Stephen J. Herman

Lung cancer screening using low-dose computed tomography in at-risk individuals: The Toronto experience

OBJECTIVE The Department of Medical Imaging at the University Health Network in Toronto is performing a lung cancer screening study, utilizing low-dose computed tomography (LDCT) as the modality. Baseline and annual repeat results are reported on the first 3352 participants, enrolled between June 2003 and May 2007. METHODS Enrollment was limited to those aged 50 years or older, with a smoking history of at least 10 pack-years, no previous cancer and general good health. A helical low-dose CT (LDCT) of the chest was performed using 120kVp, 40-60mA, images were reconstructed with 1-1.25mm overlapping slices. The primary objectives were the detection of parenchymal nodules and diagnosis of early stage lung cancer. Baseline LDCTs were termed positive if at least one indeterminate non-calcified nodule 5mm or larger in size, or non-solid nodule 8mm or larger in size was identified. Follow up periods for individuals with a positive baseline LDCT were determined by nodule characteristics. RESULTS The median age at baseline was 60 years (range 50-83), with a median of 30 pack-years of cigarette smoking (range 10-189). Baseline CT evaluations were positive in 600 (18%) participants. To date, 2686 (80%) of the participants have returned for at least one annual repeat screening LDCT. Biopsies have been recommended for 82 participants since the study began, and 64 have been diagnosed with screen-detected cancer (62 lung, two plasmacytoma of the rib). A total of 65 lung cancers have been diagnosed (62 screen-detected, 3 interim), 57 are NSCLC (82% with known stage are stage I or II) and the rate of surgical resection was 80%. Sensitivity and specificity of the protocol in successfully diagnosing early stage lung cancers were 87.7% and 99.3%, respectively. CONCLUSIONS Data indicate that LDCT can identify small lung cancers in an at-risk population. The diagnostic algorithm results in few false-positive invasive procedures. Most cancers are detected at an early stage, where the cancer is resectable with a greater potential for cure. Long-term follow up of lung cancer cases will be carried out to determine survival.

Does intensive follow-up alter outcome in patients with advanced lung cancer?

Background: Despite aggressive multimodality treatment, 5-year survival of stage III non-small cell lung cancer (NSCLC) remains <30%. To detect relapse, progression, or development of a second primary cancer early, many clinicians perform follow-up scans. To assess the impact of routine scanning, we compared clinical trial patients who had study-mandated scans with those treated off-study who had less intensive radiologic follow-up. Methods: The hospital cancer registry and trials databases were searched for patients with locally advanced NSCLC who had undergone multimodality treatment with curative intent. Baseline demographics were collected as well as frequency and results of clinical and radiologic follow-up. Results: Forty trial patients and 35 nontrial control patients were identified. Trial patients underwent significantly more imaging, particularly in the first 2 years (2.9 versus 2.0 body scans per year, p = 0.0016; 1.1 versus 0.4 brain scans per year, p < 0.001) but did not have more frequent follow-up visits. Forty-five cancers were detected (41 relapses, four metachronous primary tumors) in 44 (59%) patients. Of these, 28 (64%) sought medical attention that led to detection before a scheduled appointment or procedure. There was no significant difference in time to relapse or second primary in trial and nontrial patients (p = 0.80). Twenty-three patients had localized relapse, but only 15 could be treated with curative intent. Despite the trial group demonstrating a higher number of asymptomatic cancers and being offered potentially curative therapy more frequently, there was no significant difference in survival between trial and nontrial patients. Conclusion: In patients with locally advanced NSCLC, frequent cross-sectional imaging does not alter survival after combined modality therapy.

Computed tomography and pathologic correlations of thymic lesions.

Computed tomographic and pathologic correlations of the thymus gland were assessed in 69 patients. The sensitivity of computed tomography (CT) for undifferentiated thymic pathology is 87.1%; the specificity is 85.7%. The sensitivity of CT for neoplasm or mass is 97.1%, the specificity is 97.1%. The sensitivity of CT for lymphoid follicular hyperplasia (LFH) is 71.4%, the specificity is 97.6%. Therefore, a normal-sized thymus gland on CT does not exclude LFH. Completely preserved fat planes between thymic mass and adjacent structures on CT usually indicate a benign (noninvasive) neoplasm; completely absent fat planes usually indicate a malignant (invasive) neoplasm; partially preserved fat planes are indeterminate in assessing invasiveness. CT is also useful in showing recurrence or remnants of thymic tissue in patients who have had a previous thymectomy.

Cystic change (Pseudocavitation) associated with bronchioloalveolar carcinoma : a report of four patients

Cavitation in bronchioloalveolar carcinoma is uncommon, but apparent radiologic cavitation may be produced by other causes of abnormal air collections in and around the tumor. We report four patients whose plain films and computed tomography scans were interpreted as showing cavitary masses. Paracicatricial emphysema, fibrosis with honeycombing, and localized bronchiectasis were present pathologically to explain the abnormal air collections.

Precocious emphysema in intravenous drug abusers

It is becoming increasingly clear that obstructive airway disease and early emphysema occur in some drug addicts who intravenously abuse drugs intended for oral use. We report four patients with such a history who had clinical, pathophysiologic, and radiologic evidence of severe obstructive airway disease with hyperinflation. Three patients had bullae. All had radio-logic changes of intravenous talc granulomatosis. One patient had moderately severe emphysema at autopsy. The pathogenesis of this disease is uncertain but may involve synergism with cigarette smoke, direct toxic effects of the drug, or induced intravascular leukocyte sequestration causing proteolytic pulmonary injury.

Bronchioloalveolar carcinoma and the air bronchogram sign: a new pathologic explanation.

Bronchioloalveolar carcinoma (BAG) is one of the few lung tumors known to demonstrate the air bronchogram sign. Production of this valuable radiologic sign by this tumor has been ascribed to an “alveolar” filling process in which tumor grows along alveolar walls with preservation of the architecture and secretes copious amounts of mucus. Thus, aerated bronchi are surrounded by alveoli that are filled with mucus and tumor. We present a case in which the air bronchogram sign and pulmonary consolidation are associated with a non-secretory BAG. Alternative mechanisms that may produce the air bronchogram sign in BAG are offered.

Wegener Granulomatosis Presenting on CT with Atypical Bronchovasocentric Distribution

AbstractWe report a patient with Wegener granulomatosis who presented with nonspecific pulmonary infiltrates on routine chest radiographs, but who showed a “bronchovasocentric” distribution on CT.

Correlation of Chest Radiographic Findings With Biopsy-proven Acute Lung Rejection

The purpose of this study was to determine the chest radiographic findings of acute rejection and the accuracy of chest radiography in making this diagnosis in patients undergoing lung transplantation. For each of 100 transbronchial biopsies performed on 25 lung transplant recipients (single lung in three, double lung in 22), chest radiographs obtained within 24 hours before the biopsy were reviewed retrospectively without knowledge of clinical or biopsy information. Transbronchial biopsy revealed 42 instances of acute rejection in 17 patients and 58 instances of no acute rejection (normal, n = 43; other processes, n = 15). All pulmonary parenchymal radiographic abnormalities were assessed. Acute rejection was associated with the presence of middle or lower lung reticular interstitial or airspace disease in 21 lungs (sensitivity = 0.50 [21/42]). This pattern was seen in 18 lungs without acute rejection (specificity = 0.69 [40/58]). There was no difference in the appearance of the lungs between grades 1 and 2 acute rejection. Normal lungs were noted in 20 instances of acute rejection (48%). The authors conclude that chest radiograph findings are abnormal in about 50% of instances of biopsy-proven acute rejection. Because the appearance of acute rejection is similar to that of other conditions, the diagnosis cannot be made accurately by chest radiography.

Low-dose computed tomography (LDCT) in workers previously exposed to asbestos: detection of parenchymal lung disease.

Objectives To evaluate the lungs of asymptomatic asbestos-exposed workers who were screened for lung cancer and mesothelioma using low-dose computed tomography (LDCT) for parenchymal abnormalities. Methods Three hundred fifteen baseline LDCT studies of the chest of participants with at least 20 years’ exposure to asbestos or presence of pleural plaques before enrollment on chest radiographs were analyzed. Results Three hundred fifteen subjects were studied. The mean age was 61.7 years, and the mean exposure to asbestos was 26.9 years. One hundred seventy-five (56%) participants had absence of parenchymal findings with a mean age of 58.7 years, mean exposure of 24.6 years, and a mean smoking pack years of 19. One hundred forty subjects (44%) had parenchymal findings (138 men and 2 women) with a mean age of 65.3 years, mean exposure of 29.73 years, and a mean smoking pack years of 21.5 years. Participants who had parenchymal manifestations were more likely to be older and have longer exposure to asbestos compared to participants who had no relevant parenchymal findings. There was no statistical difference in the mean smoking pack years between the groups with and without parenchymal findings. Conclusions Low-dose CT could demonstrate parenchymal lung manifestations in this higher-risk asymptomatic group with prior exposure to asbestos in the setting of screening for lung cancer and mesothelioma. Individuals with longer exposure to asbestos and of higher age have more pulmonary abnormalities. The age and the latency of exposure play an important role given that the asbestos-related parenchymal abnormalities on LDCT were more prevalent in the elderly participants and with longer periods of exposure.

Utility of electron microscopy in the assessment of transthoracic needle lung biopsy specimens.

RATIONALE AND OBJECTIVES The authors determine the usefulness of electron microscopy (EM) in the workup of patients with certain intrathoracic masses undergoing transthoracic needle biopsy (TNB). METHODS Over a 4-year period, 1603 patients underwent TNB at our institution. Of these, 79 had EM examination of the aspirated material. The study is a retrospective review of this latter group. Previous use of EM for TNB had suggested that it may he helpful in those with pleural, chest wall, and mediastinal lesions. The 40 men and 39 women had pulmonary (n = 49), mediastinal (n = 17), pleural (n = 10), and chest wall (n = 3) lesions. RESULTS The adequate specimen rate was 59% (47 of 79) for light microscopy (LM) and 37% (29 of 79) for EM. Of the 28 patients with satisfactory specimens for both LM and EM, the correct diagnosis was obtained by LM 79% (22 of 28) and EM 96% (27 of 28) of the time. Electron microscopy was most helpful in patients with mediastinal (6 of 6 correct versus 3 of 6 for LM) and pleural (3 of 3 versus 1 of 3) lesions. CONCLUSIONS In specific circumstances, EM can be a very useful adjunct to LM in patients undergoing TNB. Problems with sample adequacy must be addressed.