Ionizing radiation therapy in dermatology. Current use in the United States and Canada

Six years’ experience of grenz ray therapy for the treatment of inflammatory skin conditions

“…Grenz rays have an HVL in water (and it will be similar for human tissue) of 0.5 mm and negligible radiation reaches beneath 2 mm into the skin, 6 whereas superficial X-rays have an HVL depth of 2 mm. 7 As inflammatory dermatoses mainly involve the upper 1 mm layer of skin, grenz rays could have a beneficial effect. 8 The exact mechanism of grenz rays on dermatoses is unknown, but their anti-inflammatory effects include a reduction in the number of Langerhans cells.…”

“…The half‐value layer (HVL) is the thickness of a material at which the intensity of radiation is reduced by half. Grenz rays have an HVL in water (and it will be similar for human tissue) of 0.5 mm and negligible radiation reaches beneath 2 mm into the skin, whereas superficial X‐rays have an HVL depth of 2 mm . As inflammatory dermatoses mainly involve the upper 1 mm layer of skin, grenz rays could have a beneficial effect .…”

Radiotherapy treatment for nonmelanoma skin cancer

“…A 1974 survey among dermatologists found that RT was used in 55.5% of dermatology clinics in USA and Canada. However, the arrival of Mohs surgery offered dermatologists high cure rates with reduced side effects [24]. In a later survey conducted in 1986, superficial radiation could only be found in 12% of dermatology training clinics [25].…”

Increased breast cancer risk after radiotherapy for acne among women with skin cancer

“…However, as late as 1975, 41.8% of US and Canadian dermatologists reported using superficial radiotherapy for acne. 1 A typical regimen for acne radiotherapy consisted of approximately 75 cGy* per cheek per week for 3 to 4 months. 2 Abbreviations used:…”