Radiation-Induced Alopecia after Endovascular Embolization under Fluoroscopy

Association of radiation-induced epilation and interventional neuroradiology procedures

INTRODUCTION

The aim of this study is to quantify the association of temporary epilation following interventional neuroradiology (INR) procedures and compare the peak skin dose (Dskin,max) threshold to published values.

METHODS

Gold Coast University Hospital (GCUH) is a major centre for INR with over 500 primarily interventional procedures performed every year. Dskin,max is calculated when the reference air kerma (Ka,r) exceeds 3 Gy. If the Dskin,max exceeds 3 Gy, the patient is followed up for any skin effects. An audit was undertaken of these results over a 2-year period.

RESULTS

From January 2020 to December 2021, 140 patients who underwent INR procedures had a Ka,r > 3 Gy, 66 resulted in a calculated Dskin,max >3 Gy, and 45 were successfully followed up. Twenty patients (44%) reported no skin effects and 25 (56%) reported skin effects, which were almost exclusively epilation. The mean (range) Dskin,max for patients with no reported skin effects and those with observed skin effects was 4.6 Gy (3.0-11.1 Gy) and 4.2 Gy (3.0-7.0 Gy), respectively.

CONCLUSION

These results demonstrate that temporary epilation was observed in 56% of patients, in a cohort of 45 patients who underwent an INR procedure with calculated Dskin,max >3 Gy and successful follow-up. The results support evidence in the literature that suggests the approximate threshold for temporary epilation reported by the International Commission on Radiological Protection (ICRP) may be too high for incidence of this effect, specifically on the scalp, when Dskin,max is calculated from Ka,r (using commonly used corrections and assumptions in the calculation).

Alopecia Induced by Fluoroscopy-guided Embolization: A Case Report

Alopecia resulting from radiation exposure occurs 2-8 weeks after exposure. It can be temporary or permanent depending on the dose of exposure. Alopecia following fluoroscopy-guided procedures are increasing in frequency. We report the case of a 22-year-old female who underwent fluoroscopically-guided embolization of an arteriovenous malformation. Twelve days after embolization, significant hair shedding was noted, resulting in a large rectangular hairless patch with no erythema or pain on the irradiated site. Hair pull test was positive and the hair mount showed dystrophic anagen hairs. Hair tug test was negative. Trichoscopy showed yellow dots, black dots, vellus hairs, and flame hairs. Histopathologic examination showed an increase in catagen and telogen hairs. On review of the procedure, she received a total peak skin dose of 4.67 Gray from the procedure. The diagnosis of radiation-induced alopecia was made and topical minoxidil was started, resulting in complete hair growth after six months. Patients undergoing fluoroscopy-guided procedures should have adequate follow-up weeks to months post-procedure to monitor for skin and hair reactions. Physicians should also consider delayed radiation reactions in patients with a history of radiation exposure. Safety protocols must be in place, and measures should be done to minimize the dose delivered.

Anagen Effluvium after Neurointerventional Radiation: Trichoscopy as a Diagnostic Ally

Minimally invasive procedures for vascular brain lesions are being performed more frequently. Radiation exposure caused by endovascular embolization of cerebral aneurysms may give rise to nonscarring scalp alopecia located in the treated area. Clinical and trichoscopic features of this type of alopecia are similar to alopecia areata (AA). Herein, we performed a comprehensive review to describe the clinical and trichoscopic characteristics of radiation-induced anagen effluvium. Predominant trichoscopic findings include black dots, yellow dots, short vellus hairs, and absence of exclamation marks hairs. It is important to consider this diagnosis in patients who have recently undergone such procedures that can easily be misdiagnosed as AA.

Hair disorders in patients with cancer

Cytotoxic chemotherapies, molecularly targeted therapies, immunotherapies, radiotherapy, stem cell transplants, and endocrine therapies may lead to hair disorders, including alopecia, hirsutism, hypertrichosis, and pigmentary and textural hair changes. The mechanisms underlying these changes are varied and remain incompletely understood, hampering the development of preventive or therapeutic guidelines. The psychosocial impact of chemotherapy-induced alopecia has been well documented primarily in the oncology literature; however, the effect of other alterations, such as radiation-induced alopecia, hirsutism, and changes in hair color or texture on quality of life have not been described. This article reviews clinically significant therapy-related hair disorders in oncology patients, including the underlying pathophysiological mechanisms, severity grading scales, patient-reported quality of life questionnaires, management strategies, and future translational research opportunities.

Hair disorders in cancer survivors

With increasing survival rates across all cancers, survivors represent a growing population that is frequently affected by persistent or permanent hair growth disorders as a result of systemic therapies, radiotherapy, surgical procedures, and therapeutic transplants. These hair disorders include persistent chemotherapy-induced alopecia, persistent radiotherapy-induced alopecia, endocrine therapy-induced alopecia and hirsutism, postsurgery alopecia and localized hypertrichosis, and persistent stem cell transplantation and targeted therapy-induced alopecia. The information contained in this continuing medical education series should facilitate a better understanding on hair disorders in cancer survivors so that adequate support and therapies may be provided.