Angiosarcoma of the Scalp and Face: A Dosimetric Comparison of HDR Surface Applicator Brachytherapy and VMAT

Abstract EN

Purpose.

Angiosarcoma of the face and scalp is a rare disease with high rates of recurrence.

The optimal treatment approach is not well defined.

This study presents a dosimetric comparison of high-dose-rate surface applicator (HDR-SA) brachytherapy to volumetric-modulated arc therapy (VMAT).

Methods.

Between 2011 and 2018, 12 patients with primary or recurrent angiosarcoma of the face or scalp were treated with HDR-SA brachytherapy using CT-based planning at our institution.

For comparison, deliverable VMAT plans for each patient were generated, and dose distribution was compared to the delivered HDR-SA brachytherapy plans.

Results.

Both VMAT and HDR-SA brachytherapy plans delivered good coverage of the clinical target.

However, the dose distribution of VMAT was significantly different from HDR-SA brachytherapy across a variety of parameters.

Mean doses to the lacrimal gland, orbit, lens, and cochlea were significantly higher with HDR-SA brachytherapy vs.

VMAT.

Brain Dmax, V80%, and V50% were also significantly higher with HDR-SA brachytherapy.

Conclusions.

There may be dosimetric advantages to VMAT over HDR-SA brachytherapy for many patients.

However, individual tumor location, patient anatomy, and treatment reproducibility may result in HDR-SA brachytherapy being the preferred technique in a subset of patients.

Ultimately, a personalized approach is likely to be the optimal treatment plan.