177Lu can be imaged after administration using SPECT/CT. Most work to date has focused on using posttreatment imaging to measure normal organ and tumor dose. We aimed to assess the impact of posttreatment SPECT/CT on the management of patients undergoing 177Lu-prostate-specific membrane antigen (PSMA) radiopharmaceutical therapy (RPT). Methods: In this retrospective study, 122 patients underwent PSMA RPT with subsequent SPECT/CT 24 h after treatment. We determined a qualitative response at each cycle and reviewed patient charts to assess the impact that posttreatment SPECT/CT had on patient management. Changes in patient management were classified as changes on the basis of progression and response, and specific cycles when they occurred were noted. Miscellaneous changes in patient management were also evaluated. Results: Among the 122 consecutive patients examined, 42%-56% exhibited stable disease, whereas 19%-39% of patients exhibited response on visual assessment across treatment cycles. In total, 49% (n = 60) of patients experienced changes in management, of which 57% (n = 34) were due to progression, 40% (n = 24) were due to response, and 3% (n = 2) were due to miscellaneous changes. Changes due to disease progression were observed mostly after cycles 2 and 4. Changes due to response to RPT occurred mostly after cycles 3 and 4. Conclusion: At our center, 49% of patients experienced changes in management based on posttreatment SPECT/CT, and most of these changes occurred at cycles 2 and 4. Integrating posttreatment SPECT/CT into routine PSMA RPT protocols can aid in patient management.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2024 Aug 08 [Epub ahead of print]
Surekha Yadav, Blair Lowery, Abuzar Moradi Tuchayi, Fei Jiang, Rachelle Saelee, Rahul R Aggarwal, Roxanna Juarez, Robert R Flavell, Thomas A Hope
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California., Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California., Division of Medical Oncology, Department of Medicine, University of California San Francisco, San Francisco, California., Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California; .