Prognostic value of interim post-treatment SPECT/CT following lutetium-177 (177Lu)-PSMA therapy in patients with metastatic castration-resistant prostate cancer: a systematic review and meta-analysis

Background: Lutetium-177 (177Lu)-PSMA radioligand therapy (RLT) is established for metastatic castration-resistant prostate cancer (mCRPC), but radiologic monitoring during the treatment lacks standardization. While interim PSMA PET/CT offers accuracy, post-treatment 177Lu-PSMA SPECT/CT provides practical advantages for early response assessment. This systematic review and meta-analysis evaluates the prognostic value of interim post-treatment SPECT/CT parameters on survival outcomes in mCRPC patients. Methods: ) and publication bias (funnel plots, Egger's test, trim-and-fill) were evaluated. Results: < 0.001). SUVmean and SUVmax reductions were non-significant. Heterogeneity was low-moderate and publication bias had minimal impact post-adjustment. Conclusion: Interim 177Lu-PSMA SPECT/CT offers prognostic insights, with new lesions and TTV increases signaling poor outcomes. Standardization and prospective validation are needed to integrate it into clinical practice.