Radiotherapy (RT) is a lynchpin of oncological treatment worldwide and can be used alone or in combination with chemotherapy and surgery to maximise tumour control, reduce tumour burden and improve quality of life.
Since its advent over a century ago, considerable advances have been made to improve the efficacy of radiotherapy, as well as minimising its toxicities. The most common manifestations of radiation toxicity are acute and chronic skin reactions, commonly described as ‘radiation dermatitis’.
A well-known effect of RT is the carcinogenic potential of ionising radiation. Patients treated with RT are at risk of radiation-induced secondary malignancies (RISM) and, in particular, secondary cutaneous malignancies such as basal cell carcinomas (BCCs) in the irradiated field. This risk is lifelong, increases with time and is dose-related. The BCCs that present in the field of radiation often follow a more aggressive and unusual course than expected. Patients who have undergone RT for breast cancer have a 9% rate of local recurrence of their original disease reported with a median follow-up of 17.2 years.