The Race For Megavoltage X-Rays Versus Telegamma

Second re-irradiation: a narrative review of the available clinical data

“…During the infancy of radiobiology research, dose-effect relationships were not well defined, neither for permanent tumor control nor for late normal tissue tolerance [3]. Furthermore, external beam treatment machines were not able to deliver a sufficient depth dose without excessive built-up dose in skin and surface-near tissues, while brachytherapy required a set of eligibility criteria, e.g., accessibility and limited tumor stage [4]. Some of the early reports contain brief descriptions of patients who received a third course of radiotherapy to the previously treated region [1].…”

Investigation of an efficient source design for Cobalt-60-based tomotherapy using EGSnrc Monte Carlo simulations

“…These wafers can be mounted independently for irradiation so that homogeneous activity is obtained; after irradiation, they can be assembled to form a source 2 × 2 × 1 cm 3 . (Grimmett et al 1952) Although in the initial phases of the development of Co-60 unit, a cube source geometry with stacked square shaped radioactive Co-60 wafers was considered, it was later abandoned (Robison 1995). In a review article Robison (1995), quoting 1953and 1954reports (Brucer et al 1953, Brucer 1954, reports that the cylindrical source shape was found to be optimal as compared to a square box shape.…”

“…(Grimmett et al 1952) Although in the initial phases of the development of Co-60 unit, a cube source geometry with stacked square shaped radioactive Co-60 wafers was considered, it was later abandoned (Robison 1995). In a review article Robison (1995), quoting 1953and 1954reports (Brucer et al 1953, Brucer 1954, reports that the cylindrical source shape was found to be optimal as compared to a square box shape. As the square source wafers, at that time, needed to be thinner (1 mm) and smaller (1 cm), the idea of having a cubical source was abandoned (Robison 1995).…”

“…In a review article Robison (1995), quoting 1953and 1954reports (Brucer et al 1953, Brucer 1954, reports that the cylindrical source shape was found to be optimal as compared to a square box shape. As the square source wafers, at that time, needed to be thinner (1 mm) and smaller (1 cm), the idea of having a cubical source was abandoned (Robison 1995). Beyond this no particular reference regarding the development of Co-60 sources in RS geometries is available in the published literature.…”

“…These codes have been widely used for the modelling of radiation therapy units (e.g. linear accelerators, Co-60 units) and radiation therapy dose calculations (Han et al 1987, Rogers et al 1988, 1995, Mora et al 1999, Ding 2002, Jeraj et al 2004. Our investigations required the MC modelling of an isotropic Co-60 source in a 6-faced polyhedron geometry.…”