CurrentGoldStandard

•Surgery remains gold standard for early stage lung cancer•Many patients cannot or prefer to not undergo surgery•SBRT/ SABR is emerging, improving alternative

•Radiosurgery targets only primary tumor•Control at 1O site excellent•But +/- 15% recur regionally (with T1& T2 patients, adequate follow up, imaging at follow-up & actuarial method)

•Identify regions at highest risk of micro-metastatic disease•Deliver ablative radiation to primary nodal drainage

Problem

Concept Under Investigation

Pulmonary Interstitial Lymphography

Pulmonary Interstitial Lymphography

Primary Nodal DrainageSquare = primary tumor

Circle = primary drainage

5 fractions, simultaneous integrated boost RapidArc, >340 d

PTV 50 Gy (primary tumor) coverage Normalized to 95%

PTV 35 Gy (nodal drainage) coverage (all >, med) 95%, 99.6%

Modulation: MU/cGy ratio (med, max) 2.8, 3.3

Conformality: V50/ PTV volume (med, max) 1.07, 1.10

NTC: Spinal cord V13.5 (med, max) 0.00, 0.20 cc

NTC: Cent airway V18 (med, max) 8.5, 17.2 cc

NTC: Total lung V20 (med, max) 5.5, 7.6%

NTC: Esophagus V27.5 (med, max) 0.0, 9.7 cc

NTC: Heart V32, Gr Vessells V47 (med) 0.10, 0.00

Treatment Planning per 0813