To determine the optimal schedule for three-dimensional verification imaging and necessary re-planning of patients undergoing IMPT for a rapidly changing tumor (small cell lung cancer).~To determine the rate of cardiac toxicities from IMPT in patients with small cell lung cancer compared with historical controls receiving photon-based treatment.~To determine the rate of pneumonitis and esophagitis from IMPT and compare with historical controls receiving photon based treatment.
To assess the safety and efficacy of intensity-modulated proton therapy (IMPT) for small cell lung cancer (SCLC)