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May 1943


Arch Derm Syphilol. 1943;47(5):657-664. doi:10.1001/archderm.1943.01500230047009

It is vaguely known that the size of the exposed area has a distinct influence on the biologic effectiveness of physically measured quantities of radiation. There are occasional references in the literature bearing on this subject, but there is no quotation of any definite numerical ratio of this relationship, especially as regards nonfiltered or slightly filtered radiation. MacComb1 recently published data showing differences in biologic reaction when areas of various sizes are exposed to nonfiltered roentgen rays of low voltage. However, in a postscript to his article, he stated that his results and conclusions fail to agree with later observations. Meyer2 published approximate curves showing the effect of variations in area with filtered radiation of high voltage.

In view of the great importance of this area factor in the treatment of cutaneous lesions, it appeared desirable to determine more accurately the effects of variation in area. The quantities