While significant advances in imaging for prostate cancer have been made, and continue to be made, there is a limit to what can be detected. Keep in mind a negative image may not mean no PCa, there can be micro-metastatic PCa (see the attached chart).
There are tests for "Circulating Tumor Cells" which you can discuss with your medical team, here's one link - https://www.cellsearchctc.com/about-cellsearch/what-is-cellsearch-ctc-test#:~:text=The%20CELLSEARCH%C2%AE%20CTC%20Test%20is%20a%20simple%2C%20actionable%20blood,circulating%20tumor%20cells%20(CTCs).
The question you have to ask yourself is if the imaging shows where the PCA is, does it change your treatment decision?
Here's an article about imaging - https://www.prostatecancer.news/2016/12/pet-scans-for-prostate-cancer.html
Some decisions to think about:
Continue to actively monitor, have a decision point about when to image again, PSA >1, 2...Certainly if you are considering radiation, knowing where the PCA is can be use in building a treatment plan with boosts to the sites and wider treatment field margins around them
If you feel based on your clinical history to date that you need to start treatment now (with those PSA results, I would not, see my clinical history in the chart I attached), then doublet or triplet therapy may be feasible options.
Kevin
Very interesting charts, thanks