Would you consider focal therapy for a patient with NCCN unfavorable intermediate risk prostate cancer but only 1/16 cores positive and it's from a targeted lesion biopsy?

Yes, definitely can consider ablation for an unfavorable intermediate risk cancer.

Is it an unfavorable intermediate risk based on the Grade group or PSA? Sometimes PSA density is more accurate than overall PSA.

In addition, there are several factors to consider, including the mm length of pattern 4...

A targeted biopsy confirms the MRI lesion is cancer so treatment should be based on imaging and not core #, core length etc. We routinely treat MRi visible and MRI invisible GG3 with both HIFU and Cryo depending on the location.