A modified 60C teletherapy unit for total body irradiation.
Int J Radiat Oncol Biol Phys
; 33(4): 951-7, 1995 Nov 01.
Article
en En
| MEDLINE
| ID: mdl-7591908
ABSTRACT
PURPOSE:
A modified teletherapy unit to achieve total body irradiation with a vertical beam in a conventional treatment room. METHODS AND MATERIALS A standard 60C teletherapy unit has been modified to achieve total body irradiation with a vertical beam in a conventional treatment room. Patients are treated in prone and supine positions. Removal of the adjustable collimator assembly of this standard machine provides a circular field of 196 cm in diameter at 167 cm from the source. Second, the machine has been elevated by about 50 cm on a metallic base to enlarge irradiation field to obtain 248 cm in diameter at 210 cm from the source, and to encompass tall patients under better conditions. A special lead conical beam flattening filter, 10-mm thick at the center, was designed to compensate the spatial inhomogeneity of the beam. An instantaneous dose rate of 6.10(-2) Gy/min is attained at the L4 level (midplane) in an average 20-cm thick patient with a source activity of 5099 RHM (air kerma rate of 44.8 Gy.h-1.m2). Between February 2, 1984 and December 27, 1990, 244 total body irradiations were performed either by single dose (n = 69, 10 Gy were given to midplane at L4 level in about 6 to 8 h, 8 Gy to the lungs), or by fractionated dose (n = 175, 12 Gy were given in 6 fractions over 3 consecutive days to midplane at L4 level, 9 Gy to the lungs).RESULTS:
The dose distribution is similar than the ones obtained by a linear accelerator with patients lying on their sides.CONCLUSION:
Patients were treated in a comfortable and highly reproductible position. Organ shielding was easily achievable. This could be a less expensive and reasonable alternative to linear accelerator.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Teleterapia por Radioisótopo
/
Irradiación Corporal Total
/
Radioisótopos de Cobalto
Límite:
Humans
Idioma:
En
Revista:
Int J Radiat Oncol Biol Phys
Año:
1995
Tipo del documento:
Article
País de afiliación:
Francia