Last October the company announced the formation of the proton beam cancer therapy centre in the capital.
The London Proton Therapy Centre will be funded with £6mln of equity from Advanced Oncotherapy and its partners along with a vendor loan from AVO.
A fund advised by Metric Capital is providing the cash. Shortly following the signing of the deal, £11mln can be drawn down.
The remainder becomes available following the completion of a £25mln cash or capital injection to bankroll the development of a manufacturing base.
AIM-listed AVO is using technology developed by scientists working on the large hadron collider at the CERN facility in Switzerland to create a low-cost proton beam treatment for cancer.
The technology is called LIGHT, which stands for Linac Image Guided Hadron Technology.
Cheaper and smaller than the current units, which are almost prohibitively expensive, the LIGHT system has the ability to propel protons at the speeds generated by much larger machines.
Proton beam therapy is expected to emerge as the go-to treatment for tumours as the price of the technology comes down.
It uses the aforementioned protons to pinpoint tumours more precisely.
This limits the damage caused by radiation to surrounding tissue and organs as well as offering patients higher disease-free survival rates.
The piece of the kit that accelerates the protons was licensed from CERN, the European Organisation for Nuclear Research, which is currently hunting the "God particle".
Chief operating officer Nicolas Serandour said vendor financing of the sort announced today had become an integral component to developing undertakings of this kind.
"We are delighted to have secured this financing partnership with Metric Capital,” he added.
The company’s partners include international companies such as Thales, Toshiba and VDL.