Permanent alopecia after cranial irradiation: dose-response relationship.
OBJECTIVE
To develop a dose-response relationship for the occurrence of permanent alopecia after cranial irradiation and to analyze potential confounding variables that may contribute to this unwanted and often unavoidable complication of treatment.


METHODS
Twenty-six patients were enrolled in this study. Three reviewers independently assessed 61 scalp regions and assigned a score for the degree of alopecia in each region using a 4-point scale. Patient and treatment data were collected using a patient questionnaire and outpatient medical chart review. The hair follicle dose was calculated for each scalp region and correlated with the alopecia score for that region. A dose-response relationship was established using the data from these correlations.


RESULTS
Permanent alopecia correlated significantly with the follicle dose only (p < 0.001). A personal history of alopecia and the use of chemotherapy correlated with permanent alopecia with borderline statistical significance (p = 0.059 and p = 0.068, respectively). Patient age, family history of baldness, gender, tobacco use, diabetes, and beam energy did not correlate with alopecia.


CONCLUSIONS
We report the first human dose-response relationship describing the effect of the follicle dose on the subsequent development of permanent scalp alopecia after cranial irradiation. This information will assist the radiation oncologist, physicist, and dosimetrist in designing a treatment plan that might minimize the risk of this untoward side effect of cranial irradiation.
Lawenda
Brian D
BD
Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, 100 Blossom Street, Boston, MA 02114, USA.
Gagne
Havaleh M
HM
Gierga
David P
DP
Niemierko
Andrzej
A
Wong
Winnifred M
WM
Tarbell
Nancy J
NJ
Chen
George T Y
GT
Hochberg
Fred H
FH
Loeffler
Jay S
JS
D000328:Adult; D000368:Aged; D000465:Algorithms; D000505:Alopecia / Q000209:etiology*; D000704:Analysis of Variance; D015986:Confounding Factors, Epidemiologic; D016371:Cranial Irradiation / Q000009:adverse effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D018859:Hair Follicle / Q000528:radiation effects*; D006801:Humans; D008297:Male; D008875:Middle Aged