The issue price of 25p is in line with last night's closing price, with the group's directors subscribing for £190,000 worth of shares.
Advanced Oncotherapy said work on its first proton beam therapy site in Harley Street has been halted due to coronavirus restrictions, but it will use the money raised to get regulatory approval of its novel technology.
As a result of the virus disruption, however, it now expects the first person to be treated in 2021 rather than at the end of this year.
In a statement, Nicolas Serandour, Advanced Oncotherapy's chief executive said he was extremely pleased to have raised the money in the current difficult environment.
“The funds raised will allow Advanced Oncotherapy to continue with the key development activities needed to obtain regulatory approval for our first LIGHT system at the Daresbury Laboratory including documentation and software development.
"The proton therapy market remains under-developed because of current high costs and a significant unmet medical need due to the rising population," he added.