Whole-Brain Radiation Therapy With or Without Hippocampal Avoidance in Limited Stage or Extensive Stage Small Cell Lung Cancer

Prior treatment

• Prior radiotherapy to the head or neck (except for T1 glottic cancer), resulting in overlap of radiation fields
• Planned concurrent chemotherapy during PCI
  • Concurrent atezolizumab permitted
• Concomitant invasive malignancy or invasive malignancy within the past five years other than non-melanomatous skin cancer; history of in situ carcinoma (e.g. ductal carcinoma in situ of breast, in situ carcinoma of the cervix, vulva or larynx) is permitted
• Pregnant or lactating women or women of childbearing potential and male participants who are sexually active and not willing/able to use medically acceptable forms of contraception; this exclusion is necessary because the radiation treatment involved in this study may be significantly teratogenic.

Lab values

• Severe, active comorbidity, defined as follows:
  • Unstable angina and/or congestive heart failure requiring hospitalization within the last 6 months
  • Transmural myocardial infarction within the last 6 months
  • Acute bacterial or fungal infection requiring intravenous antibiotics at the time of registration
  • Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects
  • Chronic obstructive pulmonary disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy at the time of registration
  • Uncontrolled, clinically significant cardiac arrhythmias
  • HIV positive with CD4 count \< 200 cells/microliter;
  • Note: Patients who are HIV positive are eligible, provided they are under treatment with highly active antiretroviral therapy (HAART) and have a CD4 count ≥ 200 cells/microliter within 30 days prior to Step 1 registration.
  • Note: HIV testing is not required for eligibility for this protocol.

Other

• Radiographic evidence of central nervous system (CNS) metastases
• Radiographic evidence of hydrocephalus or other architectural distortion of the ventricular system, including placement of external ventricular drain or ventriculoperitoneal shunt
• Contraindication to MR imaging, such as implanted metal devices or foreign bodies or severe claustrophobia

• Histologic proof or unequivocal cytologic proof (fine needle aspiration, biopsy or two positive sputa) of SCLC within 250 days prior to Step 1 registration
  • High-grade neuroendocrine carcinoma or combined SCLC and NSCLC is permitted.
• Patients must have received chemotherapy and be registered to Step 1 registration no earlier than 7 days and no later than 56 days after completing chemotherapy. Note:
  • Post-chemotherapy restaging imaging must be completed no more than 56 days prior to Step 1 registration.
  • For patients with extensive-stage small cell lung cancer who are being considered for consolidative thoracic radiotherapy after chemotherapy, concomitant administration of consolidative thoracic radiotherapy and protocol-specified prophylactic cranial irradiation with or without hippocampal avoidance is permitted.
• Patients must have a gadolinium contrast-enhanced three-dimensional (3D), spoiled gradient (SPGR), magnetization-prepared rapid gradient echo (MP-RAGE), or turbo field echo (TFE) MRI scan. To yield acceptable image quality, the gadolinium contrast-enhanced three-dimensional SPGR, MP-RAGE or TFE axial MRI scan must use the smallest possible axial slice thickness not exceeding 1.5 mm.
  • This MRI must be obtained within 56 days prior to Step 1 registration. Note: The MRI study is mandatory irrespective of randomization to the experimental or control arm of this study.
• Prior to chemotherapy +/- thoracic radiotherapy, patients must be defined as limited-stage or extensive-stage SCLC after clinical staging evaluation involving the following:
  • History/physical examination;
  • CT of the chest and abdomen with contrast (does not have to be done if the patient has had a positron emission tomography (PET) / CT scan prior to initiating chemotherapy or thoracic radiotherapy);
  • MRI of the brain with contrast or diagnostic head CT with contrast;
  • For patients without evidence of extensive-stage SCLC on chest and abdomen CT and brain MRI or head CT, a PET/CT or bone scan is required to confirm limited-stage SCLC.
• After chemotherapy, patients must be restaged prior to Step 1 registration using the same diagnostic work-up as required pre-chemotherapy. Repeat PET/CT or bone scan is not required. Patients must have:
  • History/physical examination within 30 days of Step 1 registration;
  • No CNS metastases (Repeat MRI required) within 56 days prior to Step 1 registration;
  • No progression in any site;
  • Radiographic partial or complete response to chemotherapy in at least one disease site within 56 days prior to Step 1 registration.
  • If PET/CT was obtained prior to chemotherapy, either a repeat PET/CT or CT of the chest and abdomen with contrast can be obtained for response assessment.
  • Patients who underwent resection for limited-stage SCLC prior to chemotherapy and have no radiographically evident disease for response assessment remain eligible if post-chemotherapy imaging demonstrates no progression.
• Zubrod performance status 0-2 within 30 days prior to Step 1 registration.
• Women of childbearing potential must have a negative qualitative serum pregnancy test =\< 14 days prior to Step 1 registration.
• Patients who are primary English or French speakers are eligible
• Patients must sign a study-specific informed consent prior to study entry
• The following baseline neurocognitive assessments must be completed and uploaded within 10 calendar days after or at the time of Step 1 registration: HVLT-R (recall, delayed recall, and recognition), TMT (Parts A and B), and COWA. The neurocognitive assessments will be uploaded into the NRG Oncology Rave System for evaluation by Neurocognitive Co-Chair. Once the upload is complete, within 3 business days, a notification email will be sent to the site to proceed to Step 2 registration. At minimum, the HVLT-R delayed recall must be able to be scored (i.e. completed without error) in order to be eligible.
• Patients must have a baseline raw score greater than 2 on the HVLT-R delayed recall as determined by central assessment by the Neurocognitive Co-Chair.