A pilot study of ultrasound-guided electronic brachytherapy for skin cancer

Abstract

PurposeElectronic brachytherapy (eBT) has gained acceptance over the past 5 years for the treatment of non-melanomatous skin cancer (NMSC). Although the prescription depth and radial margins can be chosen using clinical judgment based on visual and biopsy-derived information, we sought a more objective modality of measurement for eBT planning by using ultrasound (US) to measure superficial (< 5 mm depth) lesions.Material and methodsFrom December 2013 to April 2015, 19 patients with 23 pathologically proven NMSCs underwent a clinical examination and US evaluation of the lesions prior to initiating a course of eBT. Twenty lesions were basal cell carcinoma and 3 lesions were squamous cell carcinoma. The most common location was the nose (10 lesions). A 14 or 18 MHz US unit was used by an experienced radiologist to determine depth and lateral extension of lesions. The US-measured depth was then used to define prescription depth for eBT planning without an added margin. A margin of 7 mm was added radially to the US lateral extent measurements, and an appropriate cone applicator size was chosen to cover the target volume.ResultsThe mean depth of the lesions was 2.1 mm with a range of 1-3.4 mm, and the mean largest diameter of the lesions was 8 mm with a range of 2.6-20 mm. Dose ranged from 32-50 Gy in 8-20 fractions with a median dose of 40 Gy in 10 fractions. All patients had a complete response and no failures have occurred with a median follow-up of 12 months (range of 6-22 months). Also, no prolonged skin toxicities have occurred.ConclusionsA routinely available radiological US unit can objectively determine depth and lateral extension of NMSC lesions for more accurate eBT treatment planning, and should be considered in future eBT treatment guidelines.

GEC-ESTRO ACROP recommendations in skin brachytherapy

“…The dose rate allows for shorter treatment times, lasting approximately one third of the Valencia applicator times. The design of Esteya TM has significantly improved radiation leakage [41][42][43][44][45][46][47] (see separate file for table).…”

Clinical comparison of brachytherapy versus hypofractionated external beam radiation versus standard fractionation external beam radiation for non-melanomatous skin cancers

“…NMSC is comprised of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), and also includes Merkel cell carcinoma (MCC) and adnexal tumors [ 2 ]. While surgical excision is the standard of care, radiotherapy (RT) is an excellent alternative with high cure rates and good cosmetic outcome [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

Skin surface brachytherapy: A survey of contemporary practice patterns

“…Furthermore skin brachytherapy has the advantage of greater patient convenience, comparable cosmesis, and perhaps decreased cost compared to external beam therapy (8, 10, 13, 14). A simple comparison of Medicare reimbursement rates for a 6-fraction single channel HDR treatment and a 20-fraction electron beam course showed that brachytherapy was half as costly.…”