How do you advise patients on the risk for permanent alopecia following RT to the scalp?

If you are treating the skin in a certain area to definitive dose with RT for a skin primary, the patient is almost certain to have a patch of alopecia in the area of treatment. Regarding dose constraints, one older study by Lawenda and colleagues looked at 26 patients treated for CNS primaries and found a dose of 43 Gy EQD2. Using this model they estimated a < 20% risk of permanent ≥ grade 3 alopecia at 25Gy (moderate to severe alopecia). There is a more recent study from MSKCC. The dose of grade 2 alopecia in this study was calculated at 36.1Gy with no cases of grade 2 alopecia recorded under 25Gy (hair loss > 50%). Interestingly, this study also showed an improvement in alopecia with the use of topical minoxidil (photos in the paper) whi...

It’s usually not an issue because of age, hair loss, etc. Avoiding bone exposure and necrosis overshadows alopecia.