Imaging Considerations for Radiopharmaceutical Therapy: A Focus on Patients With Prostate Cancer and Neuroendocrine Tumours

Radiopharmaceutical therapy (RPT) has expanded treatment options for patients with metastatic/refractory malignancies. However, clinically significant toxicities and adverse events remain an important limitation to safe treatment delivery. Radiologists and imaging specialists play a central role in anticipating toxicity, guiding prophylactic interventions, and supporting safer, more individualized use of RPT. This overview paper covers the key aspects to evaluate on imaging and provides a blueprint on how imaging can identify RPT-related vulnerabilities and complications in patients, with an emphasis on findings that can influence eligibility assessment, preventive measures, therapeutic management, and follow-up planning. Across anatomical compartments, distinct imaging may diagnose and/or predict various adverse events, for example, pathologic fractures, spinal instability or cord compression, hematotoxicity, neurologic deterioration, intracranial hemorrhage, cardiopulmonary decompensation, pneumonitis, gastrointestinal perforation, bowel obstruction, hepatotoxicity, nephrotoxicity, xerostomia, hormonal crisis, pancreatitis, etc. This review also highlights the contribution of PET-based inter-lesional heterogeneity, total tumor burden metrics, and dosimetry to toxicity risk stratification, alongside the complementary roles of CT, MRI, and nuclear medicine imaging. Regarding structured reporting for RPT patients, a two-part report that combines standard oncologic staging with an RPT-specific complication checklist may improve patient assessment, communication of critical findings, and multidisciplinary decision-making. Robust, system-based imaging evaluation enables specialists to provide proactive guardrails for RPT safety and empowers the treatment teams to implement timely interventions.