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S. Okada



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    P1.16 - Poster Session 1 - Other Thoracic Malignancies (ID 186)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Thymoma & Other Thoracic Malignancies
    • Presentations: 1
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      P1.16-003 - Features of computed tomography images and tumor viability: 141 lesions of pulmonary metastasis of non-seminoma (ID 1863)

      09:30 - 16:30  |  Author(s): S. Okada

      • Abstract

      Background
      The standard treatment for advanced non-seminoma is to excise all residual masses, including pulmonary metastatic lesions, in patients whose tumor markers return to normal after chemotherapy. However, too many regions and too great a volume of the patient’s lung are often resected. On the other hand, viable cells are frequently not present in the resected tissue. This study therefore tried to identify distinct features of viable lesions on computed tomography (CT).

      Methods
      Figure 1From January 2008 to December 2011, 17 cases of non-seminoma with lung metastasis underwent lung resection after normalization of tumor markers (α-fetoprotein and hCG). To excise all very small or impalpable lesions, we performed lipiodol marking under computed tomography, for a maximum of 8 sites in one operation. CT images of the 141 resected lesions were investigated for size and properties, and compared with pathological findings. Statistical analysis was performed using the chi-square test.

      Results
      We confirmed viable cells in 8 of 17 cases and 47 of 141 lesions. In those cases, viable cells were detected in both lungs. However, no significant relationship was found between average size and cell viability. The minimum diameter of tumor showing positive pathological change was 3 mm. No significant relation was observed between pathological findings and CT characteristics such as solid, cystic, scar-like or clear boundary.Figure 1

      Conclusion
      The ability to excise tissue from the lung is limited, and we would like to avoid excision of lesions against which chemotherapy has already been successful and which do not contain residual cells. However, the present results suggest the difficulty of specifying regions with viable cells based on CT. For this reason, minute lesions should still be excised, and marking has a very important role to play.

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    P2.03 - Poster Session 2 - Technology and Novel Development (ID 151)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Biology
    • Presentations: 1
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      P2.03-005 - Rotary Dissector: Frictional force achieved by using the porous polypropylene Rotary Dissector in clinical settings (ID 2482)

      09:30 - 16:30  |  Author(s): S. Okada

      • Abstract

      Background
      Figure 1During thoracoscopic surgery, rounded cotton-tip dissectors (Blunt Cherry Dissectors[®]) have been used to maintain the position of the lungs. However, moistening of cotton tips due to blood or pleural effusion often makes it difficult for surgeons to maintain the lung position when using this equipment. Therefore, we developed a polygonal-shaped tip dissector using porous polypropylene, called the Rotary Dissector, in order to achieve a greater amount of frictional force against the lung. In the present study, we assessed the difference in the rotational frictional force between the Blunt Cherry Dissector and Rotary Dissector, as well as the usefulness of the Rotary Dissector in thoracic surgery.

      Methods
      The rotational frictional force of the Rotary Dissector and the Blunt Cherry Dissector was estimated using a gel. We measured the weight and volume of gel that was scooped and pushed out in one direction by each dissector. Furthermore, we used the newly developed Rotary Dissectors for video-assisted thoracic surgery (VATS), and assessed the usefulness of this equipment.

      Results
      The weight and volume of gel pushed out was 1.14 g and 948.4 mm[3] with the Rotary Dissector and 0.34 g and 270.6 mm[3] with the Cherry Dissector, respectively. Moreover, the Rotary Dissector had 3 times the frictional force compared to that of the Cherry Dissector. During VATS, we used the Rotary Dissector and successfully detached the pleural adhesion without causing any lung injuries and could maintain the lung position to obtain a clear surgical field.

      Conclusion
      Thus, we noted that Rotary Dissectors can yield a greater amount of frictional force as compared to conventional dissectors, and can be safely used in VATS.

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    P3.07 - Poster Session 3 - Surgery (ID 193)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Surgery
    • Presentations: 1
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      P3.07-022 - Preoperative lipiodol marking for small-sized lung tumors (ID 1861)

      09:30 - 16:30  |  Author(s): S. Okada

      • Abstract

      Background
      Recent advances in imaging modalities have enabled detection of small-sized lung tumors at earlier stages with resultant dramatic changes in therapeutic strategies. However, if preoperative pathological diagnosis is not possible, video-assisted thoracic surgery (VATS) for therapeutic resection as well as diagnostic excisional biopsies may be indicated. Small-sized lung tumors, such as bronchioloalveolar carcinoma, are difficult to localize during surgery by visualizing or palpating the lung surface because the lung is a soft and deformable organ and contains air. Accurate intraoperative localization of the tumor is critical to surgeons. We usually perform preoperative lipiodol marking for small-sized tumors, particularly those located deep in the lung, to create a “visible target” from an invisible and impalpable tumor. This visualization technique enables resection of marked lesions under X-ray fluoroscopy.

      Methods
      From May 2006 through March 2013, we performed preoperative lipiodol marking for 356 lesions in 215 cases in which unconfirmed lung tumors were less than 10 mm in diameter, located deep to the visceral pleura, or of ground-glass opacity. One to five markings with lipiodol were performed in each case. The mean diameter of the lesions was 7.7 ± 5.1 mm (2–33 mm), and they were located 10.1 ± 9.5 mm (0–54 mm) below the surface of the visceral pleura. CT-fluoroscopy guidance was used to inject 0.1–0.5 mL lipiodol in the vicinity of the tumor before surgery. During VATS, X-ray fluoroscopy was used to confirm lesion location and to guide resection of the lipiodol-marked lesion.

      Results
      The average duration of the marking procedure was 18.4 minutes per lesion. Regarding complications, pneumothorax occurred in 40 cases (18.6%), but there were no cases of air embolization and no histological modifications in or around lipiodol markings. Of the 356 lesions, 354 (99.4%) were detectable and safely resected. Pathological examinations revealed lung cancer in 54 lesions, atypical adenomatous hyperplasia in 8, metastatic lung tumor in 165, organized pneumonia in 115 and other benign lesions in 12.

      Conclusion
      Lipiodol marking with CT-fluoroscopy guidance before VATS is a useful technique for small and impalpable lung tumors.