title: Quantification of patient to patient variation of skin erythema developing as a response to radiotherapy.
abstract: A method is described to determine accurately skin redness during a course of radiotherapy using reflectance spectroscopy utilizing information from across the visible spectrum according to the L*a*b* color coordinate system. The method was used to quantify the development of skin erythema during and after electron beam irradiation of the chest wall following mastectomy. A number of factors were identified which could influence the wide variation in response seen between patients. These were: intra- and inter-observer variation; intra- and inter-patient variation and variation in the actual dose delivered. Statistical analysis, including an analysis of variance of inter- and intra-patient variation, revealed that the major factor that accounts for the observed difference between patients is a true inter-patient variation, with a coefficient of variation, corrected for intra-patient variation, of 43%. Within the narrow dose range administered in this study, there was no demonstrable dose-effect relationship, raising questions about the role of cell death in the basal layer of the epidermis in the pathogenesis of radiation induced erythema.
authors.affiliation: Department of Radiotherapy, The Netherlands Cancer Institute/Antoni van Leeuwenhoekhuis, Amsterdam.
authors.forename: N S
authors.initials: NS
authors.lastname: Russell
authors.forename: H
authors.initials: H
authors.lastname: Knaken
authors.forename: I A
authors.initials: IA
authors.lastname: Bruinvis
authors.forename: A A
authors.initials: AA
authors.lastname: Hart
authors.forename: A C
authors.initials: AC
authors.lastname: Begg
authors.forename: J V
authors.initials: JV
authors.lastname: Lebesque
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D004890:Erythema / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008408:Mastectomy; D008875:Middle Aged; D015588:Observer Variation; D011832:Radiation Injuries / Q000209:etiology* / Q000473:pathology; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000009:adverse effects; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D012867:Skin / Q000473:pathology / Q000528:radiation effects*; D012880:Skin Pigmentation / Q000528:radiation effects