The therapy for basal cell carcinoma, the most common form of skin cancer, uses a radioactive isotope to kill tumour cells in just half an hour while leaving the skin around it unharmed.
Although it has not yet been approved for use, a study of 1,000 patients in Rome found it completely removed tumours in 95 per cent of patients with just one treatment.
Larger trials have been set up in Germany with the intention of bringing the therapy to the market.
Basal cell carcinoma is caused by exposure to harmful UV rays from natural light or sunbeds and accounts for about 80 per cent of all skin cancer cases, or 90,000 cases a year in Britain.
It not normally metastatic, meaning it does not spread through the body or pose a threat to life, but the routine treatment is surgery which although effective can leave unsightly scars.
In some cases, for example where the tumour is on the face, there are alternative ointments and light-based therapies but most are only suitable for lumps which do not penetrate too deeply into the skin.
Now researchers say they have developed a new cream using rhenium-188, a radioactive isotope, which can kill even deep tumours without side-effects in the vast majority of cases.
A base layer applied directly onto the skin protects healthy cells from the radioactive element, which sits on top of the base where it can irradiate the skin below and shrink the tumour.
It could dramatically improve the quality of life of patients who could otherwise require skin grafts and face serious scarring as a result of surgery, researchers said.
Dr Ulli Köster, a researcher at the Institut Laue-Langevin (ILL) in Grenoble, France, where the radioactive material is produced, said: "Typically this disease is treated by surgery, and since it doesn't metastase this is usually OK.
"But the problem is if the tumour is on the face, on the nose, ear or somewhere, it is strongly disfiguring – someone can have a big scar or lose half of his face.
"This is a localised radiation therapy which in more than 95 per cent of cases a single treatment is sufficient to make the cancer go away."
Dr Maria Gonzalez, a dermatologist based at Cardiff University, said: "It is very specific types of patients who would choose this treatment.
"It would be very useful to have as an alternative to surgery. Sometimes if the tumour is very large, especially on the face, or the patient is elderly then it is not a reasonable approach to excise it (cut it out)".
Martin Ledwick, of Cancer Research UK, added: "I would imagine we are not talking about a major breakthrough but another option. It is nice to have a menu of different options for people, particularly with things that can have a cosmetic impact."