You're 90% of the way there, I'd say. The main quote to remember is from a persuasive US case, Shloendorf (sic?), per Justice Cardozo: "Every human being, of sound mind and adult years, has a right to determine what shall be done with his body".
There could be a breach of civil law, but it could also be a criminal offence. It could be a sexual offence, an offence against a minor, or an assault/ABH/GBH. Torts are civil, but they can lapse into criminal behaviour- I'm thinking of theft (the tort of conversion), so the two are rarely far apart.
That said, you should also be aware of differing forms of consent and what is required. Does silence imply consent? Must consent be informed, express or implied? How much does the doctor need to tell the patient for 'informed consent' to be found?
There was a case where non-disclosure of a 1% risk of vocal chord paralysis was informed consent (the patient was a BBC voiceover). Also, there's been cases on bodily paralysis etc.
There's also a whole body of thought on consent for/from minors too. The whole area is really a legal minefield for the unwary.
So the summarise, you seem to know your stuff, but for me, the main body of argument will lie in what 'consent' means.