ABSTRACT
This chapter presents a summary of work investigating the clinical potential of Cobalt-60 (Co-60) units for conformal radiation therapy techniques via tomotherapy. It investigates fan beam characteristics such as penumbra, and intensity modulation for various Co-60 source and hypothetical Co-60 tomotherapy unit designs. A comparison of intensity-modulated energy fluence profiles showed that irrespective of the source shape and size, the Co-60 source provides adequate intensity modulation required for tomotherapy applications. Tomotherapy can be summarized as an “optimized rotational slice intensity-modulated conformal radiation therapy” technique. Tomotherapy dose delivery can be achieved by using two approaches, axial and helical. The conventional Co-60 radiation therapy units were the main workhorse of radiation therapy departments worldwide, particularly in low and middle income countries. Non-cylindrical Co-60 source geometries in rectangular, truncated pyramid and prism shapes were initially considered for the Co-60 source shape studies. The chapter ends with a brief review of further development in Co-60-based radiation therapy.
