While everyone agrees that AS is a good option if the cancer is "indolent" and "insignificant." There is some question in how to define those terms. In Bob's reference they used anything up to 2.5cc, but they were looking at total tumor volume, and I think you were referencing the index tumor found on CDUS. For an index tumor, a commonly used size cut-off is 1.3 cc. So using that definition, yours would qualify as insignificant.
A Critical Analysis of the Tumor Volume Threshold for Clinically Insignificant Prostate Cancer Using a Data Set of a Randomized Screening TrialNCCN does not use tumor volume as a criterion for active surveillance, although some active surveillance programs do. The NCCN guidelines allow AS as an option for any man who is "low risk" (GS=6, T1c or T2a, and PSA<10). Earlier guidelines held to a tighter definition of "very low risk" PC that also included: <3 positive cores, <50% in any core and PSA Density<.15 (Epstein criteria). Some programs still hold to the tighter definition, but programs that have mpMRI/US fusion biopsies tend to be more liberal. To confuse matters further, some programs, like UCSF, use an entirely different risk stratification system that incorporates tumor volume. There is no consensus on AS criteria. It really depends on what you are comfortable with.