Understanding Resistance to Lutetium-based PSMA Radioligand Therapy for Prostate Cancer
This study is looking at why Lutetium-based PSMA-targeted radioligand therapy (RLT) might stop working for some people with prostate cancer. Researchers want to understand the relationship between the amount of radiation absorbed by tumors (whole body tumor absorbed dose) and how well the treatment works. They also want to see if a score called PORTOS (Post-Operative Radiation Therapy Outcomes Score) can predict treatment response. You could be eligible if you are starting Lutetium-based PSMA-targeted RLT and have a PSMA-avid lesion (a spot that shows up on a PSMA scan) that can be biopsied. The study aims to enroll 125 participants. The current recruitment status is unclear.
- Study design
- This is an observational study, meaning researchers will collect information without giving new treatments. It aims to enroll 125 participants.
- What's involved
- You will have a biopsy and blood draw before starting treatment, and SPECT/CT imaging after your first and fourth treatments. You may also choose to have an optional biopsy and blood draw if your cancer progresses.
- Compensation
- Not stated in the trial record.
- Follow-up
- The primary endpoints, which measure the study's success, are tracked for up to 6 months.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
Mechanisms of Resistance to PSMA Radioligand Therapy
At a glance
Conditions
Where it's being run
3 sites across 2 statesStudy leadership
- Thomas Hope, MD · PRINCIPAL_INVESTIGATOR · University of California, San Francisco
Who to contact
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What this trial measures
- Mean whole body tumor absorbed dose (WB Dose) across all metastatic lesionsUp to 6 months
The unit density sphere model will be implemented using OLINDA, a second-generation personal computer software for internal dose assessment in nuclear medicine to measure mean dose across all metastatic lesions. This approach uses the three time-point SPECT/CTs to create a whole-body dose map, which can then be segmented. Using OLINDA, the total dose to each tumor will be calculated as the integral of activity over time estimated out to 500 hours. Dose will be calculated in gray (Gy).
- Median PORTOS scoreUp to 6 months
PORTOS is a gene signature that predicts salvage radiation success. A PORTOS score of zero (called a "low" PORTOS) means it predicts no benefit from salvage radiotherapy. A PORTOS greater than zero (called a "high" PORTOS score) predicts a benefit from salvage radiation.