- The patient must not be a candidate for (or declines because of high risk) surgical resection because of medical comorbidity/risk; the patient must have undergone an evaluation by an experienced thoracic surgeon within 12 weeks prior to registration; standard justification criteria may include forced expiratory volume in 1 second (FEV1) < 40% predicted; predicted postoperative FEV1 ≤ 30% predicted; diffusing capacity of the lung for carbon monoxide (DLCO) ≤ 60% predicted; pulmonary hypertension (estimated ≥ 40 mm Hg); poor cardiac function (ejection fraction [EF] ≤ 40%); Medical Research Council (MRC) dyspnea scale ≥ 3 (corresponds to inability to walk at least 100 yards without rest); baseline hypoxemia (partial pressure of oxygen [pO2] ≤ 55 mg HG and/or pulse oxygen [ox] < 88%), baseline hypercapnia (carbon dioxide [CO2] ≥ 45 mm Hg; there are also other, less objective criteria, including severe end-organ damage from diabetes/hypertension, severe atherosclerotic disease (heart, brain, aorta, peripheral artery)