Author of

• 12791

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  P3.19 - Poster Session 3 - Imaging (ID 181)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Imaging, Staging & Screening
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 12796

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    P3.19-005 - Quantitative CT predicts histological tumor invasiveness: analysis on 211 lesions of cT1N0M0 lung adenocarcinoma (ID 1500)

    09:30 - 09:30  |  Author(s): A. Aoyama
    • Abstract

    Background
    Biological behavior of small lung adenocarcinoma differs in each patient. High intensity area of the tumor on single slice of chest CT has been reported as a prognostic factor in several studies. However, because single slice is obviously insufficient to utilize all of the information on CT images of a tumor, we applied 3- dimensional volumetric evaluation for whole tumor volume. Our study aims to predict lymph node metastasis and tumor invasiveness by means of preoperative quantitative CT for lung cancer patients.

    Methods
    From January 2011 to November 2012, 236 lesions of cT1N0M0 lung adenocarcinoma were surgically resected in our institute. Among them, total 211 lesions of 193 patients were included in this study (Age: 67.2±9.5 male/female: 94/99). We analyzed preoperative CT images of 211 lesions of resected cT1N0M0 lung adenocarcinoma retrospectively. All patients were subjected to helical scanning using sections 1mm or less thick during one breath hold. We applied threshold of -800 and -300 Hounsfield units (HU) within those CT data, calculated the tumor volume, and then, integrated them with clinico-pathological information. We defined the area -300HU and over as “solid tumor volume” and between -800 to-301 HU as “GGO tumor volume”. Spearman’s rank test was utilized for statistical analyses.

    Results
    We divided those lesions into 3 groups by solid tumor volume; less than 0.25cm[3] (n=61), 0.25 to 1.5cm[3] (n=72), and over 1.5cm[3] (n=78). Solid tumor volume correlated with histological tumor invasiveness; less than 0.25cm[3], p1to3 (0, 0%) ly1 (0, 0%) v1 (0, 0%); 0.25 to 1.5cm[3], p1to3 (6, 77%) ly1 (1, 1%) v1 (1, 1%); over 1.5cm[3], p1to3 (14, 19%) ly1 (4, 6%) v1 (14, 19%), (p<0.01, p=0.03, p<0.01, respectively). Pathological tumor differentiation was also investigated; less than 0.25cm[3], well (34, 56%) moderate (26, 43%) poor (1, 2%); 0.25 to 1.5cm[3], well (17, 22%) moderate (57, 73%) poor (4, 5%); over 1.5cm[3], well (8, 11%) moderate (51, 71%) poor (13, 18%) (p<0.01). Lymph node metastases were found in none (0%) of solid tumor volume less than 0.25cm[3], in 2 (3%) with 0.25 to 1.5cm[3], in 6 (8%) with over 1.5cm[3] (p=0.01). Moreover we calculated the proportion of solid tumor volume / (solid tumor volume + GGO tumor volume) as “solid tumor ratio”. We divided those lesions into 2 groups by solid tumor ratio; 0.3 or less (n=123), and over 0.3 (n=88). Solid tumor ratio also correlated with histological tumor invasiveness; 0.3 or less, p1to3 (0, 0%) ly1 (0, 0%) v1 (0, 0%); over 0.3, p1to3 (20, 23%) ly1 (5, 6%) v1 (15, 17%). (p<0.01, p<0.01, p<0.01, respectively) Strikingly, lymph node metastases were found in none (0%) of solid tumor ratio 0.3 or less, but in 8 (9%) with over 0.3. (p<0.01)

    Conclusion
    Both tumor volume -300HU and over “solid tumor volume” and “solid tumor ratio” significantly correlated with tumor invasiveness. Preoperative quantitative CT is probably useful for predicting tumor invasiveness and lymph node metastases, and, as a result, effectively selecting operative procedure for cT1N0M0 lung cancer whether lobectomy or segmentectomy is applicable.