Validation of Skin Field Cancerisation Index: the assessment of a solar damage severity tool for patients undergoing radiotherapy treatment for field cancerisation.

Non-interventional study design to validate a skin field cancerisation index score. De-identified photographs of skin fields will be assessed by panel members to validate a severity score. There is no active patient participation involved. This is a multi-site and multi-specialty initiative lead by Dermatologists with the primary outcome aim of validating the Skin Field Cancerisation Index (SFCI). Patient photography will be the primary method of data collection used for validating this score in line with previous skin indices. Twenty specialists around Australia will assess up to 150 photographs to measure their perceptions of SFCI which will be statistically analysed using SPSS software to identify reliability and validity of the instrument. Investigators who will be scoring include Fellows of the Australasian College of Dermatologists, Fellows of the Royal Australian and New Zealand College of Radiologists and Registered Nurses all with a special interest in dermatoses. Skin Fields that will be collected range from none to severe tumour severity based on previous dermatological experience. Skin field cancerisation is defined as: areas of solar damage involving multiple actinic keratoses (AKs), the clinical signs of photo-ageing, and variable numbers and types of melanoma and non melanoma skin cancers. This index scores a range of skin field cancerisation severities, one of which is extensive field cancerisation. extensive field cancerisation is classified as areas of involvement greater that 50cm2 or difficult to treat areas such as the nose. The skin field cancerisation index is clinical tool which assesses a range of factors that contribute to skin field cancerisation severity. There are three sub-scores within the score including: 1) Number of Actinic Keratoses, Thickness of keratoses, and clinical evidence of atypical keratoses (Bowenoid) & skin cancer (SCC/BCC) 2) Area of involvement 3) Global Assessment score resulting in a total score of the three sub-scores. These scores are calculated by assessment of the characteristics of change compared normal skin as observed in the clinical photographs. The observations are conducted between July and September 2019. Photographs are selected based off the following inclusion criteria: Photographs were selected based off the following Inclusion criteria: • Treatable region of Skin Field Cancerisation in the following regional areas: o Scalp o Forehead o Nose o Cheek (one) o Ear (one) o Forearm (one) o Back of Hand (one) o Lower leg (one) o Top of foot (one) o Chest • Photographs of participants over 18 years of age Exclusion Criteria: • Poor quality photographs • Other dermatoses effecting assessment (e.g. inflammatory skin diseases) that may confuse scorers In order to validate the SFCI a non-interventionist data collection approach will be conduced to collect pre-existing photography from dermatologist’s patient libraries. Retrospective photography will be collected from dermatologists existing medical records. The photographs are collected based on the pre-defined regions of skin field cancerisation and screened based on the above inclusion criteria. The clinical scoring phases (including the Delphi) of this study are conducted prospectively. De-identified photography will be used in the study in accordance with the Australian Privacy Principals Guidelines Act 1988. All imaging will remove eye features and other distinguishing skin markings that could be used to identify participants. Imaging is part of standard clinical care.