Inclusion Criteria:

• Patients with histologically confirmed SCLC who presented with Limited Stage (LS) at diagnosis. LS is defined as tumor confined to the hemithorax of origin, the mediastinum, and the supraclavicular nodes, which can be encompassed within a tolerable radiation therapy port.
• Measurable disease at the time of initial therapy. Also, patients will have re-staging of disease after completion of standard chemoradiotherapy (i.e. 4 cycles of etoposide and cisplatinum (or alternative regimens) and concurrent chemoradiotherapy +/- PCI). Patients could be in complete remission (CR) or partial remission (PR)
• Appropriate treatment for LS-SCLC including radiotherapy and chemotherapy. Patients who have received acceptable standard radiotherapy regimens, other than that described in section 4.1, are eligible for the trial provided that total dose of chest radiation is ≤ 5,000 cGy.
• Responsive disease to standard chemoradiation therapy as defined by RECIST
• Patients with CR after chemoradiation therapy are strongly recommended to be treated with prophylactic cranial irradiation; however, those patients who choose not receive prophylactic cranial irradiation will still be eligible and will not be excluded.
• CBC with an absolute neutrophil count (ANC) ≥ 1,000/uL, hemoglobin ≥ 8.0 g/DL and platelet count ≥ 75,000/uL.
• Normal prothrombin time (PT) and partial thromboplastin time (aPTT), unless on monitored anticoagulation therapy for medical conditions not excluded in the trial.
• Liver enzymes: total bilirubin less than or equal to 2mg/dL; AST and ALT less than 1.5X the upper limit of normal.
• Creatinine clearance of ≥ 60 mL/min
• Pulmonary: DLCO greater than 50%
• Cardiac: left ventricular ejection fraction greater than 45%
• Signed informed consent form in accordance with institutional and federal law policies.

Exclusion Criteria:

• Patient with stable (SD) or progressive disease (PD) after 4 cycles of standard cisplatin and etoposide and concurrent chest irradiation
• Pregnant or lactating woman
• HIV infection confirmed by NAT
• Common variable immunodeficiency
• Active CNS malignancy
• Active bacterial, fungal or viral infection
• Unfavorable psychosocial evaluation or history of poor compliance to prescribed medical care
• Prior history of autologous or allogeneic hematopoietic cell transplantation

• Presence of any of the following comorbid conditions:

  • History of recent myocardial infarction (within 6 months)
  • Symptomatic congestive heart failure
  • Peripheral vascular disease (including intermittent claudication or history of bypass for arterial insufficiency)
  • Untreated thoracic or abdominal aneurysm (6 cm or more)
  • History of recent cerebrovascular accident including transient ischemic attacks with residual hemiplegia/paraplegia
  • Dementia
  • Connective tissue/rheumatologic disorders and autoimmune disorders
  • History of prior solid tumor excluding skin or cervical carcinoma after curative resection