SPECT Imaging for Pharmacokinetics and dosimEtry Towards TREATment Optimization

Radium-223 will be given as per standard of care or other clinical trial. It is typically administered intravenously via slow injection once every 4 weeks with a dosage of 55 kBq/kg per cycle. Patients typically receive up to six cycles unless unacceptable toxic effects occurred, disease progression is apparent, or the patient is unable or unwilling to adhere to treatment. Three SPECT/CT studies will be performed for research purposes after 2 cycles in patients who consent to participate in this imaging and dosimetry study. These will be performed at 2-4 hr, 24 hr, and 48 hr after any cycle of Radium-223. Protocol preference is for imaging with 2 cycles, ideally cycle 1 and cycle 6, but imaging with any one or two cycle(s) is acceptable. The imaging time at each time point is approximately 30 minutes per field of view with two fields of view (1 hr total) typically collected sequentially (i.e., without repositioning the patient on the imaging table).

177Lu-DOTATATE to be given as Standard of Care (SOC) or other clinical trial. It is typically infused intravenously over a period of 20-60 minutes with peptide co-infusion prior and during the infusion. Patients will receive 4 cycles of 177Lu-DOTATATE administered approximately every 8 weeks. Treatment cycle is defined as 8 consecutive weeks (D1-D56) following a dose of 177Lu-DOTATATE. Patients receive up to four infusions of 7.4 GBq (200 mCi) every 8 weeks unless unacceptable toxic effects occurred, disease progression is apparent, or the patient is unable or unwilling to adhere to treatment. Three SPECT/CT studies will be performed for research purposes after 2 cycles in patients who consent to participate in this imaging and dosimetry study. Lu-177 SPECT CT will be performed at 24 (D2), 48 (D3), and 96 (D5) of any cycle of therapy. Imaging time at each time point is \~ 15-22 minutes per field of view with two fields of view (45 min total) typically collected sequentially.

177Lu-PSMA-617 will be given as per SOC or other clinical trial. It is typically infused intravenously over a period of 20-60 minutes. Up to 6 cycles of 177Lu- PSMA-617 will be administered approximately every 6 weeks. Treatment cycle is defined as 6 consecutive weeks (D1-D42) following a dose of 177Lu- PSMA-617. Patients will receive up to six infusions of 7.4 GBq (200 mCi) every 6 weeks unless unacceptable toxic effects occurred, disease progression is apparent, or the patient is unable or unwilling to adhere to treatment. Three SPECT/CT studies will be performed for research purposes after 2 cycles in patients who consent to participate in this imaging and dosimetry study. Lu-177 SPECT CT will be performed at 24 (D2), 48 (D3), and 96 (D5) of any cycle of therapy. Imaging time at each time point is approximately 15-22 minutes per field of view with two fields of view (45 min total) typically collected sequentially.