Hi C&Dmum, just done my little stint at work! The short answer to your question is no, you don't need physics GCSE.
Now for the long answer. I spoke to 2 students today. They're both 'mature' students (I'd say late 20's and mid 30's). Neither have any physics qualifications. Both did the access to health course, which sounded similar to yours, but specifically neither studied any physics on this course. When they applied to various uni's no-one asked about lack of physics. Nor was the subject broached at their interviews. And obviously they were both accepted onto at least one course! It seems that one of them has struggled a bit with the physics on the course, but to overcome this she hired a private tutor for a while until she learnt a few of the basics and her confidence grew. (Must admit, that's the first I've heard any students doing that!).
I also spoke to a colleague who is involved with selection of potential students. Her immediate thought was also no, you wouldn't need physics. But then she went on to remind me that because of various reasons (no fees, possibility of bursaries etc) lots of people apply for radiography these days. And that some uni's could use physics as a selection criteria, ie, to weedle out some of the applicants, although she's never done this or heard of anywhere doing it. She did say that with applicants above the age of about 25 she's more likely to consider their life experience rather than qualifications.
But finally, I think the most useful bit of advice is to contact the uni's and speak to one of the radiography lecturers. Perhaps ask to come in for a chat and a quick look round. One last thing, the one time I was invited by the uni to come and sit in on interviews for students, the thing that impressed me most were the students who had done a bit of work experience at their local hospital. You could do that either through your college or maybe directly to the head of the radiography department. This will also help you confirm in your mind that this is what you want to do, as well as showing your keeness to the uni's.
Sorry this has been so waffly. I hope it helps. Good luck. Radiography can be a rewarding career.