New imaging method aims to spot rare childhood and adult cancers without surgery

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age: ≥6 months (pediatric and adult). * Suspected or confirmed diagnosis of neuroblastoma (NB) or pheochromocytoma/paraganglioma (PPGL). * Clinical indication for SSTR and/or NET-targeted molecular imaging for initial staging, restaging, suspected recurrence, response assessment, or treatment planning. * Ability to undergo PET/CT or PET/MRI and/or SPECT/CT per protocol; for the PET/MRI subset, no MRI contraindications. * Provision of written informed consent/assent per local regulations. * Women of childbearing potential: negative pregnancy test within 72 hours prior to tracer administration and agreement to use effective contraception during the imaging window. * For the multi-tracer subset (if applicable): willingness to undergo two imaging studies within a predefined window (e.g., ≤28 days) without intervening antitumor therapy. Exclusion Criteria: * Pregnant or breastfeeding; breastfeeding participants unwilling to follow tracer-specific lactation interruption guidance per institutional policy. * Any condition that, in the investigator's judgment, precludes safe imaging or protocol compliance (e.g., uncontrolled cardiorespiratory disease, severe claustrophobia not amenable to sedation/anxiolysis). * Known hypersensitivity to study radiopharmaceuticals or their excipients. * Use of interfering medications without feasible washout: NET imaging: drugs that affect catecholamine transport/storage (e.g., labetalol, tricyclic antidepressants, certain sympathomimetics) per site SOPs. SSTR imaging: long-acting somatostatin analogues within \~3-4 weeks or short-acting within \~24-48 hours, unless clinically unavoidable. * Prior therapeutic or high-dose 131I-MIBG within a period that would confound diagnostic imaging or dosimetry (e.g., within 6 months), at the investigator's discretion. * Contraindications to required modality-specific procedures (e.g., MRI-incompatible implants for PET/MRI; iodinated/gadolinium contrast contraindication only if contrast is mandated and no alternative pathway is acceptable). * Inability to lie still for the required acquisition time and sedation not feasible per institutional policy. * Concurrent participation in an interventional study or receipt of anticancer therapy that would confound imaging interpretation within the imaging window; for multi-tracer comparisons, any interval systemic therapy between scans.