1. S L I D E 0 Invasive Mediastinal Staging Does Not Improve Outcomes Over PET Alone in Early-Stage NSCLC Treated with SBRT Christopher D. Corso MD PhD, Shane Lloyd MD, Eileen Harder BS, Brandon R. Mancini MD, Charles E. Rutter MD, Roy H. Decker MD PhD

2. S L I D E 1 Purpose/Objectives Staging workup SBRT of patients with early stage NSCLC selectively includes PET imaging followed by invasive mediastinal staging with endobronchial ultrasound (EBUS) or mediastinoscopy to confirm nodal status. Whether the addition of these invasive procedures to the staging workup improves outcomes has not been established. In this large single-institution retrospective analysis, we investigated whether invasive staging with nodal sampling improved outcomes in patients treated with SBRT when compared to PET staging alone.

3. S L I D E 2 Cohort 270 patients analyzed Median follow-up of 20.2 months. 189 underwent PET/CT imaging only 81 had invasive mediastinal staging despite having negative nodes by PET/CT PET Only (%) Mediastinal Staging (%) p-value Overall 18981 Gender Male93 (49.2)35 (43.2) 0.22 Female96 (50.8)46 (56.8) Age < 70 years53 (28.0)28 (34.6) 0.18 ≥ 70 years136 (72)53 (65.4) ECOG Performance Score 0 - 1146 (77.2)64 (79.0) 0.44 2 - 343 (22.8)17 (21.0) Smoking History No5 (2.6)2 (2.5) 0.65 Yes184 (97.4)78 (97.5) Type of mediastinal Staging EBUS47 (58.0) Mediastinoscopy32 (40.0) T Stage T1154 (79.0)61 (67.0) 0.03 T241 (21.0)30 (33) Central Tumor Location No86 (60.1)25 (33.3) < 0.0001 Yes57 (39.9)50 (66.7) Synchronous Primaries No180 (95.7)69 (85.2) 0.004 Yes8 (4.3)12 (14.8) Prior Dx of Cancer No82 (43.4)41 (50.6) 0.17 Yes107 (56.6)40 (49.4) BED of SBRT Treatment < 10015 (7.9)7 (8.6) 0.51 ≥ 100174 (92.1)74 (91.4)

4. S L I D E 3 Overall Survival Median OS: 29.2 mos (PET Only) vs 22.4 mos (Invasive) p=0.16

5. S L I D E 4 Local Recurrence Free Survival 2-year LRFS 82.5% vs. 91.5% p = 0.60

6. S L I D E 5 Regional Recurrence Free Survival 2-year RRFS 86.7% vs. 87.7% p = 0.95

7. S L I D E 6 Distant Recurrence Free Survival 2-year DRFS 79.2% vs. 92.2% p = 0.095

8. S L I D E 7 Multivariate Analysis: Overall Survival Factors included in model: –Tumor location (central vs. peripheral) –T stage –Staging method (PET Only vs. Invasive) –Synchronous primaries –Prior Lung Cancer –Other Primary Cancer –Performance Status –BED (categorical, 100) –Age ( 70) HR (95% CI)P value T Stage T11.0 T21.72 (1.09 – 2.71)P = 0.02 All other factors NS (p > 0.05) Factor significant on MVA:

9. S L I D E 8 Conclusions Mediastinal staging in the pre-treatment workup does not appear to improve OS, or RFS when compared to PET imaging alone, even when factors such as T stage, tumor location, BED and synchronous tumors are included in the model. Our analysis did not find a significant benefit to mediastinal staging in patients with early-stage NSCLC undergoing SBRT.