All men are able to enjoy a sexual relationship following surgery and radiotherapy, since their sensation of arousal, excitement and orgasm is typically unchanged. What is often lacking is the spontaneous event of a firm penis. A number of options for achieving an erection have been mentioned and one or more of these is often successful. You can experiment also with other forms of sexual intimacy – there may be new discoveries to be made!
Remember there is no potential for harm to your sexual partner from either the cancer or from any potential urinary leakage during a sexual encounter. Your partner, wherever possible, should be included in discussions about your sexuality and treatment choices.
Finally, keep in mind the larger picture. There is far more to a fulfilling relationship than an erect penis, even though the latter often becomes the focus of attention during consultations with treating doctors! There are many Resources available to assist you to explore and develop your relationship. The ultimate goal is to continue a fulfilling relationship and to be rid of a life threatening disease.