Randomized Phase II/III Trial of Prophylactic Cranial Irradiation With or Without Hippocampal Avoidance for Small Cell Lung Cancer

• PRIOR TO STEP 1 REGISTRATION

• 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 (see section 11.3 regarding axial T2/FLAIR sequence). 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. Sites may contact the Imaging Co-Chairs for further information or assistance if needed.

• 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 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; see Section 3.2.3 for details) 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

• Women of childbearing potential and male participants must practice adequate contraception

• Women of childbearing potential must have a negative qualitative serum pregnancy test =< 2 weeks prior to study entry

• Patients who are primary English or French speakers are eligible

• Patients must sign a study-specific informed consent prior to study entry

• PRIOR TO STEP 2 REGISTRATION

• 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 Dr. Wefel. 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