A recent study highlights a possible trend of radiation-related dose dependence in persistent radiation-induced alopecia (pRIA) among patients treated for primary central nervous system (CNS) tumors or head and neck sarcoma. The study results were reported in JAMA Dermatology.

The study was a retrospective cohort analysis of 71 patients who received radiation to the scalp as a cancer therapy. Patients were assessed based on radiotherapy treatment regimens and response to topical minoxidil.

The median patient age in this study at pRIA evaluation was 27 years (range, 4 to 75), and 72% of patients were female. The majority of patients (90%) were treated for CNS tumors. Patients received a median estimated radiation dose of 39.6 Gy to the scalp.


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Grade 1 alopecia was present in 56% of patients. Slightly more than half (54%) of pRIA cases showed a localized pattern, with 24% showing a diffuse pattern and 22% showing mixed patterns.

Severity of alopecia increased with the amount of radiation received. A higher dosage of scalp radiation gave an odds ratio (OR) of 1.15 (95% CI, 1.04-1.28) for more severe alopecia. With proton irradiation, the OR was 5.7 (95% CI, 1.05-30.8). Grade 2 alopecia occurred in 43% overall. The radiation dosage at which 50% of the population showed a probability of grade 2 alopecia was 36.1 Gy (95% CI, 33.7-39.6).

Among 34 evaluable patients treated with a 5% topical minoxidil solution, at a median follow-up time of 61 weeks, the rate of response was 82%. Procedural interventions for alopecia were performed on 3 patients, all of whom responded. These included hair transplantations in 2 patients and plastic surgical reconstruction in 1 patient.

“Persistent radiation-induced alopecia among patients with primary CNS or head and neck sarcomas represents a dose-dependent phenomenon that is tractable in clinical severity evaluation, clinical photographs, and trichoscopic images,” concluded the researchers in their report.

Disclosures: Multiple authors reported affiliations with industry. Please refer to the original article for a full list of disclosures.

Reference

Phillips GS, Freret ME, Friedman DN, et al. Assessment and treatment outcomesof persistent radiation-induced alopecia in patients with cancer. JAMA Dermatol. Published online August 5, 2020. doi:10.1001/jamadermatol.2020.2127