Bradley
There's no reason why you can't do it. Actually this kind of option is offered to a lot of male cancer patients who have no children (or have not completed their family), since chemotherapy and radiation can make you sterile. Egg retrieval and storage is also available to female cancer patients, but the process is a little more time consuming and requires the patient to go on medications to stimulate her ovaries to produce extra eggs, which delays the initiation of chemotherapy and radiation.
The thing with vasectomies is that it can take from 6 months to a year to clear your system of all your wigglies. So it's important to use an alternate form of contraception and do the follow-up checks in the meantime so you don't end up with a surprise. As a side note, the more you use your system, the faster the remaining wigglies are cleared out.
Love, Scully