Physikalische Grundlagen der dermatologischen Röntgentherapie und Messung ionisierender Strahlungen

Office Radiotherapy of Cutaneous Carcinomas

“…X‐Ray quality is a term used to denote the relative penetrating characteristics of an X‐ray beam. The physical term half‐value layer (HVL) and the biological term half‐value depth (HVD, D 1/2 ) define these characteristics for dermatologic radiation 15–19 …”

Radiotherapy of Cutaneous Cancers and Some Other Malignancies

“…The tables of Orton and Ellis 8a refer to doses in rads. As Wachsmann, and others have pointed out, we can neglect the difference between R and rads for small fields when applying X‐ray qualities of 20–50 kV, but for field sizes larger than 20 cm, and especially with X‐rays of harder qualities, backscatter may not be neglected. Therefore, one has to correct the air dose in “R” for field sizes from 20 to 100 cm (when using radiation qualities between 30 and 50 kV) by multiplying with a backscatter factor of 1.09–1.25, and a roentgen‐rad factor of 0.87–0.99.…”