๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Electronic Brachytherapy
Electronic Brachytherapy
Electronic brachytherapy (E-brachytherapy) differs from HDR brachytherapy as it delivers surface brachytherapy without radioactive isotopes or linear accelerators. It is essentially SRT with the radiation source present closer to the skin. As a result, the need from extensive shielding, as required with HDR brachytherapy, is eliminated.24 It also limits the size of the applicators to approximately 50 mm versus 180 mm for SRT. In a clinical study involving 122 patients with 171 NMSC lesions, E-brachytherapy was administered at 40 Gy in 8 fractions and delivered twice weekly. These patients were followed up to 1 year with good cosmetic resultsโno marked atrophy, gross telangiectasias, severe induration, loss of subcutaneous tissue, ulceration, or necrosis.25
Two prospective, single-center, nonrandomized, pilot studies treated 40 patients (20 patients in each study) with E-brachytherapy for superficial and nodular BCCs. Group 1 patients received 36.6 Gy in 6 fractions of 6.1 Gy resulting in a 90% response at year 1
and Group 2 patients received 42 Gy in 6 fractions of 7 Gy resulting in a 95% response at year 1; both groups exhibited acceptable cosmesis.26
Summarized data presented in abstract format at national meetings demonstrated a recurrence rate of less than 1% with E-brachytherapy. Most lesions were BCCs (57%) or SCCs (38%) less than 2 cm in size (97%). These NMSC lesions were treated with 40 to 45 Gy using mostly 8 fractions. Good cosmetic results accompany the recurrence rate of less than 1%, but these results are limited by a median follow-up of only 4 to 16 months.27 Thus further study is needed to better quantify both response and recurrence rates.