Radiological Innovations: Elevating Care in Oncology and Autoimmune Disorders

Clinicians are balancing survival gains from PSMA-targeted radioligand therapy against toxicity in older adults with advanced prostate cancer, while simultaneously grappling with prognostication in antibody-negative autoimmune encephalitis where conventional imaging can be nondiagnostic.

For men with metastatic castration-resistant prostate cancer, PSMA-targeted radioligand therapy with Lu-PSMA I&T is being used to pursue disease control, with data including older adults but not specifically designed for geriatric tailoring. The promise of targeted delivery sits alongside practical questions: who benefits most, how to sequence therapy among limited options, and how to mitigate hematologic and salivary toxicities that may weigh differently in frail versus fit older adults.

In reported studies of men with metastatic castration-resistant disease, Lu-PSMA I&T has been associated with higher PSA response rates and improvements in radiographic progression-free endpoints, with patient-reported outcomes favoring treatment in some cohorts; overall survival signals vary by study design and line of therapy, as summarized in phase II/III analyses of Lu-PSMA I&T. For the practicing clinician, these data help set expectations while underscoring the importance of aligning treatment intensity with individual priorities and tolerance.

Translating trial and cohort findings to the clinic requires attention to baseline functional status, polypharmacy, and concomitant organ dysfunction. Geriatric assessment domains—mobility, cognition, nutrition, and social supports—can contextualize risks such as cytopenias or xerostomia. Collaboration between nuclear medicine, medical oncology, and geriatrics improves selection and monitoring, with clear stopping rules when toxicity outweighs benefit.

Meanwhile, on the neurology service, the challenge is different. Managing autoimmunity in the brain remains complex, particularly when conventional MRI is unrevealing. In this setting, FDG-PET prognostic patterns in autoimmune encephalitis can highlight regional metabolic abnormalities linked with outcomes. These associations complement clinical examination, EEG, and antibody panels rather than replacing them.

FDG-PET can suggest regions of metabolic dysfunction and has been associated with clinical outcomes in prospective and retrospective cohorts, informing decisions in select encephalitis cases rather than dictating treatment protocols. Typical patterns—such as limbic hypermetabolism or frontoparietal hypometabolism—may evolve over time, offering a metabolic window into disease activity that can be tracked alongside symptoms and electrophysiology.

In contrast to therapeutic targeting in prostate cancer, FDG-PET functions as a diagnostic-prognostic tool in encephalitis, revealing metabolic patterns that support earlier recognition and monitoring and helping clinicians tailor workups and follow-up.

Operationally, building these approaches into practice hinges on workflows. For Lu-PSMA I&T, that includes standardized eligibility reviews, pre-therapy salivary gland counseling, hematologic monitoring, and coordination with radiation safety. For FDG-PET in suspected encephalitis, pathways that define indications after negative or equivocal MRI, harmonize acquisition protocols, and ensure timely multidisciplinary review can shorten the time from symptom onset to meaningful action.

Future directions bring the two threads closer. Companion diagnostics that refine PSMA expression thresholds and dosimetry personalization may sharpen the therapeutic index in older adults. In neuroimmunology, harmonized FDG-PET quantitation and machine-learning classifiers could translate metabolic signatures into more consistent risk stratification—still as adjuncts to, not replacements for, clinical judgment.

Key Takeaways:

• Lu-PSMA I&T shows PSA and radiographic benefits in mCRPC, with some patient-reported advantages; survival effects vary by study and setting.
• FDG-PET offers prognostic associations in autoimmune encephalitis and complements, rather than replaces, clinical assessment and antibody testing.
• Geriatric oncology decisions hinge on physiologic reserve and comorbidities, calling for careful selection and shared decision-making.
• Integrating therapeutic radioligands and metabolic imaging into multidisciplinary workflows can align efficacy goals with safety and prognostic clarity.