Had chemo and radiation improved over the last 20 years and how so?

Yes: Radiation has been developed to give more specific sites of therapy without a penumbra affecting surrounding normal tissue. As such we see use of gamma knife and cyberknife treatment giving high doses in a short period of time to a very localized area. The chemo has added new drugs working thru other mechanisms other than effecting nuclear dna such as the taxanes, gemcitabine and the platinums.