Isotretinoin and radiotherapy

Hi all

I had a lumpectomy last month and will be starting radiotherapy in a couple of weeks. I was previously taking a small dose of Isotretinoin (oral retinoid to control acne) but I stopped in November 2025 once I received my breast cancer diagnosis. I have been advised I need 3 weeks of radiotherapy because I need a Boost treatment. I have not been told what strength / Grey units I will be receiving - do they normally tell patients this? Should I ask? 

I was advised by my dermatologist when I started taking isotretinoin to avoid certain things as the drug dries out my skin, eyes, nose, lips etc. (and I have complied). Here is some wording from the British Association of Dermatologists:

• "It is best to avoid treatments such as waxing, epilation, or dermabrasion, as well as tattoos and piercings during treatment and for up to 6 months afterwards. They could cause scarring, skin irritation, or rarely, changes in the colour of your skin."

If waxing can potentially damage my skin, then I dread to think what radiation would do to me.... I have told my oncologist about this but I don't feel it has been given much consideration (maybe they have not come across previous cases involving isotretinoin before?).

Is there anyone out there who was / is on isotretinoin and has gone through radiotherapy? Please could you let me know how it was managed (did your medical team amend the dosage to make sure it was suitable for you) and what side effects did you have (if any)?

Thanks in advance!

p/s: I also reluctantly agreed to get the tattoos done, although they were tiny and the procedure quick, the pain was excruciating. I don't know if the fact I was on isotretinoin recently made it worse. But hey ho it's done now.