This is a multicenter, correlative study to existing Lutetium based prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) trials and uses.
Mechanisms of Resistance to PSMA Radioligand Therapy: Radiation Resistance Versus Dose
PRIMARY OBJECTIVES:
- To determine the relationship between whole body tumor absorbed dose and response Lutetium based prostate-specific membrane antigen-targeted radioligand therapy (177Lu-PSMA-RLT).
II. To determine the relationship between Post-Operative Radiation Therapy Outcomes Score (PORTOS) score and response to 177Lu-PSMA-RLT.
III. To determine the relative importance of radiation dose (whole body tumor absorbed dose) and radiation sensitivity (PORTOS score) as a marker of response to 177Lu-PSMA-RLT.
EXPLORATORY OBJECTIVES:
- To develop novel signature of radiation sensitivity.
II. To evaluate tumor biopsies to understand mechanisms of resistance.
III. To understand utility of post-cycle 4 single-photon emission computed tomography (SPECT/CT) to evaluate treatment response.
Study participants will undergo a biopsy and blood draw prior to the initiation of planned therapy, as well as SPECT/CT imaging performed after the first and fourth treatments. One SPECT/CT scan will be performed 24 (+/- 6) after the first treatment, and after the fourth treatment, a 24 +/- 6-hour post-treatment SPECT/CT will be performed. Additionally, study participants may choose to undergo optional biopsy and blood draw at time of progression.