K G Evans

Vancouver General Hospital, Vancouver, British Columbia, Canada

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Publications (18)155.03 Total impact

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    ABSTRACT: Major issues in the implementation of screening for lung cancer by means of low-dose computed tomography (CT) are the definition of a positive result and the management of lung nodules detected on the scans. We conducted a population-based prospective study to determine factors predicting the probability that lung nodules detected on the first screening low-dose CT scans are malignant or will be found to be malignant on follow-up. We analyzed data from two cohorts of participants undergoing low-dose CT screening. The development data set included participants in the Pan-Canadian Early Detection of Lung Cancer Study (PanCan). The validation data set included participants involved in chemoprevention trials at the British Columbia Cancer Agency (BCCA), sponsored by the U.S. National Cancer Institute. The final outcomes of all nodules of any size that were detected on baseline low-dose CT scans were tracked. Parsimonious and fuller multivariable logistic-regression models were prepared to estimate the probability of lung cancer. In the PanCan data set, 1871 persons had 7008 nodules, of which 102 were malignant, and in the BCCA data set, 1090 persons had 5021 nodules, of which 42 were malignant. Among persons with nodules, the rates of cancer in the two data sets were 5.5% and 3.7%, respectively. Predictors of cancer in the model included older age, female sex, family history of lung cancer, emphysema, larger nodule size, location of the nodule in the upper lobe, part-solid nodule type, lower nodule count, and spiculation. Our final parsimonious and full models showed excellent discrimination and calibration, with areas under the receiver-operating-characteristic curve of more than 0.90, even for nodules that were 10 mm or smaller in the validation set. Predictive tools based on patient and nodule characteristics can be used to accurately estimate the probability that lung nodules detected on baseline screening low-dose CT scans are malignant. (Funded by the Terry Fox Research Institute and others; ClinicalTrials.gov number, NCT00751660.).
    New England Journal of Medicine 09/2013; 369(10):910-9. DOI:10.1056/NEJMoa1214726 · 54.42 Impact Factor
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    ABSTRACT: To prospectively assess the safety and effectiveness of computed tomography (CT)-guided placement of fiber-coated microcoils used to guide video-assisted thoracoscopic surgical (VATS) excision of small peripheral lung nodules, with successful excision as the primary outcome and successful CT-guided microcoil placement and procedural complications as secondary outcomes. The institutional review board approved the study protocol. Informed consent was obtained from all 69 enrolled patients (30 men, 39 women; mean age, 60.7 years +/- 10.1 [standard deviation]) with 75 nodules. At CT, one end of an 80-mm long, 0.018-inch-diameter fiber-coated microcoil was placed deep to the small peripheral lung nodule, and the other end was coiled in the pleural space. VATS excision of lung tissue, nodules, and the microcoil was performed with fluoroscopic guidance. Seventy-three (97%) 4-24-mm nodules were successfully removed at fluoroscopically guided VATS excision; two nodules could not be removed. CT-guided microcoil placement was successful in all cases; however, two (3%) of 75 coils were displaced at VATS excision. Pneumothorax requiring chest tube placement occurred in two (3%) patients, and asymptomatic hemothorax occurred in one (1%) patient. The microcoil did not impede intraoperative frozen-section histopathologic analysis, which facilitated accurate clinical management in all patients. For 19 (28%) patients, the preoperative treatment plan based on bronchoscopy, needle biopsy, and positron emission tomography findings changed after VATS excision. Microcoil localization of small peripheral lung nodules enabled fluoroscopically guided VATS resection of 97% of the nodules, with a low rate of intervention (3%) for procedural complications.
    Radiology 03/2009; 250(2):576-85. DOI:10.1148/radiol.2502080442 · 6.21 Impact Factor
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    ABSTRACT: We sought to test the safety and efficacy of fluoroscopically guided, video-assisted, thoracoscopic resection after computed tomography (CT)-guided localization using platinum microcoils. Video-assisted thoracoscopic (VATS) resection of small pulmonary nodules >5 mm deep to the visceral pleura fails to locate the nodule and requires conversion to open thoracotomy in two thirds of cases. Therefore, we developed a new technique for intraoperative localization of these nodules using CT-guided placement of platinum microcoils. This study tests the safety and efficacy of this technique in a Phase I human study. Twelve patients with undiagnosed growing pulmonary nodules <20 mm were marked preoperatively using percutaneously placed CT-guided platinum microcoils. The coil was deployed adjacent to the nodule with the distal end of the coil placed deep to the nodule and the superficial end coiled on the pleural surface. The nodule and coil were excised using endostaplers guided by VATS and fluoroscopy. Histopathologic diagnosis was performed immediately after resection. CT-guided microcoil localization was successful in all patients. A small hemothorax and a pneumothorax requiring a chest tube occurred in 2 patients. Mean distance from visceral pleura to the deep edge of the nodule was 30.9 +/- 15.4 mm. VATS resection of the nodules (size = 11.8 +/- 3.2 mm) was successful in all patients. Mean microcoil localization, fluoroscopy, and operative times were 42 +/- 14, 3.1 +/- 2.0, and 67 +/- 27 minutes. A diagnosis of primary nonsmall cell bronchogenic carcinoma was made in 6 patients who then received a completion lobectomy. Six patients (hamartoma: 2, reactive lymph node: 1, bronchoalveolar cell carcinoma: 2, metastatic sarcoma: 1) did not receive further resections. Preoperative localization of pulmonary nodules using percutaneous CT-guided platinum microcoil insertion combined with operative fluoroscopic visualization is a safe, effective technique that increases the success rate of VATS excision.
    Annals of Surgery 09/2004; 240(3):481-8; discussion 488-9. · 7.19 Impact Factor
  • Lung Cancer 08/2003; 41. DOI:10.1016/S0169-5002(03)92372-5 · 3.74 Impact Factor
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    ABSTRACT: We conducted a prospective study to evaluate whether lack of an adequate increase in diffusing capacity for carbon monoxide (DL(CO)) during exercise is associated with a greater postoperative complication rate after lung resection. We used the three-equation method (3EQ-DL(CO)), a modification of the single breath DL(CO) technique to determine DL(CO) during exercise in 57 patients undergoing lung resection at Vancouver General Hospital from October 1998 to May 1999. 3EQ-DL(CO) was determined during steady-state exercise at 35% and 70% of the maximal workload reached in a progressive exercise test. Maximal oxygen uptake (VO(2)max), DL(CO) at rest, and the increase in DL(CO) during exercise were compared in relation to postoperative complications. Patients with complications had lower resting values of DL(CO) (R-DL(CO)), a smaller increase in DL(CO) from rest to 70% of maximal workload expressed as a percent of the predicted DL(CO) at rest ([70% - R]-DL(CO)%), and a lower VO(2)max than did patients without complications. Results suggested that (70% - R)-DL(CO)% was the best preoperative predictor of postoperative complications; a cutoff limit of 10% was the best index to identify complications, yielding a complication rate of 100% in patients with (70% - R)-DL(CO)% < 10% as compared with a complication rate of 10% in patients with (70% - R)-DL(CO)% >/= 10% (sensitivity = 78%, specificity = 100%). Patients who do not increase their DL(CO) sufficiently during exercise ([70% - R]-DL(CO)% < 10%) have a greater complication rate after lung resection.
    American Journal of Respiratory and Critical Care Medicine 11/2000; 162(4 Pt 1):1435-44. DOI:10.1164/ajrccm.162.4.2001117 · 11.99 Impact Factor
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    ABSTRACT: The incidence of adenocarcinoma of the cardia is increasing. The surgical management remains controversial. The present study reviews our experience with surgically resected adenocarcinoma of the cardia. A retrospective review of 153 cases of surgically resected adenocarcinoma of the cardia was performed. Preoperative radiotherapy was used in 31 patients. The surgical approach, morbidity, mortality, impact of preoperative radiotherapy, and survival were determined. The type of resection performed was a transhiatal esophagogastrectomy in 78%, a transthoracic esophagogastrectomy in 21%, and a transabdominal esophagogastrectomy in 1%. The in-hospital mortality rate was 4%. The frequency of complications was not associated with the use of preoperative radiotherapy or surgical approach. The 1-year (61%), 2-year (38%), 3-year (23%), and 5-year (16%) survival were not affected by the use of preoperative radiotherapy or surgical approach. Survival was significantly associated with stage and the presence of lymph node metastasis. Adenocarcinoma of the cardia is associated with a poor long-term prognosis. The long-term survival does not appear to be affected by the use of preoperative radiotherapy or by surgical approach.
    The American Journal of Surgery 06/1998; 175(5):418-21. DOI:10.1016/S0002-9610(98)00040-3 · 2.41 Impact Factor
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    ABSTRACT: The objective of this study was to prospectively evaluate the feasibility and efficacy of single-photon emission computed tomography (SPECT) with 18F-fluorodeoxyglucose (FDG) for differentiating malignant from benign pulmonary nodules. Twenty-six patients with 28 radiologically indeterminate focal pulmonary lesions were examined. Fasting patients were injected with 5 MBq/kg of FDG (maximum dose, 370 MBq). Imaging was performed with dual-head SPECT cameras equipped with 511-keV collimators. Seventeen of 21 pathologically malignant nodules showed FDG uptake on SPECT imaging (sensitivity, 81%). None of the seven benign modules showed uptake (specificity, 100%). SPECT imaging with FDG was positive in all 16 malignant nodules that were larger than or equal to 2 cm in diameter. However, only one (20%) of five nodules smaller than 2 cm in diameter showed positive on SPECT imaging. Using current technology, we found FDG SPECT imaging useful for distinguishing benign from malignant pulmonary nodules that were larger than or equal to 2 cm in diameter. However, because of the relatively low sensitivity of SPECT, smaller malignant nodules were not adequately revealed.
    American Journal of Roentgenology 04/1997; 168(3):771-4. DOI:10.2214/ajr.168.3.9057532 · 2.74 Impact Factor
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    ABSTRACT: Bronchioloalveolar cell adenomas (BAAs) have been described in up to 10% of patients with bronchogenic carcinoma. Their prognostic significance is unknown. The purpose of this study was to determine the prognostic implications of finding BAAs coexisting in specimens resected for primary bronchogenic carcinoma and to determine how frequently BAAs can be detected radiologically. Follow-up information for a mean of 30 months was obtained on 28 patients with a single primary bronchogenic carcinoma and one or more coexistent BAAs. Preoperative chest radiographs (n=27) and CT scans (n=24) were retrospectively reviewed to assess the number of patients in whom BAAs could be detected radiologically. There was no significant difference between percentage survival of patients with a primary bronchogenic carcinoma and coexistent BAAs when compared with the percentage predicted survival of these patients based on their primary bronchogenic carcinoma alone. BAAs could be detected retrospectively in 1 of 27 (4%) preoperative radiographs and 11 of 24 (46%) CT scans. On standard preoperative imaging for bronchogenic carcinoma, BAAs were retrospectively detected in more than one third of patients in whom they were detected pathologically. However, the presence of coexistent BAAs with bronchogenic carcinoma does not affect short- and medium-term prognosis.
    Chest 04/1996; 109(3):713-7. DOI:10.1378/chest.109.3.713 · 7.13 Impact Factor
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    ABSTRACT: We reviewed our experience from 1979 to 1990 with 160 cases of transhiatal esophagectomy for carcinoma of the lower esophagus and cardia to evaluate trends in patient selection, management, and outcome. Patients treated in the past 6 years (n = 110) and those treated before 1985 (n = 50) were similar in terms of age and sex distribution, medical history, and weight loss. The majority of tumors seen were adenocarcinoma, with patients in the latter group having significantly lower stages. Significant decreases in anesthetic time, units of blood transfusions, chest tube insertions, length of postoperative ventilation, incidence of postoperative pneumonia, and length of hospital stay were seen during the past 6 years. Wound infections increased significantly during the same period. The decrease in the 30-day mortality rate from 6% to 0.9% was not significant. Survival rates did not differ between groups, with overall rates of 62%, 40%, and 21% at 1, 2, and 5 years, respectively.
    Archives of Surgery 11/1992; 127(10):1164-7; discussion 1167-8. · 4.30 Impact Factor
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    ABSTRACT: Between August 1984 and October 1988, 7 women and 16 men underwent chest-wall resection. The 23 patients ranged in age from 17 to 79 years. Resection was done for benign lesions in 9 patients, for recurrent chest-wall sarcoma in 4 and for carcinoma involving the chest wall in 10. The number of ribs resected ranged from none to six. Prosthetic material was required for reconstruction in eight patients. There were no operative deaths and no flail segments developed postoperatively. Three patients have since died of metastatic disease, one has died of unrelated causes but with no residual disease and the remainder were alive and well at follow-up intervals ranging from 11 to 60 months. Aggressive resection, including a wide margin of healthy tissue, provides the best chance for recurrence-free survival for patients with many types of chest-wall tumour. Resection can be performed with low morbidity and satisfactory cosmetic results.
    Canadian journal of surgery. Journal canadien de chirurgie 07/1990; 33(3):229-32. · 1.27 Impact Factor
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    ABSTRACT: We determined single breath diffusing capacity (DLCO) and pulmonary capillary blood volume (Vc) in a total of 110 patients, who were being evaluated for resectional lung surgery for a localized tumor or lesion. Pathologic assessment of emphysema was obtained in 55 cases who had resection of a lung or an upper lobe, based on a standard reference panel for emphysema grading. In 86 cases, the extent of emphysema was quantitated by computed tomography (CT) of the chest. There was a significant negative correlation between Vc and emphysema assessed by either pathology or CT (r = about -0.5, p less than 0.001) similar to the correlation between DLCO and the extent of emphysema. Results of Vc were significantly lower in cases with moderate emphysema (pathologic grade greater than or equal to 30) than those with no emphysema (grade less than or equal to 5) (p less than 0.001) or mild emphysema (grade 10 to 25) (p less than 0.05), and they were significantly lower (p less than 0.05) in the group with mild emphysema compared with the group with no emphysema on pathologic assessment similar to DLCO results. Although Vc was reduced in emphysema, determination of Vc did not result in improved discrimination in separating cases with emphysema from those without emphysema when compared with DLCO.
    The American review of respiratory disease 02/1990; 141(1):53-61. DOI:10.1164/ajrccm/141.1.53 · 10.19 Impact Factor
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    ABSTRACT: To evaluate the sensitivity of diffusing capacity (DLCO) and pressure-volume (P-V) curves in the detection of emphysema, these tests were compared with pathologic assessment of emphysema in patients undergoing lung resection for a localized tumor, and with the overall extent of emphysema as assessed by computed tomography (CT). The resected lung specimens were fixed in the inflated state and cut at 1-cm intervals in the horizontal plane. The pathologic extent of emphysema was quantitated by comparison with a standard reference panel of emphysema grading. The overall extent of emphysema on CT was assessed by a visual scoring system in a total of 55 patients, 19 undergoing lung resection and 36 not undergoing lung resection. Analysis of 37 patients by pathology scores revealed 18 with no or trivial emphysema (emphysema grades less than or equal to 5; mean grade, 2.2 +/- SD 2.6) and 19 with emphysema (grades greater than or equal to 10; mean grade, 33.2 +/- SD 24.2). Diffusing capacity, the ratio of DLCO to alveolar volume (DLCO/VA), maximal lung elastic recoil (PLmax), and lung elastic recoil at 90% of total lung capacity (PL90) were significantly different between the two groups, whereas K (the exponential constant describing the shape of the P-V curve) was not. The pathology grade of emphysema showed a significant correlation with (DLCO) (r = -0.53) and DLCO/VA (r = -0.55), which was greater than the correlation with PLmax (r = -0.42) and PL90 (r = -0.43).(ABSTRACT TRUNCATED AT 250 WORDS)
    The American review of respiratory disease 06/1989; 139(5):1179-87. DOI:10.1164/ajrccm/139.5.1179 · 10.19 Impact Factor
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    ABSTRACT: A review of 33 months' experience with primary anterior mediastinal masses in 31 patients disclosed that in 9 (29%) the tumour was benign. Nineteen (86%) of the 22 malignant tumours and only 2 of the 9 benign tumours were symptomatic. Diagnosis was established by histopathologic examination of a biopsy specimen or resected tissue and serum radioimmunoassay for alpha-fetoprotein or human chorionic gonadotropin, beta-subunit. The authors present an investigational algorithm, using modern procedures, to facilitate the diagnosis of this relatively uncommon and challenging condition.
    Canadian journal of surgery. Journal canadien de chirurgie 04/1989; 32(2):139-42. · 1.27 Impact Factor
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    ABSTRACT: Neuroendocrine carcinomas of the lung are characterized by differentiation toward Kulchitsky cells and are classified as Kulchitsky-cell carcinoma (KCC) I (classic carcinoid), KCC II (atypical carcinoid), and KCC III (small-cell carcinoma). The clinical, computed tomographic (CT), and pathologic findings in 31 patients with KCC were reviewed. KCC I lesions generally occurred in younger (56 years +/- 18) nonsmoking women, were small (1.8 cm +/- 0.7 in diameter on CT scans), and were associated with lymphadenopathy in one of ten patients. KCC II tumors were found predominantly in older (66 years +/- 12) smoking men and were larger (3.9 cm +/- 1.3 in diameter, P less than .001); four of ten patients had CT evidence of lymphadenopathy. KCC III tumors occurred in older (66 years +/- 8) smoking men and were large (4.2 cm +/- 1.0); 11 of 11 patients had massive lymphadenopathy. Clinical, radiologic, or pathologic overlap was noted in three patients. Sputum cytologic and fine-needle and bronchoscopic biopsy findings were often nondiagnostic or misleading, particularly for KCC II lesions. CT of the chest provides additional discriminating information in the preoperative diagnosis of neuroendocrine lung carcinomas.
    Radiology 03/1989; 170(2):441-5. DOI:10.1148/radiology.170.2.2536187 · 6.21 Impact Factor
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    ABSTRACT: In a consecutive series of 62 lung resections for bronchogenic adenocarcinoma, 12 patients (19 percent) were found to have two or more adenocarcinomas on careful pathologic examination. These tumors all met the criteria for separate primary malignancy. In only two of the patients were the additional lesions suspected preoperatively. This incidence of multiple primary lung adenocarcinomas in apparently operable patients is several fold higher than would be anticipated from the literature. The phenomenon has important implications for preoperative radiologic evaluation, postoperative pathologic examination, assignment of TNM stage, and clinical follow-up of patients undergoing successful resection.
    Chest 02/1989; 95(1):151-4. DOI:10.1378/chest.95.1.151 · 7.13 Impact Factor
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    ABSTRACT: Computed tomography (CT) and mediastinoscopy were compared in 151 patients with bronchogenic carcinoma. In all patients in whom findings at mediastinoscopy were negative, all accessible nodes were either removed or sampled at thoracotomy. Several size criteria for identifying nodes as enlarged on CT scans were compared. The long axis greater than or equal to 15 mm and short axis greater than 10 mm had very low sensitivity (61%), and the long axis greater than 5 mm had a low specificity (23%). CT (long axis greater than 10 mm) allowed sensitivity equal to that of mediastinoscopy (79%) in the detection of mediastinal metastases, but the specificity with CT was lower (65% vs. 100%). In seven of 44 patients with nodes greater than 10 mm on CT scans and with positive findings at mediastinoscopy, tumor was present not in the enlarged nodes but rather in normal-sized nodes in a different nodal station. The sensitivity of CT for actual nodal stations involved with tumor was only 66%. Eighty-three percent of patients with false-negative findings at mediastinoscopy but only 33% of patients with false-negative findings at CT had surgically resectable stage IIIa disease.
    Radiology 06/1988; 167(2):367-72. DOI:10.1148/radiology.167.2.3357944 · 6.21 Impact Factor
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    ABSTRACT: The new International Staging System identifies a subset of patients with stage III lung cancer who have improved survival rates after surgical resection. The computed tomographic (CT), surgical, and pathologic findings in 26 patients with completely resected stage IIIa lung cancer were reviewed. Preoperative CT scans accurately demonstrated chest wall invasion in only two of ten patients with chest wall or diaphragmatic invasion. CT demonstrated pericardial involvement in only one of three patients. Tumor extension to within 2 cm of the tracheal carina was seen with CT in one of three patients. Eleven of 26 patients had limited ipsilateral mediastinal (N2) disease; eight of 11 had affected nodes greater then 10 mm on CT scans. As previously shown, CT is of limited value in the assessment of chest wall, mediastinal, pleural, or pericardial tumor extension; however, such extension does not preclude complete resection. Ipsilateral node involvement does not preclude surgery. Familiarity with the new staging system and awareness of what constitutes potentially resectable disease are necessary for an adequate assessment of CT findings.
    Radiology 02/1988; 166(1 Pt 1):75-9. DOI:10.1148/radiology.166.1.3336705 · 6.21 Impact Factor
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    ABSTRACT: Computed tomography (CT) was performed within 10 days of open lung biopsy in nine patients with fibrosing alveolitis. One-centimeter collimation contiguous scans through the chest were obtained in all patients. Additional 1.5-mm collimation scans were obtained in the area in which lung biopsy was later performed in six patients. In seven patients, CT demonstrated patchy involvement of the lung parenchyma, areas with a reticular pattern being intermingled with areas of normal lung. The reticular pattern was associated with cystic spaces 2-4 mm in diameter and was more severe in the lung periphery. Histologically, the reticular pattern corresponded to areas of irregular fibrosis. One patient had diffuse honeycombing (2-20-mm cysts), and one had honeycombing only in the lung periphery. In all patients, CT clearly defined the architectural changes seen on open lung biopsy. These changes were much better seen on the 1.5-mm than on the 10-mm collimation scans. CT may be helpful in determining the pattern and distribution of lung involvement in patients with fibrosing alveolitis and in guiding the surgeon to the most appropriate area(s) for biopsy.
    Radiology 10/1986; 160(3):585-8. DOI:10.1148/radiology.160.3.3737898 · 6.21 Impact Factor