Control of dose administered once a week and three times a day according to schedules calculated by the CRE formula, using skin reaction as a biological parameter.
Patients with breast cancer were irradiated postoperatively to bilateral parasternal fields. The validity of the Cumulative Radiation Effect (CRE) formula for treatment once a week and three times a day was analyzed, and both schedules were compared with treatment once a day (five times a week). The biological radiation effect on normal tissue was studied by reflectance spectrophotometry of skin erythema and pigmentation. Early skin reactions were identical after irradiation daily and once a week, respectively, but were found to be significantly more pronounced after irradiation three times a day than after treatment once a day, corresponding to an overexposure of 7-10%.
D001943:Breast Neoplasms / Q000532:radiotherapy; D004890:Erythema / Q000209:etiology; D005260:Female; D006801:Humans; D011830:Radiation Effects; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012867:Skin / Q000528:radiation effects*; D012880:Skin Pigmentation / Q000528:radiation effects; D013053:Spectrophotometry; D013997:Time Factors