20 MHZ ULTRASONIC-IMAGING FOR QUANTITATIVE ASSESSMENT AND DOCUMENTATION OF EARLY AND LATE POSTRADIATION SKIN REACTIONS IN BREAST-CANCER PATIENTS

Background and purpose: In dermatology high resolution ultrasonic syst em proved to be valuable in following up genuine and experimental infl ammatory dermatoses. The opportunities of 20 MHz ultrasonic imaging fo r quantitative assessment of early and late postradiation skin reactio ns are investigated. Material and methods: Between April and November 1996, 96 high resolution ultrasound examinations of the skin in 29 pat ients treated for breast cancer at the University of Ulm were analyzed . Total doses between 46 and 60 Gy were applied. The time interval bet ween the completion of radiotherapy and ultrasonic examination was les s than or equal to 3 months in 18 patients and 6-135 months in 11 pati ents. For examinations we used a digital high resolution ultrasonic sy stem with a ceramic 20 MHz transducer. Irradiated and non-irradiated s kin were compared. Results: A change of thickness and texture of the d ermis depending on the time interval between the completion of radioth erapy and ultrasonic examination and on the administered radiation dos e was found. There were significant differences between irradiated and nonirradiated skin regarding the dermal thickness in early (P < 0.001 ) as well as in late (P = 0.0018) reactions. Echogenicity of the upper and lower cerium of irradiated skin decreased in early and late react ion. In upper cerium the greatest reduction of signal intensity occurr ed in early reactions (P = 0.0001). Early reactions of the lower ceriu m differed significantly from late changes (P = 0.001). Discrepancies between visible skin reactions described by examining physicians and u ltrasonically proven changes were obvious mainly in late reactions. Co nclusions: There are specific textures of early and late postradiation skin reactions in comparison to non-irradiated skin. High resolution digital 20 MHz ultrasound is non-invasive and quantitative, and in con trast to physical examination, an easy reproducible method for assessi ng and documenting early and late skin reaction during and after radia tion therapy treatment. (C) 1997 Elsevier Science Ireland Ltd. All rig hts reserved.