Author of

• 20162

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  P1.13 - Radiology/Staging/Screening (ID 699)

  • Event: WCLC 2017
  • Type: Poster Session with Presenters Present
  • Track: Radiology/Staging/Screening
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)

  • 22763

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    P1.13-007 - Is Central Lung Tumor Location Really Predictive for Occult Mediastinal Nodal Disease in (Suspected) NSCLC Staged cN0 on PET-CT?  (ID 8779)

    09:30 - 09:30  |  Author(s): D. Van Raemdonck
    • Abstract

    Background:
    Based on a 20-30% prevalence of occult mediastinal disease, current guidelines recommend preoperative invasive mediastinal staging in patients with central tumour location and negative mediastinum on PET-CT. A uniform definition of central tumour location is lacking. Our objective was to determine the best definition in predicting occult mediastinal disease.
    
    Method:
    A single institution prospective database was queried for patients with (suspected) NSCLC staged cN0 after PET-CT and referred to invasive staging and/or primary surgery. We evaluated 5 definitions of central tumour location (table 1).
    
    Result:
    Between 2005 and 2015, 822 patients were eligible. Radio-occult lesions were excluded from analysis (n=9). Preoperative histology was NSCLC in 49% and unknown in 51%. The lesion was subsolid in 7%. Tumour stage was cT1, cT2, cT3 and cT4 in 43%, 28% 17% and 11%, respectively. Invasive mediastinal staging (EBUS and/or mediastinoscopy) was performed in 31%. Surgical resection was performed in 97%, a median of 5 (IQR 3-6) nodal stations were examined. The final pathology was squamous NSCLC, non-squamous NSCLC, or other in 38%, 54% and 7%, respectively. Any nodal upstaging was found in 21% (13% pN1 and 8% pN2-3). Central tumour location demonstrated, compared to peripheral location, a 4 times higher risk for any nodal upstaging but not for N2-3 upstaging (table 1).
    
    Conclusion:
    When modern PET-CT fusion imaging points at clinical N0 NSCLC, the prevalence of occult mediastinal nodal disease was only 8% in our patient cohort. None of the five definitions of centrality we studied was predictive for occult pN2-N3. Overall nodal upstaging was 21%, however, and all definitions of centrality then had discriminatory value. These data question whether the indication of preoperative invasive mediastinal staging should be based on centrality alone. Table 1 Figure 1