title: Systematic Endobronchial Ultrasound-guided Mediastinal Staging Versus Positron Emission Tomography for Comprehensive Mediastinal Staging in NSCLC Before Radical Radiotherapy of Non-small Cell Lung Cancer: A Pilot Study.
abstract: Despite known limitations of positron emission tomography (PET) for mediastinal staging of non-small cell lung cancer (NSCLC), radiation treatment fields are generally based on PET-identified disease extent. However, no studies have examined the accuracy of FDG-PET/CT on a per-node basis in patients being considered for curative-intent radiotherapy in NSCLC.In a prospective trial, patients with NSCLC being considered for definitive thoracic radiotherapy (± systemic chemotherapy) underwent minimally invasive systematic mediastinal evaluation with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) following noninvasive staging with integrated PET-CT.Thirty patients underwent EBUS-TBNA, with TBNA performed from a mean 2.5 lymph node (LN) stations per patient (median 3, range 1-5). Discordant findings between PET-CT and EBUS-TBNA were observed in 10 patients (33%, 95% CI 19%-51%). PET-occult LN metastases were demonstrated by EBUS in 4 patients, whereas a lesser extent of mediastinal involvement, compared with FDG-PET, was demonstrated by EBUS in 6 patients, including 2 patients downstaged from cN3 to pN2. LNs upstaged by EBUS were significantly smaller than nodes downstaged by EBUS, 7.5 mm (range 7-9) versus 12 mm (range 6-21), P = 0.005.A significant proportion of patients considered for definitive radiotherapy (+/-chemotherapy) undergoing systematic mediastinal evaluation with EBUS-TBNA in this study have an extent of mediastinal NSCLC involvement discordant with that indicated by PET-CT. Systematic EBUS-TBNA may aid in defining the extent of mediastinal involvement in NSCLC patients undergoing radiotherapy. Systematic EBUS-TBNA has the potential to contribute significantly to radiotherapy planning and delivery, by either identifying occult nodal metastases, or demonstrating FDG-avid LNs to be disease-free.
authors.affiliation: From the Department of Cancer Medicine, Peter MacCallum Cancer Institute, East Melbourne (DPS, LBI); Department of Medicine, University of Melbourne (DPS, TLL, LBI); Department of Respiratory Medicine, Royal Melbourne Hospital, Parkville (DPS, MR, LBI); Department of Respiratory Medicine, Monash Medical Centre, Clayton (DPS); Department of Radiation Oncology, Peter MacCallum Cancer Institute, East Melbourne (SS, DLB); Sir Peter MacCallum Department of Oncology, University of Melbourne (SS, DLB); Department of Nuclear Medicine (DG); Department of Cardiothoracic Surgery, Royal Melbourne Hospital, Parkville (PA); and Department of Cancer Surgery, Peter MacCallum Cancer Institute (PA), East Melbourne, Australia.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Steinfort
authors.forename: Shankar
authors.initials: S
authors.lastname: Siva
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Leong
authors.forename: Morgan
authors.initials: M
authors.lastname: Rose
authors.forename: Dishan
authors.initials: D
authors.lastname: Herath
authors.forename: Phillip
authors.initials: P
authors.lastname: Antippa
authors.forename: David L
authors.initials: DL
authors.lastname: Ball
authors.forename: Louis B
authors.initials: LB
authors.lastname: Irving
mesh_terms: D001315:Australia; D044963:Biopsy, Fine-Needle / Q000379:methods; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology* / Q000532:radiotherapy; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D061705:Image-Guided Biopsy; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000532:radiotherapy; D008297:Male; D008482:Mediastinum / Q000000981:diagnostic imaging* / Q000473:pathology*; D009367:Neoplasm Staging; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods