[The determination of the ovarian dosage in defecography on a digital C-arm unit].

When using defaecography as a radiological tool for diagnosing the anorectal function in female patients, the ovaries are inevitably directly exposed. With the aim of minimising the ovarian dose applied both the area-dose product and the surface dose above the ovaries were measured during investigations of female patients with a digital C-arm unit. These values were converted into ovarian doses using tissue-air ratios.

[A simple device for positioning and fixing the head in radiotherapy of brain tumors in frontal and lateral position].

In radiotherapy of cerebral tumors in the occipital, central, and parietal area it can be favourable to fix the patient's head in frontal or lateral position. It is true that this problem can be solved by manufacturing individual face masks of PVC with the vacuum deep-drawing method, but this method is very time- and cost-consuming. The present study suggests a simplified method using the thermoplastic polyester "Orfit".

Plastic material used to optimize radiotherapy of head and neck tumors and the mammary carcinoma.

In order to improve head and neck tumor therapy, face masks were developed. The physical and mechanical properties of 11 apparently suitable materials were tested using a phantom. According to our studies "HEXCELITE" (supplied by Medimex, Hamburg, F.

[Chest wall moulages for radiotherapy of resected breast cancer with fast electrons: comparative tests of different materials].

Irradiation of the thoracic wall with high-speed electrons is one of the standard methods of prophylaxis and therapy of local recurrences and cutaneous metastases of an operated mammary carcinoma. The surface dose, however, is only 85% of the maximum dose, due to the depth dose curve of the electron beams with the preponderantly applied energy of 7MeV. This is a poor value, since most of all recurrences appear near to the surface and so the risk of giving an insufficient dose is involved.

[Experience in the use of face masks for radiotherapy of head and neck tumors].

By means of positioning and fixation aids, the precision and reproducibility of irradiation fields in radiotherapy of malignant tumors of the head and neck can be considerably improved. Face masks made of different synthetic materials have proved to be a practicable solution of this problem. In our hospital we have developed and tested a simple and not expensive possibility of manufacturing the masks with "Baycast" (producer: Bayer AG Leverkusen).