Dermatologic Radiotherapy

TO THE ENGLISH EDITION Ionizing radiation has played an important role in the treatment of skin diseases for many decades. With strict adherence to modern standards of radiation protection, radiotherapy is a safe and effective method that benefits many patients who cannot be treated adequately by other means. Although indications for dermatologic radiotherapy have decreased significantly due to advances in other therapeutic modalities, many dermatologists feel strongly that ionizing radiation is an integral part of dermatologic therapy that should not be relinquished to other specialties because of the highly specialized anatomic, pathologic, and technologic knowledge required. A recent survey of the National Program for Dermatology showed that 44% of 2,444 responding dermatologists use radiotherapy regularly for various skin conditions, particularly in the treatment of cutaneous carcinomas. Significantly, the American Board of Dermatology has decided to continue its requirement of special knowledge in dermatologic radiation therapy for board certification. Because I have taught this dermatologic subspecialty at various levels, both in Europe and in the United States, I readily agreed to accept Pro­ fessor Braun-Falco's invitation to cooperate with him and Dr. Lukacs in the preparation of the English edition of this new guide. The text deals mostly with modern concepts of dermatologic radiotherapy and empha­ sizes practical aspects of treatment. Although it is written as an introduc­ tion for young dermatologists, it may also be useful to experienced clinicians who want to keep up with recent developments in this field.

1 physical basis of dermatologic radiotherapy.- 1.1 Electromagnetic Radiation.- 1.2 Production of X Rays.- Bremsstrahlung.- Characteristic radiation.- 1.3 The X-Ray Tube.- 1.4 Radiation Quality.- Factors affecting radiation quality.- 1.5 Radiation Quantity.- 1.6 Interaction of X Radiation and Matter.- Half-value layer (HVL); half-value thickness (HVT).- Attenuation.- 1.7 Radiation Dosimetry.- Basic concepts.- Special concepts.- Basic methods.- Dosimeters commonly used in dermatologie radiation therapy.- Frequency of calibration.- Procedure of dose measurement.- Measurement of dose distribution in the body.- 1.8 Selection of Physical Treatment Factors.- Factors affecting radiation quality.- Factors affecting radiation quantity.- Cones.- Exposure time.- Synopsis of the effects of changes in physical factors.- Practical considerations governing selection of treatment factors.- 1.9 Methods of Dermatologic Radiotherapy.- Grenz-ray therapy.- Contact therapy.- Soft x-ray therapy.- Superficial x-ray therapy.- Intermediate x-ray therapy.- Orthovoltage therapy.- Fast electrons (electron beam therapy).- 1.10 Roentgen Therapy Apparatus Used in Dermatologic Radiation Therapy.- 1.11 Radionuclides.- Gamma-ray sources.- Beta-ray emitters.- Alpha-ray emitters.- 2 general radiobiology.- 2.1 Introduction.- 2.2 Primary Reactions to Physical Processes.- Chemical reactions.- Biologic effects of radiation.- 2.3 Factors Influencing the Response to Radiation.- Dose dependence.- Effect of oxygen tension.- Linear energy transfer (LET) dependence.- Time dependence.- Biologic and clinical factors.- 2.4 Absorption of X Rays in Skin, Subcutaneous Tissue, Cartilage, and Bone.- 2.5 Effects of X Rays on Skin and Skin Appendages.- Roentgen erythema.- Histology of the cutaneous reactions to radiation.- Effect on hair follicles.- Effects on sebaceous glands and sweat glands.- Radiodermatitis.- Influence of physical treatment factors on cutaneous reactions to radiation.- 3 radiation safety and protection.- 3.1 General Considerations.- 3.2 Shielding.- Techniques.- 3.3 Dose Limits.- Occupational exposure.- Maximum permissible cumulative dosage for benign dermatoses.- 4 radiotherapy of cutaneous tumors.- 4.1 General Considerations.- Indications for x-ray therapy of cutaneous tumors.- Advantages and disadvantages of radiotherapy.- Practical procedure of x-ray therapy of cutaneous malignancies.- 4.2 Radiotherapy of Malignant Epithelial Tumors of the Skin.- General considerations.- Treatment planning.- Specific indications.- Variations of technique in different anatomic sites.- 4.3 Radiotherapy of Malignant Melanoma.- 4.4 Radiotherapy of Malignant Mesodermal Neoplasms (Sarcomas).- 4.5 Radiotherapy of Cutaneous Lymphomas, Reticuloses, and Leukemias.- 4.6 Radiotherapy of Premalignant Skin Conditions.- Pseudomalignant lesions.- 4.7 Radiotherapy of Benign Skin Tumors.- Vascular tumors.- Tumors of the lymphatic vessels.- Tumors of the connective tissue.- Benign epithelial tumors.- 5 radiotherapy of benign dermatoses.- 5.1 General Considerations.- 5.2 Specific Indications.- Viral infections.- Bacterial infections.- Protozoal infections.- Fungal infections.- Dermatitis and eczema.- Papulosquamous dermatoses.- Dyskeratoses.- Granulomatous diseases of the skin.- Diseases of the connective tissue.- Disturbances of pigmentation.- Diseases of the sebaceous glands.- Diseases of the apocrine sweat glands.- Diseases of the eccrine sweat glands.- Disorders of the hair.- Diseases of the nails.- 6 teleroentgen therapy of generalized dermatoses.- 6.1 General Considerations.- 6.2 Physical Foundation of Teleroentgen Therapy.- Distribution of the dose rate.- Depth of penetration.- 6.3 Radiation Protection in Teleroentgen Therapy.- Radiation protection for medical personnel.- 6.4 Technical Procedure.- Dosage.- 6.5 Indications for Teleroentgen Therapy.