Author of

• 10946

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

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

  • 10949

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    P1.19-003 - Test performance of PET-CT for mediastinal lymph node staging of pulmonary carcinoid tumours (ID 854)

    09:30 - 09:30  |  Author(s): M. Shackcloth
    • Abstract

    Background
    PET-CT is a standard investigation to stage the mediastinum in non-small cell lung cancer when radical management is planned. The absence or presence of mediastinal lymph node involvement on PET-CT informs surgical selection (with or without further nodal sampling). The clinical utility of PET-CT in carcinoid tumours is uncertain as its test performance at identifying mediastinal lymph node disease in these tumours is as yet undefined with such tumours being rare and FDG avidity often considered to be variable or low. As such, it is argued whether PET-CT serves the same purpose in selecting patients for radical management in carcinoid tumours as it does with other non-small cell lung cancers. The aim of this study was to determine the test performance of PET-CT for mediastinal lymph node staging of pulmonary carcinoid tumours by collating a multicentre database.

    Methods
    We collated retrospective data from 7 institutions by performing a search on pathological databases for a consecutive series of patients who underwent thoracic surgery for a carcinoid tumour from Nov 1999 - Jan 2013. Preoperative PET-CT staging reports (prior to surgery with lymph node dissection) were obtained from patients’ records and compared against the reference standard of pathologic results obtained from lymph node dissection, and test performance reported using sensitivity and specificity.

    Results
    From Nov 1999 - Jan 2013, a total of 247 patients from 7 institutions underwent surgery for a carcinoid tumour with a corresponding preoperative PET-CT scan. The mean age of the patients was 61 (SD 15) and 84 were male (34%). The pathologic sub-type was typical carcinoid in 217 patients (88%) and atypical carcinoid in 30 patients (12%). The mean SUV uptake in the primary tumour was 4.8 (SD 4). Results from lymph node dissection were obtained in 213 patients. PET-CT reported uptake at mediastinal lymph nodes in 19 patients, of which only 3 were positive on subsequent pathology. Pathological results, from lymph node dissection carried out in 213 patients at the time of surgery, found 8 patients with mediastinal lymph node positive disease, of which only 3 had been picked up in preoperative PET-CT staging. The calculated sensitivity and specificity of PET-CT to identify mediastinal lymph node disease was 38% (95% CI 8-76%) and 93% (88-96%) respectively.

    Conclusion
    In non-small cell lung cancer, preoperative PET-CT is used for nodal and distant staging to assist in the selection of patients for radical treatment. British Thoracic Society guidelines for the radical management of patients with lung cancer recommend “radical treatment without further mediastinal lymph node sampling if there is no significant uptake in normal sized mediastinal lymph nodes on PET-CT scanning”. In carcinoid tumours, our results of the largest cohort to date suggest that PET-CT has a poor sensitivity but good specificity for the presence of mediastinal lymph node metastases in the staging of pulmonary carcinoid tumours. Therefore lymph node metastases cannot accurately be ruled out in carcinoid tumours with a negative PET-CT. If treatment decisions are based on the N2 status, invasive mediastinal staging should be undertaken in carcinoid tumours.