What's missing in the conventional treatment of prostate cancer are known phenomena that alter the transformation of lower grade cancer cells and even severe metastatic prostate cancer lines. This includes specific extracts, vitamin isomers, minerals and dosages that seriously affect (e.g. kill or slow) many malignant cell lines with less (or no) side effects.
That is, that some cell lines will be slowed or stopped in their tracks with seemingly mild treatments or severe cases, synergistically treated with chemo too. Here tracking with both more thorough imaging and extra labs and markers becomes important. Best case, stopped with less drastic side effects. Next best case, slowed dramatically with less drastic side effects. Unfortunately, you need the extra support ($$$) to work extra labs and angles beyond low budget insurance or DIY if you have the real technical capability to make sure to drive things to improvement. Many things are actually cheap, but not "standard".
My cancer search always starts with Life Extension Foundation articles on cancer treatments (combined modalities - conventional and pharma+natural chemistries beyond), extra basic lab tests that might add $100-250 per test cycle (1-3 months), and papers on high dose, specific nutrient molecules with anti-inflammatory, anti-cancer, and/or immune promoting properties that change/results/improvements can be measured or tracked with the extra lab work.
Sometimes cheaper/better/more convenient medicines not available in the US are available overseas.