Progress in 3-D treatment planning for photon beam therapy.

The purpose of this report is to study the feasibility of improving dose distributions using non-coplanar photon beams from a linear accelerator. Non-coplanar beams may enter the patient in any arbitrary configuration. This type of treatment technique requires a three-dimensional (3-D) planning system. Clinical examples are used to illustrate the general problems in 3-D treatment planning, and the potential improvement over coplanar beam treatments. Features of a treatment planning system for 3-D planning are discussed.

[Introduction to the tasks of clinical dosimetry and its requirements in dosimetric methods]. / Einführung in die Aufgaben der klinischen Dosimetrie und ihre Anforderungen an Dosismessverfahren.

Requirements for clinical dosimetry procedures are derived from the radiotherapeutical necessities especially for the exceptionally suitable thermoluminescence dosimetry. With regard to the following papers discussing problems of the ambitious two-peak TLD method typical features of this method are compared with those of the classical method, respectively.

Clinical applications of thermoluminescent dosimetry.

The clinical applications of continuous cylindrical TL dosemeters, readout by linear motion through a heated oven, are presented in this work. The applications extend over high energy electron and photon therapy as well as diagnostic X-ray radiology.

[Mantle irradiation with 18 MeV photons. Measurement and calculation of dose distribution]. / L'irradiazione a mantellina con fotoni da 18 MeV. Misura e calcolo della distribuzione della dose.

Dose distribution in mantle fields irradiated with 18 MeV photons has been studied in an Alderson-Rando phantom with thermoluminescent dosimeters. The treatment was also simulated on an RT-plan 7000 computer; calculated and measured doses in anatomical sites of major interest were compared. Doses in all significant points were within +/- 7% of the doses at the reference point. Calculated and measured doses agreed within +/- 5% except points situated near unhomogeneous tissues. The authors discuss their results and present conclusions about algorithms for computer dose calculation in irregular field treatments.

Multidetector endodosimetry probe with silicon-pn-junction-diodes for in-vivo-dosimetry.

In-vivo-dosimetry is necessary to prevent overdosage during radiation treatment techniques of great risk. New special dosemeter probes with up to five Si-pn-junction-diodes in a silicone tube were developed and tested for endodosimetry. They show high efficiency and good linearity of response, without dose-rate dependence. The steep increase of the sensitivity for low energies causes a phantom depth dependence of response. A low temperature dependence but a large anisotropy of response is found for the tested diodes. These multidetector probes proved to be sufficient for direct reading endodosimetric control of dose and dose-distribution during radiotherapy.

[Development and use of an automatic conversational system for the calculation of dose in teleradiotherapy (author's transl)]. / Développement et utilisation d'un système automatique conversationnel pour le calcul des doses en téléradiothérapie

The authors describe the equipment and methods of calculation used for a system of automatic conversational dosimetry with a mini-computer. They present the dialogue of the physician with the calculator and indicate the conditions they required of such a system: i.e. rapidity of response, simplicity of use, verification of data, precision, adaptability. Testing involved 800 dosimetric cases including 300 cases of routine clinical dosimetry.