Skip to main content
. 2023 Jul 21;5(4):e220157. doi: 10.1148/rycan.220157

Figure 5:

Targeted α-particle therapy: radium 223 dichloride (223RaCl2) followed by actinium 225 (225Ac) prostate-specific membrane antigent (PSMA)–617. Images in a 66-year-old man with widely metastatic prostate cancer, with a Gleason score of 8 (4 + 4), that progressed following androgen deprivation, chemotherapy, and pelvic radiation. (A) Baseline gallium 68 (68Ga) PSMA-11 PET/CT image demonstrates intense PSMA uptake in numerous metastatic lesions (blue arrows indicate examples in the right scapula and both femurs). (B) 68Ga-PSMA-11 PET/CT image following three cycles of 223RaCl2 (a targeted α-particle therapy that incorporates within osteoblastic lesions but does not directly bind to cancer cells) shows progression of many osseous metastases (blue arrows), and the prostate-specific antigen (PSA) value increased. (C) Lutetium 177 (177Lu) PSMA-617 and 225Ac-PSMA-617 were both considered as treatment options. Following multidisciplinary discussion and shared decision-making with the patient, four cycles of 225Ac-PSMA-617 (a targeted α-particle therapy with affinity for PSMA) were administered 6 weeks apart, demonstrating dramatic response in the metastatic lesions, with near resolution of PSMA uptake at 68Ga-PSMA-11 PET/CT (blue arrows in the location of previous lesions) and a corresponding dramatic reduction in PSA.

Targeted α-particle therapy: radium 223 dichloride (223RaCl2) followed by actinium 225 (225Ac) prostate-specific membrane antigent (PSMA)–617. Images in a 66-year-old man with widely metastatic prostate cancer, with a Gleason score of 8 (4 + 4), that progressed following androgen deprivation, chemotherapy, and pelvic radiation. (A) Baseline gallium 68 (68Ga) PSMA-11 PET/CT image demonstrates intense PSMA uptake in numerous metastatic lesions (blue arrows indicate examples in the right scapula and both femurs). (B) 68Ga-PSMA-11 PET/CT image following three cycles of 223RaCl2 (a targeted α-particle therapy that incorporates within osteoblastic lesions but does not directly bind to cancer cells) shows progression of many osseous metastases (blue arrows), and the prostate-specific antigen (PSA) value increased. (C) Lutetium 177 (177Lu) PSMA-617 and 225Ac-PSMA-617 were both considered as treatment options. Following multidisciplinary discussion and shared decision-making with the patient, four cycles of 225Ac-PSMA-617 (a targeted α-particle therapy with affinity for PSMA) were administered 6 weeks apart, demonstrating dramatic response in the metastatic lesions, with near resolution of PSMA uptake at 68Ga-PSMA-11 PET/CT (blue arrows in the location of previous lesions) and a corresponding dramatic reduction in PSA.