I think the answer to the question of whether or not you raise this issue with your brother depends entirely on you. What do you want? What do you NEED?
If you confront him in some adversarial way, then he may well deny everything. This would devalidate you as a survivor and could damage the relationship you feel you have with him. But on the other hand, it may be that what you NEED is for him to take responsibility for what he did to you.
If what you want is reconciliation, on the other hand, then you still may need for him to accept responsibility. You may want to seek a way to raise the subject that would encourage him to be honest and not send him running for cover.
Confronting a sibling abuser ought to be pretty rough in any case, and you should read what Ken Singer has to say about confrontation in his article on this site on "Disclosure and Confrontation". You ought to be well prepared, and you need to feel emotionally ready. It is something I would certainly discuss with your T.
The bottom line in all this, however, is that YOU are the one who counts now, and it is YOUR needs that should take priority, not his need to remain unexposed and the family's (possible) concern that no one should rock the boat.
Decide what is best for you and go for it. It may be that you decide that you wish to let the matter rest. I would find it difficult to do that, but your case is your decision. In fact, that's the whole point. YOU have to decide. It would be one thing to remain silent as a matter of your personal decision, but something else entirely to feel condemned to silence by a perceived need to accommodate the preferences of others at such massive cost.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)