The former surgeon, dubbed Dr Death, was convicted by a Brisbane jury on Tuesday of killing three patients and permanently injuring another.
He will be sentenced on Thursday.
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Mr Lucas on Wednesday said Queensland Health (QH) had "significantly changed" now, compared to when allegations against Patel first surfaced in 2005.
"It should never happen again," he said.
"... You do acknowledge that there may be mistakes but they need to be acted on immediately.
"What happened with Patel is that people raised issues and they weren't acted on and that is the real concern."
He said the state government had eliminated the chance of such mistakes "as far as possible".
Premier Anna Bligh said a new, strict national accreditation and registration system for doctors would begin on Thursday, thanks to lessons learned from the Patel experience.
There were also new mandatory reporting of malpractice and a new commission to investigate complaints.
The government's comments came after Tony Morris QC, who oversaw the original commission of inquiry into Patel, said QH remained in danger of a similar scandal.
"Some small positive steps" had been taken to prevent a repeat of the failings that allowed Patel to be employed, he said.
"But we're nowhere near having Queensland Health in a situation where one can feel absolute confidence that a Patel scandal isn't going to happen again," Mr Morris told the ABC.
Mr Morris chaired the original commission of inquiry into the scandal at Bundaberg Base Hospital that was axed after the Supreme Court ruled Mr Morris showed ostensible bias.
Bligh pays tribute to whistleblowers
Meanwhile, Ms Bligh paid tribute to the whistleblowers, patients and families who were instrumental in bringing Patel to justice.
She singled out Toni Hoffman - the nurse who first raised her concerns about Patel - and the now independent Burnett MP Rob Messenger, who first raised the issue in state parliament.
Opposition Leader John-Paul Langbroek also paid tribute to those at the centre of the case he said exposed the worst forms of medical and government malpractice.
