Virtual Library

 x 
My Library Virtual Library FAQ

Start Your Search

J.M. Goo



Author of

  • +

    P1.19 - Poster Session 1 - Imaging (ID 179)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Imaging, Staging & Screening
    • Presentations: 1
    • +

      P1.19-015 - Clinical application of thin section chest CT with computer-aided detection system for the detection of small metastatic nodules in pulmonary metastasectomy. (ID 3428)

      09:30 - 09:30  |  Author(s): J.M. Goo

      • Abstract

      Background
      It is important to identify possible metastatic nodule prior to metastasectomy, in order to perform complete resection. Thin section chest CT (TSCT) can detect small metastatic nodules more accurately than conventional chest CT. Conventional CT is known to miss metastatic nodules that are manually palpable by up to 40%. Reported sensitivity of helical CT cannot exceed 90%, also. We adopted TSCT and applied computer-aided detection (CAD) system for the search of small metastatic nodules to improve the detection power of TSCT.

      Methods
      From March 2009 to February 2013, 333 patients were referred to thoracic surgeon for pulmonary metastasectomy. TSCT with CAD was performed in every candidate for pulmonary metastasectomy. Every nodule detected by TSCT and CAD was annotated by radiologists and the whole map and annotation numbers of nodules were reported before operation. Intraoperatively, bi-manual palpation in open metastasectomy and finger palpation in video assisted thoracoscopic surgery (VATS) were used to detect the nodules. Only operations with complete available data were included in the study and 251 operations from 239 patients were analyzed.

      Results
      A total of 1021 nodules were identified by TSCT with CAD, while 115 nodules (11.3%) were additionally detected by CAD. Among the annotated nodules, 742 nodules were palpable during operation. Including intraoperatively detected 49 nodules, a total of 824 nodules were resected. Of 527 pathologically proven malignant nodules, 518 (62.9%) nodules were metastatic lesions. Among metastatic lesions, 496 were detected by TSCT (95.8%), 9 by CAD (1.7%) and 13 by manual palpation (2.5%). Also, 11 metastatic nodules were no palpated during operation but resected according to the annotation on CT. The overall sensitivity of thin section chest CT with CAD was 97.5%. Though overall specificity of TSCT with CAD was very low as 12.1% because that of radiologist’s reading was 14.2%, specificity only for CAD was 45.6%.

      Conclusion
      TSCT could detect small subcentimetre nodules and CAD enabled detecting additional small nodules. With help of TSCT with CAD, even the metastatic nodules, which were not palpable during operation, could successfully be resected. Furthermore, TSCT with CAD could detect tiny nodules with rather high specificity compare to radiologist’s reading only. Although the number of true metastatic nodules was small and several metastatic nodules were undetected, the TSCT with CAD system increased the detection sensitivity and would be helpful in complete metastasectomy.

  • +

    P3.18 - Poster Session 3 - Pathology (ID 177)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Pathology
    • Presentations: 1
    • +

      P3.18-016 - The usefulness of frozen section diagnosis as for the decision making milestone during the surgery for pulmonary ground glass nodules: embedding medium inflation technique (ID 2946)

      09:30 - 09:30  |  Author(s): J.M. Goo

      • Abstract

      Background
      The appropriate intraoperative decision making of surgical resection for the pulmonary ground glass nodules (GGN) is often difficult. We aimed to evaluate the role of frozen section diagnosis (FSD) as for the intraoperative decision making milestone and compared its accuracy to that of preoperative CT based practice as an interim result.

      Methods
      We retrospectively reviewed FSD of 171 consecutive pulmonary GGN from February 2005 to June 2013 and compared the diagnostic accuracy. Initially, we used only conventional method (Group A) but recently, we adapted a embedding medium inflation method (Group B) for FSD. The qualities of FSD were compared with the final pathologic diagnoses of corresponding permanent paraffin sections. Also, we calculated the sensitivity, specificity, and predictive values of assessing the size of invasive portion in GGN between FSD using the inflation method and preoperative CT based practice.

      Results
      There were no differences in nodule sizes between two groups (1.45±0.6 versus 1.51±0.5, p=0.63). In group A, a correct differential diagnosis between malignancies and benign lesions were made in 138 nodules. Thirteen nodules were erroneously classified and reported as false-positive or false-negative frozen section diagnoses (Sensitivity 95.6%, Specificity 53.8%). Three nodules were under-diagnosed in FSD. One patient required a secondary operation because of false-negative frozen diagnosis at the time of initial surgery. In group B, all of 17 nodules were correctly classified by frozen section. There were no false-positive or false-negative diagnoses in terms of making a diagnosis of malignancy, resulting in 100%-sensitivity and -specificity. (Figure 1) Thirteen nodules were correctly classified as being either minimally invasive adenocarcinoma (MIA) or invasive adenocarcinoma. Three nodules were diagnosed as MIA by frozen section through measuring invasive tumor size (<5mm) concomitantly. With regards to the estimating the size of invasive components of GGN, FSD in group B was superior to measurement of solid component in GGO nodules on HRCT. (Table 1)Figure 1

      Conclusion
      The accuracy of FSD using the embedding medium inflation method in GGO nodules was outstanding compared to the conventional frozen method. Furthermore, this method can help surgeons plan the appropriate surgical treatment after wedge resection of a GGO nodule by providing accurate size estimation of the invasive components of the GGN.