level met the diagnostic criteria for gestational trophoblastic neoplasia (GTN) (group 2, n=18), and hCG surveillance alone until hCG level was normalized spontaneously (group 3, n=18). The clinical parameters of these patients were collected and analyzed.

Results

Totally 53 (4.0%) patients were included from 1,323 cases with molar pregnancy during past 16 years. Among them, the diameters of lung nodules were 0.3–2.5 cm. Chemotherapy cycles for achieving hCG normalization and the failure rate of first-line chemotherapy in group 1 were significantly increased than that in group 2 (5 vs. 3 cycles, p=0.000, 58.8% vs. 11.1%, p=0.005). The hCG level of all 18 cases in group 3 was normalized spontaneously within 6 months. Of those, lung nodules of 9 patients disappeared spontaneously, accounting for 25% (9/36) of patients who initially selected observation. The proportion of single nodule in group 3 was significantly higher than that in group 2 (10/18 vs. 2/18, p=0.012).

Conclusion

Our results suggest that lung nodule alone is not an adequate indication of chemotherapy in molar pregnancy. hCG surveillance is safe for patients with lung nodule, especially with single nodule, as long as their hCG levels do not meet International Federation of Gynecology and Obstetrics diagnostic criteria for GTN.

Microcoil-Guided Video-Assisted Thoracoscopic Excision of Nodules Suspicious for Metastasis in Patients With Extra-Thoracic Malignancies

The purpose of this study is to determine the utility of preoperative CT-guided microcoil localization followed by fluoroscopy guided video-assisted thoracoscopic resection in the diagnosis and management of small peripheral pulmonary nodules in patients with extra-thoracic malignancies. This study is a retrospective analysis of prospectively collected data between August 2003 and September 2013. Fifty patients with extra-thoracic malignancies underwent preoperative localization of small indeterminate pulmonary nodules using CT-guided microcoil localization. Nodules were then resected by video-assisted thoracoscopic resection wedge excision and intraoperative fluoroscopy guidance. Univariate and multivariate logistic regression analysis were conducted. Fifty patients with a history of 14 different extra-thoracic cancers (57% female, mean age 62 years) had 55 nodules resected (mean size = 12 mm, depth from visceral pleura = 22 mm). Histology of resected nodules showed metastasis (25 of 50 patients), benign (10 of 50), and (15 of 50) early stage primary lung cancer. Smokers were found 6 times more likely to present with primary lung cancer than metastasis (P < 0.009). CT-guided microcoil localization procedure was successful in all patients with a mean time of 31(10) minutes and allowed successful wedge resection in all cases with no major complications. The mean operative time and fluoroscopy time were 27(12) minutes and 3(5) minutes, respectively. Microcoil-guided thoracoscopic wedge resection was effective in achieving early definitive diagnosis and changed management in 50% of patients with presumed metastasis with minimal morbidity.

Indeterminate nodules in osteosarcoma: what's the follow-up?

BACKGROUND

Indeterminate pulmonary nodules in patients diagnosed with osteosarcoma present a challenge for accurate staging and prognosis. The aim of this study was to explore the significance of this finding.

METHODS

A retrospective cohort study of 120 patients with osteosarcoma was performed in the North East of England. Chest computed tomographies (CTs) at presentation were reviewed and the incidence of 'indeterminate' nodules recorded. Follow-up scans were reviewed and survival as well as prognostic features were analysed.

RESULTS

25% of our cohort presented with indeterminate nodules. Of these, 33% were subsequently confirmed as metastases, the majority within a year. Kaplan-Meier survival analysis showed that patients with indeterminate nodules fared better than those with frank metastatic disease, and similar to those who presented with a normal chest CT. We found no radiographic features that predicted survival.

CONCLUSIONS

Indeterminate nodules remain a clinical and diagnostic dilemma. Close monitoring of patients is advised during the first year from presentation, and there is potential for indeterminate nodules to develop into frank metastases later than five years from presentation.

Spontaneous regression of gestational trophoblastic neoplasia

•We present two cases of postmolar gestational trophoblastic neoplasia (GTN).•Both cases presented with lung metastases after hydatidiform mole.•Both cases showed spontaneous regression without treatment.•The mechanism behind this phenomenon remains unclear.•Patients with postmolar GTN and declining hCG values may not need chemotherapy.

Analysis of the incidence and factors predictive of outcome in patients with head and neck cancer with pulmonary nodules

BACKGROUND

The management of pulmonary nodules is challenging; unfortunately, little is known about the incidence and significance of pulmonary nodules in patients with head and neck cancer.

METHODS

A review was conducted of 400 consecutive patients with head and neck cancer. Imaging was reviewed to identify the incidence of nodules and patient, tumor, and radiological factors associated with the risk of malignancy.

RESULTS

Nodules were found in 58% of patients, with a malignant rate of 6%. Age was the only predictor of having a nodule and advanced-stage III + IV was a predictor of malignancy (P = .023; odds ratio [OR] 10.64; confidence interval 1.33-84.98).

CONCLUSION

Patients presenting with head and neck cancer have a higher incidence of pulmonary nodules and a higher risk of malignancy. In contrast to the British Thoracic Society (BTS) guidelines, which use size to guide the need for serial scans, we would recommend follow-up imaging in all patients with head and neck cancer with nodules, irrespective of size.

Prediction of pulmonary metastasis in pulmonary nodules (≤10 mm) detected in patients with primary extrapulmonary malignancy at thin-section staging CT

PURPOSE

To investigate the predictive clinical and imaging factors associated with pulmonary metastasis in pulmonary nodules (PNs) ≤10 mm in patients with primary extrapulmonary malignancy (PEPM) on initial CT as well as the inter-nodular imaging features in the non-solitary PNs patients, to make a more reliable diagnosis and appropriate management of the PNs at an earlier stage after detection.

MATERIALS AND METHODS

161 patients with PNs ≤10 mm were reviewed from April 2013 to December 2013. The nature of PNs were determined on the interval change in imaging features on serial CT images (158 patients) and histologically proven (three patients). Independent predictors of changed PNs on initial CT were examined by multivariate regression analysis.

RESULTS

36.6% of patients developed interval change in nodules size. The average interval of the first change was 65.0 days (29-144 days). Tumor staging of III (P = 0.011) and IV (P < 0.001), the nodules number of 2-4 (P = 0.016), 5-9 (P < 0.001) and 10-20 (P < 0.001), the nodules margin of being smooth (P = 0.001) and slight lobulated (P < 0.001), and nodules with no near short strips (P = 0.001) were significant predictors of changed PNs. For patients with non-solitary PNs, 40.2% had PNs with identical imaging features, the incidence rate of change of which (74.3%) was significantly higher compared with that of varied features (32.7%), P < 0.001; and 94.3% of patients had all nodules per patient showing consistent prognosis.

CONCLUSIONS

For PNs ≤10 mm in patients with PEPM on baseline CT, the morphological characteristics and primary malignancies stage could differentiate the majority of the PNs. The interval for further CT evaluation of uncertain PNs should be early at 1-3 months after detection, and increased alert is needed for the possibility of pulmonary metastasis when an early interval change was detected.

Analysis of pulmonary nodules in patients with high-grade soft tissue sarcomas

Nowadays, small pulmonary nodules are easily detectable in patients with soft tissue sarcomas (STSs) because of highly improved computed tomography (CT) technologies. The purpose of this study was to determine the frequency and significance of the pulmonary nodules detected by CT in high-grade STS patients. 124 patients with high-grade STS were retrospectively reviewed. There were 72 males (57%) and 52 females (43%). Patients’ average age was 61 years (median (quartiles) 66 years (48–75), range 8–94 years). Pulmonary nodules were detected in 49 (39.5%) of 124 patients by CT scanning at first presentation. Of 49 patients with nodules at first presentation, 34 (69.4%) had benign lesions, and 13 (26.5%) had metastatic nodules. One patient (2%) had primary lung cancer and the remaining one with one nodule could not be definitively diagnosed due to a short follow-up time. 30 patients (24.1%) of 124 patients developed pulmonary nodules during their clinical progression. Seven (23.3%) had benign lesions, whereas 21 (70%) had metastatic lesions. Primary lung cancer was detected in two patients (6.7%). The size and timing of detection of a pulmonary nodule significantly affected the final clinical diagnosisby multivariate analysis. We conclude that pulmonary nodules can be detected highly frequently in patients with high-grade STSs because of improved CT technologies. Careful follow-up is needed if nodules are detected after initial treatment or during the clinical course of the disease.

A retrospective validation study of three models to estimate the probability of malignancy in patients with small pulmonary nodules from a tertiary oncology follow-up centre

AIM

To estimate the probability of malignancy in small pulmonary nodules (PNs) based on clinical and radiological characteristics in a non-screening population that includes patients with a prior history of malignancy using three validated models.

MATERIALS AND METHODS

Retrospective data on clinical and radiological characteristics was collected from the medical records of 702 patients (379 men, 323 women; range 19-94 years) with PNs ≤12 mm in diameter at a single centre. The final diagnosis was compared to the probability of malignancy calculated by one of three models (Mayo, VA, and McWilliams). Model accuracy was assessed by receiver operating characteristics (ROC). The models were calibrated by comparing predicted and observed rates of malignancy.

RESULTS

The area under the ROC curve (AUC) was highest for the McWilliams model (0.82; 95% confidence interval [CI]: 0.78-0.91) and lowest for the Mayo model (0.58; 95% CI: 0.55-0.59). The VA model had an AUC of (0.62; 95% CI: 0.47-0.64). Performance of the models was significantly lower than that in the published literature.

CONCLUSIONS

The accuracy of the three models is lower in a non-screening population with a high prevalence of prior malignancy compared to the papers that describe their development. To the authors' knowledge, this is the largest study to validate predictive models for PNs in a non-screening clinically referred patient population, and has potential implications for the implementation of predictive models.

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.

Detection of Small Pulmonary Nodules with Ultrashort Echo Time Sequences in Oncology Patients by Using a PET/MR System

PURPOSE

To investigate the utility of a free-breathing ultrashort echo time (UTE) sequence for the evaluation of small pulmonary nodules in oncology patients by using a hybrid positron emission tomography (PET)/magnetic resonance (MR) imaging system and to compare the nodule detection rate between UTE and a conventional three-dimensional gradient-recalled-echo (GRE) technique.

MATERIALS AND METHODS

In this HIPAA-compliant, institutional review board-approved prospective study, 82 pulmonary nodules were identified in eight patients with extrathoracic malignancies. Patients underwent free-breathing UTE and dual-echo three-dimensional GRE imaging of the lungs in a hybrid PET/MR imaging unit immediately after clinical PET/computed tomography (CT). CT was considered the reference standard for nodule detection. Two reviewers identified nodules and obtained measurements on MR images. The McNemar test was used to evaluate differences in nodule detection rate between MR techniques, and interrater agreement was assessed by using Bland-Altman plots.

RESULTS

Mean nodule diameter ± standard deviation was 6.2 mm ± 2.7 (range, 3-17 mm). The detection rate was higher for UTE imaging than for dual-echo GRE imaging for nodules of at least 4 mm (82% vs 34%, respectively; P < .001), with the largest difference in detection noted in the 4-8-mm nodule group (79% vs 21%, P < .001). UTE imaging displayed a higher detection rate than dual-echo GRE imaging for nodules without fluorodeoxyglucose avidity (68% vs 22%, respectively; P < .001). Interrater reliability of nodule detection with MR imaging was high (κ = 0.90 for UTE imaging and κ = 0.92 for dual-echo GRE imaging).

CONCLUSION

A free-breathing UTE sequence has high sensitivity for the detection of small pulmonary nodules (4-8 mm) and outperformed a three-dimensional dual-echo GRE technique for the detection of small, non-fluorodeoxyglucose-avid nodules.

What is the Significance of Indeterminate Pulmonary Nodules in Patients Undergoing Resection for Pancreatic Adenocarcinoma?

OBJECTIVE

The significance of indeterminate pulmonary nodules (IPNs) in patients undergoing resection of pancreatic ductal adenocarcinoma (PDAC) is unknown. We sought to define the prevalence and impact of IPN in such patients.

METHODS

We studied all patients who underwent surgical resection of PDAC between 1980 and 2013. IPN was defined as ≥1 well-defined lung nodule(s) less than 3 cm in diameter. Survival was assessed using univariate and multivariate Cox models.

RESULTS

Of the 2306 resected patients, 374 (16.2 %) had a preoperative chest computed tomography (CT) scan. Of these patients, 183 (49 %) had ≥1 IPN. Demographic and clinicopathological characteristics were similar among patients with or without IPN (all P>0.05). Median survival was comparable among patients who did (15.6 months) or did not (18.0 months) have IPN (P=0.66). Of the 183 patients with IPN, 29 (16 %) progressed to clinically recognizable metastatic lung disease compared to 13 % without IPN (P=0.38). The presence of >1 IPN was associated with the development of lung metastasis (relative risk 1.58, 95 % CI 1.03-2.4; P=0.05). However, lung metastasis was not associated with survival (P=0.24).

CONCLUSIONS

An IPN proved to be a lung metastasis in only one of six patients with PDAC undergoing surgical resection in this study. Survival was not impacted, even among patients who developed lung metastasis. Patients with PDAC who have IPN should not be precluded from surgical consideration.

[Staging of cutaneous malignant melanoma by CT]

Malignant melanomas are a challenge in radiological imaging diagnostics as they may metastasize into every organ and tissue. Cross-sectional imaging, in particular positron emission tomography computed tomography (PET/CT) and whole body magnetic resonance imaging (MRI), are considered the standards in the staging of melanomas. Because of its excellent availability CT, however, remains a widely employed staging modality. Familiarity with the manifold CT morphology of metastasized melanomas as it is described here is essential when interpreting dedicated CT and in addition useful when interpreting PET/CT results. In individual cases CT can assist in the detection of transient metastases. In the detection of locoregional lymph node metastases CT has a median sensitivity and specificity in meta-analyses of at best 61 % and 97 %, respectively, which is inferior to the performance of ultrasound (96 % and 99 %, respectively). According to meta-analyses, in the assessment of systemic tumor spread CT can detect the majority of metastases with a sensitivity and specificity of 51-63 % and 69-78 %, respectively, which is inferior to MRI and PET/CT. Therefore, if an exact staging is required for critical management decisions, MRI or PET/CT should be employed whenever possible.

Subcentimeter pulmonary nodules are not associated with disease progression in patients with renal cell carcinoma

PURPOSE

Renal cell carcinoma most commonly metastasizes to the lung. Indeterminate pulmonary nodules develop preoperatively in half of the patients with localized renal cell carcinoma but clinical significance remains poorly defined. We determined whether the presence of indeterminate pulmonary nodules, or nodule size or number is associated with renal cell carcinoma outcomes.

MATERIALS AND METHODS

We reviewed data on 1,102 patients with renal cell carcinoma in whom chest computerized tomography was done within 6 months before nephrectomy from 2002 to 2012. Patients with metastatic disease at presentation, benign tumors, pulmonary nodules greater than 2 cm or concurrent pulmonary disease were excluded, leaving 748 available for analysis. Study outcomes included lung metastasis, any distant metastasis or death from renal cell carcinoma. Cox proportional hazards models were used to assess whether the presence of indeterminate pulmonary nodules, or nodule size or number was associated with outcomes. Models were evaluated by comparing discrimination using the Harrell c-index.

RESULTS

Indeterminate pulmonary nodules were present in 382 of 748 patients (51%). Median followup was 4.1 years (IQR 2.2-6.1). The presence of indeterminate pulmonary nodules was not associated with distant metastasis or death from kidney cancer. However, compared to subcm indeterminate pulmonary nodules the nodules greater than 1 cm were associated with metastatic disease after adjusting for tumor histology, stage and size (HR 2.48, 95% CI 1.08-5.68, p = 0.031). The outcome c-index increased slightly after adding nodule size to a predictive model adjusted for tumor characteristics.

CONCLUSIONS

No evidence in the current study suggested that indeterminate pulmonary nodules less than 1 cm are associated with renal cell carcinoma progression, although large nodules significantly predicted metastatic disease. Patients with subcm indeterminate pulmonary nodules would be unlikely to benefit from extensive postoperative chest imaging surveillance, which should be reserved for patients with nodules greater than 1 cm.

Prevalence and variables associated with solitary pulmonary nodules in a routine clinic-based population: a cross-sectional study

Objective

To determine the prevalence of solitary pulmonary nodules (SPNs) in chest radiology studies and patient’s features associated with malignancy in a non-high-risk clinical population.

Methods

Patients ≥35 years were referred for thoracic imaging in two hospitals (2010-2011). Eight radiologists determined the presence and characteristics of SPN. Selected variables were collected from radiological register and medical records. Observer agreement in the diagnosis of SPN was assessed.

Results

25,529 patients were included: 23,102 (90.5 %) underwent chest radiograph and 2,497 (9.5 %) a CT. The prevalence of SPN was 2.1 % (95 % CI 1.9 – 2.3) in radiographs and 17.0 % (95 % CI 15.5 – 18.5) in CT. In patients undergoing chest radiograph, detection of SPN with an irregular border was more frequent among smokers. In patients who had a CT, larger SPNs appeared to be associated with 60 years of age or over, diagnosis of a respiratory illness, or male gender. In addition, an irregular border was also more common among men.

Conclusions

The prevalence of SPNs detected by both radiograph and CT was lower than that shown in screening studies. Patient characteristics such as age, sex, respiratory disease, or smoking habit were associated with nodule characteristics that are known to be related with malignancy.

Key Points

• There is a lower SPN prevalence in the clinical population than in screening studies.

• SPN prevalence is associated with some patient characteristics: sex, age, imaging test.

• Nodule characteristics related to malignancy were associated with some patient characteristics.

Geriatric chest imaging: when and how to image the elderly lung, age-related changes, and common pathologies

Even in a global perspective, societies are getting older. We think that diagnostic lung imaging of older patients requires special knowledge. Imaging strategies have to be adjusted to the needs of frail patients, for example, immobility, impossibility for long breath holds, renal insufficiency, or poor peripheral venous access. Beside conventional radiography, modern multislice computed tomography is the method of choice in lung imaging. It is especially important to separate the process of ageing from the disease itself. Pathologies with a special relevance for the elderly patient are discussed in detail: pneumonia, aspiration pneumonia, congestive heart failure, chronic obstructive pulmonary disease, the problem of overlapping heart failure and chronic obstructive pulmonary disease, pulmonary drug toxicity, incidental pulmonary embolism pulmonary nodules, and thoracic trauma.

Classification of pulmonary nodules by using hybrid features

Early detection of pulmonary nodules is extremely important for the diagnosis and treatment of lung cancer. In this study, a new classification approach for pulmonary nodules from CT imagery is presented by using hybrid features. Four different methods are introduced for the proposed system. The overall detection performance is evaluated using various classifiers. The results are compared to similar techniques in the literature by using standard measures. The proposed approach with the hybrid features results in 90.7% classification accuracy (89.6% sensitivity and 87.5% specificity).