PET/CT Imaging of Small Cell Lung Cancer Using 89Zr-DFO-SC16.56

Inclusion Criteria: Subject Inclusion Criteria for Adult population * Signed, informed consent * Age 18 or more years * Histologically confirmed, SCLC, (newly diagnosed or recurrent); small cell carcinoma of unknown or non-lung origin; or other types of neuroendocrine tumor OR Histologically confirmed prostate cancer, with suspected or confirmed NEPC based upon clinical assays obtained prior to the trial OR Histologically confirmed or suspected primary brain neoplasm OR Desmoplastic small round cell tumors, osteosarcoma, Ewing's sarcoma, rabdomyosarcoma, Wilms tumors, hepatoblastomas, rhabdoid tumors and neuroblastoma patients * At least one tumor lesion on CT2 or MRI ≥ 0.8 cm OR * Tumor detectable FDG PET, PSMA PET, DOTATATE PET, MIBG SPECT (or planar MIBG scan if SPECT unavailable) OR * MRI or bone scan that shows new osseous metastases. The scans should have been obtained in the last 12 weeks * ECOG performance status 0 to 2 * Negative serum pregnancy test within 2 weeks of 89Zr-DFO-SC16.56 for women of child-bearing potential * Available archival tumor specimen suitable for DLL3 IHC or clinician already has plans to obtain tumor specimen as part of standard of care (unrelated to patient participation in 19-292) which will yield sufficient tumor specimen to allow for DLL3 IHC * For the prostate cancer patient cohort, as an alternative if archival tissue is not available, patients must be willing to undergo PET/CT guided biopsy3 as described in section 9.3. 1. Patients with SCLC will be the primary study population, however patients with other types of neuroendocrine tumors may be included at the PI's discretion. 2. Criterion is intended to demonstrate presence of imageable disease. A low-dose CT (e.g. from a PET/CT scan) may be used at PI's discretion. 3. While willingness to undergo the biopsy is required if archival tissue is not available, PET/CT guided biopsy is not a mandatory study assessment. As described in section 9.3, the guided biopsy may be waived at the discretion of the principal investigator if the DLL3 PET/CT reveals no sites of DLL3 tracer-avid tumor or if the principal investigator deems itis not in the best interest of the patient, according to best clinical judgement. The pediatric population would not be approached for an optional PET/CT-guided biopsy Subject Inclusion Criteria for Pediatric population * Signed, informed consent * Age 4 or more years * High risk neuroblastoma patients * At least one tumor lesion on CT2 or MRI ≥ 0.8 cm OR Tumor detectable FDG PET, PSMA PET, DOTATATE PET, MIBG SPECT (or planar MIBG scan if SPECT unavailable) OR MRI or bone scan that shows new osseous metastases. The scans should have been obtained in the last 12 weeks * ECOG performance status 0 to 2 * Performance Status: Subjects must have a Lansky (\<16 years) of at least 40 * Negative serum pregnancy test within 2 weeks of 89Zr-DFO-SC16.56 for women of child-bearing potential Exclusion Criteria: Subject Exclusion Criteria for the Adult population * History of anaphylactic reaction to humanized or human antibodies * Pregnant or breast feeding * Psychiatric illness that would interfere with compliance with the study procedures * Inability to undergo PET scan due to weight limit * Patients who require anesthesia or monitored sedation to tolerate PET scan procedure Subject Exclusion Criteria for the Pediatric population * History of anaphylactic reaction to humanized or human antibodies * Pregnant or breast feeding * Psychiatric illness that would interfere with compliance with the study procedures * Inability to undergo PET scan due to weight limit * Patients who require anesthesia or monitored sedation to tolerate PET scan procedure