Ritu R. Gill

Effect of Computerized Clinical Decision Support on the Use and Yield of CT Pulmonary Angiography in the Emergency Department

PURPOSE To determine the effect of evidence-based clinical decision support (CDS) on the use and yield of computed tomographic (CT) pulmonary angiography for acute pulmonary embolism (PE) in the emergency department (ED). MATERIALS AND METHODS Institutional review board approval was obtained for this HIPAA-compliant study, which was performed between October 1, 2003, and September 30, 2009, at a 793-bed quaternary care institution with 60,000 annual ED visits. Use (number of examinations per 1000 ED visits) and yield (percentage of examinations positive for acute PE) of CT pulmonary angiography were compared before and after CDS implementation in August 2007. The authors included all adult patients presenting to the ED and developed and validated a natural language processing tool to identify acute PE diagnoses. Linear trend analysis was used to assess for variation in CT pulmonary angiography use. Logistic regression was used to determine variation in yield after controlling for patient demographic and clinical characteristics. RESULTS Of 338,230 patients presenting to the ED, 6838 (2.0%) underwent CT pulmonary angiography. Quarterly CT pulmonary angiography use increased 82.1% before CDS implementation, from 14.5 to 26.4 examinations per 1000 patients (P<.0001) between October 10, 2003, and July 31, 2007. After CDS implementation, quarterly use decreased 20.1%, from 26.4 to 21.1 examinations per 1000 patients between August 1, 2007, and September 30, 2009 (P=.0379). Overall, 686 (10.0%) of the CT pulmonary angiographic examinations performed during the 6-year period were positive for PE; subsequent to CDS implementation, yield by quarter increased 69.0%, from 5.8% to 9.8% (P=.0323). CONCLUSION Implementation of evidence-based CDS in the ED was associated with a significant decrease in use, and increase in yield, of CT pulmonary angiography for the evaluation of acute PE.

Lobectomy Versus Sublobar Resection for Small (2 cm or Less) Non-Small Cell Lung Cancers

BACKGROUND We evaluated a cohort of patients who underwent resection for small (2 cm or less) non-small cell lung cancer (NSCLC) to determine if there is an association between extent of resection (lobar versus sublobar resection) and local recurrence or survival. METHODS We reviewed 468 consecutive patients who underwent resection for small NSCLC at our institution between 2000 and 2005. We excluded patients who had neoadjuvant therapy, active noncutaneous malignancies, pure bronchioalveolar carcinoma, lymph node (n = 53) or distant metastases at diagnosis, or multicentric cancers. Clinicopathologic data, recurrence, and vital status as of June 15, 2010, were retrieved. Overall and recurrence-free survival from surgery rates were assessed. RESULTS Two hundred thirty-eight patients underwent resection for primary solitary small NSCLC. Lobectomy (n = 84) was associated with longer overall (p = 0.0027) and recurrence-free (p = 0.0496) survival. Patients who underwent sublobar resection were older (p < 0.0001) and had worse pulmonary function (p < 0.0014). While there was a trend toward increased rate of local recurrence for sublobar resection (16% versus 8%, p = 0.1117), there was no difference in distant recurrence. Moreover, when lymph nodes were sampled with sublobar resection, local recurrence rate and overall and recurrence-free survival distributions were similar to those for lobectomy. CONCLUSIONS Sublobar resection is reasonable in older patients with limited cardiopulmonary function. For healthy patients, however, lobectomy remains the standard therapy, with sublobar resection with lymph node sampling representing an alternative to consider. These findings support continued effort to conduct a randomized trial of lobar versus sublobar resection, such as CALGB 140503.

Vascular Enhancement and Image Quality of MDCT Pulmonary Angiography in 400 Cases: Comparison of Standard and Low Kilovoltage Settings

OBJECTIVE The purpose of this study was to investigate the vascular enhancement and image quality of pulmonary CT angiography performed with lower peak kilovoltage settings in a large patient sample. MATERIALS AND METHODS This retrospective study was approved by our institutional review board, which waived the requirement for informed consent. Four hundred patients believed to have a pulmonary embolism were studied. All patients underwent 16- or 64-MDCT with automatic tube current modulation. The 200 patients in the standard peak kilovoltage group (mean age, 57 years; range, 22-95 years) underwent MDCT at 130 or 120 kVp. The 200 patients in the low peak kilovoltage group (mean age, 56 years; range, 21-92 years) underwent MDCT at 110 or 100 kVp. Vascular enhancement was evaluated by measurement of the attenuation value in the main pulmonary artery and segmental and subsegmental arteries. Image noise was quantified by measurement of the SD of the attenuation value in the main pulmonary artery. One blinded radiologist assessed image quality using visual scores. Wilcoxons rank test was used to evaluate differences between the groups. RESULTS Mean vascular enhancement in the main pulmonary artery had significantly higher attenuation values in the low peak kilovoltage group (376.1 +/- 102.9 HU) than in the standard peak kilovoltage group (309.2 +/- 94.8 HU) (p < 0.0001). Mean attenuation values in all measured segmental and subsegmental arteries were significantly higher in the low peak kilovoltage group than in the standard peak kilovoltage group (p < 0.0001). Image noise in the low peak kilovoltage group was significantly higher than in the standard peak kilovoltage group (p < 0.0001). There was no significant difference in the image quality scores of the two groups (p = 0.116). CONCLUSION Lowering kilovoltage improved vascular enhancement without deterioration of image quality. The results of our study confirm previously reported preliminary findings.

Non‐tuberculous mycobacterial infection among lung transplant recipients: a 15‐year cohort study

The incidence of infection with non‐tuberculous mycobacteria (NTM) after lung transplant is insufficiently defined. Data on the impact of NTM infection on lung transplant survival are conflicting.

Hyperthermic intraoperative pleural cisplatin chemotherapy extends interval to recurrence and survival among low-risk patients with malignant pleural mesothelioma undergoing surgical macroscopic complete resection

OBJECTIVE Local recurrence limits long-term survival in patients with malignant pleural mesothelioma. We investigated whether hyperthermic intraoperative cisplatin chemotherapy lavage affects the interval to recurrence and overall survival among patients with favorable prognostic factors. METHODS Using a preoperative risk assessment algorithm we had previously developed and validated, we retrospectively identified a cohort of patients treated with cytoreductive surgery from 2001 to 2009. The patients had epithelial histologic findings on biopsy and were characterized as having a low risk of early recurrence and death (ie, tumor volume ≤ 500 cm(3) and were either men with a hemoglobin level of ≥ 13 g/dL or were women). Those patients who had received hyperthermic intraoperative cisplatin chemotherapy were compared with a comparison group of those who had not. Fishers exact test was used to determine the balance of prognostic factors. The Kaplan-Meier method and log-rank tests were used to estimate and compare the interval to recurrence and overall survival. Cox proportional hazards regression was used for multivariate analysis. RESULTS The cohort criteria identified 103 patients: 72 who received hyperthermic intraoperative cisplatin chemotherapy and 31 who did not. The groups were balanced for prognostic factors, except for the use of neoadjuvant chemotherapy (more common in the comparison group). The hyperthermic intraoperative cisplatin chemotherapy group exhibited a significantly longer interval to recurrence (27.1 vs 12.8 months) and overall survival (35.3 vs 22.8 months) than the comparison group. The improved interval to recurrence and overall survival for the hyperthermic intraoperative cisplatin chemotherapy group were particularly evident among the subgroups of patients who had not received hemithoracic radiotherapy and who had pathologic stage N1 or N2 lymph node metastases. CONCLUSIONS A favorable outcome and minimal incremental morbidity support the incorporation of hyperthermic intraoperative cisplatin chemotherapy into multimodality treatment strategies for patients with low-risk epithelial malignant pleural mesothelioma.

Multimodality treatment of mesenteric desmoid tumours.

BACKGROUND Desmoid tumours are rare neoplasms characterised by clonal proliferation of myofibroblasts that do not metastasise, but often exhibit an infiltrative pattern and functional impairment. When desmoids arise in the intestinal mesentery, surgical resection is seldom possible without life-altering loss of intestinal function. METHODS Retrospective review of the clinical management of 52 consecutive patients treated for desmoids of the intestinal mesentery from January 2001 to August 2006. A multidisciplinary treatment plan was developed based on primary disease extent, tumour behaviour and resectability. Patients with stable but unresectable disease were observed without treatment. Patients with resectable disease underwent surgery, and patients with unresectable progressing disease received chemotherapy, most commonly liposomal doxorubicin, followed by surgery if chemotherapy rendered the disease resectable. RESULTS At a median follow-up of 50.0 months (range 4.6-212), 50 patients (96%) have either no recurrence or radiographically stable disease. No patient requires total parenteral nutrition. CONCLUSION These data indicate that the extent of disease; tumour behaviour and resectability are the important factors when defining a treatment plan for mesenteric desmoid tumours. A multidisciplinary approach of surgery combined with chemotherapy is an effective and function-sparing strategy for managing this disease.

Epithelial Malignant Pleural Mesothelioma After Extrapleural Pneumonectomy: Stratification of Survival With CT-Derived Tumor Volume

OBJECTIVE The purpose of this study was to assess the usefulness of CT-derived tumor volume, with control for other prognostic factors, for stratifying survival after surgery-based multimodality treatment of a large cohort of patients with epithelial malignant pleural mesothelioma. MATERIALS AND METHODS We retrospectively reviewed 338 patients with mesothelioma who underwent extrapleural pneumonectomy between 2001 and 2007. The study cohort comprised 88 patients with epithelial subtype tumors, DICOM-format CT scans, and data regarding neoadjuvant and adjuvant therapy. Tumor volume was calculated, and Kaplan-Meier survival and Cox regression analyses were performed to compare the estimated survival functions of patient subgroups based on volume and other covariates related to outcome (sex, age, preoperative platelet count, hemoglobin concentration, WBC count, clinical and pathologic TNM category, and administration of neoadjuvant and adjuvant therapy). A multivariate regression model was derived on the basis of the most significant univariate predictors. RESULTS The median estimated tumor volume was 319 cm(3) (range, 4-3256 cm(3)). In univariate analysis, tumor volume, hemoglobin concentration, platelet count, pathologic TNM category, and administration of adjuvant chemotherapy or radiation therapy met the criteria for inclusion in the reverse stepwise regression analysis. In the final model, tumor volume, hemoglobin concentration, and administration of adjuvant chemotherapy or radiotherapy were identified as independently associated with overall survival. CONCLUSION With control of prognostic covariates, CT-derived tumor volume can be used to stratify survival of patients with epithelial mesothelioma after extrapleural pneumonectomy and should be included in prognostic evaluation of patients for whom resection is being considered.

Routine Pelvic and Lower Extremity CT Venography in Patients Undergoing Pulmonary CT Angiography

OBJECTIVE The purpose of our study was to assess the utility of performing routine pelvic and lower extremity CT venography (CTV) along with pulmonary CT angiography (CTA) in all patients evaluated for pulmonary embolism. MATERIALS AND METHODS Eight hundred twenty-nine consecutive patients (281 men and 548 women) underwent CTA-CTV for pulmonary embolism. Reports were evaluated as follows: positive or negative for pulmonary embolism with or without deep venous thrombosis (DVT) or with nondiagnostic CTV. Coexisting factors of malignancy, previous venous thromboembolism (VTE), recent surgery, and cardiovascular disease comprised the high-risk group of 446 patients. The remaining 383 patients formed the low-risk group. Statistical analysis included four binary predictors (previous VTE, malignancy, cardiovascular disease, and surgery) and three binary outcome variables (pulmonary embolism, DVT, and VTE). Chi-square test and univariate and multivariate regression analyses were performed. RESULTS VTE, pulmonary embolism, and DVT occurred in 152 (18.3%), 124 (15.0%), and 61 (7.3%) of 829 patients, respectively. Between the high-risk and low-risk groups, prevalence of VTE was 114 (25.6%) of 446 and 38 (9.9%) of 383 patients, respectively (p < 0.001); prevalence of pulmonary embolism was 92 (20.6%) of 446 and 32 (8.3%) of 383 patients, respectively (p < 0.001). Isolated DVT was found in 28 (3.4%) of 829 patients. The incremental value of CTV for the entire cohort was 3.4%, 0.72% in the low-risk group (six of 829) and 2.6% (22 of 829) in the high-risk group. For outcome variable VTE, malignancy and previous VTE were statistically significant (p = 0.04 and p < 0.001, respectively); for pulmonary embolism, malignancy and previous VTE were statistically significant (p = 0.03 and p = 0.005, respectively); for DVT, only previous VTE was statistically significant (p < 0.001). CONCLUSION CTV should not be performed routinely in all patients evaluated for pulmonary embolism and may only be useful in patients with a high probability of pulmonary embolism, including those with a history of VTE and possible malignancy.

Factors Associated With Radiologists' Adherence to Fleischner Society Guidelines for Management of Pulmonary Nodules

PURPOSE In 2005, the Fleischner Society guidelines (FSG) for managing pulmonary nodules detected on CT scans were published. The aim of this study was to evaluate adherence to the FSG, adjusting for demographic and clinical variables that may contribute to adherence. METHODS Radiology reports were randomly obtained for 1,100 chest and abdominal CT scans performed between January and June 2010 in a tertiary hospitals emergency department and outpatient clinics. An automated document retrieval system using natural language processing was used to identify patients with pulmonary nodules from the data set. Features relevant to evaluating variation in adherence to the FSG, including age, sex, race, nodule size, and scan site (eg, the emergency department) and type, were extracted by manual review from reports retrieved using natural language processing. All variables were entered into a logistic regression model. RESULTS Three hundred fifteen reports were identified to have pulmonary nodules, 75 of which were for patients with concurrent malignancies or aged < 35 years. Of the remaining 240 reports, 34% of recommendations for pulmonary nodules were adherent to the FSG. Nodule size demonstrated an association with guideline adherence, with adherence highest in the >4-mm to 6-mm nodule group (P = .04) and progressively diminishing for smaller and bigger nodules. CONCLUSIONS Pulmonary nodules are prevalent findings on chest and abdominal CT scans. Although most radiologists recommend follow-up imaging for these findings, recommendations for pulmonary nodules were consistent with the FSG in 34% of radiology reports. Nodule size demonstrated an association with guideline adherence, after adjusting for key variables.

Current Trends in Radiologic Management of Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive pleural tumor with a complex growth pattern. Imaging plays a crucial role in diagnosis and management. Computed tomography (CT) has been the mainstay in the clinical evaluation of MPM; however it underestimates early chest wall invasion, peritoneal involvement, and has well-known limitations in nodal metastatic evaluation. Perfusion CT can evaluate the microvasculature of tumors; however its disadvantages, such as high radiation exposure and side effects from iodinated contrast, have limited its use to research settings. Magnetic resonance imaging (MRI) is superior to CT, both in the differentiation of malignant from benign pleural disease and in the assessment of chest wall and diaphragmatic involvement. Perfusion and diffusion MRI are promising new techniques for the assessment of tumor cellularity and microvasculature and can be used for quantitative and qualitative assessment of treatment response. Fluorodeoxyglucose positron emission tomography (FDG-PET) is useful for the differentiation of benign from malignant lesions, for staging, and for monitoring response to therapy. PET-CT is superior to other imaging modalities in detecting more extensive disease involvement and identifying unsuspected occult distant metastases. This review focuses on the practical aspects of the radiological assessment of MPM, highlighting the role of the radiologist in preoperative and postoperative evaluation with a multimodality approach.