Author of

• 10974

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  P1.21 - Poster Session 1 - Diagnosis and Staging (ID 169)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Prevention & Epidemiology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10982

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    P1.21-008 - Accuracy of nodal staging in early stage NSCLC in the modern era of PET-CT, EBUS-TBNA and multidisciplinary team approach (ID 2745)

    09:30 - 09:30  |  Author(s): K. Tonga
    • Abstract

    Background
    Accurate staging of NSCLC remains the most important step in predicting outcome. It has been proposed that PET-CT, as an addition to conventional work up, allows for more accurate pre operative detection of stage IIIa and IIIb disease. On the other hand, it appears to have limitations in reliably staging nodal involvement in early stage NSCLC. We aimed to compare pre-operative nodal staging (PET-CT and/or EBUS-TBNA findings) with post-operative histopathological results to determine the accuracy of PET- CT in a multi-disciplinary team setting.

    Methods
    This was a prospective, observational study of consecutive patients discussed through Nepean Lung Cancer MDT that underwent surgical resection for NSCLC from Jan 2010 until Feb 2013. PET-CT parameters of all patients, including FDG uptake in primary lesion(s) as well as hilar and mediastinal lymph nodes, were compared with post operative histopathology of the primary lesions and resected lymph nodes. Pre-operative nodal staging based on PET-CT +/- EBUS-TBNA was compared with post-operative histopathological staging. A PET-CT SUV (max) of equal or more than 2.5 was considered positive.

    Results
    74 patients (mean age 69 years, range 47-86, 45 M ) underwent surgical resection with lymph node dissection for NSCLC (65 lobectomies, 5 bi-lobectomies, 2 wedge resections and 2 pneumonectomies). The most common malignancy in this group was Adenocarcinoma (39 [52.7%]) followed by Squamous Cell Carcinoma (25 [33.7%]) and undifferentiated large cell carcinoma (10 [13.5%]). Most patients were post-operatively confirmed to be in early stages (32 stage I and 26 stage II) with other patients in stage III (12 IIIa and 1 IIIb) and stage IV (3). In 47% of cases, PET-CT nodal staging was concordant with final histopathological results. There was discordance in 39/74 cases with PET-CT being more likely to upstage (30/74) than to downstage (9/74) the mediastinum. Symmetrical FDG uptake in hilar lymph nodes was common amongst upstaged cases. Anthracosis/silicosis was reported in lymph node histopathology of 16/74 (%21.6) patients, with 8 upstaged by PET-CT. Overall, sensitivity of PET-CT mediastinal staging in our cohort was 31.25% with a specificity of 70.5%. This translates into accuracy of 70.2%. In 7 cases, EBUS-TBNA was performed to establish nodal staging. One case of micro-metastasis, confirmed on post-operative histopathology, was not detected on EBUS-TBNA.

    Conclusion
    Nodal staging by PET-CT in early stage NSCLC has reasonable specificity but poor sensitivity, tending to upstage rather than downstage. Benign inflammatory processes affecting intra-thoracic lymph nodes such as anthracosis/silicosis may cause false positive PET-CTs. Nodal staging based only on PET-CT is inadequate and discussion through a multidisciplinary panel as well as minimally invasive investigations such as EBUS-TBNA is recommended. This is consistent with current international guidelines.