[Conformal technics by the movement of bars in pendular fields. 2. The dosimetric aspects].
The development of conformal techniques by movement of bars in pendular fields requires a careful examination of many physical and dosimetric problems: bar-critical organ synchronization problems, dose calculation problems, and problems relative to the "shadow effect". The use of a bar in an arc field, causes to a slow gradient of dose between shielded zone and target volume with a loss of homogeneity in dose distribution. This effect is well known ("shadow effect") and depends on the fact that different points spend different times beyond the bar's shadow. In this work the problem is investigated in the case of moving bar technique, mainly for dose calculation possibilities; then the possibility is analyzed of optimizing dose distribution by means of filters whose profile can be calculated for simple geometric conditions (fixed bar on the isocenter without considering the profile of the patient). These filters will be made in our Institute and they will be tested in various conditions, for both fixed bars and moving bars in arc fields.
Fiorino
C
C
Servizio di Fisica Sanitaria, Ospedale S. Raffaele, Milano.
Ardesi
A
A
Del Vecchio
A
A
Cattaneo
G M
GM
Fossati
V
V
Fusca
M
M
Longobardi
B
B
Signorotto
P
P
Calandrino
R
R
D004867:Equipment Design; D006801:Humans; D008433:Mathematics; D008838:Microcomputers; D008961:Models, Structural; D011835:Radiation Protection / Q000295:instrumentation / Q000379:methods*; D011878:Radiotherapy / Q000295:instrumentation / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods
Tecniche conformazionali mediante il movimento delle barre nei campi pendolari: 2. Aspetti dosimetrici.