抄録
In the radiation treatment of hemangioma and naevus pigmentosus with radiophosphorus (32P), it is most important to irradiate the affected sites with adequate dose. To obtain the homogeneous irradiation with 32P the author investigated the various conditions.
1) Blotting paper with homogeneous density must be used as unhomogeneous blotting paper causes variation in the self absorption of the beta rays. The Toyo Filter No. 50 seem to be quite satisfactory.
2) Since the blotting paper has its own saturation limit with water, the blotting paper with less soaking amount of 32P-solution will cause unhomogeneous 32P-distribution and that the soaking amount should be kept always beyond the saturation limit.
3) In order to have the blotting paper contain an unhomogeneous the 32P solution homogeneously, it is preferable to dip the paper into the solution rather than drop the solution on the paper. 50mm3 per 1 cm2 of Toyo Filter Paper No. 50 seemed to be most suitable concentration to use for this purpose.
4) Celophane causes unequal filtration of beta rays due to its surface inequalities. Polyethylene is preferable for sealing the 32P-blotting paper because of its smooth surface, in addition, polyethylene absorbs less of the beta rays than celophane.
5) 32P-solution is apt to accumulate along the edges of the blotting paper. The blotting paper was prepared 3 mm wider than the affected skin area and after drying, it was adjusted to size by cutting off the edges.
6) The author irradiates with the dose of 1, 000μc-hr/cm2 (50μc/cm2×20hr). The Surface dose rate and the depth dose in this technique have been measured by the photographic method using film phantom. The surface dose rate amounts to 6.0 rep per 1μc/cm2 of 32P and the depth curve is shown in Fig. 10.
