Electronic Brachytherapy for the Treatment of Non Melanoma Skin Cancer: Results Up to 5 Years

Abstract

The objective of this study was to assess adverse effects, cosmesis, and recurrence rates up to five years following high dose rate (HDR) electronic brachytherapy for the treatment of non-melanoma skin cancer (NMSC). From July 2009 to June 2014, 200 patients with 297 NMSC lesions were treated under an IRB approved protocol with HDR electronic brachytherapy using a surface applicator to a dose of 40 Gy in 8 fractions, delivered twice weekly. A 10-50 mm surface applicator was selected to allow for complete coverage of the target lesion with acceptable margin. Photographs were taken at initial consultation and follow-up. Patient care included use of petrolatum ointment during treatment and aloe vera gel through 1 month post-treatment. At follow-up, patients were assessed for acute and late toxicities, cosmesis and local control. Treatment of 297 lesions was completed in 200 patients with a mean age 77 years (range 52-102 years). There has been one recurrence to date with a mean follow-up of 16.5 months (range 1-63 months). One-month, 3-month, 6-month, 1-year, 2-year, 3-year, 4-year and 5-year data were available for 214, 156, 98, 93, 59, 42, 16 and 10 lesions, respectively. The most frequent acute effects (defined as adverse reactions up to three months post treatment) were rash dermatitis in 256 (86.0%), pruritus in 79 (27.0%) and hyperpigmentation in 4 (1.0%) of 297 lesions treated. These acute effects were present in less than 33% of lesions 3 months after treatment and less than 1% of lesions at 1 year after treatment. The most frequent late effects were hypopigmentation in 18 (6.0%) and alopecia in 2 (1.0%) of 297 lesions at 6 months or greater after treatment. All adverse events were grade 1 or 2 except one grade 3 non-healing foot ulcer that eventually required hyperbaric oxygen. Cosmesis at one-year was excellent for 88 (97.77%) and good for 2 (2.22%) of 90 evaluable lesions, at two-years was excellent for 54 (94.73%) and good for 3 (5.26%) of 57 evaluable lesions, at three-years was excellent for 44 (89.79%) and good for 5 (10.2%) of 49 evaluable lesions, at four-years was excellent for all 17 (100%) evaluable lesions and at five-years was excellent for all 10 (100%) evaluable lesions. Treatment of NMSC with HDR electronic brachytherapy using surface applicators resulted in excellent local control (99%) and good to excellent cosmesis up to five years post-treatment. Acute toxicities resolved within one year and late toxicities were acceptable up to five years post-treatment. HDR electronic brachytherapy provides a convenient non-surgical treatment option for NMSC patients.