Calendula officinalis is a widely available natural botanical (derived from the orange-yellow petals of the pot marigold), and has been used (mainly in Europe) since at least the 12th century in the treatment of rashes, burns and inflammation of the skin. The anti-inflammatory properties of Calendula likely are derived from a class of phytochemical compounds called, triterpenoid esters. Additionally, Calendula contains a variety of antioxidant compounds (flavonoids) that may protect the skin from free radical damage.
Radiation therapy commonly causes an inflammatory skin reaction in the radiated tissues called, radiation dermatitis. This is characterized by skin redness, irritation or pain, swelling, and peeling or blistering.
As a radiation oncologist, I frequently counsel my patients on skin care during treatment and one of my favorite recommendations is to use Calendula cream (or cream or oil formulations that include Calendula) throughout the course of therapy. I recommend applying the cream to the irradiated skin 2-3 times each day (please discuss this with your own radiation oncology team to get their approval).
A large study was published, in 2004, in the Journal of Clinical Oncology, that demonstrated a very significant reduction in the risk of developing the radiation dermatitis (35% reduced risk) while using Calendula cream versus Trolamine (a skin cream that was widely used for the treatment of radiation dermatitis). Furthermore, the use of Calendula reduced pain levels by 27% over Trolamine.
You can purchase Calendula creams at many health food chains (i.e. Whole Foods Market) and supplement stores. Select formulations with no added perfumes or oddly sounding artificial chemicals.