Patient Selection: What Tumors Should Be Treated Based on Grade, Size, Location, Genetics and Risk Category?

Careful patient selection is essential for successful focal therapy (FT). In this section, we discuss the influence of tumor properties, its location, and the patient on optimal treatment planning. First, the applicability and limitations of the Gleason grading system and tumor volumetry at biopsy were elaborated upon. While Grade Groups (GG) 2 and 3 are ideal candidates for FT, high-volume GG 1 and small deposits of GG 4 may also be treated by FT. The size of the cancer acts as a surrogate for tumor aggressiveness within the GG. Second, tumor location influences treatment success and subsequent therapies. Very apical disease should be treated only with caution or in special cases. Far distal and anterior tumors may not be treated using HIFU. Third, the clinical risk categories are essential for patient selection. Monogenic and polygenic risk factors may contribute to better estimation of prognosis and treatment response, especially for borderline indications. However, more detailed research on their application in FT is required. Owing to the low prevalence of germline pathogenic mutations in the FT cohort, clinical risk groups remain the cornerstone of patient selection.