[The sensitometric recording of verification films in high-volt therapy].
Film sensitometric determinations under high voltage conditions, i.e. under radiation at an energy of at least 1 MeV, are very time-consuming and material intensive, because, with increased dose of radiation, several films have to be exposed and densitometrically measured. These results then form the basis of the preparation of the density curve. This paper describes, how, by applying a special technique (so-called sensitometric double exposure method), film sensitometry under high voltage radiation conditions may be considerably simplified and shows how the necessary resources (i.e. step-wedge = stepped photometric absorption wedge) can be made quite simply. The method described uses film DOT-I and DOT-II by Dupont, whereby the exposure of the step wedge takes place on a linear accelerator with a photo energy of 10 MeV. The results show that with a target volume dose up to 1.5 Gy the DOT-II film yields the better results, while with doses above 1.5 Gy, usage of DOT-I film is recommended.
Proske
H
H
Abteilung für Strahlentherapie, Philipps-Universität Marburg/Lahn.
Steinkamp
P
P
D006801:Humans; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity; D014963:X-Ray Intensifying Screens
Sensitometrische Erfassung von Verifikationsfilmen in der Hochvolttherapie.