Impact of Posttreatment SPECT/CT on Patient Management During ¹⁷⁷Lu-PSMA-617 Radiopharmaceutical Therapy

Percentage of patients at each cycle that had change in management based on posttreatment SPECT/CT, broken down by cycle and type of management change. Misc = miscellaneous.

Image of 72-y-old man demonstrates change in patient management because of progression, with cessation of PSMA RPT after 4 cycles. (A) Planar imaging after cycle 1 demonstrates uptake in osseous and hepatic disease. (B and C) Whole-body maximum-intensity projection images after cycle 2 (B) and after cycle 3 (C) demonstrate response to treatment with decrease in previously visualized disease. (D) Maximum-intensity projection image after cycle 4 shows increase in osseous and hepatic disease (arrows). PSA levels were stable up to cycle 3, and then increased from 20 to 82 ng/mL at cycle 4. Cycle 5 was not administered because of evidence of progression, and patient was shifted to hospice care.

Image of 70-y-old man demonstrates change in patient management because of marked response, resulting in early stopping of PSMA RPT. (A) Planar imaging after cycle 1 demonstrates uptake in osseous and nodal disease. (B) Planar imaging after cycle 2 demonstrates marked reduction in uptake in previously visualized disease (arrows), which mirrored PSA decline of 99% by cycle 2. Treatment was stopped because of marked response, and PSA had not yet progressed 7 mo after stopping treatment.

Image of 74-y-old man demonstrates change in patient management based on progression, resulting in stopping of PSMA RPT. (A) Planar imaging after cycle 1 demonstrates uptake in osseous and hepatic disease. (B–D) Planar imaging after cycle 2 (B) and after cycle 3 (C) demonstrates gradual increase in liver lesion (arrows) and reduction of uptake in existing osseous disease. (D) Development of new lesions in distal lower extremities (dotted arrow). Liver lesion continued to increase in size after cycle 4 SPECT/CT (solid arrow). Although there was partial response in osseous lesions, cycle 5 was not administered because of evidence of progression in liver lesions, and patient was converted to treatment with chemotherapy.