Date: May 20, 2007

Prof. Itzhak Kelson, Tel Aviv University

Title: DART - a New Modality for Cancer Treatment

Abstract: 
Alpha particle irradiation is known to be lethal to cancer
cells. However, there is currently no treatment that effectively
utilizes alpha particles against solid tumors. We propose a new
approach - Diffusing Alpha-emitters Radiation Therapy (DART) - that,
based on results obtained on murine models, holds great promise for
the treatment of human solid cancer. The basic idea is to insert into
the tumor a source, or a number of sources, bearing alpha emitting
atoms closely below their surface. As these atoms disintegrate, their
daughters, which are short-lived alpha-emitters themselves, recoil
into the tumor, spread through its volume and decay at therapeutically
significant distances. Each source generates a 'killing zone' whose
size is determined both by the tumor vasculature and by the half-lives
of the diffusing atoms. We implement this scheme using 228Th to
generate sources bearing 224Ra, which, once inside the tumor, release
by recoil 220Rn, 216Po and 212Pb atoms into the lesion. In this talk,
we shall discuss the basic principles involved and demonstrate the
effect of such sources on a line of experimental solid tumor models in
mice.