Abstract
The dosimetry with CdS crystal shows considerable advantages in, radiumtherapy, owing to the small size of the crystal as well as to its remarkable sensitivity to radiations, comparatively to the size. The crystal, which is insulating under resting conditions, becomes a conductor material when excited by radiations, the intensity of current being proportional to the intensity of radiations. Erroneous data may be obtained when the crystal is hit by low energy radiations; to avoid this, the crystal is shielded with a gold sheath wich rejects radiations below 100 KeV.
These dosimeters allow with relative ease the determination of isodose lines. Basing also on Verhagen's experience, the dose distribution at the periphery of the tumours is considered both in relation to the amount and time of administration.
As far as uterine tumours are concerned, it is important to determine accurately a given line of isodose in the depth, representing the distance from the radioactive preparation at which the tumour destruction can be obtained. Such line is marked by the value of 1 roentgen/minute, and the importance of its determination is also related to the frequent necessity of submitting the patient to complementary telecobaltotherapy.
Some therapeutic schemes concerned with Ra and Co60 are reported.
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